Oral exposure to bisphenol S is associated with alterations in the oviduct proteome of an ovine model, with aggravated effects in overfed females.

BACKGROUND: Bisphenol S (BPS) is a substitute for bisphenol A in plastic manufacturing and, as a potential endocrine disruptor, may alter the physiology of the oviduct, in which fertilization and early embryo development take place in mammals. The objective of this study was to assess the effect of a daily dietary exposure to BPS combined with a contrasted diet on the oviduct fluid proteome using an ovine model. RESULTS: Eighty adult cyclic ewes were allotted to four groups (20/group): overfed (OF) consuming 50 µg/kg/day of BPS in their diet, underfed (UF) consuming 50 µg/kg/day of BPS, and non-exposed controls in each diet group. After three months, the mean body condition score, plasma levels of glucose and non-esterified fatty acids were significantly higher in OF than in UF females. The proteins in collected OF samples (50 µg) were analyzed by nanoliquid chromatography coupled with tandem mass spectrometry (nanoLC-MS/MS). Overall, 1563 proteins were identified, among which 848 were quantified. Principal component analysis of the data revealed a clear discrimination of samples according to the diet and a segregation between BPS-exposed and non-exposed females in overfed ewes. Hierarchical clustering of differentially abundant proteins (DAPs) identified two clusters of 101 and 78 DAPs according to the diet. Pairwise comparisons between groups revealed a stronger effect of BPS in OF than in UF females (70 vs. 24 DAPs) and a stronger effect of the diet in BPS-exposed than non-exposed females (56 vs. 36 DAPs). Functional analysis of DAPs showed an enrichment in metabolic processes, immune system, cell response to stress, and reproductive processes. CONCLUSIONS: This work highlights for the first time the important impact of BPS on the oviduct proteome, with larger effects seen in OF than UF females. These results, together with previous ones, raise health concerns for everyone and call for a greater regulation of BPS in the food industry.

Role and action mechanisms of tPA in CRH-induced apoptosis of mouse oviductal epithelial and mural granulosa cells.

Understanding how stress hormones induce apoptosis in oviductal epithelial cells (OECs) and mural granulosa cells (MGCs) can reveal the mechanisms by which female stress impairs embryonic development and oocyte competence. A recent study showed that tissue plasminogen activator (tPA) ameliorates corticosterone-induced apoptosis in MGCs and OECs by acting on its receptors low-density lipoprotein receptor-related protein 1 (LRP1) and Annexin A2 (ANXA2), respectively. However, whether tPA is involved in corticotropin-releasing hormone (CRH)-induced apoptosis and whether it uses the same or different receptors to inhibit apoptosis induced by different hormones in the same cell type remains unknown. This study showed that CRH triggered apoptosis in both OECs and MGCs and significantly downregulated tPA expression. Moreover, tPA inhibits CRH-induced apoptosis by acting on ANXA2 in both OECs and MGCs. While ANXA2 inhibits apoptosis via phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling, LRP1 reduces apoptosis via mitogen-activated protein kinase (MAPK) signaling. Thus, tPA used the same receptor to inhibit CRH-induced apoptosis in both OECs and MGCs, however used different receptors to inhibit corticosterone-induced apoptosis in MGCs and OECs. These data helps understand the mechanism by which female stress impairs embryo/oocyte competence and proapoptotic factors trigger apoptosis in different cell types.

Exposure to atrazine and endosulfan alters oviductal adenogenesis in the broad-snouted caiman (Caiman latirostris).

