Molecular cloning, expression analysis and developmental changes in ovarian follicles of goose 3 beta-hydroxysteroid dehydrogenase 1

摘要

The enzyme 3 beta-hydroxysteroid dehydrogenase/isomerase1 (3 beta HSD1) can catalyse the conversion of pregnenolone to progesterone in the Delta(4)-3-ketosteroid metabolic pathway. The aim of the present study was to clone 3 beta HSD1 and to determine whether this enzyme in the follicular wall has an effect on yolk progesterone in geese (Anser cygnoides). A putative coding sequence of 3 beta HSD1, which was 1134 nucleotides in length, was successfully obtained by using reverse transcription polymerase chain reaction (RT-PCR). A comparison of the deduced amino acid sequence with chicken, quail, zebra finch, cattle, horse, pig, human and mouse 3 beta HSD1 showed 89.7%, 88.4%, 87.3%, 55.6%, 54.0%, 53.5%, 55.3% and 52.9% similarity, respectively. The detection of 3 beta HSD1 mRNA levels in several tissues by quantitative real-time PCR showed that the highest level of 3 beta HSD1 was in the adrenal gland, followed by the ovary, which indicated that the gene we obtained was the adrenal gland/gonad-specific one. We measured the level of 3 beta HSD1 mRNA in the follicular wall and determined the concentration of progesterone in the yolk of these ovarian follicles; the concentration of progesterone in the yolk had a pattern of expression similar to that of 3 beta HSD1 in the follicular wall during follicular development. This result suggests that the expression of 3 beta HSD1 in the follicular wall may be a main factor that contributes to the accumulation of yolk progesterone.