bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation in pre-PCR processing of FFPE samples leads to discrepancies inBRAFandEGFRmutation detection: a diagnostic RING trial
Authors: Kapp Joshua R , Diss Tim , Spicer James , Gandy Michael , Schrijver Iris , Jennings Lawrence J , Li Marilyn M , Tsongalis Gregory J , de Castro David Gonzalez , Bridge Julia A , Wallace Andrew , Deignan Joshua L , Hing Sandra , Butler Rachel , Verghese Eldo , Latham Gary J , Hamoudi Rifat A
Published: November 2014

Aims

Mutation detection accuracy has been described extensively; however, it is surprising that pre-PCR processing of formalin-fixed paraffin-embedded (FFPE) samples has not been systematically assessed in clinical context. We designed a RING trial to (i) investigate pre-PCR variability, (ii) correlate pre-PCR variation withEGFR/BRAFmutation testing accuracy and (iii) investigate causes for observed variation.

Methods

13 molecular pathology laboratories were recruited. 104 blinded FFPE curls including engineered FFPE curls, cell-negative FFPE curls and control FFPE tissue samples were distributed to participants for pre-PCR processing and mutation detection. Follow-up analysis was performed to assess sample purity, DNA integrity and DNA quantitation.

Results

Rate of mutation detection failure was 11.9%. Of these failures, 80% were attributed to pre-PCR error. Significant differences in DNA yields across all samples were seen using analysis of variance (p<0.0001), and yield variation from engineered samples was not significant (p=0.3782). Two laboratories failed DNA extraction from samples that may be attributed to operator error. DNA extraction protocols themselves were not found to contribute significant variation. 10/13 labs reported yields averaging 235.8 ng (95% CI 90.7 to 380.9) from cell-negative samples, which was attributed to issues with spectrophotometry. DNA measurements using Qubit Fluorometry demonstrated a median fivefold overestimation of DNA quantity by Nanodrop Spectrophotometry. DNA integrity and PCR inhibition were factors not found to contribute significant variation.

Conclusions

In this study, we provide evidence demonstrating that variation in pre-PCR steps is prevalent and may detrimentally affect the patient's ability to receive critical therapy. We provide recommendations for preanalytical workflow optimisation that may reduce errors in down-stream sequencing and for next-generation sequencing library generation.
Coiling and clipping of middle cerebral artery aneurysms: a systematic review on clinical and imaging outcome
Authors: Zijlstra IJsbrand A , Verbaan Dagmar , Majoie Charles B , Vandertop Peter , van den Berg Rene
Published: November 2014

Background

There is an ongoing debate on the preferred treatment of middle cerebral artery (MCA) aneurysms. The purpose of this study was to assess the clinical and imaging outcomes comparing conventional coiling and clipping of unruptured and ruptured MCA aneurysms.

Methods

We searched the electronic databases PubMed, EMBASE, and Cochrane from January 1990 to May 2014.

Results

51 studies were included in the analysis. Favorable outcome was reported in 97.0% and 77.1%, and in 97.2% and 72.8% of patients after coiling and clipping of unruptured and ruptured aneurysms, respectively. Death rates were 1.1% and 8.4% after coiling and 0.3% and 14.7% after clipping of unruptured and ruptured aneurysms, respectively. Initial adequate occlusion was obtained in 89.6% and 92.1% after coiling of unruptured and ruptured aneurysms, respectively. Only three studies on clipping reported on aneurysm occlusion during follow-up.

Conclusions

Both coiling and clipping are procedures with low mortality and morbidity rates and, although it may seem that coiling is better for ruptured aneurysms and clipping for unruptured aneurysms, no firm conclusions can be drawn due to the variation in study design and lack of standardized reporting on MCA aneurysm treatments. Standardized observational studies from prospectively kept databases are needed to allow stronger conclusions to be drawn on what is the best treatment for MCA aneurysms. Comparable with aneurysms in other locations, a multidisciplinary approach is therefore recommended with selection of treatment modality based on the clinical condition of the patient and the morphological aspects of the aneurysm.
Non-invasive assessment of functionally significant coronary stenoses through mathematical analysis of spectral ECG components
Authors: Amano Tetsuya , Shinoda Norihiro , Kunimura Ayako , Harada Ken , Uetani Tadayuki , Takashima Hiroaki , Ando Hirohiko , Kumagai Soichiro , Gosho Masahiko , Murohara Toyoaki
Published: November 2014

Objectives

The aim of this study was to evaluate the accuracy of the Multifunction CardioGram (MCG) in detecting the presence of functionally significant coronary ischaemia.

Methods and results

This prospective study evaluated the accuracy of the MCG, a new ECG analysis device used to diagnose ischaemic coronary artery disease (CAD). A consecutive 112 participants suspected to have CAD who were scheduled for elective coronary angiography (CAG) from October 2012 to December 2013 were examined. Their predictive values of relevant ischaemia were measured by MCG, standard ECG and Framingham Risk Score (FRS) and compared. Five levels of ischaemia based on CAG findings adjusted by fractional flow reserve (FFR) values and three levels of MCG score of high, borderline or low were used. The MCG (OR=2.67 (1.60 to 4.44), p<0.001) was the only test significantly associated with ischaemia level. The FFR values for individual MCG scores with low, borderline and high were 0.77 (0.70 to 0.86), 0.78 (0.71 to 0.82) and 0.69 (0.65 to 0.77), respectively, p=0.042. A high MCG score had a specificity of 90.4% (87.0% to 93.9%) in model 1 adjusted by FFR≤0.8 threshold and of 87.0% (83.2% to 90.8%) in model 2 adjusted by FFR≤0.75 threshold, and a negative predictive value of 82.5% (78.3% to 86.7%) in model 1 and of 83.8% (79.6% to 87.9%) in model 2 for the prediction of severe ischaemia.

