Juan Lin

Summary: In vitro production of porcine embryos is a complicated process that includes in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC). Insufficient cytoplasmic maturation, slow zona reaction and improper embryo culture conditions will compromise the efficiency of porcine embryo production in vitro. Previous studies have shown that insulin-transferrin-selenium (ITS) in IVM or IVC medium could improve porcine oocyte maturation, decrease polyspermy fertilization and promote subsequent embryonic development in vitro. However, the effect of ITS both in IVM and IVC media on porcine embryo production in vitro hasn’t been elucidated. In this study, we found that 1.0% ITS supplementation in IVM/IVC media promoted the expansion of cumulus cells, raised mitochondrial membrane potential, increased ATP content and reduced ROS level in matured oocytes, improved blastocyst rate and the cell number of blastocyst, simultaneously. In conclusion, the IVM/IVC media supplemented with 1.0% ITS can improve the efficiency of porcine embryo production in vitro.

Coronavirus disease 2019, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains an ongoing global public health challenge. This disease causes damage not only to the respiratory system, affecting the normal physiological function of the lungs, but also to other vital organs, such as the heart and testicles. Existing studies have shown that co-expression of angiotensin-converting enzyme 2 and transmembrane serine protease 2 is the main mechanism by which SARS-CoV-2 invades host cells. Angiotensin-converting enzyme 2-expressing cells are widespread in the corpus cavernosum, reproductive tract and testis of men, which has raised concerns. Furthermore, abnormal sex hormone levels and decreased semen parameters were observed in coronavirus disease 2019 patients. This study comprehensively assessed the effects of SARS-CoV-2 infection on the testis, semen parameters, sex hormone levels and erectile function, and discussed possible transmission routes during sexual intercourse and the effect of vaccination on male fertility.

Transcription factor AP-2-alpha (Tfap2a) is an important sequence-specific DNA-binding protein that can regulate the transcription of multiple genes by collaborating with inducible viral and cellular enhancer elements. In this experiment, the expression, localization, and functions of Tfap2a were investigated in mouse oocytes during maturation. Overexpression via microinjection of Myc-Tfap2a mRNA into the ooplasm, immunofluorescence, and immunoblotting were used to study the role of Tfap2a in mouse oocyte meiosis. According to our results, Tfap2a plays a vital role in mouse oocyte maturation. Levels of Tfap2a in GV oocytes of mice suffering from type 2 diabetes increased considerably. Tfap2a was distributed in both the ooplasm and nucleoplasm, and its level gradually increased as meiosis resumption progressed. The overexpression of Tfap2a loosened the chromatin, accelerated germinal vesicle breakdown (GVBD), and blocked the first polar body extrusion 14 h after maturation in vitro. The width of the metaphase plate at metaphase I stage increased, and the spindle and chromosome organization at metaphase II stage were disrupted in the oocytes by overexpressed Tfap2a. Furthermore, Tfap2a overexpression dramatically boosted the expression of p300 in mouse GV oocytes. Additionally, the levels of pan histone lysine acetylation (Pan Kac), histone H4 lysine 12 acetylation (H4K12ac), and H4 lysine 16 acetylation (H4K16ac), as well as pan histone lysine lactylation (Pan Kla), histone H3 lysine18 lactylation (H3K18la), and H4 lysine12 lactylation (H4K12la), were all increased in GV oocytes after Tfap2a overexpression. Collectively, Tfap2a overexpression upregulated p300, increased the levels of histone acetylation and lactylation, impeded spindle assembly and chromosome alignment, and ultimately hindered mouse oocyte meiosis.