The molecular pathways involved in oviductal adenogenesis are highly conserved among vertebrates. In this work, we study the histomorphological changes and molecular pathways involved in Caiman latirostris oviductal adenogenesis and the effects of in ovo exposure to environmentally relevant doses of endosulfan (END) and atrazine (ATZ) on these processes. To this end, the histomorphological changes at epithelial and subepithelial compartments, the protein expressions of ß-catenin and Wnt-7a, and the gene expression of metalloproteinases (MMPs) and its inhibitors (TIMPs) were evaluated as biomarkers of oviductal adenogenesis in prepubertal juvenile C. latirostris. Exposure to END altered adenogenesis-related epithelium characteristics and mRNA expression of MMP2, MMP9, and TIMP1. Exposure to ATZ increased the width of the subepithelial stroma with loosely arranged collagen fibers and increased ß-catenin expression in buds (invaginated structures that precede glands). The results demonstrate that in ovo exposure to ATZ and END alters oviductal adenogenesis at tissue, cellular, and molecular levels. An altered oviductal adenogenesis could impair fertility, raising concern on the effects of pesticide pollution in wildlife and domestic animals.

El consumo semicrónico moderado de alcohol altera la foliculogénesis y la calidad núcleo-citoplasmática oocitaria, en el ratón / Moderate semi-chronic alcohol consumption alters folliculogenesis and oocyte nuclear-cytoplasmic quality in mice

Resumen El consumo crónico de alcohol es un problema de salud mundial que afecta particularmente a la población femenina. Sin embargo, los efectos de la ingesta semicrónica en cantidades moderadas a bajas en el ovario y el oocito son poco conocidos. En un modelo murino, se administró etanol al 10% en agua de bebida (hembras tratadas) o agua (hembras control) por 15 días, y luego de la superovulación o no (ovulación espontánea), se analizó el ciclo estral y la calidad ovárico-gamética. En las hembras tratadas, la frecuencia y duración del diestro aumentó, y las frecuencias de folículos y cuerpos lúteos disminuyeron vs hembras controles, valores que se restauraron luego de la superovulación. Sin embargo, en las hembras tratadas, la tasa de proliferación celular folicular y el desbalance de la expresión ovárica de VEGF (factor de crecimiento endotelial) persistieron luego de la superovulación. El número de ovocitos ovulados con metafase II anormal, fragmentados y activados partenogenéticamente fue mayor en las hembras tratadas respecto las controles. En conclusión, el consumo semicrónico moderado de alcohol produce anestro, ciclo estral irregular, foliculogénesis deficiente y anomalías núcleo-citoplasmáticas en los oocitos ovulados. Estas alteraciones podrían constituirse en un factor etiológico de pérdida gestacional temprana y desarrollo embrionario anormal luego del consumo de alcohol.

Abstract Chronic alcohol consumption is a global health problem that particularly affects the female population. However, the ef-fects of semi-chronic ethanol intake in low-moderate amounts on the ovary and oocyte are poorly understood. In a mouse model, 10% ethanol was administered in drinking water (treated females) or water (control females) for 15 days, and after superovulation or not (spontaneous ovulation), the estrous cycle and ovarian-gametic quality were analyzed. In treated females, the frequency and duration of the diestrus increased, and the frequencies of follicles and corpus luteum decreased vs control females, values that restored after superovulation. However, in treated females, the follicular cell proliferation rate and the imbalance in ovarian expression of VEGF (endothelial growth factor) persisted after superovulation. The number of ovulated oocytes with abnormal metaphase II, fragmented and parthenogenetically activated was higher in treated females than in control ones. In conclusion, moderate semi-chronic alcohol consumption produces anestrum, irregular estrous cycle, poor folliculogenesis, and nuclear-cytoplasmic abnormalities in ovulated oocytes. These alterations could constitute an etiological factor of early gestational loss and abnormal embryonic development after alcohol consumption.

Isolation and characterization of FMRFamide-like peptides in the venoms of solitary sphecid wasps.

