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PubMed2005

High-resolution physical mapping reveals that the apospory-specific genomic region (ASGR) in Cenchrus ciliaris is located on a heterochromatic and hemizygous region of a single chromosome.

An apomictic mode of reproduction known as apospory is displayed by most buffelgrass (Cenchrus ciliaris) genotypes, but rare sexual individuals have been identified. Previously, intraspecific crosses between sexual and aposporous genotypes allowed linkage to be discovered between the aposporous mode of reproduction and nine molecular markers that had been isolated from an aposporous relative, Pennisetum squamulatum. This region was described as the apospory-specific genomic region (ASGR). We now show an ideogram of the chromosome complement for aposporous tetraploid buffelgrass accession B-12-9 including the ASGR-carrier chromosome. The ASGR-carrier chromosome has a region of hemizygosity, as determined by in situ hybridization of BAC clones and unique morphological characteristics when compared with other chromosomes in the genome. In spite of its unique morphology, the ASGR-carrier chromosome could be identified as one of the chromosomes of a meiosis I quadrivalent. A similar partially hemizygous segment was also detected in the ASGR-carrier chromosome of the aposporous buffelgrass genotype, Higgins, but not in the sexual accession B-2S. Two non-recombining BACs linked to apospory were physically mapped on a highly condensed chromatin region of the short arm of B-12-9, and the distance between the BACs was estimated to be approximately 11 Mbp, a distance similar to what previously has been shown in P. squamulatum. The short arm of the ASGR-carrier chromosome was highly condensed at pachytene and extended only 1.7-2.7 fold that of mitotic chromosomes. Low recombination in the ASGR may partially be due to its localization in heterochromatin.

Cenchrus↗
PubMed1996

SF-1: a key regulator of development and function in the mammalian reproductive system.

The orphan nuclear receptor steroidogenic factor 1 (SF-1) was isolated as a transcription factor expressed specifically in the mouse primary steroidogenic tissues. SF-1 expression occurs at the earliest stages of adrenal and gonadal development and the expression pattern is sexually dimorphic in gonads during sexual differentiation. The two hormones required for male differentiation, testosterone and Müllerian-inhibiting substance, are regulated by SF-1. Analyses of knockout mice lacking SF-1 by gene targeting disruption demonstrated that the SF-1-disrupted mice lack adrenal glands and gonads, supporting the suggestion that SF-1 is an essential regulator of the endocrine development and differentiation. Additionally, SF-1 is expressed in the pituitary gonadotropes and the ventrolateral hypothalamic nucleus, which are higher levels of the reproductive regulatory axis, of both adults and embryos. These tissues are also affected in SF-1 knockout mice, indicating that SF-1 plays extended roles at all levels of the reproductive axis, by regulating more genes involved in reproductive function and development.

Adult↗
PubMed2005

Inhibition of Staphylococcus aureus by H2O2-producing Lactobacillus gasseri isolated from the vaginal tract of cattle.

Infectious diseases are the major reproductive complication during postpartum. The bacteria that colonize the postpartum uterus of cattle are specific as well as opportunistic pathogens that include Staphylococcus aureus. The antibiotics and antiseptic agents used in the treatment of postpartum acute infections induce residues in foods, spread of bacterial resistance, increase in financial costs and failures in defense mechanisms of the host. Preventive treatment with probiotic products could decrease the use of antibiotics in dairy farming systems. Lactobacilli are present in the vaginal microflora of healthy cows. They can prevent pathogen colonization by mechanisms such as the production of antagonistic substances as lactic acid, H2O2, or bacteriocins. The aim of the present study was the selection of H2O2 generating lactobacilli from a group of 72 strains isolated from the vagina of cattle. Both Lactobacillus gasseri CRL1421 and Lactobacillus gasseri CRL1412, which share some probiotic properties, produce H2O2, detected by the plate colorimetric method. They were chosen to study the kinetics of H2O2 production under different culture conditions. Both microorganisms produced greater amounts of H2O2 in aerated than in static cultures. As L. gasseri CRL1421 had a greater capacity to generate H2O2, associative cultures with this strain and S. aureus were conducted. A significant decrease in the growth of the pathogen was detected after culture for 6h, this effect being greater under aerated conditions. The addition of catalase to mixed cultures partially abolished the inhibition, an effect that could be attributed to the combined action of H2O2 and other antagonistic metabolites. The simultaneous addition of catalase and NaOH to these cultures restored S. aureus growth. This observation suggests that the inhibition was produced by the combination of H2O2 and lactic acid, both released by the lactobacilli. Electron microphotographs showed the damage caused by the lactobacilli supernatant on the pathogenic cells. The treatment of S. aureus with lactic acid and hydrogen peroxide evidenced that each metabolite produced a different type of morphological damage. The number of viable cells obtained agrees with the electron microscopy observations. The results support the idea that L. gasseri CRL1421 could be successfully included in a probiotic product to prevent S. aureus infection in cows.

