This Week In Science

摘要

Distant regions of the genome in eukaryotic chromosomes are able to interact with each other, allowing long-range regulatory communication both in cis, between regions on the same chromosome, and in trans, between chromosomes. For example, in transvec-tion, alleles of the same gene on chromosome homologs can cross-regulate each other. Hartl et al.rn(p. 1384) study the extreme case of trans association seen in polytene chromosomes in Drosophila, which each consist of many copies of an individual chromosome associated in perfect register. Condensin II subunits are involved in polytene chromosome disassembly, and these same subunits also interfere with instances of transvection in the fruit fly, suggesting that the condensin II complex may antagonize homology-dependent chromosomal interactions.