Different Cre systems induce differential microRNA landscapes and abnormalities in the female reproductive tracts of Dgcr8 conditional knockout mice.

OBJECTIVES: The female reproductive tract comprises several different cell types. Using three representative Cre systems, we comparatively analysed the phenotypes of Dgcr8 conditional knockout (cKO) mice to understand the function of Dgcr8, involved in canonical microRNA biogenesis, in the female reproductive tract. MATERIALS AND METHODS: Dgcr8f/f mice were crossed with Ltficre/+ , Amhr2cre/+ or PRcre/+ mice to produce mice deficient in Dgcr8 in epithelial (Dgcr8ed/ed ), mesenchymal (Dgcr8md/md ) and all the compartments (Dgcr8td/td ) in the female reproductive tract. Reproductive phenotypes were evaluated in Dgcr8 cKO mice. Uteri and/or oviducts were used for small RNA-seq, mRNA-seq, real-time RT-PCR, and/or morphologic and histological analyses. RESULT: Dgcr8ed/ed mice did not exhibit any distinct defects, whereas Dgcr8md/md mice showed sub-fertility and oviductal smooth muscle deformities. Dgcr8td/td mice were infertile due to anovulation and acute inflammation in the female reproductive tract and suffered from an atrophic uterus with myometrial defects. The microRNAs and mRNAs related to immune modulation and/or smooth muscle growth were systemically altered in the Dgcr8td/td uterus. Expression profiles of dysregulated microRNAs and mRNAs in the Dgcr8td/td uterus were different from those in other genotypes in a Cre-dependent manner. CONCLUSIONS: Dgcr8 deficiency with different Cre systems induces overlapping but distinct phenotypes as well as the profiles of microRNAs and their target mRNAs in the female reproductive tract, suggesting the importance of selecting the appropriate Cre driver to investigate the genes of interest.

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.

A comparative study of the turnover of multiciliated cells in the mouse trachea, oviduct, and brain.

BACKGROUND: In mammals, multiciliated cells (MCCs) line the lumen of the trachea, oviduct, and brain ventricles, where they drive fluid flow across the epithelium. Each MCC population experiences vastly different local environments that may dictate differences in their lifetime and turnover rates. However, with the exception of MCCs in the trachea, the turnover rates of these multiciliated epithelial populations at extended time scales are not well described. RESULTS: Here, using genetic lineage-labeling techniques we provide a direct comparison of turnover rates of MCCs in these three different tissues. CONCLUSION: We find that oviduct turnover is similar to that in the airway (~6 months), while multiciliated ependymal cells turnover more slowly.

Biomechanics of epithelial fold pattern formation in the mouse female reproductive tract.

Tubular organs and tissues often show various morphological fold patterns in their luminal epithelia. Computational studies have revealed that these patterns could be explained by mechanical deformation of the epithelia. However, experimental validations of this are sparse, and the mechanisms linking genetic and cellular functions to fold mechanics are poorly understood. In the oviduct of the female reproductive tract, the epithelium forms multiple well-aligned straight folds. Disruption of Celsr1, a planar cell polarity-related gene, causes ectopically-branched folds in mice. Here we discuss the pattern formation of the folds with respect to the growth and mechanics of the epithelium, and the cellular and genetic functions, and compare these with other tubular organs such as the gut.

RAS-related protein 1: an estrogen-responsive gene involved in development and molting-mediated regeneration of the female reproductive tract in chickens.

