Biology of Reproduction最新文献

A central determinant of successful reproduction is pregnancy establishment and maintenance that relies on proper development of the conceptus (embryo/fetus and associated extraembryonic membranes including the placenta). Pregnancy loss in cattle can be caused by inadequate development and differentiation of the placenta. However, the cellular and molecular mechanisms regulating bovine placenta development and, particularly, trophoblast differentiation are not well understood. Recent single-cell RNA-seq analyses revealed dynamic changes in cell populations and gene expression patterns during bovine placental development. Here, the chromatin accessibility landscape across diverse cell populations was determined in the developing (day 40) and mature (day 170) bovine placenta using the 10X Genomics multiome (snRNA-seq and snATAC-seq) platform. Analyses revealed distinct trophoblast, mesenchyme, endothelial, immune, and epithelial cell populations characterized by unique gene expression and chromatin accessibility signatures. ATAC-seq peaks defined open chromatin regions, facilitating the identification of transcription factor binding sites and candidate gene regulatory networks (GRN) involved with trophoblast differentiation. Several transcription factors, known for their involvement in trophoblast differentiation in other mammalian species, were identified as candidate regulators of uninucleate (UNC) to binucleate (BNC) trophoblast differentiation. This study adds to our foundational understanding of gene regulation and expression in the placenta, offering insights into the mechanisms governing pregnancy loss in cattle.

Although all domestic chicken breeds originate from their wild relatives, the red junglefowl, they have been selectively bred for high yields in egg or meat production， or both. Some breeds are highly efficient in egg production, while others perform poorly, due to long-term selection aimed for different purposes. Female primordial germ cells (PGCs) are the precursors of eggs and the population size of PGCs will ultimately determine ovarian reserve of hens. In this study, we observed that the layers exhibit greater proliferation capacity and a higher number of PGCs compared to the broilers before meiosis. By comparing the PGC transcriptomes between layers and broilers, we identified potential genes that regulate cell proliferation. We further confirmed that FOXO3 expression is higher in broilers, where it inhibits the PGC proliferation both in vivo and in vitro. However, in layers, the upstream BMP signaling stimulate the phosphorylation of AKT and suppress FOXO3 activity. Consequently, the elevated BMP signaling and reduced FOXO3 co-operatively promote more robust PGC proliferation in layers compared to broilers and result in a greater number of PGCs in layers. Our data not only reveal molecular mechanisms underlying PGC growth, but also provide new clues to improve the laying performance in chicken.

This study investigated differences in uterine and serum metabolome associated with clinical cure failure of metritis in dairy cows. Metritis was diagnosed in lactating Holstein cows from two Florida dairies and defined by the presence of fetid, watery, reddish-brown vaginal discharge from 4 to 12 days postpartum (dpp). Cows with metritis (n = 24) were paired with cows without metritis of similar parity and dpp (n = 24). On the day of metritis diagnosis (day 0), all cows with metritis received antimicrobial therapy. The continued presence of the fetid, watery, reddish-brown discharge on day 5 (n = 16) was defined as clinical cure failure, whereas clinical cure was defined by its absence (n = 8). Metabolome analyses of uterine lavage (days 0 and 5) and serum samples (day 0) were conducted using untargeted gas chromatography time-of-flight mass spectrometry. Normalized data were analyzed using partial least squares-discriminant analysis and ANOVA, adjusting P-values for multiple comparisons. Differences in the uterine metabolome on day 0 associated with clinical cure failure were linked to carbohydrate, amino acid, and lipid metabolism. Greater concentrations of arachidonic acid, ribose, and glutaric acid were associated with clinical cure failure, suggesting a greater degree of tissue lesion and inflammation. No differences in the serum metabolome were associated with cure failure. No differences in uterine metabolome were associated with clinical cure failure on day 5. The findings suggest that clinical cure failure is associated with a greater uterine inflammatory process that did not persist until cure assessment day.

The conjugation of small ubiquitin-like modifiers (SUMO) to target proteins, known as SUMOylation, plays a crucial role in regulating protein homeostasis, activity, interaction with other proteins, and subcellular localization. Loss of SUMOylation in non-growing oocytes by conditional deletion of the E2 sumo conjugating enzyme, Ube2i, at the primordial follicle stage leads to female sterility due to complex changes in oocyte development, including altered folliculogenesis, defective meiotic progression, and premature loss of the ovarian reserve. In this study, proteomics was used to compare control and Ube2i conditional knockout ovaries during the first wave of folliculogenesis to identify key differences that may drive the premature follicle loss phenotype. Data are available via ProteomeXchange with identifier PXD055913. Label-free mass spectrometry results showed that 238 proteins were significantly altered more than 2-fold (P < 0.05). Proteins upregulated in the Ube2i conditional knockout ovaries included those involved in mRNA splicing and WNT signaling, while those downregulated were related to metabolism, mitochondria, and the maternal effect proteins NLRP2 and NLRP9B. The majority of differentially expressed proteins showed no change by transcriptome analysis, indicating protein level regulation and revealing potential SUMOylation targets with necessary roles in oocyte and follicle development.

