Introduction to Genetic Analysis 565

Introduction to Genetic Analysis 565 - 44200_17_p545-574...

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

View Full Document Right Arrow Icon
564 Chapter 17 Genetic Regulation of Cell Number: Normal and Cancer Cells of apoptosis. This enhancer– bcl-2 fusion causes large amounts of Bcl-2 protein to be expressed in B lympho- cytes. The plentiful Bc1-2 protein effectively blocks apoptosis in these lymphocytes, giving them an unusu- ally long lifetime in which to accumulate mutations that promote cell proliferation. for the Rb protein must be inactivated, either by the same mutation or by a different mutation in each. Most patients have one or a few tumors localized to one site in one eye, and the condition is sporadic—in other words, there is no history of retinoblastoma in the family and the affected person does not transmit it to his or her offspring. In these cases, the rb mutations arise in a so- matic cell whose descendants populate the retina (Fig- ure 17-20). Presumably, the mutations arise by chance at different times in the course of development in the same cell lineage. A few patients, however, have an inherited form of
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