It is important to identify molecular candidates involved in morphological and functional changes in the female reproductive system. We have discovered several candidate genes that were significantly altered in chick oviducts by exogenous estrogen and those candidates included dexamethasone (DEX)-induced RAS-related protein 1 (RASD1). RAS-related protein 1, a member of the Ras family of monomeric G proteins, is involved in various cellular processes including cell growth, proliferation and differentiation, as well as a cell-signaling protein regulating hormonal actions. Although the RASD1 gene was first identified as a DEX (a corticosteroid) inducible gene, there is evidence that it is also an estrogen-responsive gene. However, hormone-mediated expression and biological functions of RASD1 in the avian female reproductive system are poorly understood. Therefore, we tested the hypothesis that RASD1 may be involved in the development and remodeling of the chicken reproductive system as an estrogen-responsive gene. Here we demonstrate differential expression of RASD1 gene and candidate microRNAs (miRNAs) targeting chicken RASD1 transcripts in chicken oviducts in response to diesthylstilbestrol (DES, a synthetic non-steroidal estrogen) and the estrogen-mediated molting process. Result of the present study indicated that expression of RASD1 messenger RNA (mRNA) increased in the developing oviducts of chicks treated with DES, particularly in the glandular (GE) and luminal (LE) epithelia of the magnum and the shell gland. Also, during induced molting by zinc feeding, RASD1 expression changed in concert with changes in concentrations of estrogen in blood of laying hens. Our results revealed that expression of RASD1 mRNA decreased as the oviduct regressed and then increased as the oviduct underwent re-growth and recrudescence in hens. Furthermore, RASD1 mRNA was expressed predominantly in GE and LE of the oviduct of laying hens during regeneration of the oviduct after induced molting, but not during the period of regression of the oviduct during molting. In addition, the relative expression of candidate miRNAs (miR-30a-5p, miR-30b-5p, miR-30c-5p and miR-30d) regulating RASD1 transcripts changed in response to estrogen stimulation of chick oviducts. These results indicate that transcription of the RASD1 gene and miRNAs regulating post-transcriptional aspects of expression of RASD1 are modulated by estrogen which is critical for growth, development, remodeling and maintenance of function of the chicken oviduct.

A genome-wide study to identify genes responsible for oviduct development in chickens.

Molecular genetic tools provide a method for improving the breeding selection of chickens (Gallus gallus). Although some studies have identified genes affecting egg quality, little is known about the genes responsible for oviduct development. To address this issue, here we used a genome-wide association (GWA) study to detect genes or genomic regions that are related to oviduct development in a chicken F2 resource population by employing high-density 600 K single-nucleotide polymorphism (SNP) arrays. For oviduct length and weight, which exhibited moderate heritability estimates of 0.35 and 0.39, respectively, chromosome 1 (GGA1) explained 9.45% of the genetic variance, while GGA4 to GGA8 and GGA11 explained over 1% of the variance. Independent univariate genome-wide screens for oviduct length and weight detected 69 significant SNPs on GGA1 and 49 suggestive SNPs on GGA1, GGA4, and GGA8. One hundred and fourteen suggestive SNPs were associated with oviduct length, while 73 SNPs were associated with oviduct weight. The significant genomic regions affecting oviduct weight ranged from 167.79-174.29 Mb on GGA1, 73.16-75.70 Mb on GGA4, and 4.88-4.92 Mb on GGA8. The genes CKAP2, CCKAR, NCAPG, IGFBP3, and GORAB were shown to have potential roles in oviduct development. These genes are involved in cell survival, appetite, and growth control. Our results represent the first GWA analysis of genes controlling oviduct weight and length. The identification of genomic loci and potential candidate genes affecting oviduct development greatly increase our understanding of the genetic basis underlying oviduct development, which could have an impact on the selection of egg quality.

Dicer1, AGO3, and AGO4 microRNA machinery genes are differentially expressed in developing female reproductive organs and overexpressed in cancerous ovaries of chickens.

MicroRNA (miRNA)-mediated gene silencing is a key mechanism regulating numerous biological processes such as development of organs and tumorigenesis. The expression of miRNA machinery genes linked to miRNA biogenesis and processing is finely regulated. Despite accumulating evidence for chicken miRNA in the female reproduction system, precise regulatory mechanisms are largely unknown. Therefore, the objective of this study was to determine changes in expression levels of miRNA machinery genes in developmental stages of the oviduct and ovarian carcinogenesis of laying hens. In the present study, differential expression of miRNA machinery genes during ovarian carcinogenesis was determined using cancerous and normal ovaries collected from normal laying hens and hens with cancer. Our results showed that 3 miRNA machinery genes (, , and ) were differentially expressed as laying hens' reproductive organs developed. These genes were simultaneously upregulated in cancerous ovaries compared with those in normal ovaries. Their transcripts were abundantly localized in glandular epithelial cells of cancerous ovaries. Our results indicate that , , and play critical roles in the development of reproductive organs and ovarian carcinogenesis in laying hens, suggesting that simultaneous overexpression of these genes might serve as a prognostic factor for ovarian cancer.