Advanced maternal age (AMA) patients experience decreased success from assisted reproductive technologies (ART), attributed to the quantity and quality of oocytes, which is significantly influenced by the intrafollicular granulosa cells (GCs). In this study, we compared the mRNA and microRNA (miRNA) transcriptomes between young (< 32 y.o.) and AMA (> 38 y.o.) patients' GCs to identify potential ovarian aging-related molecular signatures. We identified 293 and 21 differentially expressed genes (DEGs) and miRNAs (DE miRNAs), respectively, between young and aged GCs. Highly expressed mitochondrial-encoded genes, MT-ND3, MT-ND6, and MT-CYB, were downregulated in aged GCs, indicating potential mitochondrial insufficiency. Additionally, pathway analysis indicates DEGs are involved in inflammation, cytokine signaling, extracellular matrix (ECM) remodeling, and angiogenesis. Key DEGs related to these processes include CXCL8, IL1B, NLRP3, SIGIRR, ANGPT2, ADAM8, and ADAMTS14. Additionally, target gene prediction and pathway analysis of DE miRNAs indicates their potential post-transcriptional regulation of genes associated with cell signaling, mitochondrial function, oxidative stress, apoptosis, and senescence pathways in addition to cytokine signaling, angiogenesis, and ECM remodeling. To investigate regulatory mechanisms further, we looked at the DEGs' convergence with the DE miRNAs predicted target genes and we identified miR-483-3p, miR-1268a, miR-4497, miR-7704, miR-135a-5p, miR-1261, and miR-4791 as potential crucial regulators of genes involved in pathways associated with inflammation, ECM, and angiogenesis. This data suggests that aged GCs have an impaired ability to elicit the same pro-inflammatory response combined with dysregulation of angiogenesis and ECM remodeling compared to young GCs, and miRNA may play a role in regulating key ovulatory processes. While this study identifies potential regulatory relationships between DE miRNAs and DEGs, experimental validation is necessary to confirm the relationships and biological relevance.

Ovarian differentiation relies on the accurate and orderly expression of numerous related genes. Forkhead box protein L2 (FOXL2) is one of the earliest ovarian differentiation markers and transcription factors. In sex determination, FOXL2 maintains the differentiation of the female pathway by inhibiting male differentiation genes, including SOX9 and SF1. In addition, FOXL2 promotes the synthesis of follicle-stimulating hormone and anti-Müllerian hormone to support follicle development. Mutations in FOXL2 are associated with numerous female reproductive diseases. A comprehensive and in-depth study of FOXL2 provides novel strategies for the diagnosis and treatment of such diseases. This review discusses the mechanism of FOXL2 in female sex differentiation and maintenance, hormone synthesis, and disease occurrence and reveals the role of FOXL2 as a central factor in female sex development and fertility maintenance. This review will serve as a reference for identifying novel targets of other regulatory factors interacting with FOXL2 in female sex determination and follicle development and for the diagnosis and treatment of female reproductive diseases.

Analysis of testis histology is fundamental to the study of male fertility, but it is a slow task with a high skill threshold. Here, we describe new neural network models for the automated classification of cell types and tubule stages from whole-slide brightfield images of mouse testis. The cell type classifier recognizes 14 cell types, including multiple steps of meiosis I prophase, with an external validation accuracy of 96%. The tubule stage classifier distinguishes all 12 canonical tubule stages with external validation accuracy of 63%, which increases to 96% when allowing for ±1 stage tolerance. We addressed generalizability of SATINN, through extensive training diversification and testing on external (non-training population) wildtype and mutant datasets. This allowed us to use SATINN to successfully process data generated in multiple laboratories. We used SATINN to analyze testis images from 8 different mutant lines, generated from 3 different labs with a range of tissue processing protocols. Finally, we show that it is possible to use SATINN output to cluster histology images in latent space, which, when applied to the 8 mutant lines, reveals known relationships in their pathology. This work represents significant progress towards a tool for robust, automated testis histopathology that can be used by multiple labs.

