Sperm-egg interaction is mediated by a sperm-associated body in quail

The present study describes the holes in the inner vitelline membrane of fertile eggs of the quail Coturnix japonica, which remain after the spermatozoa pass through. It was shown that the light-microscopically observable 'holes' correspond mostly to electron-microscopically defined 'disks', and, to a lesser extent (about 5%), real holes. Immunofluorescent staining of the vitelline membranes with an antiquail ZPC antiserum was used to discriminate the holes from the disks light-microscopically. Over 96% of holes were accompanied by calcium-coated sperm-associated bodies, indicating a close relationship between the two. There was no preferential localization of the disks, holes or sperm-associated bodies in the vitelline membrane around the egg. The sperm-associated bodies bound with the spermatozoa at the posterior end of sperm flagella. Incubation of the inner vitelline membranes, isolated from the largest follicles, with spermatozoa resulted in production only of the disks, whereas the holes (about 9%) were produced when the sperm-associated bodies were added to the system. It was suggested that the sperm-associated bodies assist fertile spermatozoa in binding to the inner vitelline membrane, making holes in the membrane and passing through them in fertile eggs.     

Why does avian influenza A virus hemagglutinin bind to avian receptor stronger than to human receptor? Ab initio fragment molecular orbital studies

Influenza A viruses attach to alpha-sialosides on the target cell surface by their hemagglutinins, which strictly recognize the difference in sialic acid-galactose linkage. Why does avian virus H3 subtype bind to avian receptor Neu5Ac(alpha2-3)Gal stronger than to human receptor Neu5Ac(alpha2-6)Gal? Why does avian H3 mutated Gln226 to Leu preferentially bind to human receptor? In this paper, we theoretically answer the questions by molecular mechanics and ab initio fragment molecular orbital (FMO) calculations. The binding energy between avian H3 and avian receptor is 8.2kcal/mol larger than that of the avian H3-human receptor complex estimated at the FMO-HF/STO-3G level, which is a reason that avian H3 binds to avian receptor stronger than to human receptor. Avian Leu226 H3 clashes to Gal unit on the avian receptor to quite decrease its binding affinity. In contrast, Gal unit on the human receptor forms intermolecular hydrophobic interaction with avian Leu226 H3 to afford moderate binding affinity.     

Transplantation and differentiation of donor cells in the cloned pigs

The application of nuclear transfer technology is an interesting approach to investigate stem and progenitor cell transplantation therapy. If stem cells are used as a nuclear donor, donor cells can engraft into cloned animals without histocompatible problems. However, it is still uncertain whether donor cells can engraft to cloned animal and differentiate in vivo. To address this problem, we transplanted donor cells to dermal tissues of cloned pigs developed by using preadipocytes as donor cells. Preadipocytes are adipocytic progenitor which can differentiate to mature adipocytes in vitro. We showed that the donor preadipocytes were successfully transplanted into the cloned pigs without immune rejection and they differentiated into mature adipocytes in vivo 3 weeks after transplantation. In contrast, allogenic control preadipocytes, which can differentiate in vitro, did not differentiate in vivo. These results indicate that donor progenitor cells can differentiate in cloned animal.     

Changes in sperm motility in response to osmolality/Ca2+ in three Indonesian fresh water teleosts: goby (Oxyeleotris marmorata), Java carp (Puntius javanicus), and catfish (Clarias batrachus)

