Research article

Novel gene expression patterns along the proximo-distal axis of the mouse embryo before gastrulation

Stephen Frankenberg^1,2 , Lee Smith³ , Andy Greenfield³ and Magdalena Zernicka-Goetz¹

¹The Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, Tennis Court Rd, Cambridge CB2 1QR, UK

²Inserm, U384, Clermont-Ferrand, F-63001, France

³MRC Mammalian Genetics Unit, Harwell, Didcot OX11 0RD, UK

author email corresponding author email

BMC Developmental Biology 2007, 7:8doi:10.1186/1471-213X-7-8

Published:	15 February 2007

Abstract

Background

To date, the earliest stage at which the orientation of the anterior-posterior axis in the mouse embryo is distinguishable by asymmetric gene expression is shortly after E5.5. At E5.5, prospective anterior markers are expressed at the distal tip of the embryo, whereas prospective posterior markers are expressed more proximally, close to the boundary with the extraembryonic region.

Results

To contribute to elucidating the mechanisms underlying the events involved in early patterning of the mouse embryo, we have carried out a microarray screen to identify novel genes that are differentially expressed between the distal and proximal parts of the E5.5 embryo. Secondary screening of resulting candidates by in situ hybridisation at E5.5 and E6.5 revealed novel expression patterns for known and previously uncharacterised genes, including Peg10, Ctsz1, Cubilin, Jarid1b, Ndrg1, Sfmbt2, Gjb5, Talia and Plet1. The previously undescribed gene Talia and recently identified Plet1 are expressed specifically in the distal-most part of the extraembryonic ectoderm, adjacent to the epiblast, and are therefore potential candidates for regulating early patterning events. Talia and the previously described gene XE7 define a gene family highly conserved among metazoans and with a predicted protein structure suggestive of a post-transcriptional regulative function, whilst Plet1 appears to be mammal-specific and of unknown function.

Conclusion

Our approach has allowed us to compare expression between dissected parts of the egg cylinder and has identified multiple genes with novel expression patterns at this developmental stage. These genes are potential candidates for regulating tissue interactions following implantation.