Developmental exposure to environmental chemicals perturbs establishment and maintenance of the ovarian reserve across the reproductive lifetime, leading to premature follicle depletion and ovarian aging. Considering humans are exposed to a complex mixture of environmental chemicals, real-life models assessing their cumulative impact on the ovarian reserve are needed. Biosolids are a source of a real-life mixture of environmental chemicals. While earlier studies demonstrated that grazing pregnant sheep on biosolids-treated pastures did not influence establishment of the ovarian reserve in fetal life, its impact on subsequent depletion of ovarian reserve during reproductive life of offspring is unknown. We hypothesized that developmental exposure to biosolids accelerates depletion of ovarian reserve. Ovaries were collected from F1 juveniles (9.5 weeks) and adults (2.5 years) born to F0 ewes grazed on control inorganic fertilizer pastures or biosolids-treated pastures from before conception and throughout gestation. The impact on follicular density, activation rate, and anti-Müllerian hormone (mediator of activation) expression by immunohistochemistry was determined. Activation rate was increased in F1 biosolids-treated pastures juveniles with a corresponding reduction in primordial follicle density. In contrast, activation rate and ovarian reserve were similar between control and F1 biosolids-treated pastures adults. The density of anti-Müllerian hormone-positive antral follicles was lower in biosolids-treated pastures juveniles, whereas anti-Müllerian hormone expression tended to be higher in antral follicles of biosolids-treated pastures adults, consistent with the changes in the ovarian reserve. These findings of detrimental effects of developmental exposure to biosolids during juvenile life that normalizes in adults is supportive of a shift in activation rate likely related to peripubertal hormonal changes.

Intrauterine adhesions (IUA) represent a prevalent uterine endometrial disorder frequently correlated with menstrual irregularities and infertility. Some members of the secretoglobin(SCGB) family have demonstrated anti-fibrotic effects, however, the specific role of SCGB1D4, one of the family members, in anti-fibrosis remains unclear. This study aimed to investigate the expression of SCGB1D4 in IUA tissues, validate the role of SCGB1D4 in endometrial fibrosis, and assess its potential therapeutic significance by analyzing clinical features and constructing rat and cell models. Clinical characteristics of patients with intrauterine adhesions (IUA) were compared and analyzed against control subjects. Additionally, a rat uterine adhesion model was successfully established using a combination of mechanical injury and infection. The expression levels of SCGB1D4 in patient tissues and animal models were detected through immunohistochemistry, Western blot, and real-time fluorescence quantitative PCR, and the changes in fibrosis markers COL1A1 and α-SMA were also evaluated. Furthermore, human endometrial stromal cell lines (HESCs) induced by transforming growth factor-β-1 conversion were differentiated into myofibroblasts to establish cell models of intrauterine adhesion. We detected the expression of SCGB1D4 and fibrosis-related factors by real-time fluorescence quantitative PCR and Western blot. Cell proliferation and cell cycle changes were assessed using flow cytometry and CCK8. IUA patients showed increased miscarriage rates and decreased endometrial thickness. Clinical tissue specimens revealed significantly lower expression of SCGB1D4 in the endometrial tissues of IUA patients, accompanied by a notable increase in COL1A1 and α-SMA. The established rat model of intrauterine adhesion exhibited decreased expression of SCGB1D4 and a significant increase in fibrosis. After overexpression of SCGB1D4 on the IUA cell model, SCGB1D4 expression was elevated, while COL1A1 and α-SMA expression was significantly reduced. Cell proliferation was inhibited and cell cycle distribution was altered. This study has confirmed the low expression of SCGB1D4 in patients with IUA, as well as in animal and cell models. Furthermore, the overexpression of SCGB1D4 in a cell model of IUA demonstrates that it may play a key role in inhibiting fibrosis. SCGB1D4 holds promise as a potential therapeutic target for IUA, providing a new avenue for overcoming fertility issues caused by IUA.

The embryonic diapause of the giant panda (Ailuropoda melanoleuca) has caused great difficulties in monitoring pregnancy in this vulnerable species. The secretion of prolactin (PRL) from anterior pituitary glandular lactotropic cells is an important signal for the termination of embryonic dormancy. Currently, the mechanism by which PRL affects embryonic diapause in giant pandas and methods for detecting PRL in this species is poorly understood. In this study, the first sandwich enzyme immunoassay for detecting PRL in giant panda urine was established by using two antigiant panda PRL antibodies prepared as coating and labeling antibodies, and PRL recombinant proteins prepared via the prokaryotic system as standards. The established method was used to detect the levels of PRL in the urine of giant pandas during pregnancy. At the same time, the changes in PRL levels in giant pandas and the relationship between PRL and progestagen levels were analyzed during the luteal phase. The results showed that in female giant pandas, PRL levels significantly increased before the progestagen peak, and during the luteal phase, the PRL level was significantly greater in giant pandas that gave birth than in those that did not give birth and those in the nonestrus group. To the best of our knowledge, this is the first study to preliminarily explore the mode of action of PRL in the gestation period of giant pandas and lays a foundation for further study of the regulatory mechanisms of endocrine hormones in the giant panda.