@ARTICLE{TreeBASE2Ref20195, author = {Yu Sun and P?draic Corcoran and Audrius Menkis and Carrie A Whittle and Siv Andersson and Hanna Johannesson}, title = { Large-scale Introgression Shapes the Evolution of the Mating-Type Chromosomes of the Filamentous Ascomycete Neurospora tetrasperma}, year = {2012}, keywords = {}, doi = {}, url = {http://}, pmid = {}, journal = {PLoS Genetics}, volume = {}, number = {}, pages = {}, abstract = {Background: The significance of introgression as an evolutionary force shaping natural populations is well established, especially in animal and plant systems. However, the abundance and size of introgression tracts, and to what degree interspecific gene flow is the result of adaptive processes, is largely unknown. Methodology/Principal Findings: In the present study, we present medium coverage genomic data from species of the filamentous ascomycete Neurospora, and use comparative genomics to investigate the introgression landscape at the genomic level in this model genus. We revealed one large introgression tract in each of the three investigated phylogenetic lineages of N. tetrasperma (sizes of 5.6 Mbp, 5.2 Mbp and 4.1 Mbp, respectively). The tract is located on the chromosome containing the locus conferring sexual identity, the mating-type (mat) chromosome. The region of introgression is confined to the region of suppressed recombination and is found on one of the two mat chromosomes (mat a). We used Bayesian concordance analyses to exclude incomplete lineage sorting as the cause for the observed pattern, and multilocus genealogies from additional species of Neurospora show that the introgression likely originates from two closely related, freely recombining, heterothallic species (N. hispaniola and N. crassa/N. perkinsii). Finally, we investigated patterns of molecular evolution of the mat chromosome in Neurospora, and show that introgression is correlated with reduced level of molecular degeneration, consistent with a shorter time of recombination suppression. Conclusions/Significance: The chromosome specific (mat) and allele specific (mat a) introgression reported herein comprise the largest introgression tracts reported to date from natural populations. Furthermore, our data contradicts theoretical predictions that introgression should be less likely on sex-determining chromosomes. Taken together, the data presented herein advances our general understanding of introgression as a force shaping eukaryotic genomes. } }

• Go to search
• Citation
• Taxa
• Matrices
• Trees
• Analyses
• 

CiteULike

Delicious

Connotea