Gene expression profiling at early organogenesis reveals both common and diverse mechanisms in foregut patterning

Abstract

The thyroid and lungs originate as neighboring bud shaped outgrowths from the midline of the embryonic foregut. When and how organ specific programs regulate development into structures of distinct shapes, positions and functions is incompletely understood. To characterize, at least in part, the genetic basis of these events, we have employed laser capture microdissection and microarray analysis to define gene expression in the mouse thyroid and lung primordia at E10.5. By comparing the transcriptome of each bud to that of the whole embryo as well as to each other, we broadly describe the genes that are preferentially expressed in each developing organ as well as those with an enriched expression common to both. The results thus obtained provide a valuable resource for further analysis of genes previously unrecognized to participate in thyroid and lung morphogenesis and to discover organ specific as well as common developmental mechanisms. As an initial step in this direction we describe a regulatory pathway involving the anti-apoptotic gene Bcl2 that controls cell survival in early thyroid development.

Highlights

► The transcriptomes of the early thyroid and lung primordia are characterized. ► Organ-specific and common motifs of gene expression are identified and validated. ► The data provide a resource for finding genes regulating foregut patterning. ► A mechanism involving Bcl2 controls cell survival in the thyroid primordium.