Conclusions

The MCG showed high specificity with a high negative predictive value, suggesting that the MCG could be used not only to identify functionally significant ischaemia but to reduce unnecessary CAGs.

Trial registration number

UMIN ID: 000009992.
Stress tolerance in a polyextremophile: the southernmost insect
Authors: Lee R.E. , Denlinger D.L.
Published: November 2014

Since biotic interactions within the simple terrestrial communities on the Antarctic Peninsula are limited compared with tropical and temperate regions, survival is largely dictated by the numerous abiotic challenges. Our research focuses on adaptations to environmental stresses experienced by the Antarctic midge (Belgica antarctica Jacobs, 1900), the southernmost free-living insect. Midge larvae can survive freezing and anoxia year-round. Not only can frozen larvae undergo rapid cold-hardening (RCH) at temperatures as low as –12 °C, but RCH develops more rapidly in frozen compared with supercooled larvae. Whether larvae overwinter in a frozen state or cryoprotectively dehydrated may depend on hydration levels within their hibernacula. Larvae constitutively up-regulate genes encoding heat shock proteins, as well as the antioxidant enzymes superoxide dismutase and catalase. Larvae accumulate osmoprotectants in response to freezing, desiccation, and exposure to seawater; exposure to one of these osmotic stressors confers cross-tolerance to the others. Molecular responses to dehydration stress include extensive genome-wide changes that include differential expression of aquaporins among tissues, upregulation of pathways associated with autophagy, inhibition of apoptosis, and downregulation of metabolism and ATP production.
INHERITANCE OF VIRULENCE IN WHEAT LEAF RUST ON THE STANDARD DIFFERENTIAL WHEAT VARIETIES
Authors: Samborski D. J. , Dyck P. L.
Published: November 2014

Populations of self-fertilized cultures from races 1, 9, 15 and 161 of wheat leaf rust were studied for inheritance of virulence on the eight standard differential wheat varieties. Race 9 was homozygous at all loci tested while the other races segregated at a number of loci. Recessive genes controlled virulence on the varieties Malalkof (gene Lr1) and Hussar (gene Lr11) respectively. Virulence to Mediterranean and Democrat was governed by a single recessive gene in race 1 and a single dominant gene in race 161. One recessive gene in races 1 and 15 governed virulence to the various alleles of the Lr2 locus, while in race 161 a second dominant gene altered the expression of avirulence of this gene on Loros (Lr24). An additional recessive gene for virulence interacted with gene LrB in Carina and Brevit. It is not known whether the gene for virulence, which corresponds to a particular host gene for resistance, is the same in each race of leaf rust that was studied. All genes for virulence segregated independently.
QUANTITATIVE INHERITANCE IN CROSSES AMONG FOUR TETRAPLOID WHEATS
Authors: Jackson B. R. , Dirks V. A. , Snyder L. A.
Published: November 2014

Four lines of Triticum durum, representing diverse levels of genetic relationship and geographic origin, were crossed to produce six segregating populations. Additive and dominance components of genetic variance were estimated for five metric characters in the F2and F4generations grown in separate years. Dominance variance predominated in two out of the six populations in F2, but was minimal in the F4generation. Additive genetic variance generally constituted the major source of genetic variance and was significantly greater than zero in all populations for every character investigated in F4. Populations based on crosses involving either of the two Ethiopian selections with either of the two North American varieties used as parents, in general showed larger amounts of genetic variance than the comparable intercross of the two North American varieties. Considerable genetic variance also existed in the populations derived from intercrossing the two Ethiopian wheats. The results of the investigation tend to support the hypothesized increase in genetic variance associated with genetic diversity, and the preponderance of additive genetic variance in naturally self-fertilizing species.
CHLOROPHYLL VARIEGATION CAUSED BY SOMATIC ELIMINATION OF AN ALIEN CHROMOSOMAL FRAGMENT INNICOTIANA TABACUM
Authors: Gupta S. B.
Published: November 2014

Hybrid derivatives of Nicotiana tabacum (n = 24) and N. paniculata (n = 12) were found to possess 24II + fg (chromosomal fragment of pnc) in the F4and later generations. These plants showed chlorophyll variegation in their stems, leaves and chlorophyllous tissue of flowers.The results indicated that the variegation was not due to any cytoplasmic factor. The chlorophyll factor was carried by the centric chromosomal fragment of N. paniculata (pnc).The irregular distribution of the centric fragment, due to nondisjunction in the somatic tissue leading to chlorophyll variegation, is discussed.
MONOSOMIC ANALYSES OF TEMPERATURE SENSITIVE DWARFISM IN COMMON WHEAT
Authors: Piech J. , Evans L. E.
Published: November 2014

Monosomic analyses of two homozygous, temperature sensitive dwarf lines were made by crossing each to the complete Chinese Spring monosomic series.Marquillo-Timstein was found to carry genes controlling dwarfism on chromosomes 1A, 2A, 2B, 2D and 3D whereas the variety Marquillo-Kenya Farmer possesses dwarfing genes on chromosomes 2A, 4B and 2D. The major difference between the two dwarfs appears to be due to differences on chromosome 4B.Study of height variation within each of the deficient F2 populations revealed that height inheritance is more complex than dwarfism and that the genes that influence dwarf frequency also influence the height of the non-dwarf portion of the segregating population.
EVIDENCE FOR GENE HOMOLOGY OF TWO PEARL-EYED GENES IN TRIBOLIUM CASTANEUM AND TRIBOLIUM CONFUSUM
Authors: Roberts C. W. , Juriloff D.
Published: November 2014

