The role of lncFABP4 in modulating adipogenic differentiation in buffalo intramuscular preadipocytes.

Intramuscular fat (IMF) is a crucial determinant of meat quality and is influenced by various regulatory factors. Despite the growing recognition of the important role of long noncoding RNAs (lncRNAs) in IMF deposition, the mechanisms underlying buffalo IMF deposition remain poorly understood. In this study, we identified and characterized a lncRNA, lncFABP4, which is transcribed from the antisense strand of fatty acid-binding protein 4 (FABP4). lncFABP4 inhibited cell proliferation in buffalo intramuscular preadipocytes. Moreover, lncFABP4 significantly increased intramuscular preadipocyte differentiation, as indicated by an increase in the expression of the adipogenic markers peroxisome proliferator-activated receptor gamma (PPARG), CCAAT enhancer binding protein alpha (C/EBPα), and FABP4. Mechanistically, lncFABP4 was found to have the potential to regulate downstream gene expression by participating in protein-protein interaction pathways. These findings contribute to further understanding of the intricate mechanisms through which lncRNAs modulate intramuscular adipogenesis in buffaloes.

Expression pattern of ATG4C and its effect on early embryonic development of porcine oocytes.

Autophagy is essential for oocyte maturation and preimplantation embryo development. ATG4C, a member of the ATG4 family, plays a crucial role in the autophagy process. The effect of ATG4C on the early embryonic development in pig has not been studied. In this study, the expression patterns of ATG4C were explored using qRT-PCR and immunofluorescence staining. Different concentrations of serum were added to in vitro maturation (IVM) medium to investigate its effects on oocyte maturation and embryonic development. Finally, the developmental potential of parthenogenetic embryos was detected by downregulating ATG4C in MII stage oocytes under 0 % serum condition. The results revealed that ATG4C was highly expressed in porcine oocytes matured in vitro and in parthenogenetic embryos. Compared with the 10 % serum group, the cumulus cell expansion, first polar body (PB1) extrusion rate, and subsequent developmental competence of embryos were reduced in the 0 % and 5 % serum groups. The mRNA levels of LC3, ATG5, BECLIN1, TFAM, PGC1α, and PINK1 were significantly increased (P < 0.05) in the 0 % serum group. ATG4C was significantly upregulated in the embryos at the 1-cell, 2-cell, 8-cell, and 16-cell stages in the 0 % serum group (P < 0.05). Compared with the negative control group, downregulation of ATG4C significantly decreased the 4-cell, 8-cell, and blastocyst rates (P < 0.05), and the expression of genes related to autophagy, mitochondria, and zygotic genome activation (ZGA) was significantly decreased (P < 0.05). The relative fluorescence intensity of LC3 and mitochondrial content in the ATG4C siRNA group was significantly reduced (P < 0.05). Collectively, the results indicate that ATG4C is highly expressed in porcine oocytes matured in vitro and in early embryos, and inhibition of ATG4C effects embryonic developmental competence by decreasing autophagy, mitochondrial content, and ZGA under serum-free condition.

Testosterone Supplementation Promotes Estrogen Synthesis of Buffalo Cumulus Cells Surrounding In Vitro-Matured Oocytes.

Cumulus cells (CCs) synthesize estrogens that are essential for follicular development. However, the effects of androgen on estrogen production in buffalo CCs remain unknown. In the present study, the impacts of testosterone on estrogen synthesis of buffalo CCs surrounding in vitro-matured oocytes were investigated. The results showed that testosterone supplementation improved both the expression levels of estrogen synthesis-related genes (CYP11A1, CYP19A1, and 17ß-HSD) and the secretion levels of estradiol in buffalo CCs surrounding in vitro-matured oocytes. Furthermore, testosterone treatment enhanced the sensitivity of buffalo CCs surrounding in vitro-matured oocytes to follicle-stimulating hormone (FSH). This study indicated that testosterone supplementation promoted the estrogen synthesis of buffalo CCs surrounding in vitro-matured oocytes mainly through strengthening the responsiveness of CCs to FSH. The present study serves as a foundation of acquiring high-quality recipient oocytes for buffalo somatic cell nuclear transfer.

