Introduction to Genetic Analysis 585

Introduction to Genetic Analysis 585 - 584 Chapter 18 The...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 584 Chapter 18 The Genetic Basis of Development have their high points at the anterior pole. In somewhat different ways, the gradients of both these proteins de- pend on the diffusion of protein from a localized origin: each protein is produced through localized translation of an mRNA species, one tethered to microtubules at the anterior pole of the syncitial embryo, and the other teth- ered at the posterior pole. The origin of the BCD gradient is quite straightfor- ward. The maternal bcd mRNA, packaged during oogen- esis into the developing oocyte, is tethered to the 2 (mi- nus) ends of microtubules, which are located at the anterior pole (Figure 18-10a). Translation of BCD pro- tein begins midway through the early nuclear divisions of the embryo. The protein diffuses in the common cytoplasm of the syncitium. Because the protein is a transcription factor, it contains signals that direct it to the nuclei. Those nuclei nearer to the anterior pole incorporate a higher concentration of the diffusing BCD protein than do those farther away; this difference re- sults in the steep BCD protein gradient (Figure 18-10b)....
View Full Document

This note was uploaded on 01/10/2011 for the course BIOL BIOL taught by Professor Johnson during the Spring '08 term at Aberystwyth University.

Ask a homework question - tutors are online