SYISL affects fetal mice muscle fiber number by regulating maternal intestinal microbiota and their metabolites
The formation of embryonic muscle fibers during the prenatal period determines the number of muscle fibers after birth. Our previous studies showed that SYISL gene knockout (KO) mice significantly increased the number of total muscle fibers, but the underlying mechanism remains unclear. In this study, we found that the development of embryonic muscle fibers was significantly influenced by the interaction between host SYISL genotype and maternal gut microbiota. SYISL KO alters the composition of the female mice maternal gut microbiota, significantly increases the relative abundance of Prevotella (P<0.05). Fecal microbiota transplantation (FMT) experiments indicated that fecal suspension from KO female mice significantly increased the number of offspring muscle fibers.  Our study provides the new evidence for the interaction between maternal single gene and gut microbiota on the embryonic muscle development of the offspring. Overall design: In order to investigate the regulatory role of SYISL during embryonic muscle development, samples of wild-type (WT) and SYISL knockout (KO) 18.5-day embryonic mouse leg muscles were collected, and RNA-seq analysis was conducted.