Evidence was presented that gene homology exists for two genes, riboflavinless, pearl-eye (pr) and pearl-eye (p), both found in Tribolium castaneum and Tribolium confusum. Both species contain the non-allelic pr and p genes. In both species the pr phenotype is expressed in three traits: pearl-eye, colourless Malpighian tubules and a lack of ability to store riboflavin in the adults. In both species the p phenotype is expressed in two traits: pearl-eye and colourless Malpighian tubules. The linkage group for the pr and p genes is the same for both species. In both species pr and p are closely linked, although the degree of linkage has yet to be established.
RECIPROCAL TRANSLOCATIONS INDUCED BY X-RAYS AND THERMO-NEUTRONS IN WILD SORGHUM (S. PURPUREO-SERICEUM ASCHERS AND SCHWEINF.)
Authors: Wu T. P. , Pi C. P.
Published: November 2014

Dry seeds of S. purpureo-sericeum were irradiated with either X-rays or thermo-neutrons with three exposures each. No difference was shown in germination between the irradiated treatments and the control. The percentage of survival was greatly reduced to 2.2% in seeds treated with X-rays. However, there was no significant difference in survival between the thermo-neutron treatments and the control. Both radiation treatments inhibited seedling height to a considerable degree, and the variability of seedling height increased with higher exposures of irradiation. The types and the frequency of induced interchanges were proportional to the exposure of thermo-neutron irradiations.Twenty six translocation heterozygous plants were analyzed and considered to be semisterile plants. Spore quartet analysis revealed that the two types of adjacent segregations occur with nearly the same frequency.Six plants with pseudo-isochromosomes were detected. Pseudo-isochromosomes were often delayed in anaphase movement. They were excluded from daughter nuclei at telophase stages and eventually became micronuclei in the spore quartets.Two plants with a ring-of-six, and one plant with two pseudo-isochromosomes plus a ring-of-six were also found among the materials irradiated with high exposures of thermo-neutrons. Pollen counts showed that they had the lowest fertility among translocation heterozygous plants and no seed was obtained.
AN ASSOCIATION OF STEM RUST AND CROWN RUST RESISTANCE IN JOSTRAIN OATS
Authors: McKenzie R. I. H. , Martens J. W. , Fleischmann G. , Samborski D. J.
Published: November 2014

Rodney backcross lines carrying single genes for stem rust resistance were tested with 10 cultures of crown rust. Lines possessing genes Pg-1, Pg-2, Pg-4 and pg-8 were susceptible to all cultures of crown rust used, whereas the line carrying Pg-3 was highly resistant to several of these cultures. Studies of 51 Victory2 x Jostrain F2 backcross families indicate that gene Pg-3 confers a moderate level of resistance to stem rust. In addition to Pg-3 a number of modifying genes appear to be required to explain the high level of stem rust resistance in Jostrain.Either one gene, Pg-3, or two closely linked genes in the Victory2 x Jostrain backcross families, confer resistance to both stem rust and crown rust. Resistance to both rusts broke down at temperatures of 25 °C and above suggesting that Pg-3 alone is responsible for resistance to both rusts.
A SERUM POST ALBUMIN SYSTEM IN MINK
Authors: Saison Ruth
Published: November 2014

Two post albumin bands in the sera of mink have been observed by horizontal starch-gel electrophoresis, a fast band, designated A, and a slow band, designated B. It is proposed that this system is composed of 2 alleles, PaAand PaB, giving rise to 3 phenotypes, PaA, PaB and PaAB. The results of tests of sera from progeny from 16 matings is in agreement with this genetic hypothesis.
CHROMOSOME NUMBERS OF SOME NORTH AMERICAN DRAGONFLIES (ODONATA)
Authors: Cruden Robert William
Published: November 2014

Chromosome numbers for 111 species of North American Odonata are reported. In five species, Enallagma cyathigerum (Charp.), Ophiogomphus bison Sclys, Dorocordulia iibera (Selys), Epitheca cynosura (Say), and Leucorrhinia frigida Hagen, primary spermatocytes from single individuals had different chromosome numbers. This is presumed to arise from either fusion or "splitting" of chromosomes. Fusion in D. libera, E. cynosura and L. frigida results in reduction of chromosome number, and "splitting" in E. cyathigerum and O. bison gives higher chromosome numbers.The idea that high chromosome numbers in Odonata are primitive is rejected. An alternative hypothesis is proposed: that low numbers are primitive (or secondarily derived) and high numbers advanced.
PROGRESSIVE VEINBANDING—A NEW MUTATION IN NICOTIANA TABACUM L.
Authors: Povilaitis Bronius , Cameron D. R.
Published: November 2014

A new mutation for chlorophyll-deficiency in Nicotiana tabacum L., called progressive veinbanding, was found in the field planting of the flue-cured tobacco variety Hicks Broadleaf. The mutant follows monogenic inheritance of a single recessive gene upon which the normal allele exhibits complete dominance. There was a definite association of the mutant type with the M—chromosome of the sylvestris genome in tests against the monosomic series.
THE INHERITANCE OF RESISTANCE TO STEM RUST RACES 56 AND 15B-1L (CAN.) IN THE WHEAT VARIETIES HOPE AND H-44
Authors: Knott D. R.
Published: November 2014