Multi-omics reveals the mechanism of rumen microbiome and its metabolome together with host metabolome participating in the regulation of milk production traits in dairy buffaloes.

Recently, it has been discovered that certain dairy buffaloes can produce higher milk yield and milk fat yield under the same feeding management conditions, which is a potential new trait. It is unknown to what extent, the rumen microbiome and its metabolites, as well as the host metabolism, contribute to milk yield and milk fat yield. Therefore, we will analyze the rumen microbiome and host-level potential regulatory mechanisms on milk yield and milk fat yield through rumen metagenomics, rumen metabolomics, and serum metabolomics experiments. Microbial metagenomics analysis revealed a significantly higher abundance of several species in the rumen of high-yield dairy buffaloes, which mainly belonged to genera, such as Prevotella, Butyrivibrio, Barnesiella, Lachnospiraceae, Ruminococcus, and Bacteroides. These species contribute to the degradation of diets and improve functions related to fatty acid biosynthesis and lipid metabolism. Furthermore, the rumen of high-yield dairy buffaloes exhibited a lower abundance of methanogenic bacteria and functions, which may produce less methane. Rumen metabolome analysis showed that high-yield dairy buffaloes had significantly higher concentrations of metabolites, including lipids, carbohydrates, and organic acids, as well as volatile fatty acids (VFAs), such as acetic acid and butyric acid. Meanwhile, several Prevotella, Butyrivibrio, Barnesiella, and Bacteroides species were significantly positively correlated with these metabolites. Serum metabolome analysis showed that high-yield dairy buffaloes had significantly higher concentrations of metabolites, mainly lipids and organic acids. Meanwhile, several Prevotella, Bacteroides, Barnesiella, Ruminococcus, and Butyrivibrio species were significantly positively correlated with these metabolites. The combined analysis showed that several species were present, including Prevotella.sp.CAG1031, Prevotella.sp.HUN102, Prevotella.sp.KHD1, Prevotella.phocaeensis, Butyrivibrio.sp.AE3009, Barnesiella.sp.An22, Bacteroides.sp.CAG927, and Bacteroidales.bacterium.52-46, which may play a crucial role in rumen and host lipid metabolism, contributing to milk yield and milk fat yield. The "omics-explainability" analysis revealed that the rumen microbial composition, functions, metabolites, and serum metabolites contributed 34.04, 47.13, 39.09, and 50.14%, respectively, to milk yield and milk fat yield. These findings demonstrate how the rumen microbiota and host jointly affect milk production traits in dairy buffaloes. This information is essential for developing targeted feeding management strategies to improve the quality and yield of buffalo milk.

Zinc improves the developmental ability of bovine in vitro fertilization embryos through its antioxidative action.

Zinc, an essential trace mineral, exerts a pivotal influence in various biological processes. Through zinc concentration analysis, we found that the zinc concentration in the bovine embryo in vitro culture (IVC) medium was significantly lower than that in bovine follicular fluid. Therefore, this study explored the impact of zinc sulfate on IVC bovine embryo development and investigated the underlying mechanism. The results revealed a significant decline in zygote cleavage and blastocyst development rates when zinc deficiency was induced using zinc chelator N, N, N', N'-Tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) in culture medium during embryo in vitro culture. The influence of zinc-deficiency was time-dependent. Conversely, supplementing 0.8 µg/mL zinc sulfate to culture medium (CM) increased the cleavage and blastocyst formation rate significantly. Moreover, this supplementation reduced reactive oxygen species (ROS) levels, elevated the glutathione (GSH) levels in blastocysts, upregulated the mRNA expression of antioxidase-related genes, and activated the Nrf2-Keap1-ARE signaling pathways. Furthermore, 0.8 µg/mL zinc sulfate enhanced mitochondrial membrane potential, maintained DNA stability, and enhanced the quality of bovine (in vitro fertilization) IVF blastocysts. In conclusion, the addition of 0.8 µg/mL zinc sulfate to CM could enhance the antioxidant capacity, activates the Nrf2-Keap1-ARE signaling pathways, augment mitochondrial membrane potential, and stabilizes DNA, ultimately improving blastocyst quality and in vitro bovine embryo development.

