Insulin-like growth factor-I and -II in buffalo ovary: mRNA expressions and partial sequences

Abstract

In the present investigation, expressions of mRNAs encoding IGF-I and IGF-II were detected in intact follicles of different sizes, granulosa cells, corpus luteum (CL) and corpus albicans (CA) from buffalo ovary, using semi-quantitative RT-PCR technique. The effect of FSH and LH on expression of mRNAs encoding IGFs and sequencing of partial IGF- I and IGF-II cDNAs were studied. The results for expression of mRNAs encoding IGF-I and IGF-II in small (< 5 mm), medium (6–9 mm) and large (> 10 mm) intact follicles and granulosa cells revealed significant increase in mRNAs expression with increase in follicle size. During luteal phase, the presence of expression of mRNAs encoding IGFs in corpus luteum (CL) and corpus albicans (CA) indicated their role in growth, differentiation and regression of luteal tissues. The treatment of granulosa cells culture with varying doses of FSH, did not show any stimulatory effect on expression of mRNAs encoding IGF-I and IGF-II. However, LH induced significantly IGF-I mRNA expression. The partial cDNA products of IGF-I and IGF-II, were sequenced. The blasting of IGF-I sequence (196 nucleotides) with that of other species exhibited the homology in the range of 93–99% whereas it was in the range of 88–100% for IGF-II sequence (154 nucleotides). The results showed that IGF-I and IGF-II play important role during follicular and luteal phases of buffalo ovary.