Potential Advantages of Unstable Interactions for Pairing of Chromosomes in Meiotic, Somatic, and Premeiotic Cells
This extract was created in the absence of an abstract.
Excerpt
In eukaryotic organisms, homologous chromosomes are sometimes associated more closely with one another than expected on a random basis. In the discussion that follows, we refer to all such situations as “pairing” regardless of the nature or extent of the nonrandomness observed. The most extreme form of pairing occurs during mid-prophase of meiosis, when replicated, partially condensed homologous chromosomes are connected along their lengths by a prominent structure, the synaptonemal complex (Moses 1968; von Wettstein et al. 1984). However, homologous chromosomes also can be nonrandomly associated in somatic cells. In some cases, association of homologous chromosomes occurs specifically in tissues or cell lineages preparing for meiosis. Homologous chromosomes in somatic or premeiotic cells may exhibit very intimate associations over much or all of their lengths, occasional physical contact at single points or small regions, or a tendency for nonrandom association in the absence of observable physical contact. It is presumed...
