bluuebunny/crossref_metadata_2025 huggingface dataset:
Decreased Density of the Platelet Serotonin Transporter in Pathological Gamblers
Authors: Marazziti Donatella , Golia Francesca , Picchetti Michela , Pioli Ellena , Mannari Patrizia , Lenzi Francesco , Conversano Ciro , Carmassi Claudia , Catena Dell’Osso Mario , Consoli Giorgio , Baroni Stefano , Giannaccini Gino , Zanda Giuseppe , Dell’Osso Liliana
Published: May 2008

Background/Aims: The aim of this study was to investigate the serotonin transporter (SERT), by means of the 3H-paroxetine ([3H]-Par) binding to platelet membranes, in patients affected by pathological gambling (PG), as compared with a similar group of healthy control subjects. Methods: Seventeen PG patients were selected amongst those who were drug-free and at the first psychiatric interview in a Department of Addiction. The diagnosis was assessed according to DSM-IV criteria and PG severity was measured by means of the South Oaks Gambling Screen. The platelet [3H]-Par binding was carried out according to a standardized method. The binding parameters, the maximum binding capacity (Bmax) and the dissociation constant (Kd), were obtained by means of the Scatchard analysis. Results: The Bmax values of PG patients were significantly lower than that of healthy subjects, while the Kd values were not different in the two groups. No significant effect of age, sex or psychiatric comorbidity on Bmax or Kd was observed; there were also no correlations between clinical and biological variables. Conclusions: PG patients showed a dysfunction at the level of the platelet SERT that would suggest the involvement of the 5-HT system in this condition.
Association between Polymorphisms in the Vesicular Monoamine Transporter 1 Gene (VMAT1/SLC18A1) on Chromosome 8p and Schizophrenia
Authors: Lohoff Falk W. , Weller Andrew E. , Bloch Paul J. , Buono Russell J. , Doyle Glenn A. , Ferraro Thomas N. , Berrettini Wade H.
Published: May 2008

Linkage studies have suggested a susceptibility locus for schizophrenia (SZ) exists on chromosome 8p21–22. The vesicular monoamine transporter 1 gene (VMAT1), also known as SLC18A1, maps to this SZ susceptibility locus. Vesicular monoamine transporters are involved in the presynaptic vesicular packaging of monoamine neurotransmitters, which have been postulated to play a role in the etiology of SZ. Variations in the VMAT1 gene might affect transporter function and/or expression, and might be involved in the etiology of SZ. Genotypes of 62 patients with SZ and 188 control subjects were obtained for 4 missense single nucleotide polymorphisms (Thr4Pro, Thr98Ser, Thr136Ile, Val392Leu) and 2 noncoding single nucleotide polymorphisms (rs988713, rs2279709). All cases and controls were of European descent. The frequency of the minor allele of the Thr4Pro polymorphism was significantly increased in SZ patients when compared to controls (p = 0.0140; d.f. = 1; OR = 1.69; 95% CI = 1.11–2.57). Assuming a recessive mode of inheritance, the frequency of homozygote 4Pro carriers was significantly increased in the SZ patients when compared to controls (24 vs. 8%, respectively; p = 0.0006; d.f. = 1; OR = 3.74; 95% CI = 1.703–8.21). Haplotype analysis showed nominal significance for an individual risk haplotype (p = 0.013); however, after permutation correction, the global p value did not attain a statistically significant level (p = 0.07). Results suggest that variations in the VMAT1 gene may confer susceptibility to SZ in patients of European descent. Further studies are necessary to confirm this effect, and to elucidate the role of VMAT1 in central nervous system physiology and possible involvement in the genetic origins of SZ.
Senescence, Apoptosis or Autophagy?
Authors: Vicencio José Miguel , Galluzzi Lorenzo , Tajeddine Nicolas , Ortiz Carla , Criollo Alfredo , Tasdemir Ezgi , Morselli Eugenia , Ben Younes Amena , Maiuri Maria Chiara , Lavandero Sergio , Kroemer Guido
Published: May 2008

Many features of aging result from the incapacity of cells to adapt to stress conditions. When damage accumulates irreversibly, mitotic cells from renewable tissues rely on either of two mechanisms to avoid replication. They can permanently arrest the cell cycle (cellular senescence) or trigger cell death programs. Apoptosis (self-killing) is the best-described form of programmed cell death, but autophagy (self-eating), which is a lysosomal degradation pathway essential for homeostasis, reportedly contributes to cell death as well. Unlike mitotic cells, postmitotic cells like neurons or cardiomyocytes cannot become senescent since they are already terminally differentiated. The fate of these cells entirely depends on their ability to cope with stress. Autophagy then operates as a major homeostatic mechanism to eliminate damaged organelles, long-lived or aberrant proteins and superfluous portions of the cytoplasm. In this mini-review, we briefly summarize the molecular networks that allow damaged cells either to adapt to stress or to engage in programmed-cell-death pathways.
Radiation-induced chromosome aberrations in mouse spermatocytes and oocytes
Authors: Tsuchida W.S. , Uchida I.A.
Published: May 2008

ICR/Swiss males and females were exposed to 300 R whole-body gamma irradiation. The frequency of aberrations in metaphase I chromosomes recovered from oocytes cultured in vitro was compared with those recovered from spermatocytes irradiated in pachytene and diplotene. The ability of oocytes collected 1 day postirradiation to mature in vitro was not affected, but significantly fewer oocytes cultured 5 days after irradiation matured. The frequency of aberrations in oocytes did not differ from spermatocytes irradiated during diplotene, but significantly more chromosome aberrations were found when pachytene spermatocytes were irradiated. Some variation in the relative frequencies of aberrations was also observed.
Identical Giemsa banding patterns of two Macaca species: Macaca mulatta and M. fascicularis
Authors: de Vries G.F. , de France H.F. , Schevers J.A.M.
Published: May 2008

Karyotypes of Macaca mulatta and M. fascicularis (2n = 42) were compared using the Giemsa banding pattern technique. No differences between the chromosomes of both Macaca species were found with conventional staining methods. In the literature the occurrence of fertile hybrids is used as an argument in favor of conspecificity. The banding patterns were evaluated by comparison of their density distribution curves. Our data indicated no significant differences between the two Macaca species.
Human Q and C chromosomal variations: distribution and incidence
Authors: McKenzie W.H. , Lubs H.A.
Published: May 2008

Chromosome preparations of 77 normal newborn babies from Grand Junction, Colorado, were stained first for G-band identification of each chromosome and subsequently stained for Q- and C-band localization. This approach permitted determination of the variation of the C region size in all chromosomes, and is the first such study reported. A total of 391 Q and C variants was described, an average of 5.08 ± 0.23 per subject; 225 were Q variants, 166 were C variants. Q variants were distributed among seven chromosomes in the genome and among 76 of the 77 subjects. Chromosomes 3 and 4 had variable Q intensities at the centromere, and the acrocentric chromosomes, 13, 14, 15, 21, and 22, had variable Q intensities in their short arms and/or satellites. C variants, though fewer in number, were more widely distributed in the genome, with at least one variant described in each chromosome. C variants were identified in 65 of the 77 subjects. Most unique were the six pericentric inversions found in chromosome 9. Except for giant satellites, no correlations were found between Q and C variants. Q and C variants evaluated in 16 members of four families showed that in nearly every case each variant observed in a child could be demonstrated in one or both parents. It is evident from this study that the magnitude of chromosomal variation in human populations is far greater than heretofore believed. It has also been shown that the combination of Q- and C-banding procedures will yield much more information than either technique used alone and is therefore the preferred approach to many population and gene localization studies.
Chromosomes and DNA of Mus: the karyotypes of M. fulvidiventris and M. dunni
Authors: Markvong A. , Marshall, Jr. J.T. , Pathak S. , Hsu T.C.
Published: May 2008

The chromosomes of the Asian mice, Mus fulvidiventris (boodugal), are typical of the Mus in general, viz., 40 telocentric chromosomes. The centromeric heterochromatin does not fluoresce brightly. The G band pattern of the euchromatin is the same as that of M. musculus. The diploid number of M. dunni is also 40, but each autosome possesses a short, heterochromatic second arm. The X chromosome is a long submetacentric, whose entire short arm and the terminal segment of the long arm are heterochromatic. The Y is a long telocentric and is heterochromatic. The G band pattern of the long arms of M. dunni is again very similar to that of M. musculus. Thus, karyotypic changes in M. dunni involved only the addition of C bands. Mus dunni and M. booduga are sympatric in many localities in India, but they can be separated by karyological and subtle morphological differences.
Identification of normal and abnormal chromosomes in tumor cells
Authors: Tiepolo L. , Zuffardi Orsetta
Published: May 2008

The cells of two ascitic effusions from human cancers of the ovary were analyzed by the fluorescence and Giemsa banding techniques. The normal chromosomes still present in the cancer cells were identified, and several chromosomes which appeared normal with the conventional techniques were found to be rearranged ones. In the rearranged chromosomes it was possible to identify chromosome material which appeared preferentially lost. The sequence of events leading to the formation of many new chromosomes were deletions, inversions, and translocations. Both ascites showed, in all cells, a relative constancy in the ratio of normal to new chromosomes, and this suggests that not all the possible combinations of normal and abnormal chromosomes can occur. In one of the ascites, six different rearrangements have been found in several cells, all involving the long arm of chromosome No. 1.
Points of exchange in a human No. 5 ring chromosome
Authors: Nakagome Y. , Iinuma K. , Taniguchi K.
Published: May 2008

A 46, XYq+, r(B) karyotype was observed in a four-month-old boy with cri du chat syndrome. The ring was identified as a No. 5 on the basis of both G-staining and quinacrine fluorescence. The break points were located at bands 5ρl5 and 5q35, i.e., his karyotype was 46, XYq+ , r(5)(pl5q35). The loss of chromosome material was estimated to be about 5.5% of a normal No. 5 chromosome. The father also had a Yq+ chromosome.
Ring chromosome 7 with variable phenotypic expression
Authors: Zackai Elaine H. , Breg W.R.
Published: May 2008

Two males with apparently identical rings of chromosome 7 and very different phenotypic features are presented. Patient 1 is severely retarded, has short stature, microcephaly, craniosynostosis, unilateral proptosis, ptosis, and microcornea, small phallus, first-degree hypospadias, and undescended testes. Patient 2 is of normal intelligence, and his only abnormalities are short stature and a small head. Study of lymphocytes at metaphase showed the same proportion of cells with the ring, 46, XY, r(7), and those without a ring, 45, XY,-7, in each case. Quinacrine fluorescence and Giemsa banding techniques showed all the bands of chromosome 7 to be present, suggesting little material missing as a result of ring formation. A similar degree of instability of the ring in each case was indicated by the frequency of abnormal cells at anaphase and telophase.
Chiasma and univalent frequencies in aging female mice
Authors: Luthardt F.W. , Palmer Catherine G. , Yu P.-L.
Published: May 2008

