mRNA Expression of Genes Associated with Puberty Onset in the Adipose and Hypothalamic Tissues of Anhui White Goat

Puberty is the process of physical maturation of an animal with the capability of sexual reproduction. In domestic animals, age at attainment of puberty is an event that contributes significantly to lifetime reproductive efficiency. Anhui white goat is a native Chinese breed, with the characters of early time puberty onset and high fecundity. However, the molecular mechanism of puberty onset has not been well understood. It has been demonstrated leptin act as a critical metabolic cue linking adipose and the onset of puberty. In the present study, we first assessed the morphological changes in adipose tissue at pre-puberty and puberty onset stages of goats, and then determined the role of leptin to activate signaling pathways which modulate the expression of hypothalamic genes involved in reproduction and metabolism. We found that leptin significantly upregulated the LEPR in the adipose tissue of goat at the puberty onset stage. Moreover, we observed that LEPR, JAK2, STAT3 (P<0.05), KISS1 (P<0.05) were also upregulated in the hypothalamic tissue, except NPY, which was downregulated. Taken together, it is, therefore, inferred that probably leptin secreted in the adipose tissue via its receptor leptin receptor through the JAK2/STA3 signal pathways, promote the upregulation of KISS I, which activates TRPCS, and, inhibit the release of NPY, thereby promoting the release of GnRH, thus hastening the onset of puberty in goat. During this process, leptin, LEPR and its signal pathways may act as a link between the adipose and puberty onset in goat. However, further more studies need to be carried out to verify this point.