Animals↗
PubMed2002

Isolation and characterization of a GnRH-like peptide from Octopus vulgaris.

Gonadotropin-releasing hormone (GnRH) is the key peptide in the hypothalamo-hypophysial-gonadal axis, the core of regulation of reproduction in vertebrates. In this study, an octopus peptide with structural features similar to vertebrate GnRHs was isolated from brains of Octopus vulgaris. This peptide showed luteinizing hormone-releasing activity in quail anterior pituitary cells. A cDNA encoding the precursor protein was cloned. The RT-PCR transcripts were expressed in the supraesophageal and subesophageal brains, peduncle complex, and optic gland. The presence of the peptide in the different brain region was confirmed with enzyme-linked immunosorbent assay and time-of-flight mass spectrometric analysis. Immunoreactive neuronal cell bodies and fibers were observed in the subpedunculate lobe that controls the optic-gland activity. Optic gland nerves and glandular cells in the optic gland were immunostained. The isolated peptide may be octopus GnRH that contributes to octopus reproduction not only as a neurohormone but also as an endocrine hormone.

Amino Acid Sequence↗
PubMed1999

Molecular cloning of cDNA for equine follistatin and its gene expression in the reproductive tissues of the mare.

A cDNA clone encoding equine follistatin was isolated from an equine ovarian cDNA library. Out of 1.2 x 10(5) independent clones screened, one positive clone was isolated and its cDNA sequence determined. The isolated clone, named EQ-FS-1, contained a complete open reading frame encoding 344 amino acid residues. The similarity of its deduced amino acid sequence to these of other mammalian species was greater than 95%. Although its expression level varied among the tissues examined, follistatin mRNA was detected in the equine uteroplacental tissues, follicles and corpora lutea by Northern blot analysis. In situ hybridization revealed that the expression of follistatin mRNA in the equine follicle was restricted exclusively to granulosa cells. When the expression pattern of follistatin mRNA in the equine uteroplacental tissues from mid- to late-pregnancy was examined, it was shown that its expression level tended to decrease after mid-pregnancy. These results suggest that follistatin acts in the reproductive tissues of the mare in maintaining pregnancy.

Amino Acid Sequence↗
PubMed2001

Epidemiology and control of Menangle virus in pigs.

OBJECTIVE: To describe the epidemiology and eradication of Menangle virus infection in pigs. DESIGN: Field observations and interventions, structured and unstructured serological surveys, prospective and cross-sectional serological studies and laboratory investigations. PROCEDURE: Serum samples were collected from pigs at a 2600-sow intensive piggery in New South Wales that experienced an outbreak of reproductive disease in 1997. Serum samples were also collected from piggeries that received pigs from or supplied pigs to the affected piggery and from other piggeries in Australia. Serum and tissue samples were collected from pigs at piggeries experiencing reproductive disease in New South Wales. Sera and faeces were collected from grey-headed flying foxes (Pteropus poliocephalus) in the region of the affected piggery. Serum samples were tested for neutralising antibodies against Menangle virus. Virus isolation was attempted from faeces. RESULTS: Following the outbreak of reproductive disease, sera from 96% of adult pigs at the affected piggery, including sows that produced affected litters, contained neutralising antibodies against Menangle virus. Neutralising antibodies were also detected in sera from 88% of finisher pigs at two piggeries receiving weaned pigs from the affected piggery. No evidence of Menangle virus infection was found in other piggeries in Australia. In cross-sectional studies at the affected piggery, colostral antibodies were undetectable in most pigs by 14 to 15 weeks of age. By slaughter age or entry to the breeding herd, 95% of pigs developed high antibody titres (> or = 128) against Menangle virus in the virus neutralisation test. Menangle virus was eradicated from the affected piggery following a program of serological testing and segregation. Neutralising antibodies against Menangle virus were also detected in P poliocephalus from two colonies in the vicinity of the affected piggery. Two piggery workers were infected with Menangle virus. There was no evidence of infection in cattle, sheep, birds, rodents, feral cats and a dog at the affected piggery. CONCLUSIONS: Serological evidence of infection with Menangle virus was detected in pigs at a piggery that had experienced reproductive disease, in pigs at two associated piggeries and in fruit bats in the region of the piggery. Two humans were infected. The mode of transmission between pigs is unknown, but spread by faecal or urinary excretion is postulated. This virus can be eradicated by the segregation of pigs into discrete age groups.