Purification of small peptide components in the venoms of the solitary sphecid wasps, Sphex argentatus argentatus and Isodontia harmandi, led to the isolation of several major peptides. Analysis of MS/MS spectra by MALDI-TOF/TOF revealed the sequence of a new peptide Sa112 (EDVDHVFLRF-NH2), which is structurally very similar to leucomyosupressin (pQDVDHVFLRF-NH2) and SchistoFLRFamide (PDVDHVFLRF-NH2), the FMRFamide-like peptides from cockroach and locust, respectively. Indeed, this new peptide, like SchistoFLRFamide, inhibited the frequency and amplitude of spontaneous contractions of the locust oviduct in a dose-dependent manner. A non-amidated peptide Sa12b (EDVDHVFLRF) was also isolated, but this peptide had no effect on spontaneous locust oviduct contraction. This is the first example of a FMRF-like peptide to be found in solitary wasp venom. Additionally, a truncated form of the myosuppressins, which has previously been synthesized and tested for biological activity, DVDHVFLRF-NH2 (Sh5b), was found for the first time as a natural product. Four other novel peptides were isolated and characterized as Sa81 (EDDLEDFNPTVS), Sa10 (EDDLEDFNPTIA), Sh41 (DDLSDFNPKV), and Sh42 (EDDLSDFNPKV). They are structurally related to each other, having a high content of acidic amino acids, but no structural similarity to any known peptides. Ion channel associated activities of Sh41 and Sh42 were tested, but did not show any activity for Na+, K+, Ca2+ channels.

Induction of reproductive activity and egg production by gonadotropin-releasing hormone in non-laying hens.

The current study was conducted to evaluate the effects of gonadotropin-releasing hormone (GnRH) analogue (Receptal) injection on reproductive traits of fully mature layers hens (32 weeks) suffered from inactive ovaries. Ninety-six non-laying hens (TETRA-SL brown egg layers), selected from a commercial flock, with similar body weight, were randomly assigned to four groups (n = 24). Hens in the 1st group served as a control. Hens of the 2nd, 3rd and 4th groups were individually intramuscularly injected every 4 days with 50, 100 and 150 µl of Receptal solution, respectively, for two times. The results stated that the injection of Receptal induced the non-laying hens to produce eggs, but control birds did not produce eggs during the experimental period. The distance between pelvic bones and between the pelvic bone and keel bone of hens was significantly improved (p < .001) in groups received different GnRH levels compared with the control group. The best results were observed in the group injected with 100 µl Receptal. Levels of LH, FSH, oestrogen and progesterone hormones were significantly (p < .05) higher in Receptal-treated groups than in the control group. Hens injected with Receptal had an increase in ovary%, yellow follicles number, oviduct% and oviduct length (p < .001) compared with the control. It was concluded that treating inactive ovaries in non-laying hens with GnRH injections for two times, 4-day intervals, is an effective procedure for inducing egg production and useful in cost reduction in layer farms, and the group treated with 100 µl Receptal had the best results.

Exposure to xenoestrogens alters the expression of key morphoregulatory proteins of oviduct adenogenesis in the broad-snouted caiman (Caiman latirostris).

Endocrine disrupting compounds (EDCs) are contaminants ubiquitously found in the environment, which pose a potential threat to aquatic and wetland ecosystems. Caiman latirostris, a crocodilian species that inhabits South American wetlands, is highly sensitive to EDC exposure. Previously, we reported that early postnatal exposure to EDCs such as Bisphenol A (BPA) and 17ß-Estradiol (E2) alters C. latirostris oviduct differentiation. The aim of this work was to elucidate the molecular mechanisms behind this alteration. To accomplish this, we established the ontogenic changes in histological features and the expression of Wnt-7a, Wnt-5a, ß-catenin, FoxA2, desmin, and alpha smooth muscle actin (α-SMA) in the oviduct of C. latirostris. Then, we evaluated the effects of BPA and E2 exposure on these histological features and protein expressions. Our results showed that during the postnatal differentiation of the oviduct the presence of histological features related to adenogenesis is associated with the levels of expression of FoxA2, ß-catenin, Wnt-5a and Wnt-7a. Early postnatal exposure to BPA and E2 decreased the presence of histological features related to adenogenesis and altered the levels of expression of FoxA2, ß-catenin, Wnt-5a and Wnt-7a, as well as the desmin/α-SMA ratio. These findings suggest that altered levels of Wnt-7a, Wnt-5a, ß-catenin and FoxA2 could play a role in the BPA and E2-induced alteration in oviduct differentiation in C. latirostris. Thus, impaired adenogenesis and, probably, impaired reproduction in wildlife naturally exposed to BPA and other estrogenic agonists cannot be completely ruled out.