Oocytes were obtained from C57BL/6J and ICR female mice ranging in age from six weeks to 15 months. Both strains demonstrated a significant increase in univalents and a significant decrease in chiasma frequencies at metaphase I with age. Strain differences were observed with respect to the specific type of univalent formation and the regression of chiasma frequency on age. Univalent formation was nonrandom and involved small chromosomes predominantly. Although the percentage of oocytes possessing univalents increased significantly with age, the vast majority possessed only one pair of univalents.
A comparison of chimpanzee and human chromosomes using the Giemsa-11 and other chromosome banding techniques
Authors: Bobrow M. , Madan Kamlesh
Published: May 2008

Chimpanzee and human chromosomes have been compared after staining by Giemsa-11, trypsin banding, quinacrine fluorescence, and centromeric heterochromatin techniques. The Giemsa-11 technique appears to stain areas containing a particular DNA satellite fraction. All but three chimpanzee chromosomes could be assigned fairly definite homologs in the human karyotype. The most common form of rearrangement between chromosomes in the two species appears to be pericentric inversion.
The association of glucose phosphate isomerase expression with human chromosome 19 using somatic cell hybrids
Authors: Hamerton J.L. , Douglas G.R. , Gee Phyllis A. , Richardson B.J.
Published: May 2008

Clones of two Chinese hamster human hybrid somatic cell lines were studied for the presence or absence of human glucose phosphate isomerase (GPI; E.C.5.3.1.9). Quinacrine mustard fluorescence was used for chromosome identification. Clones from one line could be separated into five separate classes. These are considered to represent four different nondisjunctional events. Since it is the number of non-disjunctional events which is important and not the number of clones, two representative clones from each class were analyzed. The classes were: (I) identical to parental hybrid; (II) loss of chromosome 14; (III) loss of chromosome 1; (IV) loss of chromosomes 1 and 19; and (V) loss of chromosomes 1 and 11. Concomitantly, the following human enzymes were lost; (I) none; (II) NP; (III) PGM1 and 6PGD; (IV) PGM1, 6PGD, and GPI; and (V) PGMi, 6PGD, and LDH-B. In the second hybrid line only two types of clones were observed, GPI+ and GPI–. The two GPI– clones analyzed had also lost chromosome 19. We believe the most likely explanation for these results to be the presence of the GPI structural locus on human chromosome 19. Data from these two lines also supports association of PGM1 and 6PGD with chromosome 1, of NP with chromosome 14, and LDH-B with chromosome 12.
The effects of various banding procedures on human chromosomes, studied with acridine orange
Authors: Bobrow M. , Madan Kamlesh
Published: May 2008

Human chromosome preparations were subjected to a wide range of treatments — heat, enzymatic digestion, acid, and alkali. These treatments included the conditions of a standard Giemsa-banding procedure, a trypsin-banding method, and the reverse-banding procedure of Dutrillaux and Lejeune (1971). The slides were then stained with acridine orange, which fluoresces green in combination with double-stranded, and red with single-stranded, nucleic acids. Under various conditions, including those of the three banding procedures mentioned, chromosome banding was obtained with acridine orange. The pattern was always the same and resembled “reverse” banding, with bright yellow/green fluorescence in the regions of R-bands. Quinacrine and standard Giemsa-bands corresponded to dull red/orange staining with acridine orange. The results are interpreted as suggesting that chromosome banding patterns correspond to regions whose DNA differs in the ease with which it denatures and the extent to which it reanneals. These properties could be related to variation in associated chromosomal proteins.
Relationships between patterns of chromosome banding and DNA synthetic sequences: a study on the chromosomes of the Seba’s fruit bat, Carollia perspicillata
Authors: Pathak S. , Hsu T.C. , Utakoji T.
Published: May 2008

The termination sequences of DNA replication, as visualized in tritiated-thymidine autoradiographs of chromosomes of Carollia perspicillata, appear to follow this order: euchromatin → G-bands → C-bands → facultative heterochromatin.
Assignment of the genes for human peptidase A to chromosome 18 and cytoplasmic glutamic oxaloacetate transaminase to chromosome 10 using somatic-cell hybrids
Authors: Creagan R. , Tischfield J. , McMorris F.A. , Chen S. , Hirschi M. , Chen T.R. , Ricciuti F. , Ruddle F.H.
Published: May 2008

Evidence based on analysis of mouse-human somatic-cell hybrids is presented that supports the assignment for the structural loci of peptidase A to human chromosome 18 and of cytoplasmic glutamate oxaloacetate transaminase (GOT) (EC 2.6.1.1) to chromosome 10. The medical and evolutionary significance of these assignments is discussed.
Reciprocal translocation versus centric fusion between two No. 13 chromosomes
Authors: Hsu Lillian Y.F. , Kim Hyon J. , Sujansky Eva , Kousseff B. , Hirschhorn K.
Published: May 2008

