The retromer complex is a heteropentameric protein unit associated with retrograde transport of cargo proteins from endosomes to the trans-Golgi network. Functional silencing study of the Vps26a gene indicated the important role of the retromer complex during early developmental stages in the mouse. However, individual expression patterns and quantitative analysis of individual members of the retromer complex during the early developmental stages has not been investigated. In this study, we conducted quantitative expression analysis of six retromer complex genes (Vps26a, Vps26b, Vps29, Vps35, Snx1, and Snx2) and one related receptor gene (Ci-mpr) during the eleven embryonic stages with normal MEF (mouse embryonic fibroblast) and Vps26a-/- MEF cells. Remarkably, except for Vps26a (maternal expression pattern), all tested genes showed maternal-zygotic expression patterns. And five genes (Vps26b, Vps29, Vps35, Snx2, and Ci-mpr) showed a pattern of decreased expression in Vps26a-/- MEF cells by comparative analysis between normal MEF and Vps26a-/- MEF cells. However, the Snx1 gene showed a pattern of increased expression in Vps26a-/- MEF cells. From our results, we could assume that retromer complex-related genes have important roles during oocyte development. However, in the preimplantation stage, they did not have significant roles.

Keywords: mouse embryo, mouse embryonic fibroblast, real-time RT-PCR, retromer complex