The genomic substrate for adaptive radiation in African cichlid fish
Evolutionary diversification among species attracts the attention of scientist during long time. Adaptive radiation underlies evolution and comprises the rapid adaptation of a single lineage to its changed environment which provides new resources and opens new environmental niches. Among all biological groups which have undergone evolutionary adaptive radiation the cichlids have been more studied by biologists. In this paper, authors investigated the molecular mechanisms and genomic substrates triggering rapid evolutionary diversification in African cichlid fish through comparative analysis of genomes of five different African cichlid lineages, together with an examination of the genetic changes responsible for divergence in six closely related species from Lake Victoria. They found some differences in all investigated East African lineages compared to ancestral, including increasing gene duplication, an excess of non-coding elements, accelerated evolution of coding sequence and divergence in the expression levels connected with transposons insertions. They also discovered novel microRNAs that alter gene expression in cichlids and genome-wide diversifying selection in coding and regulatory elements. Thus, authors have concluded that multiple molecular mechanisms together with relaxed purifying selection can promote evolutionary diversification in African cichlid fish. Principle results and discussion Authors selected and sequenced the genome of five lineages of African cichlids: four …
Read More