Buffalo bbu-miR-493-5p Promotes Myoblast Proliferation and Differentiation.

In recent years, the meat and dairy value of buffaloes has become a major concern in buffalo breeding, and the improvement of buffalo beef quality is key to protecting buffalo germplasm resources and solving the problem of beef supply. MiRNAs play a significant role in regulating muscle development. However, the precise mechanism by which they regulate the development of buffalo skeletal muscles remains largely unexplored. In this study, we examined miRNA expression profiles in buffalo myoblasts during the proliferation and differentiation stages. A total of 177 differentially expressed miRNAs were identified, out of which 88 were up-regulated and 89 down-regulated. We focused on a novel miRNA, named bbu-miR-493-5p, that was significantly differentially expressed during the proliferation and differentiation of buffalo myoblasts and highly expressed in muscle tissues. The RNA-FISH results showed that bbu-miR-493-5p was primarily located in the cytoplasm to encourage buffalo myoblasts' proliferation and differentiation. In conclusion, our study lays the groundwork for future research into the regulatory role of miRNAs in the growth of buffalo muscle.

Overexpression of BRG1 improves early development of porcine somatic cell nuclear transfer embryos.

The epigenetic modification levels of donor cells directly affect the developmental potential of somatic cell nuclear transfer (SCNT) embryos. BRG1, as an epigenetic modifying enzyme, has not yet been studied in donor cells and SCNT embryos. In this study, BRG1 was overexpressed in porcine fetal fibroblasts (PFFs), its effect on chromatin openness and gene transcription was examined, subsequently, the development potential of porcine SCNT embryos was investigated. The results showed that compared with the control group, the percentage of G1 phase cells was significantly increased (32.3 % ± 0.87 vs 25.7 % ± 0.81, P < 0.05) in the experimental group. The qRT-PCR results showed that the expression of H3K9me3-related genes was significantly decreased (P < 0.05), HAT1 was significantly increased (P < 0.05). Assay of Transposase Accessible Chromatin sequencing (ATAC-seq) results revealed that SMARCA4、NANOG、SOX2、MAP2K6 and HIF1A loci had more open chromatin peaks in the experimental group. The RNA-seq results showed that the upregulated genes were mainly enriched in PI3K/AKT and WNT signaling pathways, and the downregulated genes were largely focused on disease development. Interestingly, the developmental rate of porcine SCNT embryos was improved (27.33 % ± 1.40 vs 17.83 % ± 2.02, P < 0.05), the expression of zygotic gene activation-related genes in 4-cell embryos, and embryonic development-related genes in blastocysts was significantly upregulated in the experimental group (P < 0.05). These results suggest that overexpression of BRG1 in donor cells is benefit for the developmental potential of porcine SCNT embryos.

Isolation methods, proliferation, and adipogenic differentiation of adipose-derived stem cells from different fat depots in bovines.

