Abstract:Transforming growth factor-β(TGF-β) gene family plays a key role in a variety of biological processes such as cell growth,differentiation,apoptosis,and extracellular matrix synthesis and deposition.To investigate the expression of TGF-β gene family in donkeys,we performed a systematic survey of the donkey TGF-β gene family,including gene identification,expression analysis,and discussion of their functional and evolutionary relationships.The members of the donkey TGF-β gene family were identified using the HMMER software package and BLAST tools,and the sequences were analyzed in depth in combination with a variety of bioinformatics tools.Furthermore,the expression patterns of this gene family in different tissues were analyzed using transcriptome data.The results showed that the TGF-β gene family consisted of 33 members,encoding proteins with amino acids ranging from 153 to 507 aa,molecular weights ranging from 16.19 to 55.67 kD,and isoelectric point distributions ranging from 4.84 to 11.66.All members were hydrophilic proteins.Protein secondary structure prediction showed that the secondary structure of TGF-β gene family members was dominated by random coil,followed by α-helix,and finally β-fold.The results of subcellular localization showed that 31 members were located in the extracellular matrix,BMP2 was located in the endoplasmic reticulum,BMP10 was located in the plasma membrane,and BMP7 was located in the mitochondria.Phylogenetic analysis showed that the TGF-β gene family was divided into two subclasses,in which the donkey and human gene family members were clustered separately,indicating a close evolutionary relationship.The transcriptome data further showed that most TGF-β gene family members were expressed in 13 tissues of the adult donkey,with the NODAL gene showing high expression levels in all tissues.These results lay a foundation for further understanding the biological functions of TGF-β gene family in donkeys.
