The size differences among mammalian introns are due to the accumulation of small deletions

FEBS Letters

Ogata, Hiroyuki¹  Kanehisa, Minoru¹  Fujibuchi, Wataru¹ 

[1] Institute for Chemical Research, Kyoto University, Uji, Kyoto 611, Japan

关键词: Intron;    Size difference;    Deletion;    Insertion;    Mutation rate;    Isochore family;   

DOI  :  10.1016/0014-5793(96)00636-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In order to investigate the molecular mechanisms that alter intron size, we conducted an extensive interspecies comparison of homologous introns among three mammalian groups: human, artiodactyls, and rodents. The size differences of introns were statistically significant among all three groups (longest intron was for human and shortest for rodents), and appear to be due to the accumulation of small deletions, according to the separate count of insertion and deletion frequencies. The distribution of intron size differences also has a shape similar to that for the distribution of insertion/deletion sizes found in pseudogenes. It is suggested that introns are selectively neutral to small-scale changes of the genome size, which inherently contain the bias of favoring short deletions against short insertions.

【 授权许可】

Unknown