Dietary methionine requirement of Jing Brown layer hens from 9 to 17 weeks of age.

This study was conducted to evaluate the effect of dietary methionine (Met) supplementation in growth performance and reproductive performance of Jing Brown layer hens. A total of 375 9-week-old Jing Brown layer hens were allocated equally to five treatments consisting of 5 replicates with 15 hens. Hens were fed with a diet of corn and soya bean meal supplemented with 0.23%, 0.27%, 0.31%, 0.35% and 0.39% Met respectively. Different Met levels did not significantly affect average daily feed intake (ADFI), average daily gain (ADG) and feed/gain ratio (F/G) (p > 0.05), whereas flock uniformity (FU) and jejunum index were significantly different (p < 0.05), and the largest FU was observed in 0.31% Met. Dietary supplementation of Met significantly affected reproductive system development (p < 0.05), and 0.27-0.31% Met obtained optimal reproductive system development. Different Met levels significantly affected serum uric acid and alkaline phosphatase. Moreover, the relatively higher reproductive hormones in serum were observed in 0.27% Met. Analysis of quadratic curve estimation of flock uniformity, the total number of follicles, the primary follicles and the secondary follicles showed that the optimal Met levels were 0.293%, 0.286%, 0.286% and 0.288%, which could be averaged to 0.288%. These results suggested that the optimal Met requirement for Jing Brown layer hens from 9 to 17 weeks old is 0.29%.

Global analysis of differential gene expression related to long-term sperm storage in oviduct of Chinese Soft-Shelled Turtle Pelodiscus sinensis.

Important evolutionary and ecological consequences arise from the ability of female turtles to store viable spermatozoa for an extended period. Although previous morphological studies have observed the localization of spermatozoa in Pelodiscus sinensis oviduct, no systematic study on the identification of genes that are involved in long-term sperm storage has been performed. In this study, the oviduct of P. sinensis at different phases (reproductive and hibernation seasons) was prepared for RNA-Seq and gene expression profiling. In total, 2,662 differentially expressed genes (DEGs) including 1,224 up- and 1,438 down-regulated genes were identified from two cDNA libraries. Functional enrichment analysis indicated that many genes were predominantly involved in the immune response, apoptosis pathway and regulation of autophagy. RT-qPCR, ELISA, western blot and IHC analyses showed that the expression profiles of mRNA and protein in selected DEGs were in consistent with results from RNA-Seq analysis. Remarkably, TUNEL analysis revealed the reduced number of apoptotic cells during sperm storage. IHC and TEM analyses found that autophagy occurred in the oviduct epithelial cells, where the spermatozoa were closely attached. The outcomes of this study provide fundamental insights into the complex sperm storage regulatory process and facilitate elucidating the mechanism of sperm storage in P. sinensis.

Postnatal development and histofunctional differentiation of the oviduct in the broad-snouted caiman (Caiman latirostris).

Caiman latirostris is a South American crocodilian species characterized as a sentinel of the presence of endocrine-disrupting compounds (EDCs). Evaluating developmental events in hormone-dependent organs, such as the oviduct, is crucial to understand physiological postnatal development, to identify putative periods of exposure sensitive to EDCs, and/or to identify biomarkers useful to evaluate the effects of EDC exposure. In this study, we describe the histomorphological features of C. latirostris oviducts by establishing the ontogeny of changes at cellular, tissue and molecular levels from the neonatal to the pre-pubertal juvenile stages. Since the histological diagnosis of the adenogenic oviduct lies on a group of features, here we defined a histofunctional score system and a cut-off value to distinguish between preadenogenic and adenogenic oviducts. Our results showed that the maturation of the C. latirostris oviduct is completed postnatally and characterized by changes that mimic the pattern of histological modifications described for the mammalian uterus. Ontogenic changes in the oviductal epithelium parallel changes at subepithelial level, and include collagen remodeling and characteristic spatial-temporal patterns of α-actin and desmin. The expression pattern of estrogen receptor alpha and progesterone receptor evidenced that, even at early postnatal developmental stages, the oviduct of C. latirostris is a target organ of endogenous and environmental hormones. Besides, oviductal adenogenesis seems to be an estrogen-dependent process. Results presented here provide not only insights into the histophysiological aspect of caiman female reproductive ducts but also new tools to better characterize caimans as sentinels of endocrine disruption.

