bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene transfer, expression and inheritance of PRSV‐rainbow trout‐GH cDNA in the common carp, Cyprinus carpio (Linnaeus)
Authors: Zhang Peijung , Hayat Mohammad , Joyce Christopher , Gonzalez‐Villaseñor Lucia Irene , Lin C. M. , Dunham Rex A. , Chen Thomas T. , Powers Dennis A. 
Published: February 2005

AbstractA recombinant plasmid containing the Rous sarcoma virus‐long terminal repeat (RSV‐LTR) promoter linked to rainbow trout (Salmo gairdneri) growth hormone (GH) cDNA was microinjected into fertilized carp eggs. Genomic DNA extracted from pectoral fin of individual presumptive transgenic fish was analyzed by dot blot and Southern blot hybridization, using the RSV‐LTR and/or the GH cDNA sequences as probes. Out of 365 presumptive transgenic fish analyzed, 20 individuals were found to contain pRSV‐rtGH‐cDNA sequence in the genomic DNA. Expression of the trout GH polypeptide was detected by immunobinding assay in the red blood cells of nine transgenic fish tested. The level of expression, however, varied among the transgenics and could not be correlated with exogenous DNA copy number. Although there was considerable variation in the sizes of the transgenic fish, those microinjected during the one‐cell stage were (P < 0.05) 22% larger, on the average, than their sibling controls. A randomly selected fraction of the progeny derived from crosses between transgenic males and non‐transgenic females inherited the foreign DNA. These transgenic progeny grew faster (P < 0.05) than their non‐transgenic siblings.
Stage‐Specific expression of the lactate dehydrogenase‐X gene in adult and developing mouse testes
Authors: Jen J. , Deschepper C. F. , Shackleford G. M. , Lee C. Y. G. , Lau Y.‐F. C. 
Published: February 2005

AbstractLactate dehydrogenase‐X (LDH‐X), a glycolytic enzyme found only in mammalian testes and spermatozoa, is encoded by a single gene (Ldh‐x) in the mouse haploid genome. Several studies have demonstrated that LDH‐X is associated with germ cells at specific stages of development. We have examined the expression of the Ldh‐x gene during mouse spermatogenesis and testis maturation using in situ mRNA hybridization and immunocytochemistry. The results showed that transcription and translation of the Ldh‐x gene are initiated at the pachytene stage of germ cell differentiation. However, although the amount of LDH‐X protein increased as the germ cells progressed to maturation, its mRNA level was greatly decreased. These observations were confirmed by Northern analysis of total RNA derived from fractionated spermatogenic cells and developing testes. Furthermore, Northern studies also indicated two sizes of Ldh‐x transcripts among different populations of spermatogenic cells in mature mouse testis.
Collection and quality of rhesus monkey semen
Authors: Lanzendorf S. E. , Gliessman P. M. , Archibong A. E. , Alexander M. , Wolf D. P. 
Published: February 2005

AbstractElectroejaculation is an accepted method of semen collection from nonhuman primates. Although both penile and rectal probe stimulation techniques have been used, there has been a general lack of consistency and detail regarding their application. This report describes the collection, processing, and evaluation of rhesus monkey semen contrasting two methods of penile electrcejaculation: (1) a constant‐voltage method where stimulus current is a variable and (2) a constant‐current method where stimulus current is operator‐controlled. The constant‐current method was the more efficient procedure, requiring a lower stimulus current for successful electroejaculation. The intluence on semen quality of potentially toxic agents used in the procedure, surgical glove powder and electrolyte cream, was tested; both were determental as measured by motility loss. No correlation was found between coagula volume and sperm numbers. The intra‐ and interanimal variability in semen samples from six monkeys was also evaluated. Penile electroejaculation, combined with control of stimulus current, provides a consistent, successful, and humane method for the collection of semen in the rhesus monkey.
A comparison of fertilization envelope development in three species of Strongylocentrotus (S. Franciscanus, S. Droebachiensis, and S. purpuratus)
Authors: Carroll Edward J. , Cohen Jeffrey S. 
Published: February 2005

