This chapter considers some aspects of the regulatory hierarchy responsible for the asymmetric distribution and function of zygotic regulatory genes along the DV axis of early embryos. This chapter illustrates maternal and zygotic genes that are responsible for the differentiation of the dorsal–ventral pattern. Furthermore, this chapter focuses on the zen gene as a means to raise several current issues regarding DV pattern formation. This chapter also considers how zen comes to be expressed in a restricted portion of the DV axis, and how localized zen products might regulate the differentiation of the amnioserosa and other dorsally derived embryonic tissues. It also presents evidence that the zen protein is a sequence-specific transcriptional activator and discusses this observation in the context of the regulation of “target” genes responsible for the differentiation of dorsal tissues.
All Science Journal Classification (ASJC) codes