Phylogenetic analysis, tissue expression, and response to temperature variation of TRP genes in Monopterus albus.

The transient receptor potential (TRP) channels are essential in vertebrate sensory nervous systems, responding to various stimuli, including changes in environmental temperature. A recent study suggested that Trpv4 may be involved in temperature-induced sex reversal of Monopterus albus, a hermaphroditic and economically farmed fish. In this study, we obtained a total of 36 TRP genes of M. albus from 6 TRP subfamilies, and their basic physiological and biochemical characteristics were characterized. We conducted statistical and cluster analyses on 336 TRP genes from 10 species and found that they all contained the TRPA, TRPC, TRPM, TRPV, MCOLN, PKD subfamilies. In particular, Misgurnus anguillicaudatus and Paramisgurnus dabryanus also had the TRPN subfamily. In addition, we detected the expression of the TRP genes of M. albus in different sexes, different tissues and different temperatures by RT-qPCR. The results showed the expression of TRP genes was different between sexes and had tissue specificity. Most TRP genes are expressed in males (sex) or in the gonads and heart (tissue). Most importantly, we found that there are four response patterns of the TRP genes to temperature changes. Among them, most genes (20/36) are sensitive to both high and low temperatures. We detected that Trpc1, a gene sensitive only to high temperature, was mainly localized to early oocytes or seminal vesicles in gonads of different sexes, and Trpc1 was under positive selection. Our findings will provide essential data for future investigations of the role of the TRP gene family in temperature-induced sex reversal of M. albus or the role in adapting to other environmental changes.