Dynamics of planar cell polarity protein Vangl2 in the mouse oviduct epithelium.

The planar cell polarity (PCP) pathway regulates morphogenesis in various organs. The polarized localization is a key feature of core PCP factors for orchestrating cell polarity in an epithelial sheet. Several studies using Drosophila melanogaster have investigated the mechanism of the polarized localization. However, to what extent these mechanisms are conserved and how the polarization of core PCP factors is maintained in mature vertebrates are still open questions. Here, we addressed these questions by analyzing the dynamics of Vangl2, a member of core PCP factors, in the mouse oviduct epithelium. Multiple core PCP factors including Vangl2 were expressed in the mouse oviduct in postnatal stages. Vangl1, Vangl2 and Frizzled6 had polarized localization in the oviduct epithelium. Exogenously introduced expression of green fluorescent protein (GFP)-tagged core PCP factors by electroporation revealed that Vangl1, Vangl2 and Prickle2 are localized on the ovarian side of the cell periphery in the oviduct. To visualize the Vangl2 dynamics, we generated the R26-Vangl2-EGFP transgenic mice. In these mice, Vangl2-EGFP was ubiquitously expressed and showed polarized localization in multiple organs including the oviduct, the trachea, the lateral ventricle and the uterus. Fluorescence recovery after photobleaching (FRAP) analysis in the mature oviduct revealed that Vangl2 in the enriched subdomain of cell periphery (cellular edge) was more stable than Vangl2 in the less-enriched cellular edge. Furthermore, when a subregion of a Vangl2-enriched cellular edge was bleached, the Vangl2-enriched subregion neighboring the bleached region in the same cellular edge tended to decrease more intensities than the neighboring sub-region in the next Vangl2-enriched cellular edge. Finally, the polarization of Vangl2 was observed in nocodazole treated mouse viduct, suggesting the maintenance of Vangl2 asymmetry is independent of microtubule formation. Taken together, we revealed the characteristics of Vangl2 dynamics in the oviduct epithelium, and found that Vangl2 forms stable complex at the enriched cellular edge and forms compartments. Our data collectively suggest that the mechanism for maintenance of Vangl2 asymmetry in mature mouse oviduct is different from the microtubule dependent polarized transport model, which has been proposed for the reinforcement of the asymmetry of two core PCP proteins, Flamingo and Dishevelled, in the developing fly.

Effect of different light sources on reproductive anatomy and physiology of Japanese quail (Coturnix coturnix japonica).

Artificial lights are essential for controlling the reproductive tract development of birds during puberty and therefore influence reproductive quality. The aim of this study was to evaluate the effect of different light sources on reproductive anatomic and physiological characteristics of female Japanese quail (Coturnix coturnix japonica). A total of 270 birds from one day of age were housed in a masonry shed divided into six rooms with light isolation. Each room was equipped with a different type of light bulb and contained seven cages with five birds in each. The light bulbs tested were: incandescent; compact fluorescent; and light-emitting diode (LED) in the colors white, blue, red and green. The experimental design was completely randomized with six treatments and seven replications of individual birds each. The anatomic and physiological condition of the birds was evaluated at four, eight and 12 weeks of age. The white LED bulb advanced (P<0.05) the sexual maturity by one week, resulted (P<0.05) in higher live weights and greater weight and relative percentage of ovarian stroma, oviduct and ovarian tissue at eight weeks of age. Higher plasma concentrations of estradiol and lipids were also observed (P<0.05) at eight weeks under the white LED bulb. At 12 weeks of age, the magnum and isthmus folding characteristics were better (P<0.05) with the red LED bulb. In conclusion, the photostimulation with the white LED bulb was more efficient at activating the reproductive cycle, hastening the onset of sexual maturity and increasing the development of reproductive organs after puberty.

