scholarly journals Genetic analysis of hybrid incompatibility suggests transposable elements increase reproductive isolation in the D. virilis clade

2019 ◽  
Author(s):  
Dean M. Castillo ◽  
Leonie C. Moyle
Keyword(s):  
Transposable Elements ◽  
Reproductive Isolation ◽  
Interspecific Cross ◽  
Drosophila Virilis ◽  
Interspecific Crosses ◽  
Closely Related Species ◽  
Hybrid Incompatibility ◽  
Alternative Hypotheses ◽  
Hybrid Dysfunction

AbstractAlthough observed in many interspecific crosses, the genetic basis of most hybrid incompatibilities is still unknown. Mismatches between parental genomes in selfish elements and the genes that regulate these elements are frequently hypothesized to underlie hybrid dysfunction. We evaluated the potential role of transposable elements (TEs) in hybrid incompatibilities by examining hybrids between Drosophila virilis strains polymorphic for TEs that cause dysgenesis and a closely related species that appears to lack these elements. Using genomic data, we confirmed copy number differences in potentially causal TEs between the dysgenic-causing D. virilis (TE+) strain and a sensitive D. virilis (TE-) strain and D. lummei genotype. We then contrasted isolation phenotypes in a cross where dysgenic TEs are absent from both D. virilis (TE-) and D. lummei parental genotypes, to a cross where dysgenic TEs are present in the D. virilis (TE+) parent and absent in the D. lummei parent, predicting increased reproductive isolation in the latter cross. Using F1 and backcross experiments that account for alternative hypotheses, we demonstrated amplified reproductive isolation specifically in the interspecific cross involving TE+ D. virilis, consistent with the action of dysgenesis-inducing TEs. These experiments demonstrate that TEs can contribute to hybrid incompatibilities via presence/absence polymorphisms.

An X chromosome effect responsible for asymmetric reproductive isolation between male Drosophila virilis and heterospecific females

Genome ◽  
2009 ◽  
Vol 52 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Desirée Nickel ◽  
Alberto Civetta
Keyword(s):  
Reproductive Isolation ◽  
X Chromosome ◽  
Drosophila Virilis ◽  
Interspecific Crosses ◽  
Closely Related Species ◽  
Virilis Group ◽  
Failed Fertilization ◽  
Backcross Populations ◽  
Early Zygote ◽  
Male Mate

Reproductive isolation between closely related species is expressed through uncoordinated courtship, failed fertilization, and (or) postzygotic barriers. Behavioural components of mating often form an initial barrier to hybridization between species. In many animals, females are responsible for mating discrimination in both intra- and interspecific crosses; males of Drosophila virilis group represent an exception to this trend. Using overall productivity tests, we show that a lower proportion of D. virilis males sire progeny when paired with a heterospecific female ( Drosophila novamexicana or Drosophila americana texana ) for 2 weeks. This suggests male mate discrimination or some other kind of asymmetrical incompatibility in courtship and mating or early zygote mortality. We used males from D. virilis – D. novamexicana and from D. virilis – D. a. texana backcross populations to map chromosome effects responsible for male reproductive isolation. Results from the analysis of both backcross male populations indicate a major X chromosome effect. Further, we conduct a male behavioural analysis to show that D. virilis males significantly fail to continue courtship after the first step of courtship, when they tap heterospecific females. The combined results of a major X chromosome effect and the observation that D. virilis males walk away from females after tapping suggest that future studies should concentrate on the identification of X-linked genes affecting the ability of males to recognize conspecific females.

scholarly journals Limited intrinsic postzygotic reproductive isolation despite chromosomal rearrangements between closely related sympatric species of small ermine moths (Lepidoptera: Yponomeutidae)

2019 ◽  
Vol 128 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Katerina H Hora ◽  
František Marec ◽  
Peter Roessingh ◽  
Steph B J Menken
Keyword(s):  
Reproductive Isolation ◽  
Parental Species ◽  
Meiotic Chromosome ◽  
Chromosomal Rearrangements ◽  
Sympatric Species ◽  
Hybrid Fitness ◽  
New Host ◽  
Closely Related Species ◽  
Postzygotic Reproductive Isolation

