Differential expression of peroxisome proliferator-activated receptor- α, -β, and -γ during rat embryonic development

Abstract

The expression patterns of the three different peroxisome proliferafor- activated receptor (PPAR) isotypes have been determined during rat embryonic development by in situ hybridization. The expression of PPARα starts late in development, with increasing levels in organs such as liver, kidney, intestine, and pancreas, in which it will also be present later in adulthood to regulate its specific target genes. PPARα is also transiently expressed in the embryonic epidermis and central nervous system. PPARγ presents a very restricted pattern of expression, being strongly expressed in brown adipose tissue, in which differentiation it has been shown to participate. Like PPARα, it is also expressed transiently in the central nervous system. Interestingly, PPARα, -β and -γ are coexpressed at high levels in brown adipose tissue. Finally, the high and ubiquitous expression of PPARβ suggests some fundamental role(s) that this receptor might play throughout development.