Microscopic Analysis of Nuclear Speckles in a Viviparous Reptile.

Nuclear speckles are compartments enriched in splicing factors present in the nucleoplasm of eucaryote cells. Speckles have been studied in mammalian culture and tissue cells, as well as in some non-mammalian vertebrate cells and invertebrate oocytes. In mammals, their morphology is linked to the transcriptional and splicing activities of the cell through a recruitment mechanism. In rats, speckle morphology depends on the hormonal cycle. In the present work, we explore whether a similar situation is also present in non-mammalian cells during the reproductive cycle. We studied the speckled pattern in several tissues of a viviparous reptile, the lizard Sceloporus torquatus, during two different stages of reproduction. We used immunofluorescence staining against splicing factors in hepatocytes and oviduct epithelium cells and fluorescence and confocal microscopy, as well as ultrastructural immunolocalization and EDTA contrast in Transmission Electron Microscopy. The distribution of splicing factors in the nucleoplasm of oviductal cells and hepatocytes coincides with the nuclear-speckled pattern described in mammals. Ultrastructurally, those cell types display Interchromatin Granule Clusters and Perichromatin Fibers. In addition, the morphology of speckles varies in oviduct cells at the two stages of the reproductive cycle analyzed, paralleling the phenomenon observed in the rat. The results show that the morphology of speckles in reptile cells depends upon the reproductive stage as it occurs in mammals.

Oviductal extracellular vesicles miRNA cargo varies in response to embryos and their quality.

BACKGROUND: Increasing evidence points to an active role of oviductal extracellular vesicles (oEVs) in the early embryo-maternal dialogue. However, it remains unclear whether oEVs contribute to the recognition of the presence of embryos and their quality in the oviduct. Hence, we examined whether the molecular cargo of oEVs secreted by bovine oviduct epithelial cells (BOEC) differs depending on the presence of good (≥ 8 cells, G) or poor (< 8 cells, P) quality embryos. In addition, differences in RNA profiles between G and P embryos were analyzed in attempt to distinguish oEVs and embryonic EVs cargos. METHODS: For this purpose, primary BOEC were co-cultured with in vitro produced embryos (IVP) 53 h post fertilization as follows: BOEC with G embryos (BGE); BOEC with P embryos (BPE); G embryos alone (GE); P embryos alone (PE); BOEC alone (B) and medium control (M). After 24 h of co-culture, conditioned media were collected from all groups and EVs were isolated and characterized. MicroRNA profiling of EVs and embryos was performed by small RNA-sequencing. RESULTS: In EVs, 84 miRNAs were identified, with 8 differentially abundant (DA) miRNAs for BGE vs. B and 4 for BPE vs. B (P-value < 0.01). In embryos, 187 miRNAs were identified, with 12 DA miRNAs for BGE vs. BPE, 3 for G vs. P, 8 for BGE vs. GE, and 11 for BPE vs. PE (P-value < 0.01). CONCLUSIONS: These results indicated that oEVs are involved in the oviductal-embryo recognition and pointed to specific miRNAs with signaling and supporting roles during early embryo development.

Single-cell transcriptomic profiling of the neonatal oviduct and uterus reveals new insights into upper Müllerian duct regionalization.

The upper Müllerian duct (MD) is patterned and specified into two morphologically and functionally distinct organs, the oviduct and uterus. It is known that this regionalization process is instructed by inductive signals from the adjacent mesenchyme. However, the interaction landscape between epithelium and mesenchyme during upper MD development remains largely unknown. Here, we performed single-cell transcriptomic profiling of mouse neonatal oviducts and uteri at the initiation of MD epithelial differentiation (postnatal day 3). We identified major cell types including epithelium, mesenchyme, pericytes, mesothelium, endothelium, and immune cells in both organs with established markers. Moreover, we uncovered region-specific epithelial and mesenchymal subpopulations and then deduced region-specific ligand-receptor pairs mediating mesenchymal-epithelial interactions along the craniocaudal axis. Unexpectedly, we discovered a mesenchymal subpopulation marked by neurofilaments with specific localizations at the mesometrial pole of both the neonatal oviduct and uterus. Lastly, we analyzed and revealed organ-specific signature genes of pericytes and mesothelial cells. Taken together, our study enriches our knowledge of upper MD development, and provides a manageable list of potential genes, pathways, and region-specific cell subtypes for future functional studies.