AbstractThe ultrastructure of fertilization envelope (FE) development and the polypeptide spectra of Strongylocentrotus franciscanus and S. droebachiensis envelopes were compared to S. purpuratus. In S. franciscanus, the FE reached its maximum thickness of 67 nm by 3 minutes postinsemination (Pl), and final structuralization was observed by 40 minutes Pl. The fully formed FE did not have microvillar impressions (casts) and was symmetrical, with outer double laminar elements surrounding an amorphous central region. Isolated S. franciscanus FEs were soluble in reducing and denaturing solvents and the same set of 33 polypeptides ranging from 18.5 to 260 kD was detected in FEs isolated from 10 to 180 minutes Pl. The S. droebachiensis FE retained microvillar casts, assumed its definitive from by 3 minutes Pl, and was 70 nm thick between microvillar impressions. Isolated S. droebachiensis FEs were partially soluble in reducing and denaturing solvents, and the polypeptide spectra of FEs isolated between 10 and 60 minutes Pl were identical and showed 14 polypeptides from 18.5 to 265 kD. Antisera against exttracted FEs and the FE extract from S. purpuratus were immunologically cross‐reactive (using an enzyme‐linked immunosorbent assay) with S. franciscanus and S. droebachiensis FE preparations; immunoblots identified 13 and 5 cross‐reactive polypeptides, respectively. Most of the cross‐reactive polypeptides were of slightly different molecular weight. Based on comparative ultrastructural, solubility, and electrophoretic data, we suggest that S. droebachiensis FE development is most like that observed in S. purpuratus.
Multidrug resistance gene expression is controlled by steroid hormones in the secretory epithelium of the uterus
Authors: Arceci Robert J. , Baas Frank , Raponi Romeo , Horwitz Susan Band , Housman David , Croop James M. 
Published: February 2005

AbstractThe multidrug resistance (mdr) gene family has been shown to encode a membrane glycoprotein, termed the P‐glycoprotein, which functions as a drug efflux pump with broad substrate specificity. This multigene family is expressed in a tissue‐specific fashion in a wide variety of normal and neoplastic tissues. The regulation of mdr gene expression in normal tissues is not understood. We have recently shown that mdr mRNA and the P‐glycoprotein increases dramatically in the secretory luminal and glandular epithelium of the gravid murine uterus. This observation has suggested that mdr gene expression in the uterus is controlled by the physiologic changes associated with pregnancy. This report now demonstrates that mdr mRNA and P‐glycoprotein are induced at high levels in the uterine secretory epithelium by the combination of estrogen and progesterone, the major steroid hormones of pregnancy. This regulation of mdr gene expression in the uterus does not require any other contribution from the fetus or placenta. The data indicate that this gene locus is hormonally responsive to estrogen and progesterone in the uterine secretory epithelium, suggesting an important and physiologically regulated role during pregnancy.
First cell cycle of zygotes of the mouse derived from oocytes aged postovulation in vivo and fertilized in vivo
Authors: Boerjan M. L. , De Boer P. 
Published: February 2005

AbstractThis paper describes an analysis of the first cell cycle of mouse oocytes aged postovulation and fertilized in vivo. For this purpose, we developed a procedure for inducing ovulation in vivo that allows accurate timing of ovulation. The method is based on a luteinizing hormone (LH)‐releasing hormone (LHRH) administration at prcestrus. This ovulation procedure had no detectable effect on the rate of ovulation or postimplantation embryonic death. We used this method of ovulation induction in an analysis of the separate stages of the first cell cycle of in vivo fertilized postovulation aged oocytes. All stages assessed were shorter in aged oocytes (12 hr postovulation) than in zygotes from unaged oocytes (1 hr postovulation): (1) the time interval between insemination and penetration of the aged oocytes was 1.5 hr shorter than the time interval of the unaged oocytes; (2) pronuclear formation in the fertilized aged oocytes was somewhat quicker than pronuclear formation in fertilized unaged oocytes; (3) in zygotes from aged oocytes, the time between formation of pronuclei and the pronuclear membrane breakdown was 1 hr shorter than in zygotes from unaged oocytes; (4) the first cleavage division was 3 hr advanced in zygotes from aged oocytes compared with the moment of the first cleavage division in zygotes from unaged oocytes. We also determined the glutathione (GSH) content of unaged and aged oocytes to investigate a possible relationship between the rate of pronuclear formation and GSH. The level of GSH was two times lower in oocytes aged postovulation for 12 hr than in unaged oocytes. The level of GSH in fertilized, unaged oocytes was half that in unfertilized, unaged oocytes; this decline was not observed after fertilization of aged oocytes, however. In summary, we developed a procedure that allows in vivo fertilization at defined points of time after LHRH‐induced ovulation. Under the conditions used in this procedure, we could detect several differences between zygotes derived from unaged and postovulation aged oocytes.
Changes in the mitochondrial calcium influx and efflux properties are responsible for the decline in sperm calcium during epididymal maturation
Authors: Vijayaraghavan S. , Hoskins D. D. 
Published: February 2005

