bluuebunny/crossref_metadata_2025_split huggingface dataset:
P‐epitope is characteristic for the neural tissue of vertebrates
Authors: Preobrazhensky A. A. , Rodionova A. I. , Barabanov V. M. 
Published: February 2005

AbstractIn a search for antigens immunologically related to chordin, a notochord‐specific glycoprotein of sturgeneous fishes, extracts from 55 samples of human and rabbit tissues were tested for inhibition of [125I]chordin binding to rabbit polyclonal antibodies. The strongest inhibition was observed with brain extracts of both species. Human, chicken, rabbit, and newt brain extracts also inhibited chordin binding in liquid phase to monoclonal antibodies (MAbs) against the P‐epitope, the most immunogenic epitope of this glycoprotein. Immunohistochemical studies done on human and chicken embryos, newt, sterlet, and sturgeon embryos, larvae, and juveniles revealed a strong immunoreactivity of the brain, spinal cord, and tissue of the peripheral nervous system with an anti‐P MAb. Other tissues, with several exceptions, showed a negative reaction in immunohistochemical experiments. The authors found that the P‐epitope is ontogenetically expressed in the neural tissue of chicken, newt, and sterlet at the period of cytodifferentiation. Gel chromatography of human, chicken, and newt brain extracts showed that in each case the P‐epitope was associated with a polydisperse macromolecular material of similar size. These antigens were designated as neurochordins. Prolonged pronase digestion of human and chicken brain extracts resulted in fragments with M about 3 kDa (presumably glycopeptides), which reacted with anti‐P MAbs. These fragments were of the same size as corresponding glycopeptides of the pronase digest of chordin. Thus, in the present study, the P‐epitope has been shown to be characteristic for the neural tissue of several vertebrate species; in the brain, it has been found in association with neurochordins, macromolecular antigens that are presumably protein conjugates with carbohydrates.
Estimates of mRNA abundance in the mouse blastocyst based on cDNA library analysis
Authors: Weng David E. , Morgan Richard A. , Gearhart John D. 
Published: February 2005

AbstractStudies of gene expression during blastocyst formation in mouse preimplantation development have been limited by the amount of RNA available per embryo. Our present approach to this problem has been to construct a large, representative, blastocyst cDNA library in λgtll. Random hexadeoxynucleotides were used as primers with total blastocyst RNA serving as template. RNA collected from 4,100 32–64 cell embryos was used to generate a library with an initial size of 30 × 106 recombinants. By using clone frequency as a measure of relative mRNA abundance, our data support previous work on the relative and absolute amounts of actin, histone H2a, and intracisternal A particle. Furthermore, we provide estimates for the abundance of cytokeratin endo A, cytokeratin endo B, and β‐tubulin from clone frequency data. Insert sizes for isolated clones range from 200 bp to 3.6 kb with full‐length or near‐full‐length insert sizes for selected clones, indicating that random primer methods generate cDNAs which can represent a significant portion of the mRNA. We have so far characterized products whose abundance is equal to or greater than 0.002% of total RNA. This library offers the potential for the analyses of presumptive regulatory gene products in the mouse preimplantation embryo which are represented as low abundance (<1% of mRNA) RNAs.
Nucleus of the boar spermatozoon: Structure and modifications in frozen, frozen‐thawed, or sodium dodecyl sulfate‐treated cells
Authors: Courtens J. L. , Paquignon M. , Blaise F. , Ekwall H. , Plöen L. 
Published: February 2005

AbstractAfter cryosubstitution and Epon embedding, or after Nanoplast embedding and very thin sectioning, the chromatin of ejaculated or diluted boar spermatozoa appears to be formed of DNA fibers embedded in a quite homogeneous matrix. After sodium dodecyl sulfate (SDS) treatment, and to a lesser extent after freeze‐thawing, the DNA fibers are present mostly between cords, probably proteinaceous in nature. The quantity of free sulfhydryl (SH) groups, as calculated from staining by DACM and flow fluorometry, is increased in thawed or SDS‐treated cells. The quantity of NH2 groups, calculated from electron microscopy image analysis of alcoholic phosphotungstic acid‐stained cells, is decreased in thawed nuclei. The DNA is more accessible to the fluorochrome ethidium bromide after freeze‐thawing, and its sensitivity to HCI hydrolysis is modified, during the Feulgen‐like staining procedure using acriflavine. The X‐ray energy dispersive analysis of cryosections of nuclei indicates that the slight separation of DNA and nucleoproteins in freeze‐thawed spermatozoa could result from a dramatic modification of the nuclear ionic environment during thawing.
Measurement of histone mRNA transcript abundance in Xenopus oocytes by a quantitative primer extension assay
Authors: Brashears‐Macatee Sarah , Hinkley Craig , Perry Michael 
Published: February 2005