The inheritance of resistance to races 56 and 15B-1L was studied in back-crosses of Hope and H-44 to Marquis. The results indicated that both varieties carry the same three genes. Resistance to race 56 is controlled by two dominant genes, Sr 1 which conditions seedling or physiological resistance and Sr 2 which conditions adult plant resistance. At either the seedling or adult plant stage both genes must be present to provide full resistance to race 56. A single recessive gene, not yet named, provides resistance to race 15B-1L.The gene Sr 1 was transferred from Hope to Marquis by backcrossing and the line was crossed to the Chinese Spring monosomics. The gene proved to be on chromosome 2B (XIII).
A COMPARISON OF METHODS FOR ANALYZING INHERITANCE DATA FOR RESISTANCE TO RED RASPBERRY POWDERY MILDEW
Authors: Daubeny Hugh A. , Topham P. B. , Jennings D. L.
Published: November 2014

The simultaneous use of models applicable to discontinuous and continuous variation for analyzing the segregation of powdery mildew resistance in red raspberry progenies gave complementary information. The analysis based on the model for discontinuous variation supported the hypothesis that segregation was controlled by two additive genes for resistance and one epistatic gene for susceptibility. This analysis gives information on the possible genotypes of the parents which facilitates predictions on the proportion of resistant seedlings expected in breeding programs.The analysis based on the model for continuous variation also indicated that inheritance was predominantly additive with significant genetic interactions. However, the estimates of parental contributions to the progenies were more widely based, because allowance was made for the effects of different gene viabilities, of modifying genes and of environmental influences on expression of the disease. Estimates of combining ability obtained from this model facilitate predictions of mean resistance of progenies.The use of each model appeared to provide a more complete assessment of parental resistance contributions than either model used alone.
AMINO ACID ANALYSES OF THE SPECIES IN THE GENUS GOSSYPIUM
Authors: Sarvella Patricia , Stojanovic B. J.
Published: November 2014

The free and protein amino acid patterns present in the leaves of the species of the genus Gossy pium were determined. The presence or absence of the free amino acids except for glycine and γ-amino butyric acid did not appear to be of value for separation of the species. However, the patterns of the protein amino acids varied between the genomes, and seemed to separate the species. These patterns were separated into groups similar to those found for the DNA-base ratios and the cytotaxonomic grouping of the species.
SYNAPTINEMA-LIKE COMPLEX IN SPERMATIDS OF SOME MUSTELIDS
Authors: Basrur Parvathi K. , Gilman J. P. W.
Published: November 2014

Electron microscopic observations of the seminiferous epithelium of ferret and mink revealed triplets of linear densities described by previous authors in other animals as synaptinemal complex. These substructures were noted very frequently in primary spermatocytes and often also in spermatids at an early stage of spermiogenesis. It is postulated that the hitherto unrecorded presence of synaptinemal complex in spermatids may be suggestive of an initial stage in spermiogenesis at which the chromatin is in an extended state, simulating the early stage of prophase. Alternatively, the occurrence of synaptinema-like structures may indicate the failure of bivalents to separate during meiosis. The persistence of such bivalents in spermatids might represent gradual retrogressive changes in mustelid testes in preparation for the quiescent stage at the end of the breeding season.
DISTRIBUTION OF HETEROCHROMATIN IN THE CHROMOSOMES OFHAPLOPAPPUS GRACILIS
Authors: Ames Ira H. , Mitra Jyotirmay
Published: November 2014

Several approaches were employed to study the distribution of heterochromatin in root tip chromosomes of Haplopappus gracilis. Cold treatment and pretreatment in an aqueous solution of 8-hydroxyquinoline revealed achromatic gaps in metaphase chromosomes. Cold treatment also permitted the demonstration of positive heteropycnosis in prophase chromosomes. Further support for the identification of heterochromatic segments was provided by a study of the localization of chromosome aberrations induced by maleic hydrazide and an analysis of the pattern of DNA synthesis in chromosomes of root tip cells. Seven of the ten regions that were preferentially broken by maleic hydrazide also reacted differentially to cold treatment or to pretreatment with 8-hydroxyquinoline. A good correlation was found between regions that completed DNA replication late in the DNA-synnhetic period and segments that were shown to be heterochromatic by the other techniques.
VARIABILITY OF RECOMBINATION WITHIN THE PYRIDOXINE LOCUS OFNEUROSPORA
Authors: Radford A.
Published: November 2014

In a series of crosses between related strains of two alleles of the pdx-1 locus, the rate of production of prototrophs in different crosses is found to vary by at least a factor of two. Variability between the prototrophs from these crosses with respect to proximal and distal outside marker distribution is also observed. No evidence of simple genetic control of the variability is found. The most likely order of outside markers and pdx-1 alleles is pyr-1 pdx (39106) pdx (37803) col-4, but the variability is shown to be capable of changing the apparent site order.
CHROMOSOMAL ALTERATIONS IN MARINE FISH CELLS IN VITRO
Authors: Regan James D. , Sigel M. Michael , Lee William H. , Llamas Kirsten A. , Beasley Annie R.
Published: November 2014

The modal chromosome number of the GF cell line is 46, consisting of 44 telocentrics and two metacentrics. Primary grunt fin tissue exhibits 2n = 48; all are telocentric chromosomes. The modal cell of the GF cell line does not represent the in vivo genetic constitution conserved by Robertsonian translocation since the modal cells are variously haploid or nullo for the chromosome pair bearing secondary constrictions. Despite the fact that GF cells possess 44 telocentric chromosomes, only limited centric fusion appears to have occurred during 8 years of culture in vitro.
RELATIONSHIP OF TAXA IN GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION.: II. M. PIRONAE × M. DAGHESTANICA WITH REFERENCE TO M. SATIVA
Authors: Lesins K. , Gillies C. B.
Published: November 2014

