How chromosomal rearrangements shape adaptation and speciation: Case studies in Drosophila pseudoobscura and its sibling species Drosophila persimilis

Abstract

The gene arrangements of Drosophila have played a prominent role in the history of evolutionary biology from the original quantification of genetic diversity to current studies of the mechanisms for the origin and establishment of new inversion mutations within populations and their subsequent fixation between species supporting reproductive barriers. This review examines the genetic causes and consequences of inversions as recombination suppressors and the role that recombination suppression plays in establishing inversions in populations as they are involved in adaptation within heterogeneous environments. This often results in the formation of clines of gene arrangement frequencies among populations. Recombination suppression leads to the differentiation of the gene arrangements which may accelerate the accumulation of fixed genetic differences among populations. If these fixed mutations cause incompatibilities, then inversions pose important reproductive barriers between species. This review uses the evolution of inversions in Drosophila pseudoobscura and D. persimilis as a case study for how inversions originate, establish, and contribute to the evolution of reproductive isolation.

Chromosome-scale genome assemblies of aphids reveal extensively rearranged autosomes and long-term conservation of the X chromosome

“…Chromosomes may undergo extensive rearrangement via inversions, translocations, fusions and fissions (Eichler and Sankoff 2003). These macro-mutations can have dramatic consequences by altering gene regulation (Farré et al 2019;Stewart and Rogers 2019) and modifying local recombination rates (Farré et al 2013;Martin et al 2019), and they are implicated in key evolutionary processes such as adaptation and speciation (Rieseberg 2001;Kirkpatrick and Barton 2006;Chang et al 2013;Guerrero and Kirkpatrick 2014;Fuller et al 2019;Wellband et al 2019). Chromosome-scale genome assemblies are required to study such macro-mutations, and recent advances in genome assembly have reinvigorated the field (e.g.…”

The adaptive significance of chromosomal inversion polymorphisms inDrosophila melanogaster

“…Here, we review the adaptive significance of inversion polymorphisms in Drosophila melanogaster, the organism in which they were first discovered by Sturtevant (1917Sturtevant ( , 1921) (for the role of inversions in adaptation and speciation in D. pseudoobscura and Drosophila persimilis see Fuller, Koury, Phadnis, & Schaeffer, 2018; this issue). The edited volume by Krimbas and Powell (1992) gives a comprehensive treatment of Drosophila inversions; the chapter by Lemeunier and Aulard (1992) remains the most complete review of D. melanogaster inversions to date-here, we focus mainly on discussing newer findings.…”

A spontaneous complex structural variant in rcan-1 increases exploratory behavior and laboratory fitness of Caenorhabditis elegans

“…Inversion events can both change the chromatin state that a gene is found in and also suppress recombination events within the inverted region [23,24]. Finally, structural changes can create incompatibilities between populations, contributing to speciation [14,25].…”