AbstractA quantitative primer extension method was used to measure the mass of histone gene transcripts in mature oocytes of the amphibian Xenopus laevis. The procedure, using a large excess of gene‐specific oligonucleotide primer and continuous incorporation of a radiolabeled deoxynucleoside triphosphate precursor, is more sensitive and quantitative than primer extension assays employing end‐labeled primers. It was determined that there are stoichometric amounts, approximately 2 × 108 copies, of mRNA for each of the five major histone gene classes in mature Xenopus oocytes. These observations are consistent with a model whereby transcription of these genes is coordinately regulated in a cell cycle‐independent manner during amphibian oogenesis.
Analysis of the sequence and expression during sea urchin development of two members of a multigenic family, coding for butanol‐extractable proteins
Authors: Carlo Marta Di , Montana Giovanna , Bonura Angela 
Published: February 2005

AbstractTwo cDNA clones related to Paracentrotus lividus butanol‐extracted proteins, presumably belonging to cell surface proteins, were isolated by a λgt11 expression library of ovary poly A+ RNA. These clones, called bep 1 and bep4, of 1,110 and 1,071 bp, respectively, belong to a multigene family. By sequencing analysis, a special structural organization in the coding region is detected. A single copy region is inserted between two regions different from each other but similar in the two clones, which constitute two perfectly preserved domains in the genome and are not always present together in the various members of this gene family. The bep 1 and bep4 clones derive from two single genes that are polymorphic in the sea urchin genome. Expression of these clones was studied by Northern blot analysis. Both bep 1 and bep4 are transcribed during oogenesis into mRNAs of 1.4 kb, which are stored in eggs and utilized during early embryogenesis. None of these RNAs is, in fact, detectable after the gastrula stage. Moreover, the transcripts of three other members of the family are present in eggs and at the 32 cell stage, but they are also synthesized in the early developmental stages.
Relevance to prenatal diagnosis of the identification of a human Y/autosome translocation by Y‐chromosome‐specific in situ hybridisation
Authors: Ellis Patricia M. , West John D. , West Katrine M. , Murray Roderick S. , Coyle M. Christine 
Published: February 2005

AbstractRoutine cytogenetic analysis of an amniotic fluid sample revealed a large brightly fluorescent region in the short arm of chromosome 14 in an otherwise normal male karyotype (46, XY, 14p+++). This site was also present in the paternal karyotype. In situ hybridisation to a Y‐chromosome‐specific DNA probe confirmed that the father had a Y/14 translocation. The incidence of two hybridisation bodies (large hybridisation sites), detecting both the translocated Y chromatin and the normal Y chromosome, was lower in interphase nuclei (44.3%) than in metaphase spreads (95.2%). The relevance of these observations to the potential use of in situ hybridisation to intephase nuclei for prenatal diagnosis is discussed.
Gastrulation in the sea urchin Strongylocentrotus purpuratus is blocked by the fluorescein dye erythrosin B
Authors: Carroll Edward J. 
Published: February 2005

AbstractErythrosin B, a food, drug, and cosmetic dye, arrested gastrulation in embryos of the sea urchin Strongylocentrotus purpuratus. A 30 min pulse of 5 μM erythrosin B added at 18 hr postinsemination blocked gastrulation scored at 50 hr postinsemination when control embryos had completed gastrulation. Dye addition at later times had no detectable effects on development through 50 hr postinsemination. The dye may block primary invagination via its known effects on plasma membrane permeability and fluidity.
Protamine–histone replacement and DNA replication in the male mouse pronucleus
Authors: Nonchev Stefan , Tsanev Roumen 
Published: February 2005

