DIMORPHIC EXPRESSION OF TRANSCRIPTION FACTORS DURING GONADAL DEVELOPMENT IN Lepidocephalus thermalis

In fishes, the expression of steroidogenic enzyme genes and their related transcription factors are critical for the development of the gonads and the regulation of steroidogenesis. The early stages of steroidogenesis is important for biosynthesis of testosterone and estradiol. In this study, three steroidogenic enzyme genes cyp19a1, 11βhsd (11β-hydroxy testosterone) and 3βhsd (3β-hydroxy testosterone) expression in various stages of gonad development has been analysed. As this is the first recordical study of steroidogenic enzyme genes in L. thermalis, the primers of Air breathing catfish  Clarias gariepinus for the genes cyp19a1, 11βhsd and 3βhsd  has been used to find the expression level at various stages.Based on the previous studies in catfish in these genes, cyp19a1 is an ovarian aromatase found abundant in differentiating female gonads. 11βhsd has higher expression in the spawning phase of reproductive cycle and transactivates to regulate male reproduction in teleost. 3βhsd is important in both spermatogenesis and oogenesis. From similar experimental methods performed in C. gariepinus the expression level of these genes in L. thermalis is observed.

From the graph, it is evident that in L. thermalis, higher expression level by cyp19a1, 11βhsd and 3βhsd is in medium sized testis than in the other. Hence these genes play a vital role in spermatogenesis in L. thermalis.