Regulation Of Ovarian Function Research Articles

Identification of novel candidate genes for follicle selection in the broiler breeder ovary.

BackgroundBroiler breeders fed ad libitum are characterised by multiple ovulation, which leads to poor shell quality and egg production. Multiple ovulation is controlled by food restriction in commercial flocks. However, the level of food restriction raises welfare concerns, including that of severe hunger. Reducing the rate of multiple ovulation by genetic selection would facilitate progress towards developing a growth profile for optimum animal welfare.ResultsThe study utilised 3 models of ovarian follicle development; laying hens fed ad libitum (experiment 2) and broiler breeders fed ad libitum or a restricted diet (experiments 1 & 3). This allowed us to investigate gene candidates for follicular development by comparing normal, abnormal and “controlled” follicle hierarchies at different stages of development. Several candidate genes for multiple ovulation were identified by combining microarray analysis of restricted vs. ad libitum feeding, literature searches and QPCR expression profiling throughout follicle development. Three candidate genes were confirmed by QPCR as showing significant differential expression between restricted and ad libitum feeding: FSHR, GDF9 and PDGFRL. PDGFRL, a candidate for steroidogenesis, showed significantly up-regulated expression in 6–8 mm follicles of ad libitum fed broiler breeders (P = 0.016), the period at which follicle recruitment occurs.ConclusionsGene candidates have been identified and evidence provided to support a possible role in regulation of ovarian function and follicle number. Further characterisation of these genes will be required to assess their potential for inclusion into breeding programmes to improve the regulation of follicle selection and reduce the need for feed restriction.

The Ovarian Innervation Participates in the Regulation of Ovarian Functions

The release of gonadotropins is the main endocrine signal regulating ovulation and the release of hormones by the ovaries. Several types of growth factors modulate the effects of gonadotropins on the follicular, luteal and interstitial compartments of the ovaries. During the last 30 years, numerous studies have indicated that the ovarian innervations play a role in modulating the effects that gonadotropin have on the ovaries’ ability to ovulate and secrete steroid hormones. This literature review presents a summary of the experimental results obtained by analyzing the effects of stimulating or blocking the well-known neural pathways participating in the regulation of ovulation and secretion of steroid hormones. Together, the results suggest that various neurotransmitter systems modulate the effects of gonadotropins on ovulation and the ovaries capacity to secrete steroid hormones. In addition, the ovaries asymmetric capacity for ovulation and hormone secretion could be explained by the asymmetries in their innervations.

Androgens Stimulate Aromatase and P450scc in Primary Rat Granulosa Cells Independently of Follicle Stimulating Hormone.

INTRODUCTION It has long been recognized that androgens play an important role in the regulation of ovarian function. Outside of their use as substrate for estradiol production, it has been demonstrated that androgens themselves synergize with follicle stimulating hormone (FSH) to increase estradiol and progesterone production within granulosa cells (1, 2). Accordingly, granulosa cells express high levels of androgen receptor (AR). Recently, AR RESULTS

Immunohistochemical study on differential distribution of progesterone receptor A and progesterone receptor B within the porcine ovary

Progesterone plays a central role in the regulation of ovarian functions. Progesterone receptor (PGR) is expressed as two isoforms, PGRA and PGRB, which have been shown to have different functional activities. This immunohistochemical study describes the diverse localization of PGRA and PGRB in the porcine ovarian components: small and large antral follicles, early, midluteal and regressing corpora lutea. Ovaries were obtained from 10 cycling sows. PGRs were visualized by immunohistochemistry on paraffin sections using monoclonal antibodies against PGRA (clone 16) or PGRB (clone SAN 27). Moreover, to confirm the specificity of antibodies, Western blot analysis was performed. Nuclear staining for PGRs was observed in cells of granulosa and theca layer, corpora lutea and surface epithelium. Our results revealed that PGRA was the predominant PGR isoform in the pig ovary. In small antral follicles its expression was restricted to theca interna cells, but in large preovulatory follicles, both granulosa and theca layers stained for PGRA. In contrast, immunoreaction for PGRB isoform was limited to granulosa cells of large antral porcine follicles, while their theca layers were devoid of PGRB. The number of both PGRA and PGRB stained cells within the corpora lutea declined significantly during the luteal phase, which might be explained by the decreasing level of locally produced progesterone. The differential distribution and variations in the scores for PGRA and PGRB in various pig ovarian cell types during the cycle may reflect diverse functions for PGRA and PGRB as well as suggest a cell-specific influence of progesterone.