Development of decellularization protocols for female cat reproductive organs.

Decellularization is an innovative method to create natural scaffolds by removing all cellular materials while preserving the composition and three-dimensional ultrastructure of the extracellular matrix (ECM). The obtention of decellularized reproductive organs in cats might facilitate the development of assisted reproductive techniques not only in this species but also in other felids. The aim was to compare the efficiency of three decellularization protocols on reproductive organs (ovary, oviduct, and uterine horn) in domestic cats. The decellularization protocol involved 0.1% sodium dodecyl sulfate and 1%Triton X-100. Protocol 1 (P1) entailed 2-cycles of decellularization using these detergents. Protocol 2 (P2) was like P1 but included 3-cycles. Protocol 3 (P3) was similar to P2, with the addition of deoxyribonuclease incubation. Reproductive organs from nine cats were separated into two sides. One side served as the control (non-decellularized organ) while the contralateral side was the treated group (decellularized organ). The treated organs were subdivided into 3 groups (n = 3 per group) for each protocol. Both control and treated samples were analyzed for DNA content, histology (nuclear and ECM (collagen, elastin, and glycosaminoglycans (GAGs)) density), ultrastructure by electron microscopy, and cytotoxicity. The results of the study showed that P3 was the only protocol that displayed no nucleus residue and significantly reduced DNA content in decellularized samples (in all the studied organs) compared to the control (P < 0.05). The ECM content in the ovaries remained similar across all protocols compared with controls (P > 0.05). However, elastic fibers and GAGs decreased in decellularized oviducts (P < 0.05), while collagen levels remained unchanged (P > 0.05). Regarding the uterus, the ECM content decreased in decellularized uterine horns from P3 (P < 0.05). Electron microscopy revealed that the microarchitecture of the decellularized samples was maintained compared to controls. The decellularized tissues, upon being washed for 24 h, showed cytocompatibility following co-incubation with sperm. In conclusion, when comparing different decellularization methods, P3 proved to be the most efficient in removing nuclear material from reproductive organs compared to P1 and P2. P3 demonstrated its success in decellularizing ovarian samples by significantly decreasing DNA content while maintaining ECM components and tissue microarchitecture. However, P3 was less effective in maintaining ECM contents in decellularized oviducts and uterine horns.

Milk provisioning in oviparous caecilian amphibians.

Among vertebrates, the yolk is commonly the only form of nutritional investment offered by the female to the embryo. Some species, however, have developed parental care behaviors associated with specialized food provisioning essential for offspring survival, such as the production of lipidic-rich parental milk in mammals. Here, we show that females of the egg-laying caecilian amphibian Siphonops annulatus provide similarly lipid-rich milk to altricial hatchlings during parental care. We observed that for 2 months, S. annulatus babies ingested milk released through the maternal vent seemingly in response to tactile and acoustic stimulation by the babies. The milk, composed mainly of lipids and carbohydrates, originates from the maternal oviduct epithelium's hypertrophied glands. Our data suggest lactation in this oviparous nonmammalian species and expand the knowledge of parental care and communication in caecilians.

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.

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.

New Gene Markers Expressed in Porcine Oviductal Epithelial Cells Cultured Primary In Vitro Are Involved in Ontological Groups Representing Physiological Processes of Porcine Oocytes.