Altering the Microbiome Inhibits Tumorigenesis in a Mouse Model of Oviductal High-Grade Serous Carcinoma.

Studies have shown bacteria influence the initiation and progression of cancers arising in sites that harbor rich microbial communities, such as the colon. Little is known about the potential for the microbiome to influence tumorigenesis at sites considered sterile, including the upper female genital tract. The recent identification of distinct bacterial signatures associated with ovarian carcinomas suggests microbiota in the gut, vagina, or elsewhere might contribute to ovarian cancer pathogenesis. Here, we tested whether altering the microbiome affects tumorigenesis in a mouse model of high-grade serous carcinoma (HGSC) based on conditional oviduct-specific inactivation of the Brca1, Trp53, Rb1, and Nf1 tumor suppressor genes. Cohorts of control (n = 20) and antibiotic-treated (n = 23) mice were treated with tamoxifen to induce tumor formation and then monitored for 12 months. The antibiotic cocktail was administered for the first 5 months of the monitoring period in the treatment group. Antibiotic-treated mice had significantly fewer and less advanced tumors than control mice at study endpoint. Antibiotics induced changes in the composition of the intestinal and vaginal microbiota, which were durable in the fecal samples. Clustering analysis showed particular groups of microbiota are associated with the development of HGSC in this model. These findings demonstrate the microbiome influences HGSC pathogenesis in an in vivo model that closely recapitulates the human disease. Because the microbiome can modulate efficacy of cancer chemo- and immunotherapy, our genetically engineered mouse model system may prove useful for testing whether altering the microbiota can improve the heretofore poor response of HGSC to immunotherapies. SIGNIFICANCE: This study provides strong in vivo evidence for a role of the microbiome in ovarian cancer pathogenesis.

Cell-type specific analysis of physiological action of estrogen in mouse oviducts.

One of the endogenous estrogens, 17ß-estradiol (E2 ) is a female steroid hormone secreted from the ovary. It is well established that E2 causes biochemical and histological changes in the uterus. However, it is not completely understood how E2 regulates the oviductal environment in vivo. In this study, we assessed the effect of E2 on each oviductal cell type, using an ovariectomized-hormone-replacement mouse model, single-cell RNA-sequencing (scRNA-seq), in situ hybridization, and cell-type-specific deletion in mice. We found that each cell type in the oviduct responded to E2 distinctively, especially ciliated and secretory epithelial cells. The treatment of exogenous E2 did not drastically alter the transcriptomic profile from that of endogenous E2 produced during estrus. Moreover, we have identified and validated genes of interest in our datasets that may be used as cell- and region-specific markers in the oviduct. Insulin-like growth factor 1 (Igf1) was characterized as an E2 -target gene in the mouse oviduct and was also expressed in human fallopian tubes. Deletion of Igf1 in progesterone receptor (Pgr)-expressing cells resulted in female subfertility, partially due to an embryo developmental defect and embryo retention within the oviduct. In summary, we have shown that oviductal cell types, including epithelial, stromal, and muscle cells, are differentially regulated by E2 and support gene expression changes, such as growth factors that are required for normal embryo development and transport in mouse models. Furthermore, we have identified cell-specific and region-specific gene markers for targeted studies and functional analysis in vivo.

Progesterone induces porcine sperm release from oviduct glycans in a proteasome-dependent manner.