AbstractThis study was undertaken to determine the role of calcium ion, a key regulator of the intensity and form of motility in mature demembranated sperm, in the development of motility during passage through the bovine epididymis. Cellular calcium levels in bovine caput and cauda epididymal spermatozoa were measured with three different techniques. 45Ca2+ uptake measurements revealed that net calcium uptake and Ca2+‐Ca2+ exchange in caput spermatozoa were about 2 to 3 times higher than in caudal spermatozoa. Intracellular free calcium determination with the calcium fluorophore Fura 2 showed that the levels were 6 times higher in caput spermatozoa. The values for caput and caudal sperm were 875±55 nM (n = 15) and 155±6 nM (n = 24), respectively. Total cellular calcium levels quantitated by atomic absorption were 626±30 (n = 48) and 304±19 (n = 46) ng/108 sperm in caput and caudal epididymal sperm, respectively. At least one of the reasons for the high calcium content of caput epididymal sperm is the result of a higher rate and extent of mitochondrial calcium accumulation in caput compared to caudal sperm. Mitochondrial calcium uptake rates measured in digitonin permeabilized cells revealed uptake rates 2‐ to 3‐fold higher in caput compared to caudal sperm. However, mitochondrial calcium efflux rates were identical in caput and caudal epididymal sperm. The efflux rates in both cell types were unaffected by external sodium levels but were found to be proportional to pH. Alkalinization or acidification of internal pH of intact sperm resulted in a corresponding lowering or elevation of cytoplasmic free calcium levels. We propose that external calcium has access to sperm only via the mitochondria (Vijayaraghavan and Hoskins: Cell Calcium 10:241–253, 1989) and that this mitochondrial calcium is subsequently redistributed into the cytoplasmic space as a function of the internal pH. We document for the first time that changes in mitochondrial calcium handling properties are important in epididymal sperm maturation and suggest that the acquisition of sperm motility in the epididymis could be related to these changes in sperm calcium handling properties.
Effects of ultrasound on DNA and RNA synthesis in preimplantation mouse embryos
Authors: Heyner S. , Abraham V. , Wikarczuk M. L. , Ziskin M. C. 
Published: February 2005

AbstractUltrasound is used extensively to monitor the growth of ovarian follicles in in vitro feritilization and embryo transfer (IVF‐ET) programs, as well as to follow the progress of early pregnancy. There have been scattered reports in the literature that exposure to ultrasound may have an adverse effect on reproduction in the rat (Bologne et al: CR Soc Biol 177:381–387, 1983; Demoulin et al: Ann Ny Acad Sci 442:146–152, 1985), and also in humans (Demoulin et al: Ann NY Acad Sci 442:146–152, 1985). We report here that diagnostic levels of pulsed ultrasound did not affect either the number of embryos produced, or the ability to incorporate labelled precursors into DNA and RNA, respectively. Measurements of temperature elevation of ovaries exposed to ultrasound showed that neither controls nor experimental tissue exhibited temperature elevation greater than 1°C.
Assessment of the human sperm acrosome reaction using concanavalin a lectin
Authors: Holden Carol A. , Hyne Ross V. , Sathananthan A. H. , Trounson Alan O. 
Published: February 2005

AbstractA method for assessment of the human sperm acrosome reaction is reported using fluorescein isothiocyanate (FITC)‐conjugated Concanavalin A (ConA). The technique involved labelling prefixed spermatozoa, where only those spermatozoa that showed a complete loss of the acrosome bound FITC‐ConA to the acrosomal region. Competitive sugar binding studies demonstrated that binding of ConA lectin to the acrosomal area of human spermatozoa was inhibited in the presence of 0.2 M D‐mannose. Staining with the supravital stain Hoechst 33258 (H258) concomitantly with FITC‐ConA allowed determination of only those spermatozoa that had undergone a true and not degenerative acrosomal loss. Incubation of human spermatozoa with 0, 1, 5, and 25 μM calcium ionophore, A23187, for 60 min demonstrated that changes in acrosomal status due to the different treatment protocols may be determined by the dual‐staining method. Electron microscopy studies revealed that gold‐conjugated ConA bound specifically to the surface of the inner acrosomal membrane of acrosome‐reacted spermatozoa. A significant correlation (r = +.97) between transmission electron microscopy (TEM) and FITC‐ConA labelling methods of acrosomal status assessment was achieved. The simple ConA labelling procedure reported here therefore provides a reliabale method for quantitation of the physiological acrosome reaction of a population of human spermatozoa.
Spermatogenesis‐related change in the synthesis of the creatine kinase B‐type and M‐type isoforms in human spermatozoa
Authors: Huszar Gabor , Vigue Lynne 
Published: February 2005

