The association of two regions on separate mouse chromosomes is reported online by Nature. The authors suggest that physical interaction between chromosomes might play an important role in coordinating gene expression in the nucleus of higher organisms.
Naive T-helper cells differentiate into one of two cell types: TH1 or TH2 cells. The alternative pathways that distinguish TH1 cells from TH2 cells are defined by the cytokines interferon-gamma and interleukin-4, respectively. Richard Flavell and colleagues recently described the interactions between two loci on mouse chromosome 11 that regulate the expression of the TH2 cytokine genes. In this paper, the team describes the interaction between a portion of the interferon-gamma gene on chromosome 10 and the regulatory regions of the TH2 cytokine loci on chromosome 11.
The authors report that the interchromosomal interactions were as strong as the intrachromosomal interactions. Although the function of this physical association between chromosomes has not yet been established, the authors say that the interaction could regulate the rapid expression of both TH1 and TH2 cytokine genes. In addition, the team speculates that interchromosomal interactions might not be unique to the differentiation of T-helper cells, and might be important in disease.
Richard Flavell (Yale University School of Medicine and HHMI, New Haven, CT, USA)
(C) Nature press release.
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