Genome-wide identification and structural analysis of the BMP gene family in Triplophysa dalaica

Bone morphogenetic proteins (BMPs) are part of the transforming growth factor beta (TGF-β) superfamily and play crucial roles in bone development, as well as in the formation and maintenance of various organs. Triplophysa dalaica, a small loach fish that primarily inhabits relatively high elevations and cooler water bodies, was the focus of this study. Understanding the function of BMP genes during the morphogenesis of T. dalaica helps to clarify the mechanisms of its evolution and serves as a reference for the study of BMP genes in other bony fishes. The data for the T. dalaica transcriptome and genome used in this investigation were derived from the outcomes of our laboratory sequencing.

This study identified a total of 26 BMP genes, all of which, except for BMP1, possess similar TGF-β structural domains. We conducted an analysis of these 26 BMP genes, examining their physicochemical properties, subcellular localization, phylogenetic relationships, covariance within and among species, chromosomal localization, gene structure, conserved motifs, conserved structural domains, and expression patterns. Our findings indicated that three BMP genes were associated with unstable proteins, while 11 BMP genes were located within the extracellular matrix. Furthermore, some BMP genes were duplicated, with the majority being enriched in the GO:0008083 pathway, which is related to growth factor activity. It was hypothesized that genes within the BMP1/3/11/15 subgroup (Group I) play a significant role in the growth and development of T. dalaica. By analyzing the expression patterns of proteins in nine tissues (gonad, kidney, gill, spleen, brain, liver, fin, heart, and muscle), we found that BMP genes play diverse regulatory roles during different stages of growth and development and exhibit characteristics of division of labor.

This study contributes to a deeper understanding of BMP gene family member expression patterns in high-altitude, high-salinity environments and provides valuable insights for future research on the BMP gene family in bony fishes.