Constitutive Notch Signaling Causes Abnormal Development of the Oviducts, Abnormal Angiogenesis, and Cyst Formation in Mouse Female Reproductive Tract.

The Notch signaling pathway is critical for the differentiation of many tissues and organs in the embryo. To study the consequences of Notch1 gain-of-function signaling on female reproductive tract development, we used a cre-loxP strategy and Amhr2-cre transgene to generate mice with conditionally activated Notch1 (Rosa(Notch1)). The Amhr2-cre transgene is expressed in the mesenchyme of developing female reproductive tract and in granulosa cells in the ovary. Double transgenic Amhr2-cre, Rosa(Notch1) females were infertile, whereas control Rosa(Notch1) mice had normal fertility. All female reproductive organs in mutants showed hemorrhaging of blood vessels progressing with age. The mutant oviducts did not develop coiling, and were instead looped around the ovary. There were multiple blockages in the lumen along the oviduct length, creating a barrier for sperm or oocyte passage. Mutant females demonstrated inflamed uteri with increased vascularization and an influx of inflammatory cells. Additionally, older females developed ovarian, oviductal, and uterine cysts. The significant change in gene expression was detected in the mutant oviduct expression of Wnt4, essential for female reproductive tract development. Similar oviductal phenotypes have been detected previously in mice with activated Smo and in beta-catenin, Wnt4, Wnt7a, and Dicer conditional knockouts, indicating a common regulatory pathway disrupted by these genetic abnormalities.

Expression and localization of matrix metalloproteinases (MMP-2, -7, -9) and their tissue inhibitors (TIMP-2, -3) in the chicken oviduct during maturation.

Although participation of matrix metalloproteinases (MMPs) in reproductive tract remodeling has been strongly suggested in mammalian species, the role of MMPs in the avian oviduct has received little attention. To gain a better understanding of the potential role of the MMP system in avian oviduct development, mRNA and protein expression, localization of selected MMPs and their tissue inhibitors (TIMPs), and gelatinolytic activity in the oviduct of growing chickens were examined. The oviducts were collected from Hy-Line Brown hens before (10, 12, 14 and 16 weeks of age) and after (week 17) the onset of egg laying. The MMP-2, -7, -9 and TIMP-2 and -3 genes were found to be differentially expressed in all examined oviductal sections: the infundibulum, magnum, isthmus and shell gland on both mRNA (by real time polymerase chain reaction) and protein (by western blotting and immunohistochemistry) levels. In the course of oviduct development, the relative expression of all genes decreased in most sections. Protein level of MMP-9 was diminished, while MMP-7 and TIMP-3 were elevated in the oviduct of growing birds. MMP-2 and TIMP-2 protein levels remained constant, with a slight increase in MMP-2 concentration just before reaching maturity. The relative activity of MMP-2 and -9 (assessed by gelatin zymography) was higher (P < 0.05, P < 0.01) in immature birds compared with adults. Immunohistochemistry demonstrated cell- and tissue-specific localization of MMPs and TIMPs in the wall of the chicken oviduct. We concluded that changes in the expression of examined MMPs and their inhibitors, as well as alterations in MMP activity occurring simultaneously with changes in the morphology of the chicken oviduct, suggest the involvement of the MMP system in the proper development and functioning of this organ. Mechanisms regulating the expression and activity of MMPs require further clarification.

Immunohistochemical localization of progesterone receptor isoforms and estrogen receptor alpha in the chicken oviduct magnum during development.

In this work, the immunohistochemical expression of progesterone receptor (PR) isoforms and estrogen receptor alpha (ER-α), as well as the histomorphometric changes of the magnum region of the left oviduct from 8-day-old chicken embryos to one-month-old chickens were evaluated. Results indicate evident histological changes in the oviduct magnum during development mainly in the magnum's mucosa. Immunohistochemical analysis showed that the oviduct magnum from 8-day-old chicken embryos to one-day-old chickens did not present any PR isoform, but the oviduct magnum of one-week and one-month-old chickens expressed PR in the nuclei of all cell types. In epithelial cells, PR-B was the only isoform expressed; in muscle and serosa cells, PR-A isoform was the only isoform expressed; and stromal cells expressed both isoforms. The results also demonstrate positive ER-α immunostaining in the nuclei of different cells from embryonic life to later developmental stages of the oviduct magnum. Data indicate that the variations of ER-α or PR expression or dominance of either PR expression is differentially regulated depending on the cell type, the development of the oviduct, and in an age-specific manner. These variations in sex steroids hormone receptors are related with histological changes of the oviduct magnum through development.