Role of melatonin on the regulation of ovarian function: new findings in Danio rerio

Event Abstract Back to Event Role of melatonin on the regulation of ovarian function: new findings in Danio rerio Oliana Carnevali1*, Giorgia Gioacchini1, Francesca Maradonna1, Ike Olivotto1 and Beatrice Migliarini1 1 Polytechnic University of Marche, Department of Marine Sciences, Italy Melatonin is involved in a number of activities including reproduction acting on hypothalamus , pituitary and gonads . The mechanism by which melatonin acts on the reproductive axis is still unknown although this hormone does not appear to have a direct influence on GnRH neurons. The nature of relationship between pineal melatonin and reproductive physiology remains controversial, in mammals the administration of melatonin may induce or inhibit reproduction depending on the species reproductive strategy: melatonin inhibits long day summer phenotype and induces a short day winter phenotype reproduction. In these latter species, melatonin is referred to as being progonadotrophic .Conflicting conclusions on the role of melatonin in the neuroendocrine system has been also found in teleost; administration of melatonin decreases LH β and FSHβ secretion in the ell and inhibits reproduction in catfish, trout, etc…while LH β is induced in kroacker, sea bass and carp. Recently, the antioxidant activity of melatonin have been found in the mammalian oocyte evidencing the beneficial effects of this hormone on reproductive physiology by improving oocyte quality. In zebrafish, we have demonstrated a clear positive role of melatonin in follicle growth and maturation. The large variability of the impact of melatonin on brain, pituitary and on gonadal factors observed among vertebrates will be discussed. Keywords: comparative endocrinology Conference: 25th Conference of the European Comparative Endocrinologists, Pécs, Hungary, 31 Aug - 4 Sep, 2010. Presentation Type: Conference Presentation Topic: Comparative endocrinology Citation: Carnevali O, Gioacchini G, Maradonna F, Olivotto I and Migliarini B (2010). Role of melatonin on the regulation of ovarian function: new findings in Danio rerio. Front. Endocrinol. Conference Abstract: 25th Conference of the European Comparative Endocrinologists. doi: 10.3389/conf.fendo.2010.01.00011 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 26 Aug 2010; Published Online: 29 Aug 2010. * Correspondence: Dr. Oliana Carnevali, Polytechnic University of Marche, Department of Marine Sciences, Ancona, Italy, o.carnevali@univpm.it Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Oliana Carnevali Giorgia Gioacchini Francesca Maradonna Ike Olivotto Beatrice Migliarini Google Oliana Carnevali Giorgia Gioacchini Francesca Maradonna Ike Olivotto Beatrice Migliarini Google Scholar Oliana Carnevali Giorgia Gioacchini Francesca Maradonna Ike Olivotto Beatrice Migliarini PubMed Oliana Carnevali Giorgia Gioacchini Francesca Maradonna Ike Olivotto Beatrice Migliarini Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Transcriptome analysis reveals an unexpected role of a collagen tyrosine kinase receptor gene,Ddr2,as a regulator of ovarian function

Mice homozygous for the smallie (slie) mutation lack a collagen receptor, discoidin domain receptor 2 (DDR2), and are dwarfed and infertile due to peripheral dysregulation of the endocrine system of unknown etiology. We used a systems biology approach to identify biological networks affected by Ddr2(slie/slie) mutation in ovaries using microarray analysis and validate findings using molecular, cellular, and functional biological assays. Transcriptome analysis indicated several altered gene categories in Ddr2(slie/slie) mutants, including gonadal development, ovulation, antiapoptosis, and steroid hormones. Subsequent biological experiments confirmed the transcriptome analysis predictions. For instance, a significant increase of TUNEL-positive follicles was found in Ddr2(slie/slie) mutants vs. wild type, which confirm the transcriptome prediction for decreased chromatin maintenance and antiapoptosis. Decreases in gene expression were confirmed by RT-PCR and/or qPCR; luteinizing hormone receptor and prostaglandin type E and F receptors in Ddr2(slie/slie) mutants, compared with wild type, confirm hormonal signaling pathways involved in ovulation. Furthermore, deficiencies in immunohistochemistry for DDR2 and luteinizing hormone receptor in the somatic cells, but not the oocytes, of Ddr2(slie/slie) mutant ovaries suggest against an intrinsic defect in germ cells. Indeed, Ddr2(slie/slie) mutants ovulated significantly fewer oocytes; their oocytes were competent to complete meiosis and fertilization in vitro. Taken together, our convergent data signify DDR2 as a novel critical player in ovarian function, which acts upon classical endocrine pathways in somatic, rather than germline, cells.

