Divergence between the Drosophila pseudoobscura and D. persimilis genome sequences in relation to chromosomal inversions.

Published

Journal Article

As whole-genome sequence assemblies accumulate, a challenge is to determine how these can be used to address fundamental evolutionary questions, such as inferring the process of speciation. Here, we use the sequence assemblies of Drosophila pseudoobscura and D. persimilis to test hypotheses regarding divergence with gene flow. We observe low differentiation between the two genome sequences in pericentromeric and peritelomeric regions. We interpret this result as primarily a remnant of the correlation between levels of variation and local recombination rate observed within populations. However, we also observe lower differentiation far from the fixed chromosomal inversions distinguishing these species and greater differentiation within and near these inversions. This finding is consistent with models suggesting that chromosomal inversions facilitate species divergence despite interspecies gene flow. We also document heterogeneity among the inverted regions in their degree of differentiation, suggesting temporal differences in the origin of each inverted region consistent with the inversions arising during a process of divergence with gene flow. While this study provides insights into the speciation process using two single-genome sequences, it was informed by lower throughput but more rigorous examinations of polymorphism and divergence. This reliance highlights the need for complementary genomic and population genetic approaches for tackling fundamental evolutionary questions such as speciation.

Full Text

Duke Authors

Cited Authors

  • Noor, MAF; Garfield, DA; Schaeffer, SW; Machado, CA

Published Date

  • November 2007

Published In

Volume / Issue

  • 177 / 3

Start / End Page

  • 1417 - 1428

PubMed ID

  • 18039875

Pubmed Central ID

  • 18039875

Electronic International Standard Serial Number (EISSN)

  • 1943-2631

International Standard Serial Number (ISSN)

  • 0016-6731

Digital Object Identifier (DOI)

  • 10.1534/genetics.107.070672

Language

  • eng