Changes that occur within oviducts after fertilization are dependent on post-ovulation events, including oocyte-oviduct interactions. Although general processes are well-defined, the molecular basis are poorly understood. Recently, new marker genes involved in 'cell development', 'cell growth', 'cell differentiation' and 'cell maturation' processes have been identified in porcine oocytes. The aim of the study was to assess the expression profile of genes in primary in vitro cultured oviductal epithelial cells (OECs), clustered in Gene Ontology groups which enveloped markers also identified in porcine oocytes. OECs (from 45 gilts) were surgically removed and cultured in vitro for ≤ 30 days, and then subjected to molecular analyses. The transcriptomic and proteomic profiles of cells cultured during 7, 15 and 30 days were investigated. Additionally, morphological/histochemical analyzes were performed. The results of genes expression profiles were validated after using RT-qPCR. The results showed a significant upregulation of UNC45B, NOX4, VLDLR, ITGB3, FMOD, SGCE, COL1A2, LOX, LIPG, THY1 and downregulation of SERPINB2, CD274, TXNIP, CELA1, DDX60, CRABP2, SLC5A1, IDO1, ANPEP, FST. Detailed knowledge of the molecular pathways occurring in the OECs and the gametes that contact them may contribute both to developments of basic science of physiology, and new possibilities in advanced biotechnology of assisted reproduction.

Anatomical and cellular heterogeneity in the mouse oviduct-its potential roles in reproduction and preimplantation development†.

The oviduct/fallopian tube is a tube-like structure that extends from the uterus to the ovary. It is an essential reproductive organ that provides an environment for internal fertilization and preimplantation development. However, our knowledge of its regional and cellular heterogeneity is still limited. Here, we examined the anatomical complexity of mouse oviducts using modern imaging techniques and fluorescence reporter lines. We found that there are consistent coiling patterns and turning points in the coiled mouse oviduct that serve as reliable landmarks for luminal morphological regionalities. We also found previously unrecognized anatomical structures in the isthmus and uterotubal junction, which likely play roles in reproduction. Furthermore, we demarcated the ampulla-isthmus junction as a distinct region. Taken together, the oviduct mucosal epithelium has highly diverse structures with distinct epithelial cell populations, reflecting its complex functions in reproduction.

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.

A long-term in vitro culture of bovine epithelial cells on collagen rafts.

In the present work, we established and characterized a 3D functional polarized primary bovine oviduct epithelial cells (BOECs) culture on free-floating type I collagen hydrogels (rafts) at an air-liquid interface (ALI). Intercellular junctions, ultrastructural cellular morphology and the expression of the OVGP1 closely recapitulated those of the in vivo epithelium lining. These morphological and physiological epithelial cell features were maintained under standard DMEM/F12 with 10% foetal bovine serum culture medium for at least 28 days of ALI culture. The versatility of the BOECs raft cultures should allow testing of toxicity compounds, in vitro evaluation of physiological or pathological oviductal states, and the study of epithelial-mesenchymal interactions that are critical for the maintenance of oviductal homeostasis.

Ultrastructural evidence for an unusual mode of ciliogenesis in mouse multiciliated epithelia.

Multiciliogenesis is a cascading process for generating hundreds of motile cilia in single cells. In vertebrates, this process has been investigated in the ependyma of brain ventricles and the ciliated epithelia of the airway and oviduct. Although the early steps to amplify centrioles have been characterized in molecular detail, subsequent steps to establish multicilia have been relatively overlooked. Here, we focused on unusual cilia-related structures previously observed in wild-type mouse ependyma using transmission electron microscopy and analyzed their ultrastructural features and the frequency of their occurrence. In the ependyma, $\sim$5% of cilia existed as bundles; while the majority of the bundles were paired, bundles of more than three cilia were also found. Furthermore, apical protrusions harboring multiple sets of axonemes were occasionally observed (0-2 per section), suggesting an unusual mode of ciliogenesis. In trachea and oviduct epithelia, ciliary bundles were absent, but protrusions containing multiple axonemes were observed. At the base of such protrusions, certain axonemes were completely enwrapped by membranes, whereas others remained incompletely enwrapped. These data suggested that the late steps of multiciliogenesis might include a unique process underlying the development of cilia, which is distinct from the ciliogenesis of primary cilia.

