Comparative analysis of Six3 and Six6 distribution in the developing and adult mouse brain

Abstract

Six3 and Six6 genes are two closely related members of the Six/sine oculis family of homeobox containing transcription factors. Their egression and function at early stages of embryonic development has been widely addressed in a variety of species. However, their mRNA distribution during late embryonic, postnatal, and adult brain barely has been analysed. Here, we show that despite their initial overlap in the anterior neural plate, the exression of Six3 and Six6 progressively segregates to different regions during mammalian brain development, maintaining only few areas of partial overlap in the thalamic and hypothalamic regions. Six3, but not Six6, is additionally expressed in the olfactory bulb, cerebral cortex, hippocampus, midbrain, and cerebellum. These distinct patterns support the idea that Six3 and Six6 are differentially required during forebrain development. © 2005 Wiley-Liss, Inc.