The adipose-derived stem cells (ASCs) are a valuable resource for regenerative medicine and essential materials for research in fat deposition. However, the isolation procedure of ASCs has not been standardized and needs to be harmonized; differences in proliferation and adipogenic differentiation of ASCs obtained from different fat depots have not been well characterized. In the present study, we compared the efficiency of ASCs isolation by enzymatic treatment and explant culture methods and the proliferation ability and adipogenic differentiation potential of ASCs isolated from subcutaneous and visceral fat depots. The explant culture method was simple and with no need for expensive enzymes while the enzymatic treatment method was complex, time consuming and costly. By the explant culture method, a larger number of ASCs were isolated from subcutaneous and visceral fat depots. By contrast, fewer ASCs were obtained by the enzymatic treatment method, especially from visceral adipose. ASCs isolated by the explant culture method performed well in cell proliferation and adipogenic differentiation, though they were slightly lower than those by the enzymatic treatment method. ASCs isolated from visceral depot demonstrated higher proliferation ability and adipogenic differentiation potential. In total, the explant culture method is simpler, more efficient, and lower cost than the enzymatic treatment method for ASCs isolation; compared with visceral adipose, subcutaneous adipose is easier to isolate ASCs; however, the visceral ASCs are superior to subcutaneous ASCs in proliferation and adipogenic differentiation.

Functionally conserved PPARG exonic circRNAs enhance intramuscular fat deposition by regulating PPARG and HSL.

Circular RNAs (circRNA) are a kind of endogenous biological macromolecules that play significant roles in many biological processes, including adipogenesis, a precisely orchestrated process that is mediated by a large number of factors. Among them, peroxisome proliferator-activated receptor gamma (PPARG), is undoubtedly the most important regulator of adipocyte development in all types of adipose tissue. The formation of intramuscular fat (IMF), is a key factor that influences the meat quality in livestock animals. PPARG has been demonstrated to show a positive correlation with IMF deposition although the regulatory mechanism involved is not known. This study demonstrates that PPARG mediates IMF deposition by producing multiple exonic circRNAs (circPPARGs). Three circPPARGs promote adipogenic differentiation and inhibit the proliferation of intramuscular preadipocytes and these effects are conserved across several species including buffaloes, cattle and mice. Notably, circPPARG1 interacts with PPARG protein to inhibit the transcription of hormone sensitive lipase (HSL) involved in lipolysis. In addition, the positive effects of circPPARG1 on IMF deposition were identified in mice in vivo. Thus, PPARG drives IMF deposition, not only through the common transcription factor pathway, but also by producing circRNAs. This study provides new insights into our understanding of the regulatory mechanisms of PPARG in IMF deposition.

A Circular RNA Generated from Nebulin (NEB) Gene Splicing Promotes Skeletal Muscle Myogenesis in Cattle as Detected by a Multi-Omics Approach.

Cattle and the draught force provided by its skeletal muscle have been integral to agro-ecosystems of agricultural civilization for millennia. However, relatively little is known about the cattle muscle functional genomics (including protein coding genes, non-coding RNA, etc.). Circular RNAs (circRNAs), as a new class of non-coding RNAs, can be effectively translated into detectable peptides, which enlightened us on the importance of circRNAs in cattle muscle physiology function. Here, RNA-seq, Ribosome profiling (Ribo-seq), and peptidome data are integrated from cattle skeletal muscle, and detected five encoded peptides from circRNAs. It is further identified and functionally characterize a 907-amino acids muscle-specific peptide that is named circNEB-peptide because derived by the splicing of Nebulin (NEB) gene. This peptide localizes to the nucleus and cytoplasm and directly interacts with SKP1 and TPM1, key factors regulating physiological activities of myoblasts, via ubiquitination and myoblast fusion, respectively. The circNEB-peptide is found to promote myoblasts proliferation and differentiation in vitro, and induce muscle regeneration in vivo. These findings suggest circNEB-peptide is an important regulator of skeletal muscle regeneration and underscore the possibility that more encoding polypeptides derived by RNAs currently annotated as non-coding exist.

Three-dimensional glass scaffolds improve the In Vitro maturation of porcine cumulus-oocyte complexes and subsequent embryonic development after parthenogenetic activation.

