The molecular origins of morphological diversity

Gene duplication, a process whereby a region of DNA containing a gene is duplicated as a result of cell division errors, plays a major role in eukaryotic evolution. Over time, mutations in duplicate genes induce a novel evolutionary paths potentially leading to functionalization, an important source of diversification in complex organisms.

The researchers investigated two mechanisms believed to play a role in such functionalization: divergence of gene expression and of protein function. A set of 492 gene pairs associated with morphological diversification in the model organism Arabidopsis thaliana were examined and classified according to their level of morphological diversification.

Results indicated that in gene pairs with high and low morphological diversification, divergence rates are significantly higher than in pairs with no diversification. Analysis also suggested that whereas protein function plays a major role in such diversification, gene expression plays a minor one. At the genome level, instances of either mechanism leading to diversification were found to be extremely rare, indicating that only a few duplicate genes are crucial to morphological evolution.

While making up as much as one fifth of all genes in the eukaryotic cell, duplicate genes have eluded functional analysis due to their redundancy. The success of the current research demonstrates a novel approach, promising fundamental advances in our understanding of genetic function.

For more information, please contact
Dr. Kosuke Hanada
Gene Discovery Research Group
RIKEN Plant Science Center
Tel: +81-(0)45-503-9578 / Fax: +81-(0)45-503-9580
Ms. Saeko Okada (PI officer)
Global Relations Office
RIKEN
Tel: +81-(0)48-462-1225 / Fax: +81-(0)48-462-4715
Mail: koho@riken.jp