AbstractThe protamine to histone replacement in fertilized mouse eggs was studied by using antibodies to these proteins. Its course was followed with respect to DNA replication by autoradiography of 3H‐thymidine‐labeled fertilized eggs. It was found that protamines were replaced by histones before the onset of DNA replication.
Combined effect of glycerol concentration and cooling velocity on motility and acrosomal integrity of boar spermatozoa frozen in 0.5 ml straws
Authors: Fiser P. S. , Fairfull R. W. 
Published: February 2005

AbstractThe interaction of glycerol concentrations of 0–10% and cooling rates from 1 to 1,500°C/min with boar spermatozoa motility and acrosomal integrity (proportion of spermatozoa with normal apical ridge) was studied after thawing 0.5 ml straws at a constant rate. While increasing the glycerol concentration from 0 to 4% progressively improved motility, the percentage of spermatozoa with a normal apical ridge gradually decreased. The magnitudes of the respective changes depended on cooling rate. A peak value of 48.1% and rating 3.8 were obtained in semen protected with 4% glycerol, frozen at 30°C/min. Increasing the glycerol levels above 6% resulted in a gradual decrease in motility. The proportion of spermatozoa with normal apical ridge was highest in semen protected with 0–1% glycerol after cooling at 30°C/min (64.4% and 66.1%, respectively), but at these glycerol concentrations the percentage of motile spermatozoa was low. At the 30°C/min cooling rate, the decline in the proportion of cells with normal apical ridge due to increasing the glycerol levels to 3 and 4% was relatively slow (57.3% and 49.4%, respectively). Cooling at 1°C/min was detrimental to acrosomal integrity, which decreased with increasing glycerol concentration, in contrast to increasing motility, which even at its maximum, remained low. The direct plunging of straws into liquid nitrogen (1,500°C/min) resulted in damaged acrosomes in all spermatozoa with the total loss of motility. Balancing motility and acrosomal integrity, freezing boar semen protected with 3% glycerol by cooling at 30°C/min resulted in optimal survival for boar semen frozen in 0.5 ml French straws.
Ultrastructural study on the spermiogenesis and spermatozoon of the metacercariae of Microphallus primas (digenea), a parasite of Carcinus maenas
Authors: Castilho F. , Barandela T. 
Published: February 2005

AbstractThe thread‐like spermatozoon of the crab parasite Microphallus primas was studied by electron microscopy. A survey of the head region of the spermatozoon reveals three features hitherto unknown in Plathelminthes spermatozoa. The first is the aberrant inclusion of the nucleus within one of the two axonemes, limited to the head end region. The second is the coexistence, in the same axoneme, of two patterns, 9 + 0 (doublets without dynein arms) and 9 + “1”. The third is the presence of a layer of cortical microtubules running longitudinally from the zone where the nucleus goes from axoneme to the tail region (where the two flagella start). The sequence of events in spermatogenesis is similar to that described for most of the Digenea trematodes, and the spermiogenesis process conforms to a common plan in nearly the whole group.
An intercellular adhesion protein of rat testis: Isolation and preliminary characterization
Authors: D'Agostino Angela , Stefanini Mario 
Published: February 2005

AbstractBy using biochemical and immunochemical approaches, we have isolated a rat spermatocyte surface protein of an apparent molecular weight, of 80 kd involved in spermatocyte‐Sertoli cell recognition in culture. Preliminary characterization of such a molecule has demonstrated that (1) it is a nonintegral membrane component; (2) it possesses a small amount of N‐linked oligosac‐charides of the high mannose type; and (c) it is a stage‐specific molecule, being present only in middle‐late pachytene spermatocytes.
Fertilization envelope assembly in sea urchin eggs inseminated in chloride‐deficient sea water: II. Biochemical effects
Authors: Green Jeffrey D. , Glas Patricia S. , Cheng Sou‐De , Lynn John W. 
Published: February 2005

AbstractEggs of the sea urchin Strongylocentrotus purpuratus were fertilized in normal and in several chloride‐deficient sea waters ([CI−]: normal > isethionate > methyl sulfonate > bromide). The fertilization envelopes (FE) were thinner and failed to harden, and the characteristic I‐T transition did not occur. The permeability of the experimental FEs, as determined by release of protein from the perivitelline space, increased in the order of decreasing [CI−]. Release of the enzymes β‐1, 3‐glucanase and cortical granule protease were not significantly altered. On the other hand, release of ovoperoxidase was increased three to four times in bromide sea water. Furthermore, a dose‐response was observed in varying concentrations of bromide‐normal sea water. With decreasing chloride (increasing bromide) concentration, more ovoperoxidase activity was observed. Cytochemical localization of ovoperoxidase activity with diaminobenzidine revealed almost a total lack of staining of FEs from bromide‐substituted sea water. The results suggest that in chloride‐deficient sea waters protein incorporation into the nascent FE is impaired. At least in the case of bromide, the incorporation of ovoperoxidase into the nascent FE was also inhibited.
Immunolocalization of hyalin in sea urchin eggs and embryos using an antihyalin‐specific monoclonal antibody
Authors: Vater Carol A. , Jackson Robert C. 
Published: February 2005

AbstractMonoclonal antibodies were raised against purified cortical secretory vesicles (CVs) from the eggs of Stronglocentrotus purpuratus. One of the monoclonal antibodies (MAb 69‐10, an lgA) was shown by immunofluorescence labeling of intact and detergent‐lysed CVs to be directed against a CV content antigen. Immunoblot analysis of CVs revealed that MAb 69‐10 bound to a major CV polypeptide with an Mr similar to that of hyalin (i.e., 300,000). MAb 69‐10 was subsequently shown to bind to purified hyalin prepared from S. purpuratus and to cross react with hyalin prepared from Lytechinus pictus. Immunogold labeling on thin sections of unfertilized S. purpuratus eggs showed that hyalin was localized to the electron‐lucent portion of CVs. This result is in agreement with the labeling pattern obtained by Hylander and Summers (Dev Biol 93:368–380, 1982) using polyclonal antihyalin antibodies. In fertilized eggs and later‐stage embryos, hyalin was observed to be located on the external surface of the embryo. MAb 69‐10 should be useful in studies of the structure of hyalin and its function in morphogenesis.
Effect of antibodies to human seminal plasma inhibin on spermatogenesis and sperm agglutination in adult male rats
Authors: Vanage G. R. , Gopalkrishnan K. , Sheth A. R. 
Published: February 2005

AbstractIn vitro incubation of rat epididymal sperm with antiserum to human seminal plasma inhibin (As hSPl) caused agglutination of the sperm. In vivo administration of As hSPl to adult male rats resulted in a significant decrease in testicular as well as epididymal sperm counts. Furthermore, the majority (almost 90%) of the epididymal sperm were agglutinated. When these animals were mated with normal cycling females, significant reduction in fertility was observed.
Male accessory sex glands produce heparin‐binding proteins that bind to cauda epididymal spermatozoa and are testosterone dependent
Authors: Nass Sharyl J. , Miller David J. , Winer Martin A. , Ax Roy L. 
Published: February 2005

AbstractHeparin binds to bovine sperm and stimulates capacitation in vitro. Seminal plasma alters the ability of epididymal sperm to bind heparin, and several heparin‐binding proteins (HBPs) have been identified in bull seminal plasma. This study had three objectives: (1) to identify production sites of seminal plasma HBPs, (2) to determine which HBPs bound to cauda epididymal sperm, and (3) to determine whether presence of HBPs was testosterone dependent. Proteins from bull or rat seminal vesicles, prostates, and bulbourethral glands were separated by heparin affinity high‐performance liquid chromatography. HBPs were found in all accessory glands of rats and bulls, but the major source of bovine seminal plasma HBPs appeared to be seminal vesicles. Between 25% and 50% of the protein from each gland bound to the heparin column, and NaCl concentrations required to elute proteins ranged from 0.15 to 1.4 M. One‐dimensional sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) showed that major HBPs were relatively small, with molecular weights between 13 and 31 kDa, but some HBPs also exhibited higher molecular weights, between 40 and 100 kDa. Radioiodinated HBPs from each bovine gland were incubated with epididymal sperm. Labeled HBPs binding to sperm exhibited molecular weights of 14, 16, 24, and 30 kDa as determined by SDS‐PAGE and autoradiography. The HBP content of the accessory sex glands decreased significantly in castrated rats and was restored to levels of sham‐operated controls by testosterone replacement. Heparin‐binding proteins may play a role in fertilization by attaching to sperm surfaces, enabling heparin‐like glycosaminoglycans in the female reproductive tract to induce capacitation.
Activation of mammalian oocytes by a factor obtained from rabbit sperm
Authors: Stice Steven L. , Robl James M. 
Published: February 2005