In vitro maturation (IVM) methods for porcine oocytes are still deficient in achieving full developmental capacity, as the currently available oocyte in vitro culture systems still have limitations. In vitro embryo production must also improve the porcine oocyte IVM system to acquire oocytes with good developmental potential. Herein, we tested a three-dimensional (3D) glass scaffold culture system for porcine oocyte maturation. After 42 h, we matured porcine cumulus-oocyte complexes (COCs) on either two-dimensional glass dishes (2D-B), two-dimensional microdrops (2D-W), or 3D glass scaffolds. The 3D glass scaffolds were tested for porcine oocyte maturation and embryonic development. Among these culture methods, the extended morphology of the 3D group maintained a 3D structure better than the 2D-B and 2D-W groups, which had flat COCs that grew close to the bottom of the culture vessel. The COCs of the 3D group had a higher cumulus expansion index and higher first polar body extrusion rate, cleavage rate, and blastocyst rate of parthenogenetic embryos than the 2D-B group. In the 3D group, the cumulus-expansion-related gene HAS2 and anti-apoptotic gene Bcl-2 were significantly upregulated (p < 0.05), while the pro-apoptotic gene Caspase3 was significantly downregulated (p < 0.05). The blastocysts of the 3D group had a higher relative expression of Bcl-2, Oct4, and Nanog than the other two groups (p < 0.05). The 3D group also had a more uniform distribution of mitochondrial membrane potential and mitochondria (p < 0.05), and its cytoplasmic active oxygen species content was much lower than that in the 2D-B group (p < 0.05). These results show that 3D glass scaffolds dramatically increased porcine oocyte maturation and embryonic development after parthenogenetic activation, providing a suitable culture model for porcine oocytes.

BRG1 enhances porcine iPSC pluripotency through WNT/ß-catenin and autophagy pathways.

Brahma-related gene 1 (BRG1) enhances the pluripotency of embryonic and adult stem cells, however, its effect on induced pluripotent stem cell (iPSC) pluripotency has not been reported. The aim of this study was to investigate the effect of BRG1 on porcine iPSC pluripotency and its mechanisms. The effect of BRG1 on porcine iPSC pluripotency was explored by positive and negative control it. The mechanism was investigated by regulating the WNT/ß-catenin signaling pathway and autophagy flux. The results showed that inhibition of BRG1 decreased pluripotency-related gene expression in porcine iPSCs; while its overexpression had the opposite effect, the expression of WNT/ß-catenin signaling pathway- and autophagy-related genes was significantly up-regulated (P < 0.05) in the BRG1 overexpressed group when compared to the control group. Inhibited pluripotency-related gene or protein expression, decreased autophagy flux, and increased mitochondrial length and mitochondrial membrane potential (MMP) were observed when porcine iPSCs were treated with the WNT/ß-catenin signaling pathway inhibitor IWR-1. Forced BRG1 expression restored porcine iPSC pluripotency, increased autophagy flux, shortened mitochondria, and reduced MMP. Lastly, Compound C was used to activate porcine iPSC autophagy, and it was found that the expression of BRG1 and ß-catenin increased, and pluripotency-related gene and protein expression was up-regulated; these effects were reversed when the BRG1 inhibitor PFI-3 and IWR-1 were added. These results suggested that BRG1 enhanced the pluripotency of porcine iPSCs through WNT/ß-catenin and autophagy pathways.

Follistatin (FST) is expressed in buffalo (Bubalus bubalis) ovarian follicles and promotes oocyte maturation and early embryonic development.

Follistatin (FST), a member of the transforming growth factor-ß (TGF-ß) superfamily, has been identified as an inhibitor of follicle-stimulating hormone. Previous studies showed that it plays an important role in animal reproduction. Therefore, this study aims to investigate its effect on the maturation of buffalo oocytes in vitro, and the underlying mechanism of FST affecting oocyte maturation was also explored in buffalo cumulus cells. Results showed that FST was enriched in the ovary and expressed at different stages of buffalo ovarian follicles as well as during oocyte maturation and early embryo development. The FST expression level was up-regulated in MII buffalo oocytes compared with the GV stage (p < .05). To study the effects of FST on buffalo oocytes' maturation and early embryonic development, we added the pcD3.1 skeleton vector and PCD3.1-EGFP-FST vector into the maturation fluid of buffalo oocytes, respectively. It was demonstrated that FST promoted the in vitro maturation rate of buffalo oocytes and the blastocyst rate of embryos cultured in vitro (p < .05). By interfering with FST expression, we discovered that FST in cumulus cells plays a crucial role in oocyte maturation. Interference with the FST expression during the buffalo oocyte maturation did not affect the first polar body rate of buffalo oocyte (p > .05). In contrast, the location of mitochondria in oocytes was abnormal, and the cumulus expansion area was reduced (p < .05). After parthenogenetic activation, the cleavage and blastocyst rates of the FST-interfered group were reduced (p < .05). Furthermore, RT-qPCR was performed to investigate further the underlying mechanism by which FST enhances oocyte maturation. We found that overexpression of FST could up-regulate the expression level of apoptosis suppressor gene Bcl-2 and TGF-ß/SMAD pathway-related genes TGF-ß, SMAD2, and SMAD3 (p < .05). In contrast, the expression levels of SMAD4 and pro-apoptotic gene BAX were significantly decreased (p < .05). The FST gene could affect buffalo oocyte maturation by regulating the oocyte mitochondria integrity, the cumulus expansion, cumulus cell apoptosis, and the expression levels of TGF-ß/SMAD pathway-related genes.

A newly identified lncRNA lnc000100 regulates proliferation and differentiation of cattle skeletal muscle cells.

Cattle skeletal muscle development is a complex and highly coordinated biological process mediated by a series of myogenic regulators, which plays a critical role in beef yield and quality. Long non-coding RNAs (lncRNAs) have been shown to regulate skeletal muscle development. However, the molecular mechanism by which lncRNAs regulate skeletal muscle development is largely unknown. We performed transcriptome analysis of muscle tissues of adult and embryo Angus cattle to investigate the mechanism by which lncRNA regulates skeletal muscle development between adult and embryo cattle. A total of 37,115 candidate lncRNAs were detected, and a total of 1,998 lncRNAs were differentially expressed between the muscle tissue libraries of adult and embryo cattle, including 1,229 up-regulated lncRNAs and 769 down-regulated lncRNAs (adult cattle were the control group). We verified the expression of 7 differentially expressed lncRNAs by quantitative real-time PCR (RT-qPCR), and analysed the tissue expression profile of lnc000100, which is down-regulated in the longest dorsal muscle during foetal life and which is highly specifically expressed in muscle tissue. We found that the interference of lnc000100 significantly inhibited cell proliferation and promoted cell differentiation. Lnc000100 was located in the nucleus by RNA-FISH. Our research provides certain resources for the analysis of lncRNA regulating cattle skeletal muscle development, and may also provide new insights for improving beef production and breed selection.

Identification of lncRNAs associated with muscle development and skeletal muscle disease that are differentially expressed between embryo and adult cattle. We identified 1,998 differentially expressed lncRNAs between the muscle tissue libraries of adult and embryo. GO analysis showed that these lncRNAs were involved in muscle development.Construction of co-expression networks and competitive endogenous networks related to muscle development. We constructed the co-expression networks and lncRNA-miRNA-mRNA interaction networks of four differentially expressed lncRNAs.A newly identified lncRNA lnc000100 promoted myoblast proliferation and inhibited myoblast differentiation during muscle development. GO analysis showed that lnc000100 was associated with muscle development (such as muscle structure development, etc.) and skeletal muscle diseases (such as muscle hypertrophy, etc.). FISH analysis suggests that lnc000100 is localized in the nucleus and may regulate muscle development at the transcriptional/post-transcriptional level.

Testosterone supplementation improves estrogen synthesis of buffalo (Bubalus bubalis) granulosa cells.