Abstract In evolutionarily young species and sympatric host races of phytophagous insects, postzygotic incompatibility is often not yet fully developed, but reduced fitness of hybrids is thought to facilitate further divergence. However, empirical evidence supporting this hypothesis is limited. To assess the role of reduced hybrid fitness, we studied meiosis and fertility in hybrids of two closely related small ermine moths, Yponomeuta padella and Yponomeuta cagnagella, and determined the extent of intrinsic postzygotic reproductive isolation. We found extensive rearrangements between the karyotypes of the two species and irregularities in meiotic chromosome pairing in their hybrids. The fertility of reciprocal F1 and, surprisingly, also of backcrosses with both parental species was not significantly decreased compared with intraspecific offspring. The results indicate that intrinsic postzygotic reproductive isolation between these closely related species is limited. We conclude that the observed chromosomal rearrangements are probably not the result of an accumulation of postzygotic incompatibilities preventing hybridization. Alternative explanations, such as adaptation to new host plants, are discussed.

scholarly journals Homoploid hybrid speciation and genome evolution via chromosome sorting

2015 ◽  
Vol 282 (1807) ◽  
pp. 20150157 ◽  
Author(s):  
Vladimir A. Lukhtanov ◽  
Nazar A. Shapoval ◽  
Boris A. Anokhin ◽  
Alsu F. Saifitdinova ◽  
Valentina G. Kuznetsova
Keyword(s):  
Reproductive Isolation ◽  
Direct Consequence ◽  
Convincing Evidence ◽  
Interspecific Crosses ◽  
Parental Origin ◽  
Hybrid Speciation ◽  
Species Formation ◽  
Homoploid Hybrid ◽  
Creative Role

Genomes of numerous diploid plant and animal species possess traces of interspecific crosses, and many researches consider them as support for homoploid hybrid speciation (HHS), a process by which a new reproductively isolated species arises through hybridization and combination of parts of the parental genomes, but without an increase in ploidy. However, convincing evidence for a creative role of hybridization in the origin of reproductive isolation between hybrid and parental forms is extremely limited. Here, through studying Agrodiaetus butterflies, we provide proof of a previously unknown mode of HHS based on the formation of post-zygotic reproductive isolation via hybridization of chromosomally divergent parental species and subsequent fixation of a novel combination of chromosome fusions/fissions in hybrid descendants. We show that meiotic segregation, operating in the hybrid lineage, resulted in the formation of a new diploid genome, drastically rearranged in terms of chromosome number. We also demonstrate that during the heterozygous stage of the hybrid species formation, recombination was limited between rearranged chromosomes of different parental origin, representing evidence that the reproductive isolation was a direct consequence of hybridization.

scholarly journals ON THE THEORY OF SPECIATION INDUCED BY TRANSPOSABLE ELEMENTS

Genetics ◽  
1984 ◽  
Vol 107 (2) ◽  
pp. 331-341
Author(s):  
Lev R Ginzburg ◽  
Paul M Bingham ◽  
Sinjae Yoo
Keyword(s):  
Transposable Elements ◽  
Reproductive Isolation

ABSTRACT A simple methematical model describes the invasion of panmictic, sexually reproducing populations by a newly introduced transposon. The model places important constraints on the properties that transposons must have to successfully invade a population and describes the kinetics with which such an invasion will occur. Invasibility conditions serve as a basis for new, detailed scenarios whereby transposon-mediated depression in fitness produces reproductive isolation of populations. These scenarios, in turn, lead to several speculations concerning the role of transposons in evolution.

scholarly journals P-elements strengthen reproductive isolation within the Drosophila simulans species complex

2020 ◽  
Author(s):  
Antonio Serrato-Capuchina ◽  
Emmanuel R. R. D’Agostino ◽  
David Peede ◽  
Baylee Roy ◽  
Kristin Isbell ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Reproductive Isolation ◽  
Species Complex ◽  
Drosophila Simulans ◽  
Sister Species ◽  
Species Boundaries ◽  
Interspecific Crosses ◽  
Female Fecundity ◽  
Pure Species ◽  
P Elements