The centric fusion, or Robertsonian, type of translocation has been considered as a fusion of the entire long arms of two acrocentric chromosomes preceded by breakage of the centric heterochromatin. Reunion of the long arms is considered to include the centromeres, only one of which is visible by conventional staining methods. Prior to the development of the current banding techniques in human chromosome identification, the possibility that a centric fusion-like translocation might be the result of a reciprocal translocation was merely speculative. With the various banding techniques, we have identified two different types of 13/13 “centric fusion”-like translocation chromosomes with trisomy 13, i.e., one case of reciprocal translocation, 46,XX,–13,+t(13;13)(p12;q13), and one true case of centric fusion translocation, 46,XY,–13,+t(13;13)(p12;p12). In the first case, the unequal translocation of two No. 13 chromosomes was evident with the Q-and G-banding patterns; this patient also had a milder clinical manifestation of trisomy 13, since she was only partially trisomic for the long arm of No. 13. In the second case, the Q- and G-banding patterns revealed a symmetrical involvement of two No. 13 chromosomes in the translocation, and the C- and Q-banding techniques showed two distinct centromeres in the translocation chromosome. The latter patient demonstrated the typical trisomy 13 syndrome. The example of these two cases indicates that, with the current banding techniques, the true incidence of reciprocal translocations among so-called centric fusion types of translocations can be more accurately estimated.
Identification of chromosome 9 in human male meiosis
Authors: Page Brenda M.
Published: May 2008

The characteristic polymorphism of the paracentric secondary constriction region of chromosome 9 and its specific staining by a Giemsa banding technique allowed the unequivocal identification of the No. 9 in human male meiosis.
Chromosomes of Peromyscus (Rodentia, Cricetidae)
Authors: Pathak S. , Hsu T.C. , Arrighi Frances E.
Published: May 2008

All species in the genus Peromyscus possess a diploid number of 48, but the number of total chromosome arms varies from 56 (e.g., P. crinitus) to 96 (e.g., P. eremicus). Data are presented, using these two extreme cases, to illustrate that all short arms of biarmed chromosomes are made of constitutive heterochromatin. G-banding preparations revealed that the long arms (euchromatin) of the two species are essentially the same. Since constitutive heterochromatin contains few, if any, structural genes, the two species, and presumably other species as well, do not differ drastically in their information content, but differ in the amount of chromatin material, including DNA. The results indicate that in studying karyotypic evolution, C-banding and G-banding (or Q-banding) are essential tools without which erroneous conclusions may be reached.
Spontaneous univalence at male meiosis in the mouse
Authors: Purnell D.J.
Published: May 2008

A single male mouse exhibiting almost total achiasmate meiosis with a concomitant increase in univalent frequency is reported. It was impossible to state whether this condition was caused by asynapsis or desynapsis. Histological examination of the testis showed an apparent block in spermatogenesis associated with a thickening of the tunica albugenica and the appearance of large, multinucleate cells in the tubule lumens. It is postulated that this abnormality might be caused by a single recessive gene mutation.
Unbalanced X/autosomal translocation with inactivation of the normal X chromosome
Authors: Mikkelsen Margareta , Dahl Gudrun , Poulsen Hanne , Jespersen Birthe
Published: May 2008

A 20-year-old aphasic, severely retarded girl with multiple abnormalities but normal menstruation was studied by fluorescence microscopy, autoradiography, and the G-band-ing method. Autosome material most likely from the long arm of chromosome 8 was translocated onto the short arm of one X chromosome. It was not possible to show loss of X-chromosome material from the translocation chromosome. Autoradiography showed inactivation of the normal X chromosome in all suitable cells. This was in contrast to other observations which showed inactivation of the normal X in balanced X/autosomal translocations but not in the unbalanced translocations.
Giemsa banding patterns in the chromosomes of twelve species of cats (Felidae)
Authors: Wurster-Hill Doris H. , Gray C.W.
Published: May 2008

The Giemsa banding patterns in the chromosomes of 12 cat species, all previously studied with conventional techniques, have been compared. Although the basic banding pattern is largely similar among the species, several species possess distinctive banding features. Banding has permitted identification of three, rather than two, types of F-group chromosomes and has revealed that the C3 chromosome in two species is the equivalent, by banding pattern, of the F2 and F3 chromosomes in other species. The banding pattern of the X chromosome is similar among all 12 felid species and is also similar to that of the other mammalian species with “original-type” submetacentric X chromosomes which have been studied in this laboratory.
The nature and inheritance of an elongated secondary constriction on chromosome 9 of man
Authors: Fitzgerald P.H.
Published: May 2008

An unusually long secondary constriction on chromosome 9 was shown by C-staining to involve duplication of heterochromatin in this region. The constriction stained darkly following the C-staining procedure but was unstained following the G-staining procedure. The heterochromatic constriction generally completed DNA replication earlier than the remainder of chromosome 9. The abnormal chromosome was detected in 17 individuals belonging to three generations of a family. There were twice as many carriers as noncarriers. Similar excesses of carriers were noted in two other pedigrees reported in the literature. Disturbed segregation of this abnormal chromosome 9 is suggested and is consistent with the increased centromeric heterochromatin present. No linkage to chromosome 9 was demonstrated, but Rh-linkage was discounted.
Loss of DNA following C-banding procedures
Authors: Pathak Sen , Arrighi Frances E.
Published: May 2008

When metaphase chromosomes prelabeled with 3H-thymidine are treated with various C-banding procedures, autoradiographs show a significant amount of DNA loss in the euchromatic segments. The constitutive heterochromatin (C-positive areas) retain most of their label. G-band production following the trypsin procedure, however, does not indicate DNA loss.
Fertile tertiary trisomy in the mouse (Mus musculus)
Authors: De Boer P.
Published: May 2008

