Ovarian development in intrauterine growth-retarded and normally developed piglets originating from the same litter. Reproduction

Epidemiological studies in humans linking adult disease to growth in utero indicate that prenatal life is a critical period for the appropriate development of the reproductive axis. The aim of this study was to compare ovarian development in intrauterine growth-retarded and normally grown piglets originating from the same litter. Intrauterine growth-retarded piglets (runts) were identified on the basis of statistical analysis of the birth weight distribution within each litter. At birth, ovaries were collected from runt piglets (n=14) and their respective mean weight (normal, n = 14) littermates. Ovaries were weighed and fixed, and devel-opment of ovarian germ cells was quantified in haema-toxylin–eosin-stained paraffin wax sections using an image analysis system. Germ cell loss, using an in situ TdT-mediated dUTP nick-end labelling (TUNEL) assay for DNA fragmentation, and follicle cell activity, using immuno-histochemistry to demonstrate vimentin, were studied in ovarian sections. At birth, body weight and absolute ovarian mass were significantly lower in runt piglets compared with their respective normally grown littermate