ABSTRACTDetermining mechanisms that underlie reproductive isolation is key to understanding how species boundaries are maintained in nature. Transposable elements (TEs) are ubiquitous across eukaryotic genomes. However, the role of TEs in modulating the strength of reproductive isolation between species is poorly understood. Several species of Drosophila have been found to harbor P-elements (PEs), yet only D. simulans is known to be polymorphic for their presence in wild populations. PEs can cause reproductive isolation between PE-containing (P) and PE-lacking (M) lineages of the same species. However, it is unclear whether they also contribute to the magnitude of reproductive isolation between species. Here, we use the simulans species complex to assess whether differences in PE status between D. simulans and its sister species, which do not harbor PEs, contribute to multiple barriers to gene flow between species. We show that crosses involving a P D. simulans father and an M mother from a sister species exhibit lower F1 female fecundity than crosses involving an M D. simulans father and an M sister-species mother. Our results suggest that the presence of PEs in a species can strengthen isolation from its sister species, providing evidence that transposable elements can play a role in reproductive isolation and facilitate the process of speciation.IMPACT SUMMARYTransposable elements (TEs) are repetitive genetic units found across the tree of life. They play a fundamental role on the evolution of each species’ genome. TEs have been implicated in diversification, extinction, and the origin of novelty. However, their potential role in contributing to the maintenance of species boundaries remains largely understudied. Using whole genome sequences, we compared the relative content of TEs across the three species of the Drosophila simulans complex. We find that the presence of one TE, P-element, in D. simulans, and its absence in the sister taxa, differentiates the three species. P-elements (PEs) cause a suite of fitness defects in Drosophila pure-species individuals if their father has PEs but their mother does not, a phenomenon known as hybrid dysgenesis (HD). We thus studied the possibility that PEs enhance isolation between recently-diverged species. In particular, we studied whether the progeny from interspecific crosses were more prone to suffer from HD than pure species. We found that the presence of paternal PEs reduces hybrid female fecundity, mirroring observations of HD described within species. The effect of PEs is stronger in the interspecific hybrids than in pure species. Our results suggest that PEs can strengthen reproductive isolation in well-formed sister species that still hybridize in nature and pose the question of whether other TEs are involved in the formation of species or in their persistence over time.

scholarly journals Premating barriers in young sympatric snail species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arina L. Maltseva ◽  
Marina A. Varfolomeeva ◽  
Arseniy A. Lobov ◽  
Polina O. Tikanova ◽  
Egor A. Repkin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Snail Species ◽  
Sympatric Populations ◽  
Gastropod Species ◽  
Shell Size ◽  
Closely Related Species ◽  
Partial Canonical Correspondence Analysis ◽  
In The Wild ◽  
Isolation Index

AbstractSympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.

scholarly journals Molecular Signatures of Reticulate Evolution within the Complex of European Pine Taxa

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 489
Author(s):  
Bartosz Łabiszak ◽  
Witold Wachowiak
Keyword(s):  
Gene Flow ◽  
Reticulate Evolution ◽  
Modeling Framework ◽  
Closely Related Species ◽  
Interspecific Gene Flow ◽  
Nucleotide Sequence Variation ◽  
History Of ◽  
Best Fitting ◽  
Species Integrity

Speciation mechanisms, including the role of interspecific gene flow and introgression in the emergence of new species, are the major focus of evolutionary studies. Inference of taxonomic relationship between closely related species may be challenged by past hybridization events, but at the same time, it may provide new knowledge about mechanisms responsible for the maintenance of species integrity despite interspecific gene flow. Here, using nucleotide sequence variation and utilizing a coalescent modeling framework, we tested the role of hybridization and introgression in the evolutionary history of closely related pine taxa from the Pinus mugo complex and P. sylvestris. We compared the patterns of polymorphism and divergence between taxa and found a great overlap of neutral variation within the P. mugo complex. Our phylogeny reconstruction indicated multiple instances of reticulation events in the past, suggesting an important role of interspecific gene flow in the species divergence. The best-fitting model revealed P. mugo and P. uncinata as sister species with basal P. uliginosa and asymmetric migration between all investigated species after their divergence. The magnitude of interspecies gene flow differed greatly, and it was consistently stronger from representatives of P. mugo complex to P. sylvestris than in the opposite direction. The results indicate the prominent role of reticulation evolution in those forest trees and provide a genetic framework to study species integrity maintained by selection and local adaptation.

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