AbstractIn this study a fraction was prepared from rabbit sperm that activated rabbit and mouse oocytes following injection into the cytoplasm. The sperm factor activated oocytes exhibited cortical granule exocytosis, pronuclear formation, and cleavage. The sperm factor was soluble in aqueous solution and was not active extracellularly. Unlike most artificial activation methods that are only effective with aged oocytes, the sperm factor activated recently ovulated oocytes. The factor appears to be a protein or associated with a protein but not an acrosomal protein. Fractions from both mouse and bull sperm did not activate rabbit or mouse oocytes. Their inactivity may be owing to the techniques used to recover the fractions or differences between species in sperm morphology and fertilization processes. These observations support the hypothesis that oocyte activation is induced by a factor within sperm that is released into the cytoplasm of the oocyte at the time of sperm–oocyte fusion.
Cleavage development of bovine oocytes fertilized by sperm injection
Authors: Keefer Carol L. , Younis Abdelmoneim I. , Brackett Benjamin G. 
Published: February 2005

AbstractWhole in vitro capacitated bovine spermatozoa were microinjected directly into the ooplasm of in vitro matured bovine oocytes in order to determine whether oocytes fertilized by sperm injection could undergo normal pronuclear formation and cleavage development. Immature oocytes recovered from follicles (2–5 mm) of unstimulated ovaries were cultured for 24–25 h in modified TCM 199 medium supplemented with heat‐treated day 20 cow serum, luteinizing hormone (LH), and estradiol 17‐B. In vitro capacitated, frozen‐thawed spermatozoa were injected into the ooplasm, and the injected oocytes were cultured for an additional 24–28 h. Twenty‐one percent (21/101) of the sperm‐injected oocytes contained a sperm within the ooplasm; however, only 2% (2/101) cleaved. The remaining oocytes either did not contain a sperm or had degenerated. After oocyte activation induced by a 5 min incubation in 1 μM A23187, sperm nuclear decondensation occurred in the A23187‐activated, injected oocytes but not in the unactivated, injected controls (37% vs. 0% after 3 h). Those injected, activated oocytes that contained a male pronucleus also exhibited a female pronucleus and second polar body. Furthermore, a significantly higher number (28%, 6/21) of the injected, activated oocytes cleaved to a two‐ to four‐cell stage after 48 h than did the injected, unactivated oocytes (4%). These results indicate that, unlike hamster and rabbit oocytes, bovine oocytes are not sufficiently stimulated by the injection procedure to complete meiosis, but, upon activation by calcium ionophore, they will undergo normal‐appearing cleavage development following fertilization by sperm injection.
Atypical spermatogenesis in Murex brandaris
Authors: Amor M. J. , Durfort M. 
Published: February 2005

AbstractAtypical spermatogenesis in Murex brandaris occurs in specific areas of the testis. In the early stages, a large nucleus is apparent, together with highly electrodense drops of chromatin spread through the caryoplasm. Many mitochondria are observed at one point of the cytoplasm, and numerous centrioles appear. In the following stages, vacuolization and degeneration of the chromatin are apparent, producing half moon‐shaped chromatinic bodies called “caryomerites.” Some degeneration of the chondrioma occurs too. Later, the chromatin degenerates and the centrioles produce cilia, while the Golgi body, highly secretory at this stage, produces electrodense PAS‐ as well as Thiery‐positive granules. Moreover, a vermiform‐shaped anuclear ciliated cell with numerous electrodense cytoplasmic granules is observed in the M. brandaris atypical spermatozoon.