Animals↗
PubMed2001

Dispersal costs set the scene for helping in an atypical avian cooperative breeder.

The ecological constraints hypothesis is suggested to explain the evolution of cooperative breeding in birds. This hypothesis predicts that the scene for cooperative breeding is set when ecological factors constrain offspring from dispersal. This prediction was tested in the atypical cooperative breeding system of the long-tailed tit, Aegithalos caudatus, by comparing the degree of philopatry and cooperation in an isolated and a contiguous site whilst experimentally controlling for confounding aspects of reproduction. No difference was found between the two sites in the survival of offspring but a greater proportion were found to remain philopatric in the isolated site. This difference was caused by greater philopatry of normally dispersive females suggesting, as predicted, that dispersal costs were greater from this site. Furthermore, a greater proportion of males and females cooperated following breeding failure in the isolated site than in the contiguous site. Thus, as has been suggested for typical avian cooperative breeders, dispersal costs, relative to philopatric benefits, appear to set the scene for cooperative breeding in long-tailed tits.

Animals↗
PubMed1982

Anatomy and function of the reproductive tract in the captive male tree shrew (Tupaia belangeri).

The reproductive anatomy of the male tree shrew (Tupaia belangeri) was examined and compared with other Tupaiidae. The testes are located prepenially in a pigmented scrotum which is fused to the base of a pendulous penis. The terminal portion of the vas deferens is differentiated into an ampullary gland and joins the duct of the seminal vesicle to form a short ejaculatory duct. The prostate is a compact bilateral body drained by a main collecting duct. In the aggregate, these features indicate that the reproductive system in Tupaia is primate in character. Testicular function in tree shrews is affected by both social and seasonal factors. When males were housed communally, the majority exhibited testicular degeneration accompanied by a loss in the weight and fructose content of the seminal vesicles and in pigmentation of the scrotum. These changes may be due to the presence of dominant conspecifics since animals kept in isolation undergo normal sexual development. Animals captured throughout the year and isolated show seasonal fluctuations in androgenic and spermatogenic function. Reproductive capacity is maximal during the winter and minimal during the summer. Local environmental factors appear to regulate reproductive function so that the greatest number of births occur during the dry season.

Animals↗
PubMed2006

Genetical and biotechnological methods of utilization of female reproductive potential in mammals.