Atrazine triggers developmental abnormality of ovary and oviduct in quails (Coturnix Coturnix coturnix) via disruption of hypothalamo-pituitary-ovarian axis.

There has been a gradual increase in production and consumption of atrazine (ATR) in agriculture to meet the population rising demands. Female reproduction is necessary for growth and maintenance of population. However, ATR impact on females and particularly ovarian developmental toxicity is less clear. The aim of this study was to define the pathways by which ATR exerted toxic effects on ovarian development of ovary and hypothalamo-pituitary-ovarian (HPO) axis. Female quails were dosed by oral gavage from sexual immaturity to maturity with 0, 50, 250 and 500 mg ATR/kg/d for 45 days. ATR had no effect on mortality but depressed feed intake and growth and influenced the biochemical parameters. Notably, the arrested development of ovaries and oviducts were observed in ATR-exposed quails. The circulating concentrations of E2, P, LH and PRL were unregulated and FSH and T was downregulated in ATR-treated quails. The mRNA expression of GnRH in hypothalamo and LH in pituitary and FSH in ovary was downregulated significantly by ATR exposure and FSH and PRL in pituitary were upregulated. ATR exposure upregulated the level of P450scc, P450arom, 3ß-HSD and 17ß-HSD in ovary and downregulated ERß expression in female quails. However, ATR did not change ERα expression in ovary. This study provides new insights regarding female productive toxicology of ATR exposure. Ovary and oviduct in sexually maturing females were target organs of ATR-induced developmental toxicity. We propose that ATR-induced developmental abnormality of ovary and oviduct is associated with disruption of gonadal hormone balance and HPO axis in female quails.

Oviducal gland microstructure of Raja miraletus and Dipturus oxyrinchus (Elasmobranchii, Rajidae).

We studied the morphology and histology of the oviducal gland (OG) in the brown ray (Raja miraletus) and the long-nosed skate (Dipturus oxyrinchus) to understand its functional role in the reproductive strategy of these species. The external morphology of the gland was similar in both species, with lateral extensions like those found in other members of the Rajidae. Microscopic analysis showed a similar internal organization in both species. Immature and developing glands did not react to histochemical techniques. On reaching maturity, the OG had the largest width due to an increase in the production of secretory materials. In both species, the club zone of the gland showed a strong reaction to Periodic acid-Schiff (PAS) and alcian blue (AB) stains, indicating production of neutral and sulfated acid mucins. The secretory material produced by the papillary zone varied greatly between the two species. Both displayed tubular glands similar to those observed in the club zone, but in D. oxyrinchus the region near the lumen was intensely PAS+, whereas the last row of tubules of the brown ray stained intensely for a mixture of neutral and sulfated mucins. The baffle zone was the most conspicuous and extensive segment of all OGs, and it did not react to PAS/AB. The terminal zone, which is responsible for production of hair filaments, differed between the two species in terms of composition and organization of serous and mucous glands. This difference probably is related to the different substrates in which they release the egg capsules. Individual sperm detected in the brown ray baffle lamellae could be the result of a recent mating, whereas their presence in the deep recesses of the baffle and in the terminal zone of the long-nosed skate might indicate sperm storage.

Diethylstilbestrol regulates expression of avian apolipoprotein D during regression and recrudescence of the oviduct and epithelial-derived ovarian carcinogenesis.