A fertile, tertiary trisomic female mouse, daughter of a Harwell-bred T70H female, produced fertile male and female tertiary trisomics in an outcross to a Swiss random-bred male. Morphologically recognizable and nonrecognizable 41-chromosome male and female progeny were obtained. In the morphologically recognizable animals, the most obvious abnormality was a malformation of the bones of the skull. Fertility of the tertiary trisomic sons was impaired. Conception rate amounted to 29 %, and an average litter size of 3.33 + 1.73 (N = 18) was recorded.
Nonrandom arrangement of human chromatin: topography of disomic markers X, Y, and 1h+
Authors: Hoehn H. , Martin G.M.
Published: May 2008

Numerical and structural variants (47,XXX; 92,XXXX; 47,XYY; 92,XXYY; 92,lh+lh+) were used to determine the topography of chromatins of different molecular composition in cultivated fibroblast-like cells. In postlogarithmic populations of interphase nuclei, the statistical patterns of chromocenter distributions of 2n and 4n strains were similar, as were the principal modes of the lh+ and X strains. A different pattern was obtained for the pair of Y bodies, and there were classes with intimate associations of chromocenters in both the Y and lh+ strains. It appears that (1) “ectopic pairing” involves specific chromosomes by virtue of segments of constitutive heterochromatin; (2) certain chromosomes are attracted to nuclear structures such as the nuclear margin (inactive X) or the nucleolus (Y), whereas others are not (lh+); and (3) homeologous genomes tend to remain segregated in euploid nuclei of tetraploid cultures; observations on the behavior of the lh+ homeologs during nuclear division were consistent with this interpretation, but quantitation at mitosis may be difficult with human material.
The possibility of latent centromeres and a proposed nomenclature system for total chromosome and whole arm translocations
Authors: Hsu T.C. , Pathak S. , Chen T.R.
Published: May 2008

Translocations involving entire chromosomes or whole chromosome arms may not necessarily require deletion of a centromere. Conceivably, in the process of centromeric or telomeric fusion or of fusion of a centromere with a telomere, centromeric inactivation may occur, thus preserving both centromeres—one functional, the other latent—in the resultant translocation chromosome. If such latent centromeres exist and, in addition, are capable of being reactivated, it would explain how additional functional centromeres are acquired in the reverse process of chromosomal fission or fragmentation. A system of nomenclature is proposed for identifying the origin and nature of these chromosomal rearrangements.
The site of 5S RNA genes in human chromosome 1
Authors: Atwood K.C. , Yu M.T. , Johnson L.D. , Henderson A.S.
Published: May 2008

The major site of genes for human 5S RNA is in the long arm of chromosome 1. We find no evidence of sites in other chromosomes; if such exist, they are much smaller than the site in 1q.
Attraction between centric heterochromatin of human chromosomes
Authors: Schmid M. , Vogel W. , Krone W.
Published: May 2008

An analysis of the pattern of association of acrocentric chromosomes with nonacrocentric chromosomes in human lymphocyte metaphases was performed. This pattern is nonrandom with respect to chromosome length and intrachromosomal distribution. There is a general preference for the centric regions, most pronounced at the proximal segments of the long arms of chromosomes 1, 9, and 16, which is interpreted to reflect heterochromatin attraction during interphase. Comparison of the association patterns of homologous chromosome l’s differing with regard to the size of their heterochromatic regions corroborates this interpretation. The possible significance of heterochromatin attraction for the formation of spontaneous and induced chromosome anomalies is discussed.
Mapping G-bands on human prophase chromosomes
Authors: Bigger T.R.L. , Savage J.R.K.
Published: May 2008

Ohnuki’s method for demonstrating coils in human metaphase chromosomes also reveals a fine G-band pattern on prophase chromosomes of sufficient clarity to justify an attempt at mapping. Maps are provided for each chromosome to show the maximum number of prophase bands observed, and an intermediate stage in chromosome contraction, tracing the pathways of apparent band fusion as the cell progresses to metaphase, is presented. The prophase bands on many chromosomes tend to occur in distinct groups, the members of which ultimately merge to give the dark G-bands of metaphase chromosomes. Every G-band of the standard metaphase pattern is compounded from two or more prophase bands. In the least contracted prophase chromosomes examined, some bands are seen which have no obvious metaphase counterpart. There are marked similarities between banded prophases and the chromomere pattern seen at meiotic prophase. However, since chromosome contraction is a dynamic process, agreement between maps will be expected only for corresponding degrees of chromosome contraction.
Assignment of the gene for human uridine monophosphate kinase to chromosome 1 using somatic cell hybrid clone panels
Authors: Satlin A. , Kucherlapati R. , Ruddle F.H.
Published: May 2008

Evidence from mouse-human somatic cell hybrids is presented for the assignment of the gene for uridine monophosphate kinase (ATP: nucleoside monophosphate phosphotransferase, E.C. 2.7.4.4) to human chromosome 1. The use of the “clone panel” in this determination and its value as a systematic method for gene mapping is discussed.
A simple statistical analysis of Indian muntjac Giemsa band patterns
Authors: Smith T.F. , Grunwald M. , Artwich R. , Hill H.Z.
Published: May 2008

Indian Muntiacus muntjac G-banded chromosomes were used for computerized analysis for standardized karyotype generation. Individual chromosomes on high-contrast photographic negatives were scanned densitometrically. Alignment of each chromosome for analysis was achieved by locating predominant peaks as well as the centromere. This provided better alignment than the use of the chromosome-end locations. The standardized set was obtained by determining the root-mean-square average density along 10–20 homologous chromosomes. The resulting standard karyotype differs from those published earlier. Prophase chromosomes exhibited greater detail than more condensed metaphase chromosomes. Although Indian muntjac chromosomes were used as a model, the method of analysis should be readily adaptable for examining chromosomes of any origin. The analytic technique should be within the capabilities of the smallest cytogenetic laboratories.
A method for preparing chromosomes from peripheral blood in the mouse
Authors: Triman K.L. , Davisson M.T. , Roderick T.H.
Published: May 2008

