Whole genome-wide analysis of DEP family members in sheep ( Ovis aries ) reveals their potential roles in regulating lactation

Background Sheep milk is an attractive nutritional and functional food source. Some Dishevelled, Egl-10 and pleckstrin (DEP) domain-containing proteins can regulate lactation performance in mammals. However, systematic study of the role of sheep DEP family members in regulating lactation is currently lacking. This study aimed to reveal the roles of sheep DEP family members in lactation by exploring their genetic characteristics and functional features at the whole genome-wide level. Results Twenty DEP family members were identified in the sheep genome, and they can be divided into four major groups. Ka/Ks calculations suggest that the purifying selection is the main pressure acting on DEP genes. In the late pregnancy and lactation periods, the expression levels of eight DEP genes exhibited significant differences in the mammary gland. In addition, nutritional conditions have a great influence on the expression of DEP family members, and the DEP gene family underwent more expansion than the average gene family in the early stages of biological evolution. The Mirrortree assays indicated that the DEP family members coevolved in biological evolution. Conclusions Our research provides a better understanding of the characters of the DEP domain-containing protein family and their potential roles in regulating lactation in sheep. Moreover, these results of our study may contribute to the genetic improvement of milk performance in dairy sheep breed. Graphical Abstract