Divergence and evolution of cotton bHLH proteins from diploid to allotetraploid.

ABSTRACT: Polyploidy is considered a major driving force in genome expansion, yielding duplicated genes whose expression may be conserved or divergence as a consequence of polyploidization.We compared the genome sequences of tetraploid cotton (Gossypium hirsutum) and its two diploid progenitors, G. arboreum and G. raimondii, and found that the bHLH genes were conserved over the polyploidization. Oppositely, the expression of the homeolgous gene pairs was diversified. The biased homeologous proportion for bHLH family is significantly higher (64.6%) than the genome wide homeologous expression bias (40%). Compared with cacao (T. cacao), orthologous genes only accounted for a small proportion (41.7%) of whole cotton bHLHs family. The further Ks analysis indicated that bHLH genes underwent at least two distinct episodes of whole genome duplication: a recent duplication (1.0-60.0 million years ago, MYA, 0.005??60.0 MYA, 0.312?

SUBMITTER: Liu B 

PROVIDER: S-EPMC5824590 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature