Expression of androgen-producing enzyme genes and testosterone concentration in Angus and Nellore heifers with high and low ovarian follicle count

Single and joint toxic effects of four antibiotics on some metabolic pathways of zebrafish (Danio rerio) larvae

In China, antibiotics are commonly used for human and veterinary medicine, and they are present in various environmental media. Thus, the toxic effects of antibiotics on organisms have attracted the attention of society and scientists alike. In this study, zebrafish embryos were used to test the single and joint toxicity of four antibiotics, sulfamonomethoxine (SMM), cefotaxime sodium (CFT), tetracycline (TC), enrofloxacin (ENR), and their combinations, combining the results of experimental and omics techniques. Following exposure to antibiotics for 120 h, the body lengths of zebrafish larvae in all 100 μg/L antibiotic groups were significantly shortened, and the reactive oxygen species (ROS) content in the 100 μg/L Mix group was significantly increased. Transcriptome sequencing (RNA-seq) showed that the mRNA level of numerous genes was significantly changed in the five antibiotic treatment groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differentially expressed genes revealed a significant enrichment of the steroid biosynthesis and other metabolism pathways. Hub gene analysis highlighted dhcr24, acat1, aldh1a2, aldh8a1, suclg2, hadh, and hsdl2 as the key genes, and hub gene expression changes because of the antibiotic treatment suggested that the metabolic system of the zebrafish larvae was severely disrupted by the interaction with other genes. In conclusion, single or joint exposure to different antibiotics at environmental concentrations affected the early development and metabolic system of zebrafish larvae, and our results provide fundamental evidence for future studies of antibiotic toxicity in aquatic organisms.

TGF-β1 sustains germ cell cyst reservoir via restraining follicle formation in the chicken

The transforming growth factor β (TGF-β) superfamily members are important molecules that regulate many ovarian functions under normal physiological and pathological conditions. TGF-β1 and its receptors are highly expressed in the ovarian cells of many species. However, the effect of TGF-β1 on the capacity of the avian germ cell reservoir remains unknown. In this study, 5-day-old chicks were injected with TGF-β1 (2.5, 12.5, and 62.5 μg/kg body weight) for 3 days to assess the effect of TGF-β1 on early follicle development. Morphological analysis showed that treatment with TGF-β1 (12.5 μg/kg) increased the number of germ cell cysts and reduced the number of primordial and growing follicles. The diameter and area of oocytes and follicles were decreased after TGF-β1 treatment. Immunohistochemical staining of the proliferating cell nuclear antigen revealed that the ratios of the positive somatic and granulosa cells were decreased by 16.2% and 2.48%, respectively. Furthermore, more apoptotic cells were observed in the TGF-β1 group than those of the control by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. In addition, we cultured the 5d chicken ovaries for 3 days in vitro and found that treatment with TGF-β1 (10 ng/mL) manifested similar results as the in vivo experiment. However, the negative effect of TGF-β1 on early ovary development was rescued by treatment with a TGF-βR1 inhibitor SD208, resulting in increased expression of steroidogenic enzymes and cell cycle-regulating proteins. In conclusion, TGF-β1 could maintain the germ cell reservoir by restraining follicle activation involving reduced cell proliferation and steroidogenic enzymes gene expression at the early stage of ovarian development.

Can the antral follicular count modulate the gene expression of bovine oviducts in Aberdeen Angus and Nelore heifers?

The number of visible ovarian antral follicles (antral follicle count—AFC) is repeatable in bovine individuals, but highly variable between animals, and with differences between Bos taurus and Bos indicus breeds. Several studies have tried to determine the correlation between AFC and increased fertility in cattle. While the impacts of AFC on embryo production, hormonal levels, and pregnancy rates have been described, the molecular effects of AFC on bovine oviducts have not yet been investigated. Here, the aim was to investigate the impact of breeds, such as Aberdeen Angus and Nelore heifer with high or low AFC, on abundance of transcripts and protein related to oviductal transport, sperm reservoir formation, monospermy control, and gamete interaction in the oviducts. In summary, the ovulation side was the major factor that affected transcript abundance on bovine oviducts. However, a discreet effect among AFC and cattle breeds was also observed. Based on this, we concluded and reinforced here that differential microenvironments between ipsilateral and contralateral oviducts have a major effect on modulating the transcripts related to oviductal transport, sperm reservoir formation, monospermy control, and gamete interaction. However, we cannot exclude that there is minimal effect of AFC or breed on regulation of some genes (such as AGTR1, ACE1, FUCA1, and VEGFA) in bovine oviducts.

Single-cell analysis of differences in transcriptomic profiles of oocytes and cumulus cells at GV, MI, MII stages from PCOS patients

Polycystic ovary syndrome (PCOS) is a common frequent endocrine disorder among women of reproductive age. Although assisted reproductive techniques (ARTs) are used to address subfertility in PCOS women, their effectiveness is not clear. Our aim was to compare transcriptomic profiles of oocytes and cumulus cells (CCs) between women with and without PCOS, and assess the effectiveness of ARTs in treating PCOS patients. We collected oocytes and CCs from 16 patients with and without PCOS patients to categorize them into 6 groups according to oocyte nuclear maturation. Transcriptional gene expression of oocyte and CCs was determined via single-cell RNA sequencing. The ratio of fertilization and cleavage was higher in PCOS patients than in non-PCOS patients undergoing ARTs, and there was no difference in the number of high-quality embryos between the groups. Differentially expressed genes including PPP2R1A, PDGFRA, EGFR, GJA1, PTGS2, TNFAIP6, TGF-β1, CAV1, INHBB et al. were investigated as potential causes of PCOS oocytes and CCs disorder at early stages, but their expression returned to the normal level at the metaphase II (MII) stage via ARTs. In conclusion, ARTs can improve the quality of cumulus-oocyte complex (COC) and increase the ratio of fertilization and cleavage in PCOS women.