Development of the pancreas in Xenopus laevis

Xenopus embryos have several experimental advantages for studying developme nt. Although these advantages have traditionally been used to elucidate mec hanisms of early development, they can also be exploited to investigate iss ues later in development such as organogenesis. We have begun to study panc reatic organogenesis in Xenopus, Using histological and molecular marker an alysis, 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 endo crine hormones, exocrine gene products, and pancreatic transcription factor s. Interestingly, the endocrine hormone insulin has restricted expression i n the dorsal pancreas. Investigation of pancreatic specification during gas trulation demonstrates that insulin expression is regionalized along the do rsoventral axis early in development. (C) 2000 Wiley-Liss, Inc.