Ovarian follicle development in Booroola sheep exhibiting impaired bone morphogenetic protein signalling pathway

The role of bone morphogenetic proteins (BMPs) in the regulation of ovarian function has been extensively investigated but the mechanism of regulation is not well understood. The aim of this study was to investigate the effect of mutation in the BMP receptor in Booroola sheep on the number of primordial follicles and rate of follicle recruitment in comparison with that in normal merino sheep in vivo. Whole sheep ovaries at the time of birth, 1.5 and 5 years old were collected and processed for the follicle quantification, using computerised stereological methods and statistical analyses. At birth, the total number of primordial follicles in Booroola sheep was significantly lower than in merino sheep. At 1.5 and 5 years, a reversed pattern in favour of Booroola ewes was seen with significantly more primordial follicles than merino. In parallel, the rate of primordial follicle recruitment to developing cohort was substantially lower in Booroola ewes with only 51 and 66% of primordial follicle consumption at 1.5 and 5 years respectively compared to 92 and 97% in merino ewes. On other hand, the mean numbers of developing primary follicles were smaller in Booroola sheep at the time of birth, yet, Booroola ewes possess more primary follicles than merino at 1.5 years. These findings suggest that attenuation of the intraovarian signalling pathway of BMPs may in fact be a successful means of rationalising follicle consumption, preventing unnecessary loss of follicles from the initial primordial follicle pool, hence increasing reproductive longevity and fertility.

Localization of Estrogen Receptor Alpha and Progesterone Receptor B in the Bovine Ovary During the Follicular and Luteal Phase of the Sexual Cycle

Summary Ovarian steroid hormones, mainly estrogen and progesterone, play a central role in the regulation of ovarian functions. The biological effects of progesterone (PR) and estrogen (ER) are dependent on the activation of both PR and ER isoforms. In the present study, we studied the cellular distribution and localization of progesterone receptor B (PR-B) and estrogen receptor alpha (ERα) in the bovine ovaries during the follicular and luteal phases of the sexual cycle using immunohistochemical methods. The estrous cycle stage of 23 Holstein bovines was evaluated by gross and histological appearance of ovaries and blood steroid hormone values. Tissue samples from ovaries were fixed in 10% formaldehyde for routine histological processing. ERα immunoreactivity was observed in nuclei of granulosa cells of growing follicles at all stages from primary to mature follicles, epithelial cells of the germinal epithelium, stroma cells, theca cells, corpora lutea cells and cells of the corpora albicantia. Nuclear staining for PR-B was not detected in the granulosa cells in all sizes of follicles, but was positively stained in germinal epithelium cells, stroma cells, corpora albicantia cells and corpora lutea cells. In conclusion, ERα and PR-B immunoreactivity in bovine ovary were not indicate too much difference between the phases of the sexual cycle but have important differences in cell-spesific localization.

Receptors for thyroid-stimulating hormone and thyroid hormones in human ovarian tissue

Dysfunction in thyroid regulation can cause menstrual and ovulatory disturbances, the mechanism of which is not clear. The distribution and activity of the thyroid-stimulating hormone (TSHR), and the thyroid hormone receptors (TR) alpha1, alpha2 and beta1 in human ovarian tissue and in granulosa cells was studied using immunohistochemistry, reverse-transcriptase polymerase chain reaction (RT-PCR), quantitative PCR and immunoassays. Strong immunostaining of TSHR, TRalpha1 and TRbeta1 was observed in ovarian surface epithelium and in oocytes of primordial, primary and secondary follicles, with minimal staining in granulosa cells of secondary follicles. Granulosa cells of antral follicles expressed TSHR, TRalpha1 and TRbeta1 proteins. Messenger RNA for all receptors was present in ovarian tissue. Mature human granulosa cells expressed transcripts for 5' deiodinases types 2 and 3, but not type 1, indicating the possibility of conversion of peripheral thyroid hormone thyroxin (T(4)). Granulosa cells stimulated with TSH showed a significant increase in cAMP concentrations after 2 h of culture (P = 0.047), indicating activation through TSHR. Stimulation with T(4) resulted in increased extracellular signal-regulated kinase 1 and 2 activation after 10, 30, 60 min and 24 h. These data demonstrate that TSH and thyroid hormone receptors may participate in the regulation of ovarian function.

