Fishing pluripotency mechanisms in vivo

Abstract

To understand the molecular mechanisms that regulate the biology of embryonic stem cells (ESCs) it is necessary to study how they behave in vivo in their natural environment. It is particularly important to study the roles and interactions of the different proteins involved in pluripotency and to use this knowledge for therapeutic purposes. The recent description of key pluripotency factors like Oct4 and Nanog in non-mammalian species has introduced other animal models, such as chicken, Xenopus, zebrafish and medaka, to the study of pluripotency in vivo. These animal models complement the mouse model and have provided new insights into the evolution of Oct4 and Nanog and their different functions during embryonic development. Furthermore, other pluripotency factors previously identified in teleost fish such as Klf4, STAT3, Sox2, telomerase and Tcf3 can now be studied in the context of a functional pluripotency network. The many experimental advantages of fish will fuel rapid analysis of the roles of pluripotency factors in fish embryonic development and the identification of new molecules and mechanisms governing pluripotency.

Keywords: Medaka; Nanog; Oct4; pluripotency.; teleost fish.

Figure 1

Nanog and Oct4 expression during medaka and mouse development. The circular blue arrow indicates the totipotent cycle. Cells and tissues types that express Oct4 or Nanog are boxed in blue when their mRNA expression are detected and/or boxed in green when their protein expressions are detected. Both Nanog and Oct4 have similar expression patterns in medaka and mouse, although mouse Nanog is first detected at the morula stage.