Medicago pironae Vis. and M. daghestanica Rupr. are related to the extent that viable F1 hybrids can be easily obtained. These species should, therefore, be grouped taxonomically closer than has been done in the past. Their relationship to M. sativa L. is more remote, as judged by failure in hybridization. The M. pironae × M. daghestanica F1 hybrids were completely self-sterile and sterile on backcrossing to both parents. Pollen of the hybrids was close to 100% protoplasm-empty. Meiosis proceeded irregularly in 55% of metaphase I and diakinesis cells. At AI and All chromatin bridges were observed in 65% and 90% of cells, respectively. At pachytene, strands of unequal lengths and different chromomere patterns indicated cryptic chromosomal or genie dissimilarities.
LINKED GENES ARISING AMONG MULTIPLE MUTANTS IN EMS-TREATED SACCHAROMYCES
Authors: Lindegren Gertrude , Courtis William S. , Shult Ernest E.
Published: November 2014

Previous work has established that EMS treatment of Saccharomyces yields a relatively efficient method for harvesting viable biochemical mutants, and that cells bearing multiple biochemical deficiencies occur with unusually high frequency. In addition a genetic analysis of these multiple mutations has shown a non-random "clustering" of these multiple mutations relative to the total chromosome map.Apparently for reasons which are not immediately clear, EMS-treatment produces an unexpectedly rich abundance of multiple mutations among genetically linked loci. Conceivably, this could occur if only specific chromosomal regions were "open" to the mutagenic action of EMS at any given time.
THE SENSITIVITY OF VARIOUS GERM-CELL STAGES OF THE MALE MOUSE TO RADIATION INDUCED TRANSLOCATIONS
Authors: Léonard A. , Deknudt Gh.
Published: November 2014

Adult male BALB/c mice were given whole body X-irradiation with 300 R. Directly after X-irradiation each male was mated to one virgin female of the same strain and received one fresh female per week during 9 weeks. The male F1 offspring was killed when mature and the testes removed and analysed for the presence of chromosome rearrangements at diakinesis — first metaphase stage of meiosis. Whereas no aberration was recorded among the 171 F1 ♀♀ from the control series, chromosomal abnormalities were observed in 41 F1 ♀♀ from the irradiated series. The incidence of males with aberrations was respectively 5.1% the first week, 10.4% the second week, 21.7% the third week, 2.2% the fourth week and 6.3% the fifth. No aberration was observed in the 129 F1 males sired between the sixth and ninth weeks. It may be concluded that irradiated spermatids yield approximately four times as many cases of aberration in viable F1 ♀♀ as do irradiated mature spermatozoa and about ten times as many as the most mature spermatocytes whereas no aberrations were recovered from irradiation of the spermatogonia. The most common aberrations found in the F1 males of the irradiated series were the reciprocal translocations.
THE EFFECT OF THE BASIC COLOR FACTOR c ON XANTHOPHYLL PIGMENTATION IN DIPLOID ALFALFA
Authors: Clement Jr. William M.
Published: November 2014

The c locus in alfalfa was found to inhibit the formation of xanthophyll as well as anthocyanin pigments. Plants with one or more genes for xanthophyll, but homozygous recessive for the c locus, had cream colored flowers. Phenotypically, the flowers of these plants resembled those from plants homozygous recessive for the loci controlling xanthophyll and anthocyanin production but dominant for the C locus. However, seeds from cream colored plants in this experiment are light in color and the stems lack anthocyanin, in contrast with other cream colored plants which have dark seeds and anthocyanin in the stem. The pigments responsible for the cream color were not identified. Additional studies on flower color inheritance in alfalfa are needed since observed ratios did not always agree with expectations based on previous work.
PREFERENTIAL PAIRING OF CHROMOSOMES IN A TETRAPLOID HYBRID BETWEENORYZA GLABERRIMAANDO.SATIVA
Authors: Oka Hiko-Ichi
Published: November 2014

A tetraploid hybrid was obtained from a cross between induced tetraploid strains of Oryza sativa L. and O. glaberrima Steud., which differed in glutinous (waxy) vs. non-glutinous starch (gl: +) and other genes. In the hybrid, as compared with the parental strains, there was a reduced number of quadricvalents and a relatively high degree of fertility. Segregation ratios for the glutinous gene observed in the back-cross and F2generation appeared to be modified not only by preferential homogenetic pairing but also by gametic selection. Taking into account the effect of gametic selection estimated from simplex heterozygotes, it was suggested that preferential pairing could take place to a certain extent. It seems to be difficult to measure quantitatively the degree of preferential pairing in tetraploid species hybrids, unless the effect of various segregation-distorting factors can be accounted for.
QUANTITATIVE STUDY OF INTRASPECIFIC VARIATION OF DNA PER CELL INPICEA GLAUCAANDPINUS BANKSIANA
Authors: Miksche Jerome P.
Published: November 2014

Intraspecific variation of DNA per cell was established chemically and cytophotometrically for 17 seed sources of Picea glauca, and cytophotometrically for 11 sources of Pinus banksiana. The DNA Feulgen absorption per cell varied from the lowest to the highest amount by factors of 1.6 and 1.5 for Picea glauca and Pinus banksiana, respectively. Intraspecific DNA also varies with intraspecific nuclear volume. Intraspecific variation of histone was similar to the observed DNA variation. A regression analysis between DNA per cell and latitude provided evidence that eastern and western population series of Picea glauca existed in the seed sources studied. Two-year seedling height growth results demonstrated that eastern seed sources are different from western seed sources. Seedling height in the western provenances varied inversely with DNA content; i.e., seed sources with small DNA per cell displayed greater growth, whereas the eastern sources did not display the inverse relationship between DNA amount and 2-year growth.
SPERMATOCYTE GRANULES INDROSOPHILA MELANOGASTER
Authors: Erickson John , Acton A. B.
Published: November 2014

Granular inclusions are found in testes from a cn bw stock of Drosophila melanogaster, and maternally derived lines, such as SD. In late larval and early pupal stages, these granules show a polarized distribution within primary spermatocytes corresponding to the polarity basic to the type of meiotic drive where certain homologues reach that pole of the spermatocyte leading to functional sperm. In adult males, the granules are found in intercellular patches in the testes. Electron microscopy shows the spermatocyte granules to be spheroids of about 0.7 μ; dividing, or double forms resulting from division, are about 1.8 μ long. They contain numbers of ribosome-like particles and fine strands presumed to be DNA. The acridine orange test for nucleic acids was positive. Each granule is surrounded by two layers of unit membrane and a third such membrane envelopes the individual or the pair of granules, as the case may be. The third membrane layer (and additional membranes sometimes seen) is thought to be due to entrance of the granules into the host cell through the cisternae of the endoplasmic reticulum. Transmission of the granules is strictly maternal and independent of chromosome constitution. Transmission by contagion was not found. Spermatocyte granules are not requisite to the effectiveness of the SD meiotic drive system, which regularly carries them. A slightly lowered fertility of females carrying the granules was found but no similar effect is produced in males. The evidence suggests that they are parasitic organisms, probably Rickettsiae.
LATE DNA REPLICATION PATTERN IN SEX CHROMOSOMES OF MELANDRIUM
Authors: Choudhuri Hiran C.
Published: November 2014

DNA replication patterns in somatic cells of female and male Meladrium album were studied with autoradiographic methods. The S-period and the average generation time have been estimated to be 5.7 and 15.5 hours respectively. The heterochromatin observed in interphase nuclei may represent the late replicating and presumably inactivated sex chromosome.One arm of one X chromosome is late replicating in females. In the Y chromosome a region near the centromere replicates late in the S-period. The DNA replication sequence in sex chromosomes of female and male cells of Melandrium album suggests that their pattern is similar to that of mammalian sex chromosomes.
MEIOSIS IN THE GRASSHOPPER: CHIASMA FREQUENCY AFTER ELEVATED TEMPERATURE AND X-RAYS
Authors: Church Kathleen , Wimber Donald E.
Published: November 2014

Grasshoppers were given an acute dose of X-rays, injected with H3-thymidine and thereafter maintained at 42 °C. Autoradiographic analysis of testicular tubules taken at daily intervals after injection gave meiotic stage durations. The mean chiasma frequency was reduced 4 days after the hoppers were placed at 42°, in both X-rayed and non-irradiated animals, and remained low in the non-irradiated animals throughout the experiment. In the X-rayed animals the chiasma frequency rose to control levels on die 6th day and dropped again thereafter. Analysis of the data indicates a period ending approximately at zygotene during which chiasma frequency can be reduced by high temperature. The chiasma frequency can be increased by irradiating leptotene-zygotene. The end of the heat and X-ray sensitive stages are temporally distinct. Univalents were never produced by the heat treatment. Changes in chiasma frequency are restricted to the four pairs of larger chromosomes where multiple chiasmata are commonly found. Hence, the presence or absence of chiasmata shows a complex interaction with the physical environment.
INTRASPECIES AUTOSOMAL POLYMORPHISM AND CHROMOSOME REPLICATION IN AKODON MOLINAE (RODENTIA: CRICETIDAE)
Authors: Bianchi N. O. , Contreras J. , Dulout F. N.
Published: November 2014

Cell spreads from bone marrow, spleen, testis and liver of four male and four female Akodon molinae (Rodentia:Cricetidae) were used for chromosome analysis and sex chromatin scoring. Chromosome replication at the beginning and end of the S period were analysed in bone marrow cells.In five animals (three males and two females) the diploid chromosome number was 42; the other three (1 male and 2 females) had a modal number of 43. In the former animals pairs 1,2,19,20 and the Y chromosome were easily identified morphologically. Chromosomes 1 were large and metacentric. In specimens with 43 chromosomes, pairs 2-20-XY were similar to those of animals with 42. Instead of having two number 1 homologues, these animals showed three unpaired chromosomes, one chromosome 1, one subterminal chromosome (1a) homologue of the long arm of the chromosome 1 and one submetacentric chromosome (1b) homologue of the short arm of the chromosome 1 Chromosomes 1a and 1b were considered to have arisen by a Robertsonian mechanism of centric fission of chromosome 1 plus a pericentric inversion.Studies of sex chromosome replication showed that the Y chromosome was the last to start and to end DNA synthesis in male complements. In females one X chromosome was the last to start replication. No late replicating X chromosome at the end of the S period was found. Coincidently, no sex chromatin could be detected in females.Analysis of late replication patterns in chromosomes 1, 1a and 1b, indicates that pericentric inversions can shift the replicating moment of the chromosomal regions involved in the rearrangement.
RADIO-SENSITIVITY IN RAGI (ELEUSINE CORACANA)
Authors: Goud J. V. , Nayar K. Muraleedharan , Rao M. Goalkrishna
Published: November 2014

Dry seeds of three varieties of ragi (Eleusine coracana) were subjected to gamma irradiation with acute dosage of 20 Kr and 30 Kr. The mutagenic effects of gamma rays in the M1generation and the mutation frequency with regard to chlorophyll and viable mutations in the M2generation were studied.The LD50appears to be around 30 Kr for ragi, although there are enormous varietal differences. Purna is the least and H22the most sensitive to gamma irradiation in the M1generation. There is a direct correlation between the radiation effect produced as measured by seedling growth, pollen fertility and seed fertility with the dosage used. Multivalent formation, lagging chromosomes and stickiness, etc. were observed in meiotic studies in the M1generation.The frequency of chlorophyll mutations was less in populations irradiated with 30 Kr than with 20 Kr. A wide spectrum and a high frequency of viable mutations were produced in Purna. The mutation frequency (viable + chlorophyll) increased with the dosage. The 200 isolated viable mutations included many agronomic types which are useful either directly or in conventional plant breeding.
THE CHROMOSOME COMPLEMENT OF RABBIT BLASTOCYSTS IN RELATION TO THE TIME OF MATING AND OVULATION
Authors: Shaver Evelyn L. , Carr D. H.
Published: November 2014

Six-day blastocysts were recovered from rabbits mated at various intervals from 0 to 10 hours after an ovulation-inducing injection of chronic gonadotrophin. Ten of eighty or 13% of the blastocysts from animals mated between 6 and 9 hours after injection were triploid in chromosome constitution. When karyotyped, seven of the triploids had an XXY and three an XXX sex chromosome complex. The incidence of chromosome abnormalities at delay intervals from 0 to 4 hours was 5%, approximately. No triploids were found at these times. The sex chromosome complex of 6-day blastocysts was XY in 54% and XX in 46% of the blastocysts. No difference in the sex ratio was noted with delayed mating.
ABERRANT SEGREGATION: A NEW CASE INDROSOPHILA MELANOGASTER
Authors: Hanks G. D. , Torgerson R. O.
Published: November 2014

Males from an ebony strain of Drosophila melanogaster show a consistent and deviant sex ratio in their progenies (53 to 57% females). The cause is a major gene on the X chromosome at approximately 48. Zygotic mortality is not the cause; therefore, a prezygotic mechanism is probably responsible. There is good evidence for a suppression effect (2 to 4%) by the autosomal component in the ebony strain. No effect was found for the two Y chromosomes tested.
THE DEVELOPMENT OF DNA CONTAINING NUCLEAR BRIDGES IN HUMAN CELLS
Authors: Mukherjee Anil B. , Cohen Maimon M.
Published: November 2014

Nuclear bridges were observed in human cells of malignant origin and a small proportion of PHA-stimulated normal human lymphocytes (3.8%). Such structures were not seen in benign tissue or lymphocytes cultured without PHA. Classification of such bridges on the basis of morphologic development suggests a process leading to an abnormal nuclear division yielding hypodiploid micro-nuclei. H3-thymidine incorporation studies indicate that these bridges contain DNA.
THE BOTCH GENE IN GOSSYPIUM ARIDUM
Authors: Douglas Charles R.
Published: November 2014

Sixty-four diploid plants from crosses of Uplant cotton, Gossypium birsutum L., with a wild Mexican species, G. aridnm (Rose and Standl.) Skov., were examined for the expression and segregation of a gene, called the botch gene, from G. aridum. Twelve of the plants were examined cytologically. The phenotypic expression of the gene included leaves with very irregular margins, early abscission of flower buds, shortened internodes and a pseudo-death of the plant. It was suggested that plants expressing the botch gene could be useful in studies of flower abscission and plant aging.
HUMAN CHROMOSOME MORPHOLOGY. I. STUDIES ON NORMAL CHROMOSOME CHARACTERIZATION, CLASSIFICATION AND KARYOTYPING
Authors: Al-Aish Matti S.
Published: November 2014

Chromosome measurements including relative total length, arm ratio and centromeric index of the human complement were presented. Based on these data the human complement was classified into metacentric, submetacentric, subtelocentric, and acrocentric chromosomes and arranged into a mammalian style karyotype. On the basis of this classification a new karyotype was suggested to facilitate analysis of Denver Group III (X—6—12) and divide it into four subunits. Metacentric chromosomes 10 and 16 were detached from their respective groups in this new karyotype.
KARYOTYPE ANALYSIS OF THE NOVA SCOTIAN SPECIES OF STREPTOPUS MICHX. (LILIACEAE)
Authors: Bent A. E. , Smith E. C.
Published: November 2014

Chromosome numbers previously reported for S. amplexīfolius var. americanus (2n = 32) and S. roseus var. perspectus (2n = 16) were confirmed from several collections in Nova Scotia. Idiograms were prepared for the two species. Karyotype formulas are as follows: S. amplexifolius var. americanus, K(2n) = 32 = 10J + 2V + 12j + 8v; S. roseus var. perspectus, K(2n) = 16 = 6J + 2J + 8v. Present evidence indicates that S. amplexifolius var. americanus may be an allotetraploid rather than an autotetraploid.
GENETIC HOMEOSTASIS INDROSOPHILA MELANOGASTER
Authors: Walton P. D.
Published: November 2014

The literature provides three explanations of the way in which genetic homeostasis functions. An attempt was made to determine which of these was applicable to the changes which occurred when selection for geotaxis was relaxed in certain strains of Drosophila melonogaster. The strains, for which selection stopped, were divided into two parts and generations were advanced in two environments. One was the same as that in which selection had been made and the other was new. When selection was relaxed strains reverted to a mean geotactic score close to that of the populations from which they had been selected. This change was more rapid in the new environment. A series of diallel crosses compared strains for which selection was continued with those for which it was relaxed. An analysis of the components of genetic variation showed that the principle change that had taken place was in the additive component of genetic variation. It was concluded that genetic homeostasis resulted from the action of natural selection on additive genetic variance, a conclusion which is in agreement with one of the three current hypotheses.
INHERITANCE OF RESISTANCE TO POWDERY MILDEW IN THE CULTIVATED STRAWBERRY
Authors: Hsu C. S. , Watkins R. , Bolton A. T. , Spangelo L. P. S.
Published: November 2014