Effect of GnRH antagonist on primordial follicle survival in the primate ovary

OBJECTIVE: Among the autocrine/paracrine regulators of ovarian function that have been identified, the role of the GnRH/GnRH receptor system in the ovary has received renewed interest. Direct effects of GnRH analogs on the rodent ovary are well established, however a role for GnRH analogs in the primate ovary is less clear. We have demonstrated a rapid and pronounced destruction of primordial follicles in the mouse ovary by short-term treatment with GnRH antagonists (Fertil Steril 2005; 83:1333).

Molecular characterization of follicle stimulating hormone receptor (FSHR) gene in the Indian river buffalo ( Bubalus bubalis)

Follicle stimulating hormone (FSH) plays a central role in regulation of ovarian function in mammals. The actions of follicle stimulating hormone are mediated through receptors present on the granulosa cells of the ovary. In the present study we have cloned and characterized the FSHR gene of buffalo. Sequence analysis indicated that the buffalo FSHR cDNA sequence comprised of an open reading frame of 2085 bp encoding a 695 amino acid protein. Its nucleotide sequence showed more than 80% similarity to the homologous genes of mammalian species. At amino acid level buffalo FSHR exhibited a high percentage (84–96.7%) of identity with the corresponding mammalian homologs. This is the first isolation and characterization of FSHR cDNA from buffalo ovary.

The Role of BMP Signalling Pathway in the Regulation of Ovarian Follicle Development.

Bone morphogenetic proteins (BMPs) regulation of ovarian function has been investigated in several animal models, demonstrating their role in primordial germ cell formation, primordial-to-primary follicle recruitment, follicle development, steroidogenesis and ovulation. However, the mechanism by which BMPs regulate individual processes of ovarian function is not well understood. The aim of this study was to investigate the effect of the BMP receptor mutation in Booroola sheep on primordial follicle formation and rate of recruitment in comparison to that in normal merino sheep in vivo. Whole ovaries from Booroola and merino sheep at birth, 1.5 years and 5 years of age were obtained by bilateral ovariectomy and processed for the quantification of primordial and primary follicles using computerised stereological methods (Stereo Investigator Software Version 7, MicroBrightField, Inc.) and JMP 6 statistical package (SAS Institute Inc, 2005). Regardless of animal strain, the overall absolute number of primordial and primary follicles per ovary of newborn sheep was considerably higher than in the 1.5 and 5-year old ewes. Log transformed data analyses revealed that the total number of primordial follicles in newborn Booroola sheep was significantly (P=0.0065) lower than in merino of the same age. At 1.5 years a trend showing a considerable reversal in the number of primordial follicles was observed in Booroola ewes, which then significantly (p<0.0036) increased at 5 years of age. The rate of primordial follicle recruitment was substantially lower in Booroola ewes compared with that in merino, as reflected by the difference in the absolute number of primordial follicles remaining at 1.5 and 5 years of age. Immediately after birth, the mean total number of primordial follicles in Booroola strain was only 36% of that present in the merino strain. This ratio became 207% and 367% at 1.5 and 5 years, respectively. The ratios of primordial follicle consumption in Booroola ewes were 51% and 66% up to the age of 1.5 and 5 years respectively compared to 92% and 97% of primordial follicles have been used in merino ewes. On the other hand, the mean numbers of primary follicles per ovary in newborn animals was similar in both sheep strains. However, at 1.5 years, Booroola ewes possess more primary follicles than merino, and the absolute number of primary follicles present at 1.5 years was equal to 26% of the number present at birth, compared with only 8% of primary follicles present in merino ewes. At 5 years of age the primary follicles were not counted in either animal strain. These findings suggest that attenuation of the intraovarian signaling pathway of BMPs may in fact be a successful means of rationalizing follicle consumption, preventing unnecessary loss of follicles from the initial follicle pool, hence increasing reproductive age and fertility.

Integration of physiological mechanisms that influence fertility in dairy cows

Fertility in dairy cows has been declining for the past three decades. Genetic selection for increased milk production has been associated with changes in key metabolic hormones (growth hormone, insulin, IGF and leptin) that regulate metabolism by homoeostasis and homeorhesis. These metabolic hormones, particularly insulin, provide signals to the reproductive system so that regulation of ovarian function is coordinated with changes in metabolic status. Studies have shown, for example, that increasing circulating insulin concentrations during the early postpartum period can advance the resumption of oestrous cycles by enhancing follicular growth. However, high concentrations of insulin can be detrimental to the developmental competence of oocytes, which is also influenced by the supply of fatty acids at the systemic level and at the ovarian level. Insulin status is also associated with the incidence and characteristics of abnormal ovarian cycles. These changes can occur without significant variation in circulating gonadotrophin concentrations. This suggests that additional factors, such as peripheral metabolites, metabolic hormones and locally produced growth factors, may have a modulating role. Recent evidence has demonstrated that ovarian responses to metabolic signals and nutrient profile vary according to the stage of the reproductive cycle. Improved understanding of this multifactorial process enables nutrition to be matched to genotype and milk production, with a positive impact on pregnancy rate.

