Chromatin zigzags

Gene-poor chromosomal regions are more often found in the nuclear periphery, and gene-rich regions are more often found in the nuclear interior. But Shopland et al. (page 27) are the first to analyze how multiple gene-poor and gene-rich regions are organized relative to each other. They find that gene-rich regions often cluster together while pushing interspersing genic deserts to the nuclear periphery, even in the absence of active transcription.

Shopland et al. studied a 4.3-Mb region of mouse chromosome 14 that has four gene-rich regions interspersed with four gene deserts. FISH probes that distinguished the genic and nongenic regions showed that the chromosome bent into three classifiable patterns: a striped pattern that resembled the linear sequence order; a zigzag pattern with the four coding regions next to one another and the gene deserts...