In mammals, the oviduct retains sperm, forming a reservoir from which they are released in synchrony with ovulation. However, the mechanisms underlying sperm release are unclear. Herein, we first examined in greater detail the release of sperm from the oviduct reservoir by sex steroids, and secondly, if the ubiquitin-proteasome system (UPS) mediates this release in vitro. Sperm were allowed to bind to oviductal cells or immobilized oviduct glycans, either bi-SiaLN or a suLeX, and channeled with steroids in the presence or absence of proteasome inhibitors. Previously, we have demonstrated progesterone-induced sperm release from oviduct cells and immobilized glycans in a steroid-specific manner. Herein, we found that the release of sperm from an immobilized oviduct glycan, a six-sialylated branched structure, and from immobilized fibronectin was inhibited by the CatSper blocker NNC 055-0396, akin to the previously reported ability of NNC 055-0396 to inhibit sperm release from another oviduct glycan, sulfated Lewis-X trisaccharide. Thus, CatSper may be required for release of sperm from a variety of adhesion systems. One possible mechanism for sperm release is that glycan receptors on sperm are degraded by proteasomes or shed from the sperm surface by proteasomal degradation. Accordingly, the inhibition of proteasomal degradation blocked sperm release from oviduct cell aggregates both immobilized oviduct glycans as well as fibronectin. In summary, progesterone-induced sperm release requires both active CatSper channels and proteasomal degradation, suggesting that hyperactivation and proteolysis are vital parts of the mechanism by which sperm move from the oviduct reservoir to the site of fertilization.

The growth hormone and insulin-like growth factor 1 axis in cattle during the peri-ovulatory period activates the synthesis and release of oviductal contraction related substances.

Growth hormone (GH) and insulin-like growth factor 1 (IGF1) are crucial for female reproductive functions. The cyclic regulation of the local GH/IGF1 axis in the oviduct and its involvement in oviductal contraction in cattle has not been investigated. Thus, the messenger RNA (mRNA) expression for GH receptor (GHR), IGF1, IGF1 receptor (IGF1R) in the whole oviducts, as well as in cultured bovine oviductal epithelial cells (BOECs) were evaluated. The GHR, IGF1, and IGF1R mRNA expression was significantly higher during postovulatory phase. The luteinizing hormone (LH), estradiol-17ß (E2), and LH + E2 treatments significantly increased GHR and IGF1 mRNA expression in cultured BOECs. Further, GH and combination of GH with LH and E2 upregulated IGF1 mRNA expression in the BOECs. Moreover, IGF1 + LH and combined IGF1 + LH + E2 treatments significantly increased prostaglandin synthesis cascade enzyme mRNA expression in the BOECs. An ex vivo microdialysis assay revealed that GH and IGF1 induced the release of oviductal contraction related prostaglandins, endothelin-1, and angiotensin II in follicular and postovulatory phases. Together, the findings strongly suggest that the presence of the active GH/IGF1 axis during the peri-ovulatory period, regulating the local system for the release of oviductal contraction related substances, which may provide the optimal oviductal environment for gametes and early embryo.

Chemical and functional analyses of Rhinella icterica (Spix, 1824) toad secretion screened on contractions of the heart and oviduct in Locusta migratoria.

Rhinella icterica is a Brazilian toad with a parotoid secretion that is toxic to insects. In this work, we examined the entomotoxicity of this secretion in locust (Locusta migratoria) semi-isolated heart and oviduct preparations in vitro. The parotoid secretion caused negative chronotropism in semi-isolated heart preparations (at the highest dose tested: 500 µg) and markedly enhanced the amplitude of spontaneous contractions and tonus of oviduct muscle (0.001-100 µg). In addition, the secretion enhanced neurally-evoked contractions of oviduct muscle, which was more sensitive to low concentrations of secretion than the semi-isolated heart. The highest dose of secretion (100 µg) caused neuromuscular blockade. In zero calcium-high magnesium saline, the secretion still enhanced muscle tonus, suggesting the release of intracellular calcium to stimulate contraction. Reverse-phase HPLC of the secretion yielded eight fractions, of which only fractions 4 and 5 affected oviduct muscle tonus and neurally-evoked contractions. No phospholipase A2 activity was detected in the secretion or its chromatographic fractions. The analysis of fractions 4 and 5 by LC-DAD-MS/MS revealed the following chemical compounds: suberoyl arginine, hellebrigenin, hellebrigenin 3-suberoyl arginine ester, marinobufagin 3-pimeloyl arginine ester, telocinobufagin 3-suberoyl arginine ester, marinobufagin 3-suberoyl arginine ester, bufalin 3-adipoyl arginine, marinobufagin, bufotalinin, and bufalitoxin. These findings indicate that R. icterica parotoid secretion is active in both of the preparations examined, with the activity in oviduct possibly being mediated by bufadienolides.

