Why Is the Centromere So Cold?
- The Murdoch Institute for Research into Birth Defects, Royal Children’s Hospital, Parkville 3052, Australia
This extract was created in the absence of an abstract.
Chromosomes are known to contain local hot and cold spots that undergo quite different rates of meiotic recombination. The question of why such regional variation in recombination rates exists on chromosomes holds a strange mix of intrigue and frustration for geneticists. One of the human chromosomes that has been carefully studied over the years in this regard is the X chromosome. These studies have concentrated on the evaluation of the recombination rates across various subregions of this chromosome and have, by and large, avoided the more recalcitrant centromere domain. In this issue, Mahtani and Willard (1998) present an analysis of recombination across the centromere itself and provide data indicating a significantly lower exchange rate at the centromere than the average rate of female meiotic recombination on the human X chromosome. In the current climate where much attention is focused on centromere research, this work provides both useful information and a timely reminder for yet another one of the many unique and difficult-to-study properties of the centromere.
The notion that the centromere exerts a direct, negative effect on meiotic recombination both within itself and on proximal chromosomal DNA was recognized >60 years ago (Beadle 1932; Mather 1938). This effect, termed the centromere effect, has now been documented in wide-ranging organisms, including Drosophila, Neurospora, Arabidopsis, budding and fission …