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.

Extracellular Vesicles and the Oviduct Function.

In mammals, the oviduct (or the Fallopian tube in humans) can be divided into the infundibulum (responsible for oocyte pick-up), ampulla (site of fertilization), isthmus (where preimplantation embryos develop), and uterotubal junction (where embryos transit to the uterus). The oviductal fluid, as well as extracellular vesicles produced from the oviduct epithelial cells, referred to as oEVs, have been shown to improve the fertilization process, prevent polyspermy, and aid in embryo development. oEVs contain molecular cargos (such as miRNAs, mRNAs, proteins, and lipids) that can be delivered and fuse to recipient cells. oEVs produced from the ampulla appear to be functionally distinct from those produced from the isthmus. In multiple species including mice, cats, dogs, pigs, and cows, oEVs can be incorporated into the oocytes, sperm, and embryos. In this review, we show the positive impact of oEVs on gamete function as well as blastocyst development and how they may improve embryo quality in in vitro conditions in an assisted reproductive technology setting for rodents, domestic animals, farm animals, and humans.

Bovine Oviduct Epithelial Cell-Derived Culture Media and Exosomes Improve Mitochondrial Health by Restoring Metabolic Flux during Pre-Implantation Development.

Oviduct flushing is enriched by a wide variety of nutrients that guide the 3-4 days journey of pre-implantation embryo through the oviduct as it develops into a competent blastocyst (BL). However, little is known about the specific requirement and role of these nutrients that orchestrate the early stages of embryonic development. In this study, we aimed to characterize the effect of in vitro-derived bovine oviduct epithelial cell (BOECs) secretion that mimics the in vivo oviduct micro-fluid like environment, which allows successful embryonic development. In this study, the addition of an in vitro derived BOECs-condition media (CM) and its isolated exosomes (Exo) significantly enhances the quality and development of BL, while the hatching ability of BLs was found to be high (48.8%) in the BOECs-Exo supplemented group. Surprisingly, BOECs-Exo have a dynamic effect on modulating the embryonic metabolism by restoring the pyruvate flux into TCA-cycle. Our analysis reveals that Exo treatment significantly upregulates the pyruvate dehydrogenase (PDH) and glutamate dehydrogenase (GLUD1) expression, required for metabolic fine-tuning of the TCA-cycle in the developing embryos. Exo treatment increases the influx into TCA-cycle by strongly suppressing the PDH and GLUD1 upstream inhibitors, i.e., PDK4 and SIRT4. Improvement of TCA-cycle function was further accompanied by higher metabolic activity of mitochondria in BOECs-CM and Exo in vitro embryos. Our study uncovered, for the first time, the possible mechanism of BOECs-derived secretion in re-establishing the TCA-cycle flux by the utilization of available nutrients and highlighted the importance of pyruvate in supporting bovine in vitro embryonic development.

Getting to and away from the egg, an interplay between several sperm transport mechanisms and a complex oviduct physiology.

In mammals, the architecture and physiology of the oviduct are very complex, and one long-lasting intriguing question is how spermatozoa are transported from the sperm reservoir in the isthmus to the oocyte surface. In recent decades, several studies have improved knowledge of the factors affecting oviduct fluid movement and sperm transport. They report sperm-guiding mechanisms that move the spermatozoa towards (rheotaxis, thermotaxis, and chemotaxis) or away from the egg surface (chemorepulsion), but only a few provide evidence of their occurrence in vivo. This gives rise to several questions: how and when do the sperm transport mechanisms operate inside such an active oviduct? why are there so many sperm guidance processes? is one dominant over the others, or do they cooperate to optimise the success of fertilisation? Assuming that sperm guidance evolved alongside oviduct physiology, in this review we propose a theoretical model that integrates oviduct complexity in space and time with the sperm-orienting mechanisms. In addition, since all of the sperm-guidance processes recruit spermatozoa in a better physiological condition than those not selected, they could potentially be incorporated into assisted reproductive technology (ART) to improve fertility treatment and/or to develop innovative contraceptive methods. All these issues are discussed in this review.