Extracellular Vesicles from Follicular and Ampullary Fluid Isolated by Density Gradient Ultracentrifugation Improve Bovine Embryo Development and Quality.

Extracellular vesicles (EVs) have been isolated from follicular (FF) and ampullary oviduct fluid (AOF), using different isolation methods. However, it is not clear whether different purification methods can affect the functionality of resulting EVs. Here, we compared two methods (OptiPrep™ density gradient ultracentrifugation (ODG UC) and single-step size exclusion chromatography (SEC) (qEV IZON™ single column)) for the isolation of EVs from bovine FF and AOF. Additionally, we evaluated whether the addition of EVs derived either by ODG UC or SEC from FF or AOF during oocyte maturation would yield extra benefits for embryo developmental competence. The characterization of EVs isolated using ODG UC or SEC from FF and AOF did not show any differences in terms of EV sizes (40-400 nm) and concentrations (2.4 ± 0.2 × 1012-1.8 ± 0.2 × 1013 particles/mL). Blastocyst yield and quality was higher in groups supplemented with EVs isolated from FF and AOF by ODG UC, with higher total cell numbers and a lower apoptotic cell ratio compared with the other groups (p < 0.05). Supplementing in vitro maturation media with EVs derived by ODG UC from AOF was beneficial for bovine embryo development and quality.

Altrenogest affects expression of galectin-3 and fibroblast growth factor 9 in the reproductive tract of sows.

A synthetic progestin altrenogest (ALT) is used to synchronize the estrus cycle of swine for fixed-time artificial insemination (AI) and has been shown to improve follicular development and reproductive performances in post-weaning sows. However, the effects of ALT treatment on reproductive tracts, including the ovaries, oviducts and uterus have not been yet clarified. In this study, we examined the expression of genes involved in endometrial responses in ALT-treated sows. ALT did not significantly alter luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol profiles in blood compared to untreated control. Quantitative RT-polymerase chain reaction (qRT-PCR) analysis showed that the expression of genes encoding galectin-3 (LGALS3) and fibroblast growth factor 9 (FGF9) was upregulated in the reproductive tracts of ALT-treated sows, including the ovaries, oviducts and uteri. Moreover, ALT treatment induced the expression of FGF9 and galectin-3 proteins, and promoted their localization to the luminal epithelium of the oviducts and uterus. Our findings suggest that the enhancement of reproductive performance shown by ALT-treated sows is associated with the upregulation of galectin-3 and FGF9, which are essential for endometrial receptivity, successful implantation, and pregnancy.

Artificial Intelligence-Based Quantification of Epithelial Proliferation in Mammary Glands of Rats and Oviducts of Göttingen Minipigs.