We have developed a simple, reproducible microtechnique for obtaining metaphase chromosomes from peripheral blood of live mice. The method has been successful with mice of several different genetic backgrounds and has been repeated in three other laboratories.
Giemsa staining of the sites replicating DNA early in human lymphocyte chromosomes
Authors: Kim My.A. , Johannsmann R. , Grzeschik K.-H.
Published: May 2008

A timetable for the initiation of DNA replication in human lymphocyte chromosomes has been established by a technique which allows detection of areas of chromosomes replicating at a given interval of the S-phase. The resolution of the method, using 33258 Hoechst-Giemsa staining, is more refined than that obtained with 3H-thymidine autoradiography. Early replicating regions coincide with R-bands. The timetable is rather coarse since replication may start asynchronously in the same region of homologous autosomes of the same metaphase and since even the sequence of bands appearing on individual chromosomes sometimes deviates from the rule.
A replica plating method for CHO cells using nylon cloth
Authors: Stamato T.D. , Karig Hohmann L.
Published: May 2008

A new technique of replica plating for CHO cells has been developed in which the pattern of colonies growing in a tissue culture plate is reproduced on a nylon cloth. The efficiency of replica plating onto the nylon cloth is affected by the colony size and the time of cloth-to-plate contact. Maximum replica plating efficiency (80–90 %) occurs using 5- to 6-day-old colonies and a contact time of 4 h. The method easily allows 104 colonies to be examined for mutant phenotypes. The effectiveness of the technique is demonstrated by isolation of a clone deficient in activity of glucose-6-phosphate dehydrogenase.
Chromosomal banding patterns in Akodon arviculoides (2n=14), Akodon sp. (2n=24 and 25), and two male hybrids with 19 chromosomes
Authors: Yonenaga Y. , Kasahara S. , Almeida E.J.C. , Peracchi A.L.
Published: May 2008

Chromosomal polymorphism resulting from two pericentric inversions in Akodon arviculoides (2n = 14) has been described (Yonenaga, 1972a). In this paper the banding patterns are presented and identification of the inverted segments of the autosomal pairs 2 and 3 is made. The karyotype of Akodon sp., which varies in diploid number (2n = 24 and 25), is described and shown to be due to the presence of a small submetacentric chromosome in the 2n=25 individuals. The karyotypes of two 2n = 19 males studied show that they are hybrids between Akodon arviculoides (2n = 14) and Akodon sp. (2n = 24).
Giemsa-banding and the identification of the Y/autosome translocation in the African marsh mongoose, Atilax paludinosus (Carnivora, Viverridae)
Authors: Pathak S. , Stock A.D.
Published: May 2008

The diploid chromosome number of 35 in the male and 36 in the female African marsh mongoose, Atilax paludinosus, has been confirmed. C- and G-banding analyses have shown that the Y chromosome is probably translocated onto the proximal end of the acrocentric partner of a heteromorphic autosomal pair (C3). The other partner is a subtelocentric with a heterochromatic short arm. During the translocation process, this short arm was removed and presumably lost. The sex determining mechanism in Atilax could be written as XX in the female and XYA-A in the male.
Pachytene mapping of the male Chinese hamster
Authors: Pathak S. , Hsu T.C. , Markvong Amara
Published: May 2008

Minced seminiferous tubules of male Chinese hamsters, when treated with a mixture of trypsin (one part) and McCoy’s 5a growth medium with 20 % fetal calf serum (nine parts) at 4° C, washed twice with the regular growth medium, incubated at 37° C in growth medium for 4 h, and harvested without Colcemid and hypotonic pretreatments, gave excellent pachytene morphology for studies on chromomere patterns. The Giemsa banding patterns of all somatic metaphase chromosomes except the sex chromosomes of the hamster cells correspond well to the chromomere patterns of the meiotic pachytene bivalents.
A chromosome rearrangement in an orangutan studied with Q-, C-, and G-banding techniques
Authors: Seuánez H. , Fletcher J. , Evans H.J. , Martin D.E.
Published: May 2008

A constitutional chromosome rearrangement in a phenotypically normal male orangutan is described. The rearrangement resulted from three breakages in chromosome 9 and involved a pericentric inversion and additional reciprocal transpositions of the terminal segments of both arms. Q-, G-, and C-banding studies were carried out, and it was shown that the chromosome affected was a member of the only pair in the complement that lacked a centromeric C-band and that its G-banding pattern closely resembled that of chromosome 12 in man. The origin of the rearrangement and the role of such rearrangements in producing chromosome polymorphisms are discussed, particularly in relation to evolution and speciation. An additional pair of heteromorphic chromosomes (No. 23) is also described. The short arm satellited region of one member of the pair was found to be variable and strongly C-banded.
Studies of the squirrel monkey, Saimiri sciureus, genome
Authors: Lau Y.-F. , Arrighi F.E.
Published: May 2008

Chromosomal banding analyses have revealed two nonhomologous pericentric inversions in the telocentric group of chromosomes of a squirrel monkey, Saimiri sciureus. This individual is probably an intersubspecific hybrid whose parents originated from different geographical locations. The C-banding pattern shows polymorphism in location and amount of constitutive heterochromatin in at least four pairs of chromosomes. Ammoniacal silver (Ag-AS) staining specific for locating the nucleolar organizers indicates that these are located on only one pair of chromosomes and that there is a difference in the size of the nucleolus organizer regions between the homologs of this pair.
A child with presumptive monosomy 21 (45,XY,–21) in a family in which some members are Gq–
Authors: Davis J.G. , Jenkins E.C. , Klinger H.P. , Weed R.G.
Published: May 2008

