Development of the pancreas in Xenopus laevis

Xenopus embryos have several experimental advantages for studying development. Although these advantages have traditionally been used to elucidate mechanisms of early development, they can also be exploited to investigate issues later in development such as organogenesis. We have begun to study pancreatic organogenesis in Xenopus. Using histological and molecular marker analysis, we characterized the anatomy of the developing pancreas in Xenopus embryos from the time of initial pancreatic rudiment formation to the time when the tadpole starts to feed. We examined the expression of various endocrine hormones, exocrine gene products, and pancreatic transcription factors. Interestingly, the endocrine hormone insulin has restricted expression in the dorsal pancreas. Investigation of pancreatic specification during gastrulation demonstrates that insulin expression is regionalized along the dorsoventral axis early in development.