Relative expression of insulin genes I and II during pancreatic development in fetuses of rats with streptozotocin-induced diabetes.

The relative expression of insulin genes I and II in the developing pancreas of fetuses from female rats with streptozotocin-induced diabetes was investigated by reverse transcription and polymerase chain reaction analysis. Unlike the fetuses of normal rats, in which the ratio of the pancreatic abundance of insulin I mRNA to that of insulin II mRNA increases during late gestational development, peaks around birth, and then decreases to adult values, the ratio in the offspring of diabetic mothers remained relatively constant (1.6 to 2.2) throughout this period at values similar to those of normal adult animals. These results suggest that changes in the maternal environment attributable to diabetes affect the relative expression of insulin genes I and II, and that the two genes are regulated by distinct mechanisms.