The investigations included: 1/ Establishment of culture systems that would maintain the three-dimensional structure of bovine intact early antral follicles (EAF) or isolated cumulus-oocyte-granulosa complexes (COCGs) and increase the resulting portion of cumulus-oocyte complexes (COCs) with normal morphology for subsequent in vitro maturation (IVM) and in vitro fertilization (IVF), 2/ Quality assessment of IVM bovine oocytes and resulting day-8 blastocysts produced in TCM199 medium supplemented with fetal bovine serum (FBS), fatty acid free bovine serum albumin (fafBSA) or polyvinylpyrrolidone (PVP40), 3/ Testing the polymorphism of the genes: retinol binding protein (RBP4), epidermal growth factor (EGF), prostaglandin-endoperoxide synthase 2 (PTGS2), insulin-like growth factor 2 (IGF2), amphiregulin (AREG) and prolactin (PRL), and their effects on reproductive traits in swine. Isolated COCGs created in culture follicle-like structures and their oocytes achieved meiotic competence and matured to metaphase II at a higher rate than did oocytes from smaller diameter follicles which were cultured intact. The proportion of COCs with normal morphology significantly increased when isolated COCGs were embedded in microdrops of collagen gel or cultured on inserts covered with gel rather than in large gel volumes. No significant effect of maturation media composition on meiotic spindle morphology and the rate of apoptotic bovine oocytes was observed. Among day-8 embryos derived from oocytes matured with PVP40 a reduced blastocyst rate and elevated apoptotic index were found, whereas total cell count was not affected. Gene expression study also revealed a decrease in relative abundance for IGF2 and its receptor (IGF2R), and heat shock protein 70 (Hsp70) genes in PVP40 group and a significant elevation in fafBSA derived embryos. The significant effect of reproduction traits of swine (litter size and litter weight) was found for RBP4, EGF, IGF2 and AREG genes. A new polymorphism was also revealed within a promoter region of PRL gene.

Animals↗
PubMed1999

Antigen-presenting cells in the human female reproductive tract: analysis of antigen presentation in pre- and post-menopausal women.

PROBLEM: To determine whether cells in the female reproductive tract (FRT) are functionally capable of presenting antigen to T cells. METHOD OF STUDY: Analysis was done by determining the proliferation of purified autologous T cells to antigen, following co-incubation with non-proliferating cell suspensions isolated from the uterus and prepared by enzymatic digestion of reproductive tract tissues from hysterectomy patients with benign disease. RESULTS: All uterine preparations analyzed were functionally capable of presenting antigen; the ability to present antigen was independent of pre- and post-menopausal status. In contrast, some, but not all, tissues from the ovary, Fallopian tube, cervix, and vagina were capable of presenting antigen. CONCLUSION: These results suggest that the human FRT is an inductive site for immune responses. Regulation of antigen presentation in the reproductive tract may be important for protection against sexually transmitted diseases.

Antigen Presentation↗
PubMed1999

Zebrafish stat3 is expressed in restricted tissues during embryogenesis and stat1 rescues cytokine signaling in a STAT1-deficient human cell line.

Transcription factors of the STAT family are required for cellular responses to multiple signaling molecules. After ligand binding-induced activation of cognate receptors, STAT proteins are phosphorylated, hetero- or homodimerize, and translocate to the nucleus. Subsequent STAT binding to specific DNA elements in the promoters of signal-responsive genes alters the transcriptional activity of these loci. STAT function has been implicated in the transduction of signals for growth, reproduction, viral defense, and immune regulation. We have isolated and characterized two STAT homologs from the zebrafish Danio rerio. The stat3 gene is expressed in a tissue-restricted manner during embryogenesis, and larval development with highest levels of transcript are detected in the anterior hypoblast, eyes, cranial sensory ganglia, gut, pharyngeal arches, cranial motor nuclei, and lateral line system. In contrast, the stat1 gene is not expressed during early development. The stat3 gene maps to a chromosomal position syntenic with the mouse and human STAT3 homologs, whereas the stat1 gene does not. Despite a higher rate of evolutionary change in stat1 relative to stat3, the stat1 protein rescues interferon-signaling functions in a STAT1-deficient human cell line, indicating that cytokine-signaling mechanisms are likely to be conserved between fish and tetrapods. Dev Dyn 1999;215:352-370.

Amino Acid Sequence↗
PubMed2001

Molecular characterization of Menangle virus, a novel paramyxovirus which infects pigs, fruit bats, and humans.

