scholarly journals Genetics and Lineage-Specific Evolution of a Lethal Hybrid Incompatibility BetweenDrosophila mauritianaand Its Sibling Species

Genetics ◽  
2009 ◽  
Vol 181 (4) ◽  
pp. 1545-1555 ◽  
Author(s):  
M. Victoria Cattani ◽  
Daven C. Presgraves
Keyword(s):  
Sibling Species ◽  
Hybrid Incompatibility ◽  
Lethal Hybrid

scholarly journals A triple-hybrid cross reveals a new hybrid incompatibility locus between D. melanogaster and D. sechellia

2019 ◽  
Author(s):  
Jacob C. Cooper ◽  
Ping Guo ◽  
Jackson Bladen ◽  
Nitin Phadnis
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Genetic Basis ◽  
Whole Genome ◽  
Hybrid Incompatibility ◽  
Highly Dispersed ◽  
Hybrid Cross ◽  
Lethal Hybrid ◽  
Incompatibility Locus ◽  
Unknown Region

AbstractHybrid incompatibilities are the result of deleterious interactions between diverged genes in the progeny of two species. In Drosophila, crosses between female D. melanogaster and males from the D. simulans clade (D. simulans, D. mauritiana, D. sechellia) fail to produce hybrid F1 males. When attempting to rescue hybrid F1 males by depleting the incompatible allele of a previously identified hybrid incompatibility gene, we observed robust rescue in crosses of D. melanogaster to D. simulans or D. mauritiana, but no rescue in crosses to D. sechellia. To investigate the genetic basis of D. sechellia resistance to hybrid rescue, we designed a triple-hybrid cross to generate recombinant D. sechellia / D. simulans genotypes. We tested the ability of those genotypes to rescue hybrid males with D. melanogaster, and used whole genome sequencing to measure the D. sechellia / D. simulans allele frequency of viable F1 males. We found that recombinant genotypes were rescued when they contained two specific loci from D. simulans – a region containing previously identified Lethal hybrid rescue (Lhr), and an unknown region of chromosome 3L which we name Sechellia aversion to hybrid rescue (Satyr). Our results show that the genetic basis for the recent evolution of this hybrid incompatibility is simple rather than a highly dispersed effect. Further, these data suggest that fixation of differences at Lhr after the split of the D. simulans clade strengthened the hybrid incompatibility between D. sechellia and D. melanogaster.

scholarly journals Laboratory and microcosm experiments reveal contrasted adaptive responses to ammonia and water mineralisation in aquatic stages of the sibling species Anopheles gambiae (sensu stricto) and Anopheles coluzzii

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nwamaka Oluchukwu Akpodiete ◽  
Frédéric Tripet
Keyword(s):  
West Africa ◽  
Anopheles Gambiae ◽  
Emerging Adults ◽  
Sibling Species ◽  
Adult Emergence ◽  
Ecological Speciation ◽  
Sensu Stricto ◽  
Rice Fields ◽  
Anopheles Coluzzii ◽  
Phenotypic Quality

Abstract Background The sibling species of the malaria mosquito, Anopheles gambiae (sensu stricto) and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype-by-Environment (G × E) interactions, have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields, which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae (s.s.) Methods To highlight G × E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across two contrasted microcosms to highlight G × E interactions under conditions such as those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae (s.s.) strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae (s.s.), and vice versa, in the rain puddle environment. Conclusions Evidence for such G × E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice fields in An. coluzzii may have been an important driver of its ecological speciation.

scholarly journals A Quantitative Genetic Analysis of Male Sexual Traits Distinguishing the Sibling Species Drosophila simulans and D. sechellia

Genetics ