bluuebunny/crossref_metadata_2025 huggingface dataset:
Emerging new alleles suggest high diversity of HLA‐C locus
Authors: Lebedeva T.V. , Ohashi M. , Huang A. , Vasconcellos S. , Flesch S. , Yu N.
Published: January 2005

Abstract:  Human leukocyte antigen (HLA)‐C has only recently emerged as an important transplantation antigen and as a receptor for natural killer cells. Over the last few years, sequence‐based typing (SBT) revealed the true diversity of HLA‐C locus; however, the frequency at which new alleles are detected still remains high. During routine SBT of 3500 samples for the National Marrow Donor Program®, we have identified 20 new HLA‐C alleles reported in this article in 26 individuals. New variants have been characterized by direct sequencing of polymerase chain reaction product obtained by allele‐specific amplification of potential new alleles. Most of the new alleles carry coding substitutions of residues located within the antigen‐binding groove. The substitutions are predominantly located in the α2‐helix which is consistent with the unique to HLA‐C conservation of α1‐helix. Seven new alleles, or 35%, have been identified in African Americans, two of them in three and four individuals each, suggesting that these alleles may not be rare. This observation reflects the fact that the minority groups, previously under‐represented in the HLA research pools subjected to SBT, now begin to emerge as a main source of new HLA‐C alleles. This study further confirms that HLA‐C locus is at least as polymorphic as HLA‐A and HLA‐B.
Interleukin‐6 (IL‐6) − 373 A9T11 allele is associated with reduced susceptibility to chronic periodontitis in Japanese subjects and decreased serum IL‐6 level
Authors: Komatsu Y. , Tai H. , Galicia J.C. , Shimada Y. , Endo M. , Akazawa K. , Yamazaki K. , Yoshie H.
Published: January 2005

Abstract:  We investigated whether interleukin‐6 (IL‐6) gene polymorphisms could be associated with chronic periodontitis (CP) and serum IL‐6 level. One hundred and twelve CP and 77 non‐CP Japanese subjects were analyzed for IL‐6 −597 (G/A), −572 (C/G), −373 (AnTm), −190 (C/T), and −174 (G/C) polymorphisms. We could only detect −572 and −373 polymorphisms and found that the frequency and carriage rate of the −373 A9T11 allele were significantly higher in non‐CP subjects. Enzyme‐linked immunosorbent assay confirmed that the −572 and −373 G[A9T11] haplotypes were associated with lower serum IL‐6 level. These findings suggest that IL‐6 −373 A9T11 allele could be associated with reduced susceptibility to CP among Japanese subjects and decreased serum IL‐6 level.
A “CELL‐CONTACT TEMPERATURE‐SENSITIVE” MUTANT OF THE CELLULAR SLIME MOLD DICTYOSTELIUM MUCOROIDES
Authors: Ishida Shuji
Published: January 2005

A mutant (TS‐2) that is temperature‐sensitive with respect to cell contact was isolated from the cellular slime mold, Dictyostelium mucoroides. The TS‐2 were able to grow and develop normally at 21°C, but unable to grow at 31.5°C. When TS‐2 were allowed to develop until the aggregation stage at 21°C and then shifted to 31.5°C, they instantly lost cell‐to‐cell contact, resulting in disintegration of the aggregation stream and flattening of the aggregation center. Although a slug transferred to 31.5°C retained its original shape, loss of cell‐to‐cell contact within the cell mass was evidenced by several facts. The TS‐2 interphase amebas, at 31.5°C, also lost cell‐to‐substratum contact, and the loss of contact was followed by the production of cell‐wall substance on their surface. The production of the same substance at 31.5°C was also observed in cells at aggregation and migration stages, but not in those at the vegetative stage. When TS‐2 cells at various developmental stages were kept at 31.5°C for various periods of time and returned to 21°C they lost morphogenetic capacity in proportion to the production of the cell‐wall substance.
IMMUNOHISTOCHEMICAL DETECTION OF VITELLOGENIN IN THE OVARY AND FAT BODY DURING A REPRODUCTIVE CYCLE OF THE COCKROACH, BLATTELLA GERMANICA
Authors: TANAKA AKIRA , ISHIZAKI HIRONORI
Published: January 2005

Vitellogenin was immunohistochemically demonstrated in the ovary and fat body during a reproductive cycle. In terminal oocytes of 4‐day adults, vitellogenin began to appear in yolk spherules at the cell periphery. The vitellogenin‐containing spherules increased in size and number to occupy the whole cell 2 days later. In the female fat body, vitellogenin began to appear in 3‐day adults. It was distributed diffusely in the cytoplasm, at a much lower concentration than in the oocytes, during the vitellogenic period. In 11‐day adults whose vitellogenesis had terminated, a higher concentration of vitellogenin was found in the cytoplasmic inclusions of the fat body. Vitellogenin was not detected in the male fat body.
LOCALIZATION AND MULTIPLE FORMS OF ACETYLCHOLINESTERASE IN SEA URCHIN EMBRYOS
Authors: OZAKI HIRONOBU
Published: January 2005

Acetylcholinesterase during the development of the sea urchin Pseudocentrotus depressus was examined by enzyme assay (the colorimetric method of Ellmanet al.), histochemistry (a Cu‐thiocholine method), polyacrylamide gel electrophoresis and DEAE‐Sephadex ion exchange chromatography.

The enzyme activity is detected in the unfertilized egg, remains low during cleavage, elevates slightly through gastrulation, and then increases rapidly thereafter. The intense activity is localized in the mesenchyme cells associated with the larval skeleton of young pluteus larvae, and their cell membranes and nuclear envelops. Soluble enzyme accounts for 60% of the total activity. The additional 34% is extracted by 1% Triton X‐100 from particulates. The soluble enzyme consists of two forms. Both are strongly acidic proteins which are similar in electric charge, but dissimilar in size, being 180,000 and 280,000 in molecular weights. The enzyme released from the membrane by the detergent possesses a component which is not present in the soluble complement of the enzyme. It is not a secondary product of the soluble enzyme interacting with the detergent.

Acetylcholinesterase serves as a marker of late differentiation and regional differentiation in the sea urchin embryo.
STUDY OF THE NUCLEI ISOLATED FROM NEWT EMBRYOS BY THE USE OF FICOLL
Authors: TAKAHASHI YOSHIHIRO , ASAO TEZRO
Published: January 2005

1) Nuclei were isolated from early newt embryos using Ficoll in the isolation medium. Nuclei thus isolated were almost free from cytoplasmic contamination, with minimum loss of the nuclear constituents. The characterization of the nuclei thus isolated, including the determination of RNA polymerase activity and analysis of population of RNA's synthesized, is described.

2) In addition, the nuclei isolated from blastulae were characterized by electron microscopic observation, by the determination of RNA polymerase activity and by analysis of the chromatin constituents.
VEGETALIZATION OF SEA URCHIN LARVAE INDUCED WITH cAMP PHOSPHODIESTERASE INHIBITORS
Authors: YOSHIMI TAKAHITO , YASUMASU IKUO
Published: January 2005

Treatment of sea urchin embryos with cAMP phosphodiesterase (PDE)‐inhibitors such as caffeine (4×10−3 M), theophylline (8×10−3M), or nicotinamide (10−2M), at the morula stage for only a couple of hours, yields vegetalized larvae. Most of the embryos treated with these reagents before the morula stage develop to blastulae filled with mcsenchyme‐like cells. Almost all embryos at the blastula stage develop normally even if they are treated with a PDE‐inhibitor for a considerable period. The rate of 3H‐valine incorporation into protein in the morulae is reduced by caffeine and theophylline, but does not decrease in the presence of nicotinamide. Actinomycin D cancels the vegetalizing effect of PDE‐inhibitors on the morulae.
SCANNING ELECTRON MICROSCOPIC STUDY ON THE SURFACE CHANGE OF EGGS OF THE TELEOST, ORYZIAS LATIPES, AT THE TIME OF FERTILIZATION
Authors: IWAMATSU TAKASHI , KEINO HIROOMI
Published: January 2005

The surface change of the egg of the teleost, Oryzias latipes, during fertilization was observed with a scanning electron microscope. The microvilli of the outer surface of the unfertilized egg show a slight difference in density between the animal and vegetal pole areas. In the initial step of the breakdown of cortical alveoli (CA), several small holes or gapes are formed at the apical part of the CA membrane, becoming a large aperture from which the alveolar contents are discharged. The formation of microvilli is observed on the inner surface of the exposed cavity left by the CA, starting from the periphery of the aperture and propagating throughout the whole inner surface in accompaniment with the release of the alveolar contents. After the completion of CA breakdown, the CA membrane cannot be distinguished from the original egg plasma membrane.
PREPARATION AND PROPERTIES OF NUCLEI FROM THE POSTERIOR SILK GLANDS OF THE SILKWORM BOMBYX MORI
Authors: CORNET P. , CHAVANCY G. , DAILLIE J.
Published: January 2005

An original method to isolate nuclei from the posterior part of the silk glands has been developed. After a collagenase and Triton X–100 treatment, silk glands were filtered through a steel sieve. This step, which is the most efficient one for the purification, is followed by several washings. The preparation of nuclei is fairly pure, RNA: DNA ratio being 0.3 at the end of the whole procedure, and the final DNA recovery quite satisfactory (40–60%). Although chromatin of the purified nuclei is unusually condensed, and in spite of RNase activity, RNA transcription measured in vitro is quantitatively significant (0.01 % of the total DNA). This transcription, resulting from the activity of endogenous RNA polymerases, reaches a maximum when nuclei were extracted from animals on the 4th day of the fifth instar. Differences with results obtained in vivo are discussed.
DIFFERENTIATION OF PARTIALLY MESODERMALIZED ECTODERM; HOMOIOGENETIC AND HETEROGENETIC INDUCTION BY PRIMARILY INDUCED PART OF THE ECTODERM
Authors: NISHIJIMA KATSUSHI , NODA SHINICHI , KURIHARA KAZUSHIGE , SASAKI NAOI
Published: January 2005

Using embryos of the Japanese newt, Cynops pyrrhogaster, homoiogenetic and heterogenetic induction were investigated in the partially mesodermaelzed presumptive ectoderm. Half of the isolated presumptive ectoderm was placed in contact with the swimbladder of the crucian carp, Carasius auratus, for 15 or 60 min, while the other half was stained with Nile blue sulfate at the same time. The distribution of the stained cells in the tissues evoked in the explants was examined after cultivation for 10 days.

Some mesodermal tissues were composed of both stained and unstained cells. This indicates homoiogenetic induction by the primarily induced part of the ectoderm on the other half. The neural and epidermal tissues in the explants were composed of stained cells only, except in one case. We conclude that the neural tissues are derived from cells not placed in contact with the swimbladder and that they are induced by the primarily induced part of the ectoderm.
INSTABILITY OF MESSENGER AND RIBOSOMAL RNA IN A GLUE‐PROTEIN MUTANT OF Bombyx mori
Authors: KAMIJO SEIJI , KAWAGUCHI YUTAKA , FUJII HIROSHI , SAKAGUCHI BUNGO , DOIRA HIROSHI , KUHARA SATORU , ASO YOICHI , KOGA KATSUMI , HAYASHI KATSUYA , SHIMOTOHNO KUNITADA
Published: January 2005

The mucous glands of Bombyx pupae secrete glue proteins which attach deposited eggs to the mounting sheet. A mutant of a dominant gene, named no glue (Ng), produces nonadhesive eggs which have a low capacity for glue‐protein synthesis. In the present study it was shown that the mucous glands of Ng silkworms showed rapid degradation of mRNA as well as rRNA during development; this may cause the low capacity for glue‐protein synthesis in the mutant organ. In contrast, the mucous glands of normal silkworms showed a significant increase in content of RNA's until the maximum rate of glue‐protein synthesis was achieved. The degradation of RNA in the Ng mucous gland was inhibited by actinomycin D injected into the body fluid. Thus it is supposed that the Ng gene codes for a presumptive controller RNA, which would be the mediator of RNA instability in the mucous glands of Ng pupae.
A DETAILED FATE MAP OF THE WING DISC OF SARCOPHAGA PEREGRINA
Authors: AKIYAMA YOSHINORI , OHTAKI TETSUYA
Published: January 2005

In order to construct an anlageplan of the imaginal disc, various fragments of the wing disc from mature larvae of Sarcophaga peregrina were implanted into host larvae of the same age. The implants were metamorphosed with the host and the differentiated adult structures were analyzed.

On the basis of the results obtained from the transplanted disc fragments, a fate map of the wing disc was satisfactorily constructed.

The fate map of S. peregrina is similar to an earlier study of Drosophila, but the PAA, PWP, and AP are located in different positions from those of Drosophila.
VEGETALIZATION OF PRESUMPTIVE ECTODERM OF NEWT GASTRULAE IN A TRANSFILTER EXPERIMENT WITH FISH SWIMBLADDER AS THE INDUCTOR
Authors: KAWAKAMI IZUMI , SASAKI NAOI , SATO ATSUKO , OSAKO NOBUMITSU
Published: January 2005

The diffusibility of the vegetalizing factor was examined by a transfilter culture using an ethanol‐fixed swimbladder of the crucian carp (Carassius auratus) as the inductor and presumptive ectoderm from gastrulae of Cynops pyrrhogaster as the responding tissue. Nucleopore filters, about 12–14 μm thick, with nominal pore sizes of 0.05, 0.1, 0.6, 0.8, 3.0 and 8.0 μm were interposed between the interacting tissues. The responding pieces of ectoderm were removed from the assemblies after contact for 0.5, 1, 3, or 24 hr and cultured in Holtfreter's solution for 10 days at 20°C.

The inductions observed were almost entirely mesodermal, although masses of endoderm‐like yolky cells were seen in explants and neural tissues in a few cases. Filter membranes with pores of 0.05 to 8.0 μm did not interfere with the vegetalizing effect.

Under an electron microscope, small cytoplasmic cones of the responding cells of the presumptive ectoderm were observed in the pores of the interposed filter after 3 hr's contact. The cones grew longer as the cultivation time increased, but even after 24 hr there was no contact between the interacting tissues. Since 3 hr's contact between the interacting tissues was sufficient to cause full vegetalization on the transfilter culture with the swimbladder, the formation of the cytoplasmic outgrowths had no significance in the induction.
STRAIN‐SPECIFIC APPEARANCE OF A POSSIBLE FETAL α‐GLOBIN POLYPEPTIDE CHAIN IN MICE
Authors: IKAWA YOJI , SOMA GEN‐ICHIRO , MATSUGI TAKAYASU , OBARA NAOKO , SUDO KATSUKO , SUZUKI KIYOSHI , MORIWAKI KAZUO
Published: January 2005

DDD mouse embryos at 12–16 days of gestation have a putative ‘fetal’α‐globin polypeptide chain, detected by its lower electrophoretic mobility than the authentic α‐globin chain on acidic urea‐Triton gel. When hepatic erythroid cells of DDD embryos were contaminated with yolk sac erythroid cells, two α‐bands were visible, but only ‘fetal’α seemed to be synthesized, because in embryos of strain ddY which share a common ancestry with DDD, only ‘fetal’α was detectable by autoradiography when the hepatic erythroid cells of embryos of more than 15 days of gestation showed an authentic adult α‐globin chain other than this ‘fetal’α‐globin chain. If this ‘fetal’α‐globin chain is structurally different from the yolk sac α and adult peripheral blood α‐globin chains, then switching over of the transcription of α‐globin polypeptide chain occurs in hepatic erythroid cells of mid‐late DDD embryos. However, it is still possible that this ‘fetal’α‐globin chain is formed by post‐translational modification of the authentic α‐globin chain. The α‐globin chains of hepatic erythroid cells of C57BL/6 and BALB/c embryos had similar mobilities to those of yolk sac and adult erythroid cells.
LOCALIZATION AND SEGREGATION OF MATERNAL RNA'S DURING EARLY CLEAVAGE OF XENOPUS LAEVIS EMBRYOS
Authors: SAGATA N. , OKUYAMA K. , YAMANA K.
Published: January 2005

The localization and segregation of maternal RNA's during early cleavage of Xenopus laevis embryos were studied. Blastomeres and hemispheres of eggs and early embryos were separated manually and the amounts of ribosomal RNA and poly(A) +RNA extracted from each blastomere and hemisphere were determined by optical density measurement and by 3H‐poly(U) hybridization, respectively. It was found that both kinds of the maternal RNA's were more abundant (two‐thirds of the total) in the animal hemisphere (cells), while they were evenly distributed between the dorsal and ventral halves. This pattern of localization remained unchanged from the egg to the blastula stage, indicating that these maternal RNA's were segregated into blastomeres quite simply by cell division. Gel electrophoresis showed that the size distributions of poly(A) +RNA and poly(A) sequences obtained from different blastomeres of 8‐cell embryos did not differ greatly. It was also found that cytoplasmic polyadenylation of maternal RNA, which occurs during early cleavage and blastulation, took place equally in all regions of the cleaving embryos, suggesting no regional difference in the localization of maternally inherited nonpolyadenylated RNA. These observations are discussed in relation to previous findings on differences along the animal‐vegetal and dorsal‐ventral axes of the early amphibian embryo.
INDUCING TIME FOR NEURAL TISSUES IN GASTRULA ECTODERM OF CYNOPS PYRRHOGASTER
Authors: OHARA AKITO
Published: January 2005

The inducing times for spinal cord and deuterencephalon in Cynops gastrula were determined by the sandwich method. The extreme posterior of the archenteron roof at the slit‐blastopore stage (tail organizer) was used as an inducer. First, the presumptive ectoderm of the earliest gastrula (0‐hr stage) was put in contact with the organizer for 6 to 24 hr. Spinal cord and deuterencephalon were induced in almost all explants after 24 and 21 hr of contact, respectively, indicating that 24 hr is enough time for differentiations of both spinal cord and deuterencephalon. Next, presumptive ectoderm of 6‐ to 21‐hr exogastrulae was put in contact with the organizer until the 24‐hr stage. Results showed that the net inducing times for spinal cord and deuterencephalon were 18 and 15 hr, respectively, and that neural competence appeared in the presumptive ectoderm at the 6‐hr stage (straight‐blastopore stage).
Biochemical Studies on the Acrosome Reaction of the Starfish, Asterias Amurensis II. Purification and Characterization of Acrosome Reaction‐Inducing Substance
Authors: IKADAI HIROYUKI , HOSHI MOTONORI
Published: January 2005

The acrosome reaction‐inducing substance (ARIS) was purified from egg jelly of the starfish, Asterias amurensis. The purification procedure included elimination of neutral glycoproteins from the ARIS fraction by isoelectric pointprecipitation and subsequent gel filtrations on Sephadex G–50 and Bio‐Gel A‐50m columns. The final preparation of ARIS was homogeneous as judged by cellulose acetate electrophoresis of ARIS and by ion‐exchange chromatography on DEAE‐Sephadex A–25 of S‐carboxymethylated ARIS. ARIS is a very large, sulfated glycoprotein containing fucose, galactose, galactosamine and glucosamine as sugar components. It requires diffusible cofactor (Co‐ARIS) for full biological activity. A Pronase digest of ARIS retained its capacity to induce the acrosome reaction when Co‐ARIS was added to the bioassay system. The physiological significance of the carbohydrate moiety of ARIS is discussed.
A Normal Table of Early Development in Bombina Orientalis (Boulenger), in Relation to Rearing Temperature
Authors: MICHAEL PREMA
Published: January 2005

The effect of temperature on the rate of development of Bombina orientalis has been investigated. Eggs obtained by hormonal stimulation were reared at 9 to 22.5°C with a variation of ±0.5°C, and development was followed up to the neurula stage.

Between 20 and 22.5°C development proceeded normally with very little variation in time. Large time deviations were evident at temperatures below 18°C, particularly after the commencement of gastrulation. Abnormalities occurred at low temperatures and were common at 9°C. At 7°C initial cleavage was incomplete and further development did not occur.
In Vitro Orientation of Fibroblasts and Myoblasts on Aligned Collagen Film
Authors: YOSHIZATO KATSUTOSHI , OBINATA TAKASHI , HUANG HONG‐YH , MATSUDA RYOICHI , SHIOYA NOBUYUKI , MIYATA TERUO
Published: January 2005

A collagen film in which the collagen fibers were aligned was prepared and characterized by scanning electron microscopy. Cell orientation on this film was studied in vitro using human fibroblasts and chick embryo myoblasts. Ninety‐four percent of innoculated fibroblasts were aligned along the direction of the collagen fiber. The cell orientation was disturbed when cytochalasin B or colchicine was added to the culture medium. The myoblasts showed a similar alignment along the direction of collagen fiber. The scanning electron microscopic observation revealed that none of the cytoplasmic extensions had consistent relationships to the direction of collagen fiber. Myoblast fusion was accelerated on the aligned membrane as compared to a randomly oriented film, suggesting some role of contact guidance in muscle cell differentiation.
Mitosis in Beating Cardiac Muscle Cells from Newt Embryos In Vitro
Authors: KANEKO HIROYUKI , SHIN‐ICHI ABE , ITO SHIZUO
Published: January 2005

Cardiac muscle cells from newt embryos were cultured at relatively low cell density. Within 10 days in culture, 2 cell types (spindle and flat type) were distinguished both among beating and non‐beating cells. Mitosis in single beating cells was frequently observed both in spindle and flat cells. Some cells maintained almost constant contractile activities throughout the mitotic stages, while the others transiently stopped beating during mitosis, which accords well to the case in chick embryos (1). Ultra‐thin section shows the presence of myofibril's structure in a dividing cell, as shown in newborn rats (2, 3, 4), chick embryos (1, 5, 6, 7) and adult newts (8, 9). As a consequence of mitosis, 3 types (spindle, flat and mixed type) of beating colonies developed after 34 weeks in culture. Cell proliferation was accompanied with pulsation and could be directly pursued till the 4th division, suggesting that differentiated myocardiac cells with myofibrils proliferate by their mitoses in vivo, maintaining rhythmic contraction.
Maintenance and Growth of the Horny Processes of the Medaka, Oryzias latipes, in Vitro
Authors: IWATA AKIKO , UWA HIROSHI
Published: January 2005

The maintenance and growth of the horny processes of the medaka, Oryzias latipes, were investigated in vitro by organ culture of the anal‐fin. Processes were induced in adult females by oral administration of ethisterone. On this day, anal‐fins were removed and cultured with in media containing androgen. Early processes elongated in these media during six to eight days of culture, though they degenerated in androgen‐free control media. They developed to nearly the same degree as those in intact fins in medium 199 and CMRL‐1066, while they degenerated to various extents in Eagle's MEM and Dulbecco's modified EM. These results suggest that scleroblasts maintain the mass and secrete the horny substance in vitro in the presence of androgen and essential nutrients. Early processes developed on the fifth day of treatment.
Chick Embryo Extract, Muscle Trophic Factor and Chick and Horse Sera as Environments for Chick Myogenic Cell Growth
Authors: HAGIWARA YASUKO , KIMURA ICHIRO , OZAWA EIJIRO
Published: January 2005

Chick myogenic cells grew in a medium composed of Eagle's minimum essential medium (MEM), horse serum (HS), and one of the essential factors needed for myogenic cell growth (EFMG), that is, chick embryo extract (EE), chick serum (CS), or the muscle trophic factor (MTF). But they did not grow in the absence of the EFMG. In the absence of HS, they scarcely grew in a medium composed of MEM, and EE or MTF. They grew in a medium composed of MEM and CS; they grew much better in a medium composed of MEM, CS, and HS.

In the presence of one of the EFMG, the optimal HS concentration for growth varied depending on its lot. At higher HS concentrations, growth was suppressed. Further, it was suggested that an inhibitory substance(s) for myogenic cell growth was present in HS. The inhibitory effects can usually be minimized by diluting the serum with an artificial medium.
Acid Release at Activation and Fertilization of Starfish Oocytes
Authors: PEAUCELLIER GERARD , DOREE MARCEL
Published: January 2005

Fertilization or activation by ionophore A 23187 induces a transient acid release in prophase‐blocked and in maturing oocytes of Asterias rubens and Marthasterias glacialis. 1‐Methyladenine‐induced maturation is not accompanied by acid release. There is no significant difference in the kinetic and amount of acid release related to the nature of activation or the stage of oocytes in each species. The amount of acid released per oocyte volume is smaller than total “fertilization acid” of sea urchin eggs but comparable to its Na‐insensitive component. Cortical reaction can be initiated without significant acid release in ammonia treated oocytes. A burst of sodium influx occurs at activation or fertilization of oocytes. Kinetic and amount of Na influx are comparable to acid release. Vitelline membrane elevation is impaired upon activation of oocytes in the absence of extracellular sodium but a significant although smaller release of acid occurs. This suggests that starfish oocytes release acid by a mechanism differing from the Na+‐H+ exchange of sea urchin eggs.
A Cell Kinetic and Cytological Study on the Asymmetric Cell Division of Thymic Lymphoblasts of the Embryonic Rat
Authors: SUGIMOTO MASANOBU , YASUDA TOMOYOSHI
Published: January 2005

Cell division of thymus lymphoid cells from embrynonic and young rats was investigated cytologically on cell smears, focusing attention on asymmetric cell division. Some of thymic lymphoblasts displayed features implicating asymmetric cell division. At the telophase of such cells, two immature daughter cells looked dissimilar: one of them was smaller in size and possessed a more condensed nucleus, compared with the counterpart cell. Furthrmore, in most cases the cytoplasm of the smaller daughter cell was stained with Giemsa more deeply. It was suggested that the asymmetry of the nucleus emerges at anaphase and telophase probably due to some polarized situation of the cytoplasm. Asymmetrically‐dividing cells were relatively frequently observed during the developmental period when large lymphoblasts actively transform into smaller lymphocytes :16% to 17% of whole dividing cells were under asymmetric cell division on days 16 and 17 of gestation, while less than 5% on day 19 or thereafter. In correlation with this observation, asymmetrically‐dividing cells were more frequently observed among large lymphoblasts than among other smaller cell fractions. These results support the view that the asymmetric cell division may play some essential role in the transformation of large lymphoblasts into smaller lymphocytes.
Early Events in Anuran Amphibian Fertilization: An Ultrastructural Study of Changes Occurring in the Course of Monospermic Fertilization and Artificial Activation
Authors: CHARBONNEAU M. , PICHERAL B.
Published: January 2005

In unfertilized frog eggs, the plasma membrane displays an animal vegetal polarity characterized by the presence of short microvilli in the vegetal hemisphere and long microvilli or ridge‐like protrusions in the animal hemisphere. The densities of microvilli are similar in the two hemispheres.

The fertilizing sperm always fuses with the animal hemisphere of the egg and induces a wave of exocytosis of cortical granules from its site of penetration. Similar spreading of the cortical reaction is seen on activation by pricking the egg cortex. The integration of the cortical granule membrane with the plasma membrane is rapidly followed by elongation of microvilli, which is progressively realized all over the egg surface from the site of sperm entry or the site of pricking. At this time, the length and shape of the microvilli in the animal and vegetal hemispheres are similar and their densities are the same as in unfertilized eggs.

A “smoothing” wave can be seen on the living egg, 40–60 seconds after pricking, starting around the site of pricking. This wave of microvillar elongation is accompanied by changes in intensity of diffracted light spots observed at the surface of the egg. This pattern might result from rapid and progressive thickening of the cortex that would drive pigment granules into the cytoplasm. The Brownian movement of these granules is thought to be responsible for the observed diffracted light spots.

Electrical stimulus or the ionophore A23187 induced activation reactions similar to those triggered by the sperm or by pricking, except that the cortical reaction began simultaneously in several distinct sites of the cortex.
Influence of Temperature on Glucose Metabolism of Round Spermatids of Rats
Authors: NAKAMURA MASAHISA , FUJIWARA AKIKO , SUZUKI AKIRA , OKINAGA SHOICHI , ARAI KIYOSHI
Published: January 2005

Glucose utilization by spermatids was found to be 17.37±0.37 nmoles/hr/106 cells at 34°C and 28.94±1.12nmoles/hr/106 cells at 40°C. A good parallelism was observed between the increased rate of glucose utilization and lactate production at 40°C. There was no significant change in the levels of glycolytic intermediates in the cells, except for marked accumulations of fructose‐1, 6‐diphosphate, dihydroxyacetone phosphate and glyceraldehyde‐3‐phosphate in the presence of glucose (1 mM). Glucose oxidation in the citrate cycle by spermatids was higher at 40°C than at 34°C, but was never greater than 2% of the overall rate of glucose utilization. In addition, glucose did not prevent decrease of ATP at either 34 or 40°C. The effects of temperature on the activities of 11 glycolytic enzymes were examined. The activities of aldolase and phosphoglyceromutase were similar between 30 and 34°C, but increased markedly at 40°C. The higher temperature increased the Vmax values, without affecting the Kms. The activities of other glycolytic enzymes were similar at the different temperatures. These findings indicate that the increased overall rate of glucose utilization in glycolysis at higher temperature is due to increased Vmax values of aldolase and phosphoglyceromutase.
Effect of α,α′‐dipyridyl on Exogut Formation in Vegetalized Embryos of the Sea Urchin
Authors: MIZOGUCHI HAZIME , YASUMASU IKUO
Published: January 2005

In presumptive vegetalized embryos, obtained by 3‐hr treatment with chloramphenicol at the 16–32 cell stage, the rates of [14C]proline incorporation into the collagen fraction and production of the [14C]hydroxyproline residues increased during development between 16 hr (equivalent to mesenchyme blastula stage) and 40 hr (the early pluteus stage) after fertilization at 20°C. In presumptive vegetalized embryos, the radioactivity of [14C]hydroxyproline residues was higher at the mesenchyme blastula stage (16 hr after fertilization), but lower at the post‐gastrula stage than in normal embryos. In normal embryos at the post‐gastrula stage, [14C]hydroxyproline residues were mainly found in isolated spicules, and the amounts of [14C]hydroxyproline residues in other parts were much lower than in vegetalized embryos, which had few, if any, spicules. α, α′‐Dipyridyl, an inhibitor of prolyl hydroxylase, inhibited the hydroxylation of [14C]proline residues in presumptive vegetalized and normal embryos, and blocked the formation of the archenteron and exogut.
Effects of UV‐irradiation at Various Wavelengths on Sterilizing Drosophila Embryos
Authors: TOGASHI SHIN , OKADA MASUKICHI
Published: January 2005

Embryos of Drosophila melanogaster at the early intravitelline nuclear multiplication stage were irradiated with UV light at the posterior pole. The sterility and mortality of these embryos were examined in relation to the dose and wavelength of the UV light.

Sterility, expressed either as the frequency of pole‐cell‐deficient embryos, or as the frequency of agametic adults, was found to be dependent on the wavelength of UV light. UV‐irradiation at 280 nm was found moot effective in causing sterility on Drosophila embryos. The minimum dose of radiation to give a 100% sterility was 200 J/m2 at 280 nm, and 400 J/m2 at 254 nm. In contrast, mortality showed no dependency on the wavelength.

The possibility that nucleic acids in the posterior region is a target of 280 nm radiation is discussed.
Spermiogenesis in the Flatworm, Notoplana Japonica with Special Attention to the Organization of an Acrosome and Flagella
Authors: KUBO‐IRIE MIYOKO , ISHIKAWA MASARU
Published: January 2005

Ultrastructural changes during spermiogenesis in the flatworm, Notoplana japonica were studied with special attention to organizing process of an acrosome and flagella. During spermiogenesis, the Golgi complex develops conspicuously but it fails to organize the structure of an acrosomal vesicle. Consequently, no acrosome is formed at the apex of the sperm. As a substitute for an acrosomal structure, the slender process at the tip of the mature sperm is prominently occupied with glycogen granules.

The axoneme of the flagellum is formed from the basal body in the protrusion which is juxtaposed to the nucleus of the early spermatid. Two flagella associated with an electron‐dense structure (EDS) extend superficially from the spermatid body in opposite directions. Progressively, they take an acute angle to each other and finally run alongside the sperm body. The axoneme consits of nine peripheral doublets with arms, a central cylinder containing an electron dense core, a less dense intermediate zone and fine spokes between the cylinder and doublets.
Induction of the Acrosome Reaction of Sea Urchin Spermatozoa by Means of Urea
Authors: KATO KOICHI H. , SUGIYAMA MASAO
Published: January 2005

Urea is an effective reagent for inducing the acrosome reaction of spermatozoa in sea urchins. Urea‐treated spermatozoa are capable of fertilizing eggs in Ca‐deficient sea water. The pH of the urea solution is an important factor affecting the induction of the acrosome reaction. The reaction occurs at a high percentage in urea Solution at pH's higher than 7.8, while the reaction is almost completely suppressed at pH 7.2. Ca++ is also an important factor for the induction of the reaction, although the minimum concentration required is very low.

The acrosomal filament formed in urea solution is similar in shape to that formed in egg‐water, when fixed after 10 seconds' urea‐treatment. The acrosome granule material is found around the basal portion of the acrosomal filament.
Ultrastructural Study of Changes in Cell Morphology and Extracellular Matrix in Prospective Endodermal Cells of Newt Embryos (Cynops pyrrhogaster) before and during Gastrulation
Authors: KOMAZAKI SHINJI
Published: January 2005

The cell morphology, cell‐to‐cell contact behavior and extracellular matrix (ECM) of inner cells (prospective endodermal cells) of newt (Cynops pyrrhogaster) embryos were examined from the morula to gastrula stage by light and electron microscopy. The inner cells showed increased cell‐to‐cell contact from the early blastula to early gastrula stage. The cells formed blebs (5–15 μm in diameter) during the blastula stage, and started to form filopodia and lamellipodia before gastrulation. Alcian blue and lanthanum nitrate treatment revealed ECM components on the cell surface in the early blastula stage and these components increased in amount from the late blastula to early gastrula stage. It is suggested that the increase in ECM components on the cell surface may have some relation with changes in cell‐to‐cell contact and formation of processes on the cell surface. Besides the cell surface ECM components, glycogen‐like granules were observed in intercellular spaces. From the distribution of granules in gastrulae, it is suggested that these may be important in maintaining intercellular spaces for migration of invaginating cells.
Protein Synthesis during Photocontrolled Progression of the Cell Cycle in Single‐celled Protonemata of the Fern Adiantum Capillus‐veneris
Authors: NAGATANI AKIRA , SUZUKI HIDEHO , FURUYA MASAKI
Published: January 2005

Protein synthesis during photoinduced, synchronous progression of the cell cycle in single‐celled protonemata of the fern Adiantum capillus‐veneris was studied by tracer techniques. Nuclei of the protonemata were labelled with 3H‐thymidine during spore germination so that the amount of 3H incorporated into the TCA‐insoluble fraction of the cells could be used as a measure of the cell number in each sample. The rate of the incorporation of 14C‐amino acids into TCA‐insoluble materials was not significantly varied at different stages of the cell cycle or by treatment with blue light. Extracts of cells labelled with 35S‐methionine at various times after the transfer from red light condition (G0) to darkness (G1 to S) were analyzed by two‐dimensional gel electrophoresis. At least 3 of about 200 spots showed significant changes in intensity on fluorograms. Spot A (molecular weight 20,000, isoelectric point 6.3) was detectable only in early G1, whereas spot B (molecular weight 19,500, isoelectric point 6.3) was found only in the late G1 and S phases. When the cells were exposed to blue light before the dark incubation, the times of disappearance of spot A and appearance of spot B were advanced depending upon the progression of the cell cycle but not upon the clock time.
Neural Induction by Treatment with Ca2+‐free Saline Solution in the Gastrula Ectoderm of Cynops pyrrhogaster and Inhibition of Neural Induction with Fetal Calf Serum
Authors: SUZUKI MICHIHIRO
Published: January 2005

The relation between the inducing activity and the cell‐dissociation effect of Ca2+‐free (or Ca2+, Mg2+‐free) saline solution (CF or CMF) on the early gastrula ectoderm was examined. In the culture medium containing no fetal calf serum (FCS), most ectoderm cells treated with CF or CMF died within a few days and only a few differentiated into epidermal cells. However, when the culture medium contained 2% FCS, ectoderm cells treated with CF or CMF differentiated into neural crest derivatives (NCDs), such as mesenchyme cells, pigment cells, and nerve cells. The frequency of the induction depended only on the duration of CF‐ or CMF‐treatment. FCS alone had no inducing activity on ectoderm cells. On the contrary a high concentration of FCS gave an inhibitory effect on the induction. These results indicate that CF is a neuralizing factor and that CF‐treated cells require FCS, not for induction, but for survival and differentiation. With CF, the maximum induction of NCDs required a longer duration than that necessary for complete cell‐dissociation. This result suggests that the induction depends on some effects of CF other than cell‐dissociation.
Voltage Noise Changes during Monospermic and Polyspermic Fertilization of Mature Eggs of the Anuran, Rana temporaria
Authors: CHARBONNEAU M. , MOREAU M. , PICHERAL B. , GUERRIER P. , VILAIN J. P.
Published: January 2005

The electrical response of mature anuran eggs to the fertilizing sperm consists of a rapid depolarization and a decrease in resistance of the plasma membrane (fertilization potential) and serves as a fast block to polyspermy. We report here that the fertilization potential, previously thought to be the earliest electrical response of the egg, is preceded in Rana temporaria by changes in voltage noise. Voltage noise was recorded after insemination and compared in monospermic and NaI‐induced polyspermic eggs. Fertilization potential in monospermic eggs arised at 1 min 45 sec to 2 min 15 sec after insemination, and that in NaI‐induced polyspermic eggs did at 3 min to 3 min 30 sec after insemination. However, the increase in voltage noise was detected at the similar time (1–2 min 30 sec) after insemination in both the eggs. The duration of voltage noise increase before the fertilization potential was larger in polyspermic eggs (50–105 sec) than in monospermic eggs (10–40 sec). Polyspermic fertilization in Rana temporaria induced by NaI was checked by visualizing multiple sperm entry sites with the scanning microscope. The process of sperm entry and the development of the fertilization body are similar to those occurring with monospermic fertilization; furthermore all supernumerary sperm fuse only with the animal hemisphere of the egg. Although the physiological basis of the changes in voltage noise is unclear, these alterations appear to be the earliest electrical response to sperm yet reported.
Appearance of Primordial Germ Cells in Young Chick Blastoderms Cultured in vitro
Authors: SUTASURYA L. A. , YASUGI S. , MIZUNO T.
Published: January 2005

Appearance of primordial germ cells (PGCs) in young chick blastoderms was investigated by the cultivation of only the epiblast or hypoblast. Presumptive PGCs exist in the epiblast before primitive‐streak formation. They translocate gradually to the lower layer during early stages of primitive‐streak formation, though substantial number of presumptive PGCs remain in the upper layer. The existing primary hypoblast under the epiblast is dispensable for the further differentiation of the PGCs.
Prothoracicotropic Hormone Bioassay: Pupal‐Adult Bombyx Assay
Authors: ISHIZAKI HIRONORI , SUZUKI ATSUSHI , MORIYA IKUO , MIZOGUCHI AKIRA , FUJISHITA MARIKO , O'OKA HISAYOSHI , KATAOKA HIROSHI , ISOGAI AKIRA , NAGASAWA HIROMICHI , SUZUKI AKINORI
Published: January 2005