Presumptive monosomy for chromosome 21 was found in a male child with multiple malformations and severe psychomotor retardation. Chromosome analyses of cells from blood and skin samples were performed at intervals during the first few years of his life. In preparations stained with nonbanding as well as quinacrine, Giemsa, and reverse acridine orange banding techniques, only one No. 21 chromosome could be detected with no apparent abnormalities of the other chromosomes. The proband’s phenotypically normal father, paternal grandfather, brother, and paternal aunt have a deletion for a short segment of the long arm of a G-group chromosome. Genetic-marker studies allow the exclusion of a number of blood groups as being associated with No. 21. There is inconclusive evidence suggesting that expression of the Duffy blood group, which has been mapped to chromosome 1, may be influenced by genetic information on chromosome 21. This family is of potential value for further gene-mapping studies.
Chromosome banding pattern relationships of hares, rabbits, and pikas (order Lagomorpha)
Authors: Stock A.D.
Published: May 2008

The chromosome banding patterns of the domestic rabbit, Oryctolagus cuniculus, the brush rabbit, Sylvilagus bachmani, and the snowshoe hare, Lepus americanus, are nearly identical except for minor differences in the amount of constitutive heterochromatin present. The major mechanisms of chromosome evolution in leporid lagomorphs are centric fusion and addition of heterochromatin. The G- and C-banding patterns of the pika, Ochotona princeps, revealed little easily recognized structural homology with the leporid species. Several tentative banding pattern matches were found for segments of some chromosomes of Ochotona, indicating that tandem fusions may have been responsible for structural modification of the early lagomorph genome. Chromosome evolution in the lagomorphs and the use of chromosomal data in studies of mammalian systematics are discussed.
Cell surface antigens
Authors: Moore E.E. , Jones C. , Puck T.T.
Published: May 2008

A stable human-Chinese hamster ovary cell hybrid has been produced which, in addition to the complement of Chinese hamster ovary (CHO-K1) chromosomes, contains only one human chromosome, No. 11. The human cell-surface antigens whose expression is controlled by human chromosome 11, and are expressed by this hybrid, have been defined as the AL immunogenetic complex. Although one component of this immunogenetic complex (a1) is also expressed by human red blood cells, a second component (a2) is not. Killing of an aι+ hybrid by anti-a1 serum and complement can be completely inhibited by glycophorin, the major glycoprotein component of the human erythrocyte membrane. In the presence of complement, antiserum prepared against glycophorin will kill only those cells which express a1. The anti-a1 killing activity of the anti-glycophorin can be adsorbed out only by those cells which express ai. Therefore, it is concluded that the ai cell-surface antigen has at least one antigenic component in common with glycophorin.
Meiotic behavior of five human reciprocal translocations
Authors: Chandley A.C. , Seuánez H. , Fletcher J.M.
Published: May 2008

Meiotic studies have been carried out in five human male translocation heterozygotes. An account of the cytological observations is given together with information concerning their reproductive history and fertility.
Translocations of acrocentric chromosomes and their implications in the evolution of sheep (Ovis)
Authors: Bunch T.D. , Foote W.C. , Spillett J.J.
Published: May 2008

Cytogenetic evidence suggests that the caprids (sheep and goats) evolved from a common ancestor with a 2n=60 karyotype. Although goats (Capra) retained the primitive 2n=60 karyotype, sheep (Ovis) underwent a sequential reduction in the number of chromosomes by means of acrocentric translocation. The formation of the first metacentric autosome (Ml) occurred in the aoudad (Ammotragus) and urial (O. vignei), resulting in a 2n=58 karyotype. The G-bands are homologous, which implies both genotypes arose from a common ancestor, possibly a rupicaprid. Based on G-bands, acrocentric chromosomes 1 and 7 of the 2n=60 karyotype formed the Ml. The X chromosome, which is the second longest acrocentric in the 2n = 60 karyotype, became the longest acrocentric in Ammotragus and Ovis (2n = 58). The second pair of metacentrics to evolve, which is ranked in the M3 position of the 2n=54 karyotype, resulted from the translocations of acrocentric chromosomes 4 and 14 or 15 in the 2n = 60 karyotype. The M2 was the third pair of metacentrics to be formed and resulted from the translocations of acrocentric chromosomes 3 and 12 or 13 in the 2n = 60 karyotype. The G-bands of all 2n = 54 karyotypes are homologous, which indicates origin from a common ancestor. Evidence is presented that suggests a prezygotic selection is bringing about a reduction in diploid chromosome numbers. The possible roles of fission and fusion in the karyotypic evolution of Ovis are discussed.
Quantitative application of RNA-DNA hybridization in situ
Authors: Wolgemuth-Jarashow D.J. , Jagiello G.M. , Atwood K.C. , Henderson A.S.
Published: May 2008

A linear relationship between the amount of rDNA present and the number of autoradiographic silver grains observed after rRNA-DNA hybridization in situ was demonstrated using male mouse meiotic tissue as a test system.
Nondisjunction in aging female mice
Authors: Martin R.H. , Dill F.J. , Miller J.R.
Published: May 2008

