Mouse Embryonic Development

Abstract

Neural development is a fundamental process carried out during early mouse development. After several of decades of research, involve in this field, a lot of unanswered questions have been unresolved. It is not clarified when neural induction takes place and what influence is emanated by embryonic and extraembryonic tissues in this development thereby to form a prober, functional CNS. This study is focusing in the participation of extraembryonic tissues in neural development. We will try to demonstrate the exact role of extraembryonic ectoderm (ExE) and distal visceral endoderm (DVE) in this procedure by using an in vivo ExE-ablated called Ets2 mutant embryos and an in vitro ExE or/and DVE ablated wild type embryos. It is widely accepted that only a few papers attempt to explain the role of the above tissues therefore this lack of knowledge is tingle our interest in this unexplored field.

Introduction and Background

1. Overview of early mouse development

Embryonic development of mouse begins with fertilization of the oocyte by the sperm. The zygote undergoes several mitotic cell divisions, leading to development of an embryo. At embryonic day 3.5, the blastocyst formed and consists of two distinct lineages: the inner cell mass (ICM) and the trophectoderm (TE). TE will give rise to the progenitors of the placenta: the extraembryonic ectoderm (ExE) and the ectoplacental cone (EPC). On the other hand, ICM will go on to form virtually all of the tissues of the mouse embryo. At embryonic day 4.5, implantation occurs and at this stage ICM differentiated into the primitive ectoderm (a multilayered cuboidal epithelium) and the primitive endoderm. Shortly after implantation, around E5.0, formation of the proamniotic cavity occurs and that force the transformation of the primitive ectoderm into a single-cell-thick epithelium, the epiblast. The epiblast will give rise to the entire fetus and the extraembryonic mesoderm whereas, the primitive endoderm will...