Sperm of most fresh water teleosts become motile when released into the hypotonic fresh water environment, but the role of osmolality and Ca2+ on sperm motility is not clear. Osmotic pressure and Ca2+ concentrations increase from fresh water to brackish water. Java carp Puntius javanicus and catfish Clarias batrachus live and reproduce only in fresh water. On the other hand, goby Oxyeleotris marmorata can acclimate and reproduce from fresh water to brackish water. In the present study, sperm motility and trajectory were compared among these three Indonesian endemic species. Sperm of Java carp, goby, and catfish begun to move in the hypotonic condition (< 200 mOsm/kg). However, the response to Ca2+ was different among these teleosts. In the presence of Ca2+, Java carp sperm swam in circular paths and immediately become quiescent, suggesting that Java carp sperm motility is activated in hypotonic aquatic environment without Ca2+. Goby sperm swam straightforward in the presence or absence of Ca2+. Percentages of motile sperm increased in 100-200 mOsm/kg but suppressed by removal of Ca2+. Regarding sperm motility and trajectory, no response was found in catfish sperm. These results suggest that a response to Ca2+ is different among sperm of the three species and suited to their habitat.     

Epidemiological study of the relationship between sleep disturbances and somatic and psychological complaints among the Japanese general population

Sleep and Biological Rhythms - There have been only a few studies on the relationship between sleep disturbances and somatic and psychological complaints in Japanese people. In this study, we...     

Conferring cadmium resistance to mature tobacco plants through metal-adsorbing particles of tomato mosaic virus vector

Tomato mosaic virus vectors were designed that produced, by a translational readthrough, a fusion protein consisting of coat protein and metal-binding peptide, as a result of which particles were expected to present the metal-binding peptides on their surface. When inoculated in plants, they were expected to replicate and form a metal-adsorbing artificial sink in the cytoplasm, so as to reduce metal toxicity. Vectors were constructed harbouring sequences encoding various lengths of polyhistidine as a metal-binding peptide. One of the vectors, TLRT6His, which contains a 6 x histidine sequence, moved systemically in tobacco plants, and its particles were shown to retain cadmium ions by an in vitro assay. When a toxic amount of cadmium was applied, the toxic effect was much reduced in TLRT6His-inoculated tobacco plants, probably as a result of cadmium adsorption by TLRT6His particles in the cytosol. This shows the possible use of an artificial sink for metal tolerance and the advantage of employing a plant viral vector for phytoremediation.     

Localization of mRNAs for phosphatidylinositol phosphate kinases in the mouse brain during development

The gene expression for seven phosphatidylinositol phosphate kinases (PIPKs)-types Ialpha, Ibeta, Igamma, types IIalpha, IIbeta, IIgamma, and type III-was examined using in situ hybridization histochemistry, in the mouse brain during normal development. In the embryonic mouse brain, positive expression signals were detected only for the genes encoding PIPK Igamma and PIPK IIbeta in both the cerebral ventricular and mantle zones, with weaker signals in the former zone. On the other hand, the genes encoding all PIPKs were essentially detected in the external granule cell layer which represents the germinal zone for the neuronal granule cells. In the postnatal brain, among the seven PIPKs, the expression for genes encoding PIPK Igamma and IIbeta is evident in most gray matter, while the expression for the other five types was weak in the cortical gray matter and negligible in most non-cortical gray matter such as the diencephalon and brain stem nuclei. While the expression for most PIPKs in the mature hippocampus was distinct, the expression in the CA3 and the dentate gyrus was less definite for the genes encoding PIPK Ialpha and IIgamma, respectively. The distinct expression for the gene encoding PIPK IIalpha was detected in the postnatal white matter such as the cerebellar medulla, the corpus callosum, the hippocampal fimbriae, and the internal capsule.     

Oxygen- and carbon monoxide-binding kinetic parameters for liposomal heme under semi-physiological condition

Binding and dissociation rate constants of oxygen and carbon monoxide with the meso-tetra(α,α,α,α-(o-pivalamidophenyl))porphinato iron-mono(1-lauryl-2-methylimidazole) complex incorporated into the liposomes of dimyristoylphosphatidylcholine (liposomal heme) were measured with flash-photolysis method at pH 7.0 and 20 °C. Extra large quantum yield was observed for the photo-dissociation of the oxygen adduct, while that for the CO adduct was relatively small. Rate constants for the binding and the dissociation were comparable to those of hemoglobin except for the oxygen-binding rate constant.