Blockage of adult development by brain removal and its resumption by application of the prothoracicotropic hormone (PTTH) were studied using pupae of a racial hybrid J‐122 × C‐115 of Bombyx mori. A log‐linear dose‐response relationship was obrained after injection of a PTTH solution. The Bombyx‐unit of PTTH has been defined from this dose‐response curve.
Species Specificity of the Insect Prothoracicotropic Hormone (PITH): the Presence of Bombyx‐and Samia‐Specific PTTHs in the Brain of Bombyx mori
Authors: ISHIZAKI HIRONORI , MIZOGUCHI AKIRA , FUJISHITA MARIKO , SUZUKI ATSUSHI , MORIYA IKUO , O'OKA HISAYOSHI , KATAOKA HIROSHI , ISOGAI AKIRA , NAGASAWA HIROMICHI , TAMURA SABURO , SUZUKI AKINORI
Published: January 2005

Crude extracts of Bombyx mori brains can provoke adult development when injected into brain‐removed dormant pupae of Bombyx mori and Samia Cynthia ricini. From this fact the prothoracicotropic hormone (PTTH) of Bombyx has long been thought to be species‐nonspecifically active on Samia. Chemical fractionation of Bombyx brain or head extracts by fractional precipitation with acetone, Sephadex G‐50 gel‐filtration, and DEAE‐Sepharose CL‐6B chromatography, however, separated the fractions which activated Bombyx brainless pupae from those which activated Samia. Those results reveal the existence of two species‐specific PTTHs.
Respiration of Sea Urchin Spermatozoa in the Presence of a Synthetic Jelly Coat Peptide and Ionophores
Authors: SUZUKI NORIO , OHIZUMI YASUSHI , YASUMASU IKUO , ISAKA SABRO
Published: January 2005

Sperm respiration and motility of the sea urchin Hemicentrotus pulcherrimus were studied at pH 6.8 in the presence of a synthetic jelly peptide (Gly‐Phe‐Asp‐Leu‐Asn‐Gly‐Gly‐Gly‐Val‐Gly) and monovalent cationic ionophores. The synthetic peptide stimulated sperm respiration and motility to the level of that found in normal sea water (pH 8.2) with half‐maximal stimulation at approximately 100 pM. Monensin and valinomycin also stimulated sperm respiration with half‐maximal effects at 7 μM and 0.7 μM, respectively. The stimulation of sperm respiration by the peptide and monensin was dependent on external Na+, but was not dependent on the osmolarity of the suspending medium. Approximately 50 mM Na+ was required for half‐maximal respiratory responses to the peptide and monensin.
Ultrastructural Changes of the “Truncated Cone” during the Acrosome Reaction in Japanese Abalone Spermatozoa
Authors: SHIROYA YOKO , SAKAI YOSHI T.
Published: January 2005

An electron‐dense structure termed the “truncated cone” covers the apical surface of the acrosomal contents except for the trigger region in Haliotis discus spermatozoa. The truncated cone, having a slant height of 0.3 μm and diameters of circular top and base of 0.3 and 0.6 μm, shows striations with a periodicity of 6.6 to 8.0 nm. During the acrosome reaction, the truncated cone elongates simultaneously with the protrusion of the acrosomal process through the truncated cone. As the growth of the acrosomal process further proceeds, the truncated cone transforms into a cylindrical shape and eventually reaches 1 μm in length and 0.2 μm in diameter. The elongated truncated cone is characterized by regularlly helical striations with a periodicity of 19 to 21 nm with an inclination of 40° to 46°. These results may suggest that the truncated cone is composed of coiled filaments, which coil up further during the acrosome reaction causing the truncated cone to slenderize and elongate. The elongation is also achieved by stretching of the coil. In H. discus hannai Ino, structural changes in the truncated cone show close homology to those in H. discus. No such morphologically unique organelle has been found in other species thus far.
Cycloheximide Insensitive Amoebo‐Flagellate Transformation in Starved Amoebae of Physarum polycephalum
Authors: UYEDA TARO Q. P. , FURUYA MASAKI
Published: January 2005

The requirement of protein synthesis for amoebo‐flagellate transformation of Physarum polycephalum was re‐examined. When amoebae were grown on nutrient agar in association with live food bacteria and harvested in mid‐exponential phase of growth, it took ca. 2 hours for half the cells to form flagella after suspension in phosphate buffer. The transformation was completely inhibited by 5 μg/ml cycloheximide. To the contrary, when the amoebae in mid‐exponential phase were starved for 3 hr on non‐nutrient agar and then suspended in phosphate buffer, the duration required for this process was shortened to ca. 8 min and it was not inhibited by up to 100 μg/ml cycloheximide. A similar result was obtained using bactobolin, another inhibitor of protein synthesis. When amoebae were starved on non‐nutrient agar containing 5 μg/ml cycloheximide, however, the starvation effect described above was not observed. The results indicate that protein(s) necessary for the transformation might be synthesized during the starvation period, and that the amoebo‐flagellate transformation may or may not require concomitant protein synthesis depending upon preculture conditions.
Development of Intracellular Membrane Systems in the Columnar Epithelium of the Urinary Bladder of the Euryhaline Goby Gillichthys mirabilis
Authors: PISAM MONIQUE , LORETZ CHRISTOPHER A. , BERN HOWARD A.
Published: January 2005

The membrane systems in “columnar cells” of the goby urinary bladder were studied after staining with ferrocyanide‐reduced osmium tetroxide (Karnovsky). In addition to the endoplasmic reticulum, two distinct systems of membranes were observed: 1) a vesiculotubular system made up of vesicles and short tubules located between the Golgi area and the apical membrane and 2) well‐developed infoldings of the laterobasal plasma membrane which form either complete or fenestrated sheets. Adaptation to 5% seawater or prolactin exposure of seawater fish induces a proliferation of these membrane systems and, in particular, of the complete infoldings of the laterobasal plasma membrane. These observations suggest high activity of these bladder cells in osmoregulatory adjustments to hypotonic environments. The divergence between cytological and physiological indicators of activity is considered.