AbstractWe have demonstrated earlier that the per sperm creatine‐N‐phosphotransferase (CK) activity was increased in oligospermic vs. normospermic men. The increased sperm CK activity is related to higher concentrations of cellular CK, which may indicate a defect of cytoplasmic extrusion during spermatogenesis. In the present work, we examined whether in spermatozoa, similar to muscle, there is a change in the synthesis of B‐CK and M‐CK isoforms during cellular differentation. In 109 normospermic and 50 oligospermic specimens (sperm concentrations 60.6 ± 3.7 vs. 8.8 ± 1.3 million sperm/ml; all values expressed as mean ± SEM), the relative concentrations of the M‐CK isoform (M‐CK / M‐CK+B‐CK) were 27.2% ± 2.1% vs. 6.7% ± 0.9% (P < 0.001). The per sperm CK activities showed comparable differences (0.21 ± 0.02 vs. 0.89 ± 0.1 CK IU/100 million sperm; P < 0.001) in the two groups, and there was a close correlation between per sperm CK activities and M‐CK concentrations (R = 0.69, P < 0.001, N = 159). This indicates that the loss of cytoplasm and the commencement of M‐CK isoform synthesis are related events during the last phase of spermatogenesis, also that the incidence of spermatozoa with incomplete cellular maturation is higher in oligospermic specimens. In characterizing the M‐CK, we found that sperm (unlike muscle tissue) lack the MB hybrid of CK dimers. However, in the presence of muscle M‐CK, the muscle‐sperm MB‐CK hybrid has formed. Thus in sperm and muscle the M‐CK isoforms are structurally different, whereas the B‐CKs are apparently homologous. We suggest that the relative concentrations of sperm M‐CK isoform is a biochemical marker of cellular differentiation that may also predict the functional intetrity, such as fertilization potential, of spermatozoa.
Ultrastructure of the sperm and spermatogenesis in five South African species of the trochid genus Oxystele (Mollusca, Prosobranchia)
Authors: Hodgson A. N. , Heller J. , Bernard R. T. F. 
Published: February 2005

AbstractSperm of Oxystele are of the primitive type, which is typical of molluscs using external fertilization. They comprise a head, which is composed of a barrel‐shaped nucleus and large conical acrosome; a midpiece of five or six spherical mitochondria; and a tail, with a 9 + 2 arrangement of microtubules. The morphology of the sperm broadly resembles that of the sperm of other trochids as well as that of the sperm of the Pleurotomariidae, Haliotidae, and Fissurellidae but differs considerably from that of the Patellidae. Each of the five species examined was found to have a different sperm morphology. Our results support the suggestion of Heller and Dempster (in preparation) that Oxystele variegata Anton actually consists of two sympatric species. The morphological changes that occur during spermatogenesis are very similar in all species and resemble descriptions given for other molluscs with primitive sperm.
Antigens on rat spermatozoa with a potential role in fertilization
Authors: Shalgi R. , Matityahu A. , Gaunt S. J. , Jones R. 
Published: February 2005

AbstractEight monoclonal antibodies (McAbs), directed against antigens on rat cauda epididymal spermatozoa, were tested for their capacity to interfere with fertilization in vitro as a means of identifying molecules a potential role in sperm‐egg recognition and fusion. Antigens recognized by the McAbs were visualized on live spermatozoa by indirect immunofluorescence (IIF) and characterized by immunoblotting. Five McAbs (designated 1B5, 2C4, 4B5, 5B1, and 8C4) recognized antigens specifically on the sperm acrosome and three (designated 2B1, 2D6, and 6B2) bound to the flagellum. Of the eight McAbs investigated, three (2B1, 2C4, and 6B2) were effective in blocking fertilization in vitro when added as culture supernalants to mixtures of sperm and eggs. McAb 6B2 was inhibitory due to its ability to agglutinate spermatozoa. McAbs 2B1 and 2C4 did not agglutinate capacitated spermatozoa, had no observable effect on motility, and yet blocked fertilization in a dose‐dependent manner. McAb 2C4 did not give a reaction on immunoblots, but the 2B1 antigen was identified as an Mr 40 kD glycoprotein. McAb 2B1 appeared to block fertilization at the level of zona binding, whereas the effects of 2C4 were directed more against zone penetration and/or fusion with the vitellus. When sperm‐egg complexes were stained with 2C4 or 2B1 McAbs and viewed by IIF, all spermatozoa that were attached to the zona showed fluorescence on the head. These results suggest that different antigens on the rat sperm head participate in different aspects of the fertilization process and that during capacitation there is either exposure of these antigens or else they migrate to their site of action from the flagellum.
Changes in nuclear structure during eupyrene spermatogenesis in Murex brandaris
Authors: Amor M. J. , Durfort M. 
Published: February 2005