The role of GtxA during Gallibacterium anatis infection of primary chicken oviduct epithelial cells.

Gallibacterium anatis (G. anatis), one of the major pathogens causing reproductive tract disorders in laying hens, leads to a reduction in egg production and increased mortality, caused by either single or mixed infections with other pathogens. As a specific virulence factor of G. anatis, the role of GtxA in layers' salpingitis remains unclear. In this study, we explored the effect of GtxA on G. anatis infection by comparing wild strain Yu-PDS-RZ-1-SLG (RZ) and its GtxA deleted counterpart RZΔgtxA in primary chicken oviduct epithelial cells (COEC). Their adherence, invasion, cytoxicity, and ability to induce apoptosis and and cytokine secretion were evaluated and the cytotoxicity and cytokine secretion of the recombinant GtxA protein and its N-terminal adenylate cyclase and C-terminal RTX hemolysin domain were also analyzed. We found that the adhesion ability of RZΔgtxA was significantly lower than that of parental strain RZ, and its toxicity to COEC was weakened; Meanwhile, apoptosis was inhibited and the expression of IL-6, IL-2, TNF-α and IFN-γ were dramatically reduced in COEC infected by RZΔgtxA. In contrast, the recombinant protein GtxA inhibited the proliferation of oviduct cells and induced obvious cytotoxicity, and the expression of IL-6, TNF-α and IFN-γ were up-regulated in COEC interacted with recombinant proteins. Our study indicates that GtxA promotes G. anatis adherence to cells, changes cells permeability and expression of inflammatory factors, resulting in cell damage and apoptosis.

Early embryo-maternal communication in the oviduct: A review.

An intact embryo-maternal communication is critical for the establishment of a successful pregnancy. To date, a huge number of studies have been performed describing the complex process of embryo-maternal signaling within the uterus. However, recent studies indicate that the early embryo communicates with the oviductal cells shortly after fertilizationand that this is important for the successful establishment of pregnancy. Only if the early embryo is capable to signal the mother within a precise timeframe and to garner a response, will the embryo be able to survive and reach the uterus. This review will give an overview of all the experimental designs which have investigated embryo-maternal interaction in the oviduct. In addition to that, it will provide a comprehensive analysis of the findings to date elucidating the morphological and molecular changes in the oviduct which are induced by the presence of the early embryo highlighting how the tubal responses affect embryo development and survival.

YAP and TAZ are required for the postnatal development and the maintenance of the structural integrity of the oviduct.

The development of the Müllerian ducts into the female reproductive tract requires the coordination of multiple signaling pathways that regulate proliferation, apoptosis and differentiation. The Hippo pathway has been reported to interact with several pathways with established roles in Müllerian duct development; yet, its potential roles in reproductive tract development and function remain mostly uncharacterized. The objective of this study was therefore to characterize the roles of the Hippo transcriptional coactivators YAP and TAZ in the female reproductive tract using transgenic mouse models. This report shows that the concomitant conditional inactivation of Yap and Taz in the mouse Müllerian duct mesenchyme results in postnatal developmental defects of the oviduct. Most notably, discontinuities in the myosalpinx layer lead to the progressive formation of cystic dilations of the isthmus. These defects prevented embryo transport and subsequent implantation in older animals, causing infertility. The loss of YAP/TAZ did not appear to affect other biological processes known to be required for the maintenance of oviductal wall integrity, such as TGF-ß/SMAD and Notch signaling and the biogenesis of miRNA, suggesting that the Hippo pathway acts independently of these processes to direct oviduct development. Taken together, these results suggest redundant and essential roles for YAP and TAZ in the postnatal development of the oviduct and the maintenance of its structural integrity.