Placental traits, and plasma concentration and placental mRNA expression of IGF-I in Bafra sheep breed with different birth type

Abstract

Insulin-like growth factors (IGF) promote follicle development, ovulation, and embryonic development and affect placental and fetal growth and development in many mammalian species. Therefore, this study aimed to determine the relationship between birth type, plasma concentration, and placental mRNA expression of IGF-I in Bafra ewes. A total of 30 ewes, which have single (n=15) or twin (n=15) gestation and at least gave birth to 2, have been used as experimental animals. Before mating, blood samples were collected from the jugular vena of all ewes. Following lambing, birth type, live weight, and sex of lambs and placental traits have been recorded. Plasma IGF-I concentration was determined using a commercial ELISA kit. IGF-I gene expression level has been determined by real-time quantitative polymerase chain reaction. No difference was found between single and twin-bearing sheep in terms of placental weight and various cotyledon characteristics in the study. In contrast, total cotyledon weights were lower in singleton gestation than those in twin (P<0.05). Similarly, the total and medium cotyledon number and cotyledon efficiency of Bafra ewes with single deliveries were lower than Bafra sheep with twin births (P<0.05). Although the birth type did not affect both placental gene expression level and plasma concentration of IGF-I, sheep that gave birth to twins exhibited 0.908 times more gene expression than that to single births. The study results showed that birth type did not affect plasma IGF-I concentration and placental IGF-I gene expression level in Bafra sheep breed but changed placental characteristics.