Apolipoprotein D (APOD) is a glycoprotein which is widely expressed in mammalian tissues. It is structurally and functionally similar to the lipocalins which are multiple lipid-binding proteins that transport hydrophobic ligands and other small hydrophobic molecules, including cholesterol and several steroid hormones. Although multiple functions for APOD in various tissues have been reported, its expression, biological function, and hormonal regulation in the female reproductive system are not known. Thus, in this study, we focused on correlations between APOD and estrogen during development, differentiation, regression, and regeneration of the oviduct in chickens and in the development of ovarian carcinogenesis in laying hens. Results of the present study indicated that APOD messenger RNA (mRNA) expression increased (P < 0.001) in the luminal and glandular (GE) epithelia of the chicken oviduct in response to diethylstilbestrol (a nonsteroidal synthetic estrogen). In addition, the expression of APOD mRNA and protein decreased (P < 0.001) as the oviduct regressed during induced molting, and gradually increased (P < 0.001) with abundant expression in GE of the oviduct during recrudescence after molting. Furthermore, APOD mRNA and protein were predominantly localized in GE of cancerous, but not normal ovaries from laying hens. Collectively, results of the present study suggest that APOD is a novel estrogen-stimulated gene in the chicken oviduct which likely regulates growth, differentiation, and remodeling of the oviduct during oviposition cycles. Moreover, up-regulated expression of APOD in epithelial cell-derived ovarian cancerous tissue suggests that it could be a candidate biomarker for early detection and treatment of ovarian cancer in laying hens and in women.

Characterization and miRNA-mediated posttranscriptional regulation of vitelline membrane outer layer protein I in the adult chicken oviduct.

The laying hen is the best model for oviduct growth and development. The chicken oviduct produces the egg components, including the egg white and eggshell. However, the mechanism of egg component production during oviduct development requires further investigation. Vitelline membrane outer layer protein 1 (VMO-1) is found in the outer layer of the vitelline membrane of avian eggs. Comparison of the chicken VMO-1 protein-coding sequence and the human, mouse, rat, and bovine VMO-1 proteins via multiple sequence alignment analysis revealed high degrees of homology of 55%, 53%, 48%, and 54%, respectively. Although the avian homologue of VMO-1 is highly expressed in the magnum of the oviduct, little is known about the transcriptional and posttranscriptional regulation of VMO-1 during oviduct development. The results of this study revealed that estrogen induces VMO-1 messenger RNA (mRNA) expression in oviduct cells in vitro. The expression of genes interacting with VMO-1 by RNA interference (RNAi) functional analysis revealed that ovomucin expression was decreased by VMO-1 silencing. In addition, gga-miR-1623, 1552-3p, and 1651-3p influenced VMO-1 expression via its 3'-UTR, suggesting the posttranscriptional regulation of VMO-1 expression in chickens. Collectively, these results suggest that VMO-1 is an estrogen-induced gene that is posttranscriptionally regulated by microRNAs (miRNAs). The present study may contribute to an understanding of egg component production during chicken oviduct development.

Follistatin is essential for normal postnatal development and function of mouse oviduct and uterus.

Female mice lacking the follistatin gene but expressing a human follistatin-315 transgene (tghFST315) have reproductive abnormalities (reduced follicles, no corpora lutea and ovarian-uterine inflammation). We hypothesised that the absence of follistatin-288 causes the abnormal reproductive tract via both developmental abnormalities and abnormal ovarian activity. We characterised the morphology of oviducts and uteri in wild type (WT), tghFST315 and follistatin-knockout mice expressing human follistatin-288 (tghFST288). The oviducts and uteri were examined in postnatal Day-0 and adult mice (WT and tghFST315 only) using histology and immunohistochemistry. Adult WT and tghFST315 mice were ovariectomised and treated with vehicle, oestradiol-17ß (100ng injection, dissection 24h later) or progesterone (1mg×three daily injections, dissection 24h later). No differences were observed in the oviducts or uteri at birth, but abnormalities developed by adulthood. Oviducts of tghFST315 mice failed to coil, the myometrium was disorganised, endometrial gland number was reduced and oviducts and uteri contained abundant leukocytes. After ovariectomy, tghFST315 mice had altered uterine cell proliferation, and inflammation was maintained and exacerbated by oestrogen. These studies show that follistatin is crucial to postnatal oviductal-uterine development and function. Further studies differentiating the role of ovarian versus oviductal-uterine follistatin in reproductive tract function at different developmental stages are warranted.