Menangle virus (MenV), isolated in August 1997 following an outbreak of reproductive disease in a piggery in New South Wales, is the second previously unclassified member of the family Paramyxoviridae to be identified in Australia since 1994. Similar to Hendra virus (HeV), MenV appears to be a virus of fruit bats (flying foxes) in the genus Pteropus. No serological cross-reactivity was detected between MenV and other known paramyxoviruses and to facilitate virus classification a cDNA subtraction method was used to obtain viral-specific cDNA from MenV-infected cells. Cloning and sequencing of the products enabled the entire sequences of the NP, P/V, M, F, and HN genes to be determined. Comparison of the nucleotide and deduced amino acid sequences for each gene with members of the family Paramyxoviridae, determination of the P gene mRNA editing strategy, and phylogenetic analyses confirmed that MenV is a new member of the genus Rubulavirus. However the deduced protein sequence of MenV HN exhibited only limited sequence homology when compared with attachment proteins of other paramyxoviruses. Key differences within the amino acid residues considered important determinants of neuraminidase activity suggest MenV HN is unlikely to possess the same degree of neuraminidase activity characteristic of other rubulavirus and respirovirus HN proteins.

Amino Acid Sequence↗
PubMed2006

Isolation of myosin XI genes from the Closterium peracerosum-strigosum-littorale complex and analysis of their expression during sexual reproduction.

Myosins comprise a large superfamily of molecular motors that generate mechanical force in ATP-dependent interactions with actin filaments. On the basis of their conserved motor domain sequences, myosins can be divided into at least 17 classes, 3 of which (VIII, XI, XIII) are found in plants. Although full sequences of myosins are available from several species of green plants, little is known about the functions of these proteins. Additionally, sequence information for algal myosin is incomplete, and little attention has been given to the molecular evolution of myosin from green plants. In the present study, the Closterium peracerosum-strigosum-littorale complex was used as a model system for investigating a unicellular basal charophycean alga. This organism has been well studied with respect to sexual reproduction between its two mating types. Three types of partial sequences belonging to class XI myosins were obtained using degenerate primers designed to amplify motor domain sequences. Real-time polymerase chain reaction analysis of the respective myosin genes during various stages of the algal life cycle showed that one of the genes was more highly expressed during sexual reproduction, and that expression was cell-cycle-dependent in vegetatively grown cells.

Amino Acid Sequence↗
PubMed1992

Steroid metabolism by ovarian follicles and extrafollicular tissue of the guppy (Poecilia reticulata) during oocyte growth and gestation.

In the viviparous guppy, fertilization and gestation are intrafollicular. Fully developed embryos are ovulated at the end of gestation just prior to parturition. The metabolism in vitro of various radiolabeled steroid precursors by isolated ovarian follicles at various stages of the reproductive cycle and extrafollicular (EF) tissue of the guppy was investigated. While estradiol-17 beta was one of the end products of metabolism in vitellogenic follicles, 17 alpha, 20 beta-P and several 5-reduced metabolites were synthesized by postvitellogenic follicles. The yield of 17 alpha, 20 beta-P, however, was much lower than some 5 beta-reduced metabolites synthesized by postvitellogenic follicles. Gestation stage follicles rapidly converted the precursors into 5-reduced and polar 7-hydroxylated steroids, and their glucuronides. Although postpartum follicles showed very poor potential for steroid metabolism, they synthesized estradiol-17 beta from testosterone. These results demonstrate distinct changes occurring in the steroidogenic potential of the follicles during the reproductive cycle. Unlike in other viviparous vertebrates, no particular steroid seems to be involved in maintaining gestation in the guppy; all the steroid precursors are converted into highly polar metabolites and their conjugates during gestation, thereby facilitating their excretion. The EF ovarian tissue also synthesized 7-hydroxylated steroids and their glucuronides, providing evidence for the first time that the teleost ovarian EF tissue plays a role in steroidogenesis. The possible physiological significance of the synthesis of the novel polar steroids by the follicles and the EF tissue is discussed.

17-alpha-Hydroxyprogesterone↗
PubMed1987

Gonadal steroids and neurosecretion: facilitatory influence on LHRH and neuropeptide Y.

Luteinizing hormone releasing hormone (LHRH) is regarded as the primary hypothalamic signal that controls reproduction in the rat. Neuropeptide Y, a recently isolated hypothalamic peptide, appears to regulate LHRH secretion. Our studies show that gonadal steroids act in multiple ways to enhance the neurosecretory functions of each of these neuronal systems and, in addition, they promote excitation by NPY of LHRH release from the hypothalamic nerve terminals.