Quantitative assessment of proliferation can be an important endpoint in toxicologic pathology. Traditionally, cell proliferation is quantified by labor-intensive manual counting of positive and negative cells after immunohistochemical staining for proliferation markers (eg, Ki67, bromo-2'-deoxyuridine, or proliferating cell nuclear antigen). Currently, there is a lot of interest in replacing manual evaluation of histology end points with image analysis tools based on artificial intelligence. The aim of the present study was to explore if a commercially available image analysis software can be used to quantify epithelial proliferative activity in rat mammary gland and minipig oviduct. First, algorithms based on artificial intelligence were trained to detect epithelium in each tissue. Areas of BrdU- or Ki67-positive nuclei and negative nuclei were subsequently quantified with threshold analysis. Artificial intelligence-based and manually counted labelling indices were strongly correlated and equally well detected the estrous cycle influence on proliferation in mammary gland and oviduct epithelium, as well as the dramatically increased proliferation in rat mammary glands after treatment with estradiol and progesterone. In conclusion, quantification of epithelial proliferation in two reproductive tissues can be achieved in a reliable fashion using image analysis software based on artificial intelligence, thus avoiding time- and labor-intensive manual counting, requiring trained operators.

Corticosterone induced apoptosis of mouse oviduct epithelial cells independent of the TNF-α system.

It has been reported in recent studies that restraint stress on pregnant mice during the preimplantation stage elevated corticotrophin-releasing hormone (CRH) and glucocorticoid levels in the serum and oviducts; furthermore, CRH and corticosterone (CORT) impacted preimplantation embryos indirectly by triggering the apoptosis of oviductal epithelial cells (OECs) through activation of the Fas system. However, it remains unclear whether TNF-α signaling is involved in CRH- and/or glucocorticoid-induced apoptosis of OECs. In the present study, it was shown that culture with either CRH or CORT induced significant apoptosis of OECs. The culture of OECs with CRH augmented both FasL expression and TNF-α expression. However, culture with CORT increased FasL, but decreased TNF-α, expression significantly. Although knocking down/knocking out FasL expression in OECs significantly ameliorated the proapoptotic effects of both CRH and CORT, knocking down/knocking out TNF-α expression relieved only the proapoptotic effect of CRH but not that of CORT. Taken together, our results demonstrated that CRH-induced OEC apoptosis involved both Fas signaling and TNF-α signaling. Conversely, CORT-induced OEC apoptosis involved only the Fas, but not the TNF-α, signaling pathway. The data obtained are crucial for our understanding of the mechanisms by which various categories of stress imposed on pregnant females impair embryo development, as well as for the development of measures to protect the embryo from the adverse effects of stress.

The effect of polychlorinated biphenyls (PCBs) on bovine oviductal contractions and LIF synthesis during estrous cycle, in vitro studies.

Polychlorinated biphenyls (PCBs) are a group of synthetic xenobiotics that have been used in many industrial applications. Currently, PCBs are among the most prominent environmental contaminants. Previously we showed that PCBs impair secretion of prostaglandins (PGs) at the oviduct. PGs are involved in the regulation of oviductal contractions and the synthesis of leukemia inhibitory factors LIF. Since oviductal contractions are crucial for gamete and embryo transport, and LIF is essential for embryo implantation, the direct effect of PCBs on oviductal motor activity and LIF mRNA expression were investigated. Oviductal strips and cells were taken from cows during the estrous cycle and were treated with PCBs at concentrations close to their environmental ranges. All the studied PCBs decreased the force of the contractions of the longitudinal and circular muscles of the isthmus. Additionally, these PCBs decreased the amplitude of the longitudinal muscle of the oviduct. Moreover, PCB-30-OH and PCB-153 increased the mRNA expression of LIF. Since PCBs inhibit the motor function of the oviduct and stimulate the synthesis of LIF, it is possible that PCBs can slow gamete or embryo transport and increase the potential for pathological embryo implantation in the oviduct.

Alterations in egg white-related genes expression in response to hormonal stimulation.