Granulosa cells (GCs) synthesize estrogens needed for follicular growth. However, the effects of androgen on estrogen production in buffalo GCs remain unclear. In this study, the impacts of testosterone on estrogen synthesis in buffalo GCs were examined. The results showed that testosterone that was added to cell medium at a concentration of 10-7 mol/L and applied to GCs for 48 or 72 h enhanced the estrogen synthesis of buffalo GCs. This study provides a theoretical basis for further exploration of ovarian endocrine mechanism for steroidogenesis.

Comparison of symmetrical and asymmetrical cleavage 2-cell embryos of porcine by Smart-seq2.

Early cleavage (EC) influences the development of the pre-implantation and post-implantation embryo. Symmetric cleavage (Sym) and asymmetric cleavage (Asy) have been observed in EC, but its molecular mechanism remains unclear. This study was designed to pick out the key candidate genes and signaling pathway between Sym and Asy embryos by applying Smart-seq2 technique. In in-vitro fertilization (IVF) 2-cell embryos, Sym embryos and Asy embryos accounted for 62.55% and 37.45%, respectively. The 2-cell rate, blastocyst rate and total blastocyst cells of Sym group were significantly higher than those of Asy group (31.38% vs 18.79%, 47.55% vs 29.5%, 71.33 vs 33.67, P < 0.05). The 2-cell rate, blastocyst rate and total blastocyst cell number in parthenogenetic activation (PA) embryos in Sym group were significantly higher than those in Asy group (40.61% vs 23.64%, 63.15% vs 30.11%, 50.75 vs 40.5, P < 0.05). A total of 216 differentially expressed genes (DEGs) incorporating 147 genes up-regulated and 69 genes down-regulated genes were screened under the p-value <0.05 and |log2 (fold change)| ≥ 1 when compared with Sym group. Further Gene Ontology (GO) analysis showed that these DEGs were related to the regulation of metabolic process, cell cycle, chromosome segregation, centromeric region and microtubule cytoskeleton. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the DEGs were mainly enriched to oocyte meiosis, cell cycle, p53 and Hippo signaling pathways. We concluded that asymmetric cleavage is a consequence of altered gene expression. Atg4c, Sesn2, Stk11ip, Slc25a6, Cep19 and Cep55 associated with mitochondrial function and cytoskeletal structure were probably the key candidate genesto determine the zygote cleavage pattern.

Hypoxia enhances steroidogenic competence of buffalo (Bubalus bubalis) granulosa cells.

Granulosa cells (GCs) synthesize estrogens needed for follicular growth. However, the effects of hypoxia on steroidogenesis in buffalo GCs remain unclear. In this study, the impacts of hypoxic conditions (5% oxygen) on estrogen synthesis in buffalo GCs were examined. The results showed that hypoxia improved both the expression levels of estrogen synthesis-related genes (CYP11A1, CYP19A1, and 3ß-HSD) and the secretion levels of estradiol in buffalo GCs. Hypoxic conditions promoted the sensitivity of buffalo GCs to FSH. Furthermore, inhibition of cAMP/PKA signaling pathway (H89, a cAMP/PKA signaling pathway inhibitor) reduced both the expression levels of estrogen synthesis-related genes (CYP11A1, CYP19A1, and 3ß-HSD) and the secretion levels of estradiol in hypoxia-cultured buffalo GCs. Besides, inhibition of cAMP/PKA signaling pathway lowered the responsiveness of buffalo GCs to FSH under hypoxic conditions. The present study indicated that hypoxia enhanced the steroidogenic competence of buffalo GCs principal by affecting cAMP/PKA signaling pathway and subsequent sensitivity of GCs to FSH.

Epifriedelanol delays the aging of porcine oocytes matured invitro.

Oocyte aging directly affects the subsequent embryonic development. Epifriedelanol is the active ingredient of Aster tataricus L.F. extract, and it possesses potential anti-cancer, anti-inflammatory and antioxidant properties. In addition, epifriedelanol can slow the aging of human skin fibroblasts. To explore the effect of epifriedelanol on the aging of porcine oocytes matured in vitro, the aging model was first established, epifriedelanol was added to in vitro maturation (IVM) medium to investigate its anti-aging effects by observing oocyte maturation and embryonic development potential, and analyzing aging-related gene expression, reactive oxygen species and mitochondrial membrane potential levels. It was found that typical aging of porcine oocytes appeared from 66 h during in vitro maturation. Compared with the 44 h group, a larger perivitelline space, increased abnormality of microtubulin formation, and significantly lower blastocyst rate were observed in the 66 h and 72 h groups. Compared with the 0 µg/mL group, the first polar body extrusion, cleavage and blastocyst rates were significantly improved (P < 0.05) in 10 µg/mL group. The expression of oocyte developmental potential-related, SIRT family-related, antioxidant and anti-apoptotic-related genes was significantly up-regulated (P < 0.05), p53 and pro-apoptotic genes were significantly down-regulated (P < 0.05). In addition, the reactive oxygen species level was significantly decreased (P < 0.01), the mitochondrial membrane potential was significantly elevated (P < 0.01) in 10 µg/mL group. In conclusion, epifriedelanol delays the aging of porcine oocytes cultured in vitro by up-regulating SIRT family gene expression, enhancing the antioxidant and anti-apoptotic capacity of oocytes.

Whole-genome transcriptome and DNA methylation dynamics of pre-implantation embryos reveal progression of embryonic genome activation in buffaloes.

BACKGROUND: During mammalian pre-implantation embryonic development (PED), the process of maternal-to-zygote transition (MZT) is well orchestrated by epigenetic modification and gene sequential expression, and it is related to the embryonic genome activation (EGA). During MZT, the embryos are sensitive to the environment and easy to arrest at this stage in vitro. However, the timing and regulation mechanism of EGA in buffaloes remain obscure. RESULTS: Buffalo pre-implantation embryos were subjected to trace cell based RNA-seq and whole-genome bisulfite sequencing (WGBS) to draw landscapes of transcription and DNA-methylation. Four typical developmental steps were classified during buffalo PED. Buffalo major EGA was identified at the 16-cell stage by the comprehensive analysis of gene expression and DNA methylation dynamics. By weighted gene co-expression network analysis, stage-specific modules were identified during buffalo maternal-to-zygotic transition, and key signaling pathways and biological process events were further revealed. Programmed and continuous activation of these pathways was necessary for success of buffalo EGA. In addition, the hub gene, CDK1, was identified to play a critical role in buffalo EGA. CONCLUSIONS: Our study provides a landscape of transcription and DNA methylation in buffalo PED and reveals deeply the molecular mechanism of the buffalo EGA and genetic programming during buffalo MZT. It will lay a foundation for improving the in vitro development of buffalo embryos.

Lipopolysaccharide accelerates tryptophan degradation in the ovary and the derivative kynurenine disturbs hormone biosynthesis and reproductive performance.

Lipopolysaccharide (LPS), also known as endotoxin, is a component of the outer membrane of gram-negative bacteria. LPS is released into the surrounding environment during bacterial death and lysis. Due to its chemical and thermal stability, LPS can be detected anywhere and easily exposed to humans and animals. Previous studies have shown that LPS causes hormonal imbalances, ovarian failure, and infertility in mammals. However, the potential mechanisms remain unclear. In this study, we investigated the effects and mechanisms of LPS on tryptophan degradation, both in vivo and in vitro. The effects of kynurenine, a tryptophan derivative, on granulosa cell function and reproductive performance were explored. Results showed that p38, NF-κB, and JNK signaling pathways were involved in LPS-induced Ido1 expressions and kynurenine accumulation. Furthermore, the kynurenine decreased estradiol production, but increased granulosa cell proliferation. In vivo, experiments showed that kynurenine decreased estradiol and FSH production and inhibited ovulation and corpus luteum formation. Additionally, pregnancy and offspring survival rates decreased considerably after kynurenine treatment. Our findings suggest that kynurenine accumulation disrupts hormone secretion, ovulation, corpus luteal formation, and reproductive performance in mammals.