267. A role for transforming growth factor-β 1 (TGF-β1) during the establishment of folliculogenesis

A group of structurally related proteins, known as the transforming growth factor-β (TGF- β) superfamily, have been implicated in the local regulation of ovarian function. It is unclear what role TGF-β1–3 plays in folliculogenesis during the period after birth in the rat. We investigated whether the TGF-β ligands and their receptors were present during this period of development and the effects of TGF-β1 on granulosa cell function (proliferation, apoptosis, steroidogenesis). Ovaries from rats 4, 8 and 12 days of age were isolated and RNA extracted and reverse transcribed for real-time PCR. The expression of the TGF-β ligands and TGFβRI and TGFβRII were measured. Granulosa cells isolated from DES treated immature rats were treated with FSH (100ng/mL) and TGF-β1 (1 or 10ng/mL) for 2hr, n = 4 replicates. The RNA was extracted and prepared for RT–PCR. The expression of cyclin D2, FKHR, SCC, 3βHSD and StAR were measured. TGFβRI and TGFβRII proteins were localised to postnatal rat ovary by immunohistochemistry. TGF-β1–3, TGFβRI and TGFβRII were present in rat ovaries as early as 4 days after birth. Expression of TGF-β1 mRNA increased 2-fold between day 4 and 12. TGF-β2 and TGF-β3 mRNAs declined between day 4 and 8 and remained low at day 12. The type I and II TGF-β receptors were differentially regulated with TGFβRI expression high at day 4, declining at day 8. In contrast, TGFβRII appeared to be ubiquitously expressed. Cyclin D2 mRNA expression was enhanced in the presence of both TGF-β1 and FSH, whereas FKHR mRNA expression declined. TGF-β1 had no impact on the steroidogenic mRNAs. TGFβRI and TGFβRII proteins were localised to the cytoplasm of oocytes, granulosa cells and theca cells. These studies indicate that TGF-β1 can exert effects on ovarian folliculogenesis as it is established during the postnatal period. Proliferation and apoptosis appear to be targets of TGF-β1 action. Supported by the NHMRC of Australia (Regkeys 241000, 198705, 441101 &amp; 465415)

Role of photoperiod and melatonin in the regulation of ovarian functions in Indian carp Catla catla: basic information for future application

The major carp Catla catla is a popular freshwater edible fish and an extensively cultured species in India. However, basic information on the physiology of reproduction is lacking in this species. By virtue of its surface feeding habit, it maintains close contact with environmental light, and is a species of choice for the study of temporal organization of reproduction under natural and experimental conditions for understanding environmental and/or endocrine mechanisms that control the annual reproductive cycle. The present review covers information gathered in recent years to emphasize the temporal pattern of reproductive events and the importance of photoperiod and melatonin, a hormone of the pineal gland that links the environment with the endocrine system in the regulation of reproduction. Finally, the outcome of the research is discussed in terms of its direct and indirect applications to aquaculture of this species with a view to manipulate its breeding at a desired time of the year to meet market demand.

Mutational analysis of BMP15 and GDF9 as candidate genes for premature ovarian failure

Mutational screening of the bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) genes in a population with premature ovarian failure (POF) identified no new mutations. However, three single nucleotide polymorphisms in the BMP15 gene, two in the 5' untranslated region (31T>G and 71C>G) and another in exon 1 (387G>A), were found to be common in both POF and control groups.

Regulation of ovarian function by lymphocyte-parenchymal interactions

Regulation of ovarian function by lymphocyte-parenchymal interactions

Immune system involvement in the regulation of ovarian function and augmentation of cancer

Increasing evidence indicates a role for the immune system and mesenchymal-epithelial interactions in the regulation of ovarian function. Cytokines produced by mesenchymal cells can stimulate development and regression of ovarian structures. We report here that mesenchymal cells releasing surface molecules among epithelial cells--namely vascular pericytes and monocyte-derived cells (MDC)--and intraepithelial T lymphocytes are associated with oogenesis and formation of new primary follicles in both fetal and adult human ovaries. These activated mesenchymal cells interact with the ovarian surface epithelium, which appears to be a source of secondary germ cells and granulosa cells. Activated pericytes and MDC are also associated with stimulation of thecal development during selection of growing secondary follicles from the cohort of primary follicles. However, survival of the dominant follicle during mid-follicular phase selection is associated with a lack of activity of mesenchymal cells and retardation of thecal development, since immature granulosa cells lacking aromatase are unable to resist high levels of thecal androgens. Once the selected follicle matures (late follicular phase), it shows enhanced activity of thecal mesenchymal cells and advanced thecal development. Corpus luteum (CL) development is accompanied by a high activity of vascular pericytes and MDC. In mature CL and CL of pregnancy, luteal MDC and pericytes show a stable (inactive) state. Regression of the CL is associated with regression of pericytes, transformation of MDC into dendritic cells, infiltration by T lymphocytes, and binding of immunoglobulin G to the luteal cells. The immunoglobulin M (IgM) binds to young but not mature luteal cells. In the CL of pregnancy, IgM binds to luteal vessels, but not to luteal cells. Regressing CL shows IgM binding to both luteal cells and vessels. In ovarian cancers, highly activated MDC and sometimes activated pericytes (poorly differentiated carcinomas) are present. IgM binding is similar to that seen in the CL of pregnancy. These data indicate that vascular pericytes, MDC, T cells, and immunoglobulins may play an important role in the regulation of ovarian physiology and contribute to the augmentation of ovarian cancer growth.

Null Mutation in Transforming Growth Factor β1 Disrupts Ovarian Function and Causes Oocyte Incompetence and Early Embryo Arrest

TGFbeta1 is implicated in regulation of ovarian function and the events of early pregnancy. We have investigated the effect of null mutation in the Tgfbeta1 gene on reproductive function in female mice. The reproductive capacity of TGFbeta1 null mutant females was severely impaired, leading to almost complete infertility. Onset of sexual maturity was delayed, after which ovarian function was disrupted, with extended ovarian cycles, irregular ovulation, and a 40% reduction in oocytes ovulated. Serum FSH and estrogen content were normal, but TGFbeta1 null mutant mice failed to display the characteristic proestrus surge in circulating LH. Ovarian hyperstimulation with exogenous gonadotropins elicited normal ovulation rates in TGFbeta1 null mutant mice. After mating with wild-type stud males, serum progesterone content was reduced by 75% associated with altered ovarian expression of mRNAs encoding steroidogenic enzymes 3beta-hydroxysteroid dehydrogenase-1 and P450 17 alpha-hydroxylase/C17-20-lyase. Embryos recovered from TGFbeta1 null mutant females were developmentally arrested in the morula stage and rarely progressed to blastocysts. Attempts to rescue embryos by exogenous progesterone administration and in vitro culture were unsuccessful, and in vitro fertilization and culture experiments demonstrated that impaired development is unlikely to result from lack of maternal tract TGFbeta1. We conclude that embryo arrest is due to developmental incompetence in oocytes developed in a TGFbeta1-deficient follicular environment. This study demonstrates that TGFbeta1 is a critical determinant of normal ovarian function, operating through regulation of LH activity and generation of oocytes competent for embryonic development and successful initiation of pregnancy.

α 1-Adrenergic receptor in rat ovary: Presence and localization

Noradrenaline modulates ovarian steroidogenesis, stimulates ovulation, and probably promotes follicular development in the ovary. It has been suggested that these effects of noradrenaline are mediated by α- and/or β-adrenergic receptors (ARs) in the ovary. The purpose of the present study was to examine whether α 1-AR is present in the rat ovary. In Western blotting, antibody against α 1-ARs recognized a major protein in the ovary of adult (10-week-old) rats with a molecular weight of 80 kDa, which is similar to that of the α 1B-AR subtype. Immunohistochemistry using this antibody showed that α 1-AR was detected at various sites in the ovary, including large antral follicle, germinal epithelium at the circumference of large antral follicle, corpus luteum, and interstitial tissue. These results confirm that the ovary contains α 1-AR (probably α 1B-subtype), and suggest that this receptor mediates some of the activities of noradrenaline in the regulation of ovarian functions. Furthermore, we found that α 1-AR is present in oocyte of large antral follicle, suggesting that noradrenaline acts on oocyte via this receptor.