AbstractChanges in nuclear structure during eupyrene spermatogenesis of Murex brandaris have been studied using light and electron microscopy. In the first phases, spermatogonia show round nuclei, with several electrodense masses of chromatin and a thin layer of heterochromatin associated with the nuclear membrane. Primary spermatocytes possess larger nucleii, with less condensed chromatin, and the synaptonemal complexes are apparent. During spermiogenesis, chromatin becomes lamellar, and the nucleus twists about its principal axis while it elongates. The nuclear twisting is accompanied by a progressive chromatin condensation, which causes a highly electrodense nucleus at the end of the process.
Oogenesis: Chromatin and microtubule dynamics during meiotic prophase
Authors: Mattson Britta A. , Albertini David F. 
Published: February 2005

AbstractChanges in the organization of germinal vesicle chromatin in mouse oocytes have been analyzed by fluorescence microscopy with respect to progressive stages of follicular development and the disposition of oocyte cytoplasmic microtubules. Four discrete patterns of chromatin organization exist in germinal vesicle (GV)‐stage oocytes isolated from the ovaries of 21–25‐day‐old gonadotropin‐primed mice. Analysis of ovarian cryosections stained with the DNA‐binding fluorochrome Hoechst 33258 indicates that sequential changes in GV chromatin occur duing folliculogenesis that result in the formation of a continuous perinucleolar chromatin sheath at the time of antrum formation. Specific alterations in the cytoplasmic microtubule complex of GV‐stage oocytes were observed that correlate with chromatin patterns. The extensive cytoplasmic microtubule complex seen in oocytes of preantral follicles initially localizes to perinuclear areas of the ooplasm. This is followed by a progressive reduction in cytoplasmic microtubules and the appearance of prominent microtubule‐organizing centers at the nuclear periphery. Coordinated nuclear and microtubular alterations also occur under in vitro conditions prior to progression of meiosis to prometaphase‐1. The results are discussed with respect to the ongoing differentiation of the oocyte nucleus and the microtubule cytoskeleton during folliculogenesis in preparation for the resumption of meiosis.
Protein synthesis and secretion in the human epididymis and immunoreactivity with sperm antibodies
Authors: Ross Peter , Kan Frederick W. K. , Antaki Pierre , Vigneault Normand , Chapdelaine Alcide , Roberts Kenneth D. 
Published: February 2005

AbstractThe synthesis and secretion of proteins in the different regions of the human epididymis were studied in vitro. Epididymal tissues obtained from patients undergoing castration for prostatic carcinoma or from cadavers were incubated in the presence of [35S]methionine, and the resulting radiolabeled proteins were analysed on SDS‐PAGE. The corpus region was found to be the most active segment in total protein synthesis. Significant qualitative and quantitative changes were observed in the pattern of proteins secreted from the different epididymal regions. To establish those epididymal proteins that interact with maturing sperm, the secreted products were immunoreacted with antibodies raised against a Triton X‐100 extract of ejaculated human sperm heads. The antibodies react mainly with the head region of ejaculated spermatozoa as judged by indirect immunofluorescence. Protein A‐gold labeling of freeze‐fracture images showed gold particle distribution on the sperm plasma membrane. Western blot analysis of the secreted proteins revealed four bands (66, 37, 32, and 29 kDa) in the proximal regions and six additional bands 80, 76, 48, 27, 22, and 17 (kDa) in the distal part of the epididymis. Immunoprecipitation of the secreted proteins with these antibodies revealed six radioactive bands of 170, 80, 76, 60, 48, and 37 kDa, which indicates that certain proteins of epididymal origin bind to the sperm plasma membrane.