Introduction to Genetic Analysis 582

Introduction to Genetic Analysis 582 - 44200_18_p575-610...

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

View Full Document Right Arrow Icon
581 18.2 Binary fate decisions: the germ line versus the soma MESSAGE The cytoskeleton serves as a highway system for the directed movement of subcellular particles and organelles. Determining germ-line cells through cytoskeletal asymmetries In many organisms, a visible particle is asymmetrically distributed to the cells that will form the germ line. These particles are called P granules in Caenorhabditis elegans, polar granules in Drosophila, and nuage in frogs. They are thought to be transport vehicles that ride on speciFc cytoskeletal highways to deliver attached regula- tory molecules, which are the germ-cell determinants, to future germ-line cells. In C. elegans and Drosophila, the evidence relating germ-line determination to mecha- nisms that depend on the cytoskeleton is particularly strong. Let’s consider each of these cases in turn and then review the features thay they have in common. DETERMINING THE C. ELEGANS GERM LINE The early cell divisions of the C. elegans zygote provide an example of how cytoskeletal asymmetries help form the germ line. One of the favorable properties of C. elegans as an experimental system is that the same pattern of cell divisions is present from one worm to another—and this pattern can be readily followed under the micro-
Background image of page 1
This is the end of the preview. Sign up to access the rest of the 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