The reproductive tract in avian females is sensitive to hormonal regulation. Exogenous estrogen induces immature oviduct development to improve egg production after molting. In this process, regressed female reproductive tract is regenerated in response to the secretion of estrogen. However, there is limited knowledge on the physiological mechanisms underlying the regulation of the avian female reproductive system. In our previous study, results from microarray analysis revealed that the expression of genes encoding egg white proteins is affected during molting. Herein, we artificially induced the molting period in chickens through a zinc-containing diet. Subsequently, changes in the expression of genes encoding egg white proteins were confirmed in the oviduct tissue. The levels of MUC5B, ORM1, RTBDN, and TENP mRNA were significantly high in the oviduct, and the genes were repressed in the regression phase, whereas these were expressed in the recrudescence phase, particularly in the luminal epithelium and glandular epithelium of the oviduct, during molting. Moreover, we observed that gene expression was induced in the magnum, the site for the secretion of egg white components. Next, differences in expression levels of the four genes in normal and cancerous ovaries were compared. Collectively, results suggest that the four selected genes are expressed in the female chicken reproductive tract in response to hormonal regulation, and egg white protein-encoding genes may serve as modulators of the reproductive system in hens.

Effects in broiler hens of genetic lines differing in fertility, biotin supplementation, and age on relative abundance of oviductal transforming growth factor-ß and carbonic anhydrase mRNA transcripts.

There was evaluation of effects of biotin administration on oviductal abundance of transforming growth factor-ß (TGF-ß) and carbonic anhydrase (CA) mRNA transcript in younger and older broiler hens of relatively lesser and greater fertility lines. Additionally, effects of biotin supplementation on attenuation of age-related subfertility were evaluated. Hens from the relatively greater (Line D, n = 60) and lesser (Line B, n = 60) fertility rate line were randomly assigned to three treatment groups. Biotin was not or was administered in drinking water from 30 to 33 (younger age) and 53 to 56 (older age) wk of age to have access to no biotin (T0), or 0.3 (T1), or 0.45 (T2) mg/L of biotin. There was assessment the relative oviductal abundances of TGF-ß and CA mRNA transcript abundances. Supplemental biotin and age had no effect on the relative abundance of oviductal TGF-ß mRNA transcript in hens of Line D. There, however, was a ten-fold greater abundance of TGF-ß in hens of the T0 group of Line B compared with Line D. Relative abundance of TGF-ß mRNA transcript was greater in younger hens of Line B; however, biotin supplementation of older hens of the T2 group of Line B resulted in a similar TGF-ß abundance to that of younger hens. Inconstant with the TGF-ß abundance, CA abundance in hens of Line B was not affected by supplemental biotin or bird age. Overall, differences in TGF-ß or CA abundances did not affect fertility of broiler hens.

Identification, Localization in the Central Nervous System and Novel Myostimulatory Effect of Allatostatins in Tenebrio molitor Beetle.

Allatostatins (ASTs) are pleiotropic insect neuropeptides that are potent myoinhibitors of muscle contractions. In this study, we identified and immunolocalized peptides from the MIP/AST and PISCF/AST families in the nervous system of a model beetle, Tenebrio molitor. Neurons containing MIPs were immunolocalized in the brains of adults and the ventral nerve cords of larvae, pupae and imagines of this species as well as in the retrocerebral complex. PISCFs were immunolocalized in the ventral nerve cord of all stages as well as the brain of the adult beetle. Faint signals were also observed in the corpus allatum but not in the corpus cardiacum. The results allowed us to deduce the sequences of three neuropeptides belonging to MIP/ASTs, Tenmo-MIP4-NWGQFGXWa, Tenmo-MIP5-SKWDNFRGSWa and Tenmo-MIP6-EPAWSNLKGIWa, and one peptide from the PISCF/AST family, QSRYXQCYFNPISCX. Furthermore, we showed for the first time myostimulatory action of endogenous MIP/ASTs. Tenmo-MIP5 caused dose-dependent stimulation of the contractile activity of the beetle oviduct muscles, showing a sigmoidal curve up to 81.20% at the 10-8 M concentration, and the EC50 value for the myostimulatory effect of this peptide was 8.50 × 10-12 M. This is the first report of myostimulatory action of an endogenous myoinhibitory peptide in insect muscles.