GSE133088
Persistent epigenetics changes due to elevated temperature during early development in mature zebrafish gonads
Sexual development is a process regulated by complex interactions of molecular events that define the final sexual phenotype. Although the genetic and transcriptomic mechanisms involved in the formation of an ovary or a testis are largely studied, the epigenetic mechanisms regulating the fate of an undifferentiated gonad remain poorly understood. Using the zebrafish model (Danio rerio), we exposed larvae of two independent families to high temperature during sex differentiation (18-32 days post fertilization), and by a targeted sequencing approach, we analyzed the methylation profiles of 18 genes related to sexual development in mature gonads two months after the exposure. Gene expression patterns were measured by qPCR in order to correlate them with the DNA methylation. Methylation profiles were family-dependent. However, general patterns of sexual dimorphism were observed in the DNA methylation levels of steroidogenic enzymes (e.g. cyp19a1a, hsd17b1 and hsd11b2), transcription factors (e.g. dmrt1 and amh) and epigenetic-related (dnmt1) genes. In testes, temperature was able to alter the methylation levels of some genes by hypermethylation (cyp19a1a, cyp11a1, amh) or hypomethylation (dmrt1), whereas in ovaries, no changes in the methylation levels were observed. Our results indicate that high temperature during sex differentiation altered methylation in the adult fish gonads and as a novelty, methylation patterns of some genes (e.g., cyp11c1, hsd11b2, dmrt3a and ar) were described here for the fish time in fish. Overall design: We analyzed DNA methylation level in the promoter regions of 18 genes in mature testis and ovaries (90 dpf) of laboratory zebrafish strains exposed to 28ºC and 36ºC during its gonadal development. Methylation patterns were analyzed by Multiplex Bisulfite Sequencing (MBS, Anastasiadi et al. 2018)