Comparative Genomics Identifies the Evolutionarily Conserved Gene as a Target of eca-miR-1 Involved in the Skeletal Muscle Development of Donkeys.

Species within the genus are valued for their draft ability. Skeletal muscle forms the foundation of the draft ability of species; however, skeletal muscle development-related conserved genes and their target miRNAs are rarely reported for . In this study, a comparative genomics analysis was performed among five species (horse, donkey, zebra, cattle, and goat), and the results showed that a total of 15,262 (47.43%) genes formed the core gene set of the five species. Only nine chromosomes (Chr01, Chr02, Chr03, Chr06, Chr10, Chr18, Chr22, Chr27, Chr29, and Chr30) exhibited a good collinearity relationship among species. The micro-synteny analysis results showed that was evolutionarily conserved in chromosome 1 in . Furthermore, donkeys were used as the model species for to investigate the genetic role of in muscle development. Interestingly, the results of comparative transcriptomics showed that the gene was differentially expressed in donkey skeletal muscle S1 (2 months old) and S2 (24 months old), as verified via RT-PCR. Dual-luciferase test analysis showed that the gene was targeted by differentially expressed miRNA (eca-miR-1). Furthermore, a total of 17 gene family members were identified in the whole genome of donkey, and a heatmap analysis showed that was a key member of the gene family, which is involved in skeletal muscle development. In conclusion, the gene was conserved in , and was targeted by eca-miR-1, which is involved in skeletal muscle development in donkeys.