Oocytes from CBA mice varying in age from 2 to 11 months were cultured to the metaphase II stage of meiosis and the chromosomes analyzed. The oocytes from three maternal age groups were compared with respect to the mean number of oocytes obtained per mouse, the frequency of maturation to metaphase II, and the frequency of numerical chromosome abnormalities. Both the mean number of oocytes obtained per mouse and the frequency of maturation decreased markedly with maternal age. The frequency of chromosome abnormalities in the oocytes increased with maternal age from the young to the middle-aged mice but dropped off in the oldest maternal age group. No hyperploid (n + 1) oocytes were observed in the young or old group of mice, but 5.2 % hyperploidy occurred in the middle-aged group. It is suggested that the lack of hyperploid oocytes in the old CBA females might be due to a threshold effect in which oocytes that are damaged by the number of univalents present at metaphase I become atretic and do not progress to metaphase II. The frequency of diploid (2n) oocytes was 1.7 % and was not maternal-age dependent.
Increased sister chromatid exchange in bone marrow and blood cells from Bloom’s syndrome
Authors: Shiraishi Y. , Freeman A.I. , Sandberg A.A.
Published: May 2008

Bone-marrow cells from a patient with Bloom’s syndrome cultured for 48 h in the presence of BudR exhibited a striking increase in the number of sister chromatid exchanges (SCEs) in comparison to that in the marrow cells of a patient with treated polycythemia vera (PV). Thus, it appears that an increased incidence of SCE in Bloom’s syndrome occurs in various differentiated types of cells, not just blood lymphocytes, and constitutes the syndrome’s most characteristic cytogenetic feature. In contrast, the incidence of SCE was not increased in marrow cells and lymphocytes of the particular PV patient studied here, whose cells did exhibit increased numbers of chromatid and chromosome gaps and breaks, presumably as result of the patient’s earlier treatment. An increased frequency of SCE was demonstrated in Bloom’s syndrome lymphocytes using both a technique based on BudR incorporation and one based on labeling with tritiated deoxycytidine. This observation constitutes evidence against the increase of SCE being due to an unusual reaction to BudR. By conventional cytogenetic techniques, chromosome instability, including chromatid and chromosome breaks, but no homologous chromatid interchanges were also recognized in Bloom’s syndrome bone-marrow cells incubated in vitro (without BudR) for either 1.5 or 46 h. This observation points to the existence of chromosome instability in vivo.
Robertsonian polymorphism and constitutive heterochromatin distribution in chromosomes of the rainbow trout (Salmo gairdneri)
Authors: Thorgaard G.H.
Published: May 2008

White-blood-cell culture was used to examine the chromosomes of 53 rainbow trout (Salmo gairdneri) from three locations in the Pacific Northwest of the United States. A Robertsonian chromosome polymorphism is present, resulting in diploid numbers of 60, 59, or 58 in different individuals with 104 chromosome arms. The low level of intraindividual Robertsonian variation, differences in the number of subtelocentric chromosomes between individuals with different chromosome numbers, and frequencies of fish with different chromosome numbers in one population suggest that the interindividual differences are inherited and not somatic. C-banding shows that constitutive heterochromatin is localized near the centromeres and near the secondary constriction on one chromosome pair.
Enhanced anchorage independence and tumorigenicity of aneuploid Chinese hamster cells with nearly doubled chromosome complements
Authors: Klinger H.P. , Shin S. , Freedman V.H.
Published: May 2008

The role of a cell’s chromosome complement in its tumorigenic and anchorage-independent growth properties in vitro was investigated by injecting a Chinese hamster cell line and its subclones into immunodeficient nude mice and by plating the cells in a semisolid medium containing methylcellulose. The parental WOR-6 cell clone originally consisted of 89 % 1s cells and 11 % cells with a nearly double (2s) complement. Tumors that developed from WOR-6 were found to consist entirely or primarily of cells with near 2s chromosome complements. Subclones of WOR-6 that contained only 1s cells rarely produced tumors in nude mice, even at high inoculum doses, whereas clones containing a high fraction of 2s cells were consistently tumorigenic. The degree of cellular tumorigenicity thus correlated with cell ploidy. In addition, serial passage of WOR-6 cells in semisolid medium resulted in selective enrichment for near 2s cells and, concomitantly, greatly enhanced tumorigenicity. Analyses of G-banded chromosomes revealed that the 1s cells of the WOR-6 parental clone, which has a modal chromosome number of 21 and a range of 18 to 23, is completely or partially monosomic for some chromosomes and trisomic for others. The 2s cells, selected both in vivo through growth as tumors in nude mice and in vitro in semisolid medium, appeared to have resulted from preferential duplication of certain chromosomes of the 1s cells. Our results therefore suggest that cells which develop multiple copies of selected genes, while remaining functionally hemizygous for other loci, acquire an enhanced anchorage-independent growth potential in vitro and increased tumorigenicity. This conclusion is consistent with the observation that cellular tumorigenicity is correlated with anchorage independence (Freedman and Shin, 1974) and lends support to Ohno’s (1974)
The relationship between chromatid interference and the mapping function
Authors: Sturt E. , Smith C.A.B.
Published: May 2008

A formula for a general mapping function involving only the number of chiasmata between two points on the chromosome and the average excess of four-stranded double exchanges over two-stranded double exchanges is derived. A formula is also given for deriving the proportion of three-stranded double exchanges after any given number of chiasmata; this is related to mapping for linkage with the centromere. It is shown that this proportion tends to a limit of 2/3 after a large number of chiasmata, whether or not chromatid interference is operating.