Yu Zhang

The gut microbiota in sows is important for the health of the host, and potential benefits may also be transferred to piglets during pregnancy. Therefore, systematic studies investigating the changes in the gut microbiota of sows are needed to elucidate the microbial compositions and functions. This study was conducted at 12 time points to investigate the temporal variations in gut microbiota on Days 27, 46, 64, 81, 100, and 113 during gestation (G) and Days 3, 5, 7, 10, 14, and 21 during lactation (L). Results suggested that the gut microbiota changed across the perinatal period with microbial function and abundance varying between the prenatal and postnatal periods. The alpha diversity was higher in the postnatal period than in the prenatal period. Thirty-eight genera were distributed between the two periods with Methanobrevibacter, Desulfovibrio, Akkermansia, and Turicibacter being enriched in the prenatal period while Eubacterium, Actinobacillus, Paludibacter, Butyricimonas, Megasphaera, Succiniclasticum, Acidaminococcus, and Rummeliibacillus were enriched in the postnatal period. Analysis done at the different time points of the prenatal period suggested that Days 27 and 113 had more microbial biomarkers than other days. Bacteroidales, Bacteroidia, and Prevotella were enriched on the 27th day, while bacteria belonging to the Clostridium and Ruminococcaceae were enriched on the 113th day. On the other hand, Clostridiales, Ruminococcaceae, Clostridia, and unclassified Christensenellaceae were enriched three days after delivery. Predicted microbial KO functions were also more enriched on Day 27 of the gestation period and Day 3 of the lactation period. Random forest, a machine learning method, was used to identify the top five important genera of Megasphaera, Stenotrophomonas, Phyllobacterium, Catenibacterium, and Turicibacter, while the most important function was arginine and proline metabolism. These systematic results provide important information for the gut microbiota of sows.

Skeletal muscle plays a crucial role in physical activity and in regulating body energy and protein balance. Myoblast proliferation, differentiation, and apoptosis are indispensable processes for myoblast myogenesis. Profilin 2a (PFN2a) is a ubiquitous actin monomer-binding protein and promotes lung cancer growth and metastasis through suppressing the nuclear localization of histone deacetylase 1 (HDAC1). However, how PFN2a regulates myoblast myogenic development is still not clear. We constructed a C2C12 mouse myoblast cell line overexpressing PFN2a. The CRISPR/Cas9 system was used to study the function of PFN2a in C2C12 myogenic development. We find that PFN2a suppresses proliferation and promotes apoptosis and consequentially downregulates C2C12 myogenic development. The suppression of PFN2a also decreases the amount of HDAC1 in the nucleus and increases the protein level of p53 during C2C12 myogenic development. Therefore, we propose that PFN2a suppresses C2C12 myogenic development via the p53 pathway. Si-p53 (siRNA-p53) reverses the PFN2a inhibitory effect on C2C12 proliferation and the PFN2a promotion effect on C2C12 apoptosis, and then attenuates the suppression of PFN2a on myogenic differentiation. Our results expand understanding of PFN2a regulatory mechanisms in myogenic development and suggest potential therapeutic targets for muscle atrophy-related diseases.