The inheritance of resistance to powdery mildew was investigated in 64-somewhat interdependent progenies produced among 32 North American strawberry cultivars or selections. The data were analyzed by both the quantitative method based on continuous variation and the Mendelian method based on discontinuous variation. The quantitative analysis indicated that non-additive variance was more important than additive variance and that epistatic variance was considerable. The Mendelian analysis supported the hypothesis that segregation depended on two additive genes for resistance and one epistatic gene far susceptibility. The breeding procedure of progeny selection followed by individual selection was suggested for the improvement of powdery mildew resistance in strawberry based on the complementary information obtained from both analyses.
LEAF RUST RESISTANCE OF TRANSEC WHEAT
Authors: Luig N. H.
Published: November 2014

The same single dominant factor in the wheat-rye translocation line Transec controls resistance to Australian leaf rust strains in the seedling and adult plant stages. Transec did not derive the major factor for adult plant resistance from its Chinese Spring parent. The two factors which are both on chromosome 4A appear to be loosely linked.
ELECTRON-DENSE STRUCTURES INNEUROSPORA CRASSA. I. MESOSOMES
Authors: Kozar F. , Weijer J.
Published: November 2014

Complex lamellar and vesicular membranous structures have been observed in electronmicrographs of germinating conidia of N. crassa. These structures appeared to be morphologically similar to structures referred to as mesosomes in a number of gram-positive bacteria.
ELECTRON-DENSE STRUCTURES INNEUROSPORA CRASSA. II. LOMASOME-LIKE STRUCTURES
Authors: Kozar F. , Weijer J.
Published: November 2014

An electron microscope investigation of germinating conidia of Neurospora crassa (St. Lawrence strain) has revealed the presence of lomasome-like structures. These structures are differentiated from mesosomes in that lomasomes are vesicular or tubular in nature, and always located at the periphery of the cell, whereas mesosomes are myelinoid-like bodies, often interconnected with large vesicles and mitochondria. Lomasomes were frequently observed in vacuolating cells.
MEIOTIC SYNCHRONY, CYTOPLASMIC CONTINUITY AND CYTOMICTIC PHENOMENA DURING MICROSPOROGENESIS OFPRUNUS AVIUM
Authors: Whelan Ernest D. P. , Hornby C. A.
Published: November 2014

Examination of whole anther squashes of seven cultivars of sweet cherry (Prunus avium L.) revealed meiotic synchrony within a locule, all meiocytes being at a similar stage of division.Cytoplasmic connections between neighbouring meiocytes characterized meiosis I and were most evident in diplonema. Inter-meiocyte connections were not seen in meiosis II nor between the meiocytes and the tapetum.The parallel between the presence of cytoplasmic connections during meiosis I and the degree of synchronization of the meiocytes, followed by the absence of these connections and greater asynchronization of stage during meiosis II, suggests that the two observations are related.Cytomixis, in the sense of transfer of nuclear material, was observed occasionally between inter-connected meiocytes, but was considered to be an induced artifact.
DIGENIC INHERITANCE OF MALE STERILITY IN PLANTAGO LANCEOLATA
Authors: Ross M. D.
Published: November 2014

Gynodioecy is an outbreeding mechanism where both male-sterile (i.e. female) and hermaphrodite plants are found. Plantago lanceolata is gynodioecious, and ratios of 1:1, 3:1, 7:1 and 15:1 obtained in the descendants of a male-sterile plant indicate that there are two duplicate dominant genes for hermaphroditism, and that the double recessive, ms1ms1ms2ms2, is male sterile. Descendants of other male-sterile plants produced different results suggesting the presence of some additional factor affecting the inheritance of male sterility.
THE STRANDEDNESS OF CHROMOSOMES: EVIDENCE FROM CHROMOSOMAL ABERRATIONS
Authors: Heddle John A.
Published: November 2014

If cells are irradiated late in the mitotic cycle (late G2or early prophase), at the following anaphase they frequently exhibit characteristic chromosomal configurations known as sidearm bridges. These are often interpreted as sub-chromatid aberrations and are taken as evidence that chromosomes are multi-stranded. This interpretation, although recently challenged, is supported by experiments based upon the normal replication that converts chromatids to full chromosomes. The rationale is that aberrations involving only one chromatid of a chromosome are converted by replication to chromosome aberrations involving both chromatids. After replication, therefore, there should be no chromatid aberrations remaining unless the initial aberration involved less than a full chromatid. The results show that chromatid aberrations do appear after chromosomal replication: at the second mitosis after irradiation. Another experiment shows that most such chromatid aberrations are not the result of errors in the replication of previous chromatid aberrations.
HOMOEOLOGOUS RELATIONSHIP OF RYE CHROMOSOME VI WITH TWO HOMOEOLOGOUS GROUPS FROM WHEAT
Authors: Lee Y. H. , Larter E. N. , Evans L. E.
Published: November 2014

On the basis of its property to genetically compensate for chromosomes of homoeologous group 3 of wheat (T. aestiυum L. em. Thell.), it is suggested that Secale cereale L. chromosome I (as originally designated by Evans and Jenkins, 1960; later as VI by Riley and Macer, 1966) be redesignated as 3R. This would bring to a total of four the number of chromosomes of rye whose homoeologous relationship with wheat is known, viz. 2R, 3R, 5R and 6R.In addition to its compensating properties for group 3, 3R also exhibited partial homoeology for homoeologous group 1, specifically with chromosome ID. As a possible explanation for this behavior, it is suggested that 3R is a translocated chromosome constituting one of the three translocations known to differentiate the chromosome complements of S. cereale and S. montanum.