Animals↗
PubMed1994

Rat gonadotropin-releasing hormone (GnRH) receptor: tissue expression and hormonal regulation of its mRNA.

The binding of gonadotropin-releasing hormone (GnRH) to its receptor in the anterior pituitary gland is the key molecular interaction regulating the reproductive process of mammals. Here, we report the isolation of a cDNA representing this receptor from rat anterior pituitary and the regulation of expression of its mRNA. The rat GnRH receptor cDNA was composed of 2909 nucleotides and encoded a protein containing 327 amino acids having a seven transmembrane topology. Northern blot analysis on RNA from rat pituitary, ovary and testis showed four different transcripts (5.0, 4.5, 2.5 and 1.3 kb) of which the 5.0 kb form was most abundant. The levels of expression of the transcripts were found to be highest in the pituitary followed by the ovary and the testis (about 40% and 5% compared to pituitary, respectively). Using the more sensitive reverse transcriptase/PCR technique, we also detected GnRH receptor mRNA in the adrenal and the hypothalamus. Measurement of pituitary GnRH receptor mRNA levels (the 5.0 kb form) during the estrous cycle showed the lowest levels at estrus (1.0-fold), a 2.2 +/- 0.57 (mean +/- SEM) -fold increase at diestrus I, a 3.5 +/- 0.41-fold increase at diestrus II, a 2.6 +/- 0.34-fold increase on the morning of proestrus, and a 1.9 +/- 0.25-fold on the afternoon of proestrus. Removal of the ovaries led to a 2.7 +/- 0.29-fold increase in GnRH receptor mRNA levels in the pituitary gland; treatment of ovariectomized rats with estrogen resulted in a significant decrease in GnRH receptor mRNA levels. Our studies demonstrate ovarian regulation of GnRH receptor mRNA expression in the anterior pituitary gland.

Amino Acid Sequence↗
PubMed2005

Anti-Müllerian hormone initiates growth of human primordial follicles in vitro.

Survival and growth of follicles in human ovarian tissue is presently only performed with limited success. We evaluated the effect of anti-Müllerian hormone (AMH) and/or testosterone on follicular growth during a 4-week culture period using ovarian cortical tissue from six women in their reproductive years. The cortex of each biopsy was isolated and immediately cryopreserved upon collection and stored in liquid nitrogen. After thawing the tissue was placed in culture. After the culture period all follicles were counted on histological sections and classified for viability and stage of development. Based on evaluation of 6603 follicles it was found that the number of growing follicles significantly increased during the culture period as compared to the uncultured control, irrespective of the composition of the culture medium. Furthermore, significantly more follicles advanced to the primary and secondary stage (p<0.05) in tissue cultured with AMH (54%) as compared to tissue cultured in control medium (41%). The mean diameter of follicles classified as primary follicles was significantly enhanced in tissue cultured in the presence of AMH (p=0.002) and AMH plus testosterone (p<0.001) as compared to that observed in tissue cultured with control medium and medium containing testosterone alone. In contrast the mean diameter of the oocyte and its nucleus remained similar irrespective of culture medium. In conclusion, AMH seems to affect early stages of human follicular development by enhancing recruitment, survival and/or growth during a 4-week culture period.

Adult↗
PubMed2004

Safe and acceptable strategies for producing foreign molecules in plants.

The ability to express foreign genes using transgenic technologies has opened up options for producing large quantities of commercially important industrial or pharmaceutical products in plants. These technologies have made it possible to use well-developed systems of commercial agriculture that were developed principally to produce raw material for large-scale food, feed or processing applications for the production of foreign molecules. The possibility of the novel industrial or pharmaceutical molecules produced in such plants, or components derived from them, contaminating the environment and food chains has become especially controversial. This potential contamination has prompted detailed consideration of how such crops and the molecules that they produce can be effectively isolated and contained. First, the crop can be completely isolated physically from its food or feed counterpart during every aspect of its development and commercialization. Second, genetic isolation systems or genetic barriers that prevent normal reproduction can be used to reduce the likelihood of the industrial or pharmaceutical crop entering the food chain.

Biotechnology↗