Testicular development in male lambs prenatally exposed to a high-starch diet

Abstract

Maternal nutrition during critical gestation periods impacts on offspring in later life; effects of high-starch maternal diet on testicular development in lambs were addressed. Dairy ewes were fed diets providing either 27% (Starch, S) or 11% (Fiber, F) of starch from mating to lambing (∼147 days; S147, F147) or for the last 75 days of gestation (S75, F75). Testes of single male lambs were measured and then sampled for histological and gene expression analyses at selected ages. Testicular dimensions and weight were similar among groups, but the total area of seminiferous tubules increased with age and tended to be higher (p = 0.057) in lambs from starch- than fiber-fed ewes. Sertoli and germ cells number increased with age, but was not influenced by maternal diet. Transcript abundances of androgen receptor (AR), insulin-like growth factor 1 (IGF1), and hydroxysteroid (17-beta) dehydrogenase 3 (HSD17B3) was similar between S147 and F147 lambs (p > 0.1). Abundance of luteinizing hormone/choriogonadotropin receptor (LHCGR) and steroidogenic acute regulatory protein (STAR) was higher in young vs older lambs, whereas insulin-like growth factor 2 (IGF2) levels increased with age. The expression of vascular endothelial growth factor A (VEGFA), Anti-Müllerian hormone (AMH), IGF1, follicle stimulating hormone receptor (FSHR), and insulin-like growth factor 2 receptor (IGF2R) was not influenced by maternal diet or lamb age (p > 0.1). In conclusion, a high-starch maternal diet did not influence gene expression, but may have affected testicular structure in infant offspring, as seen by an increase in the total area of seminiferous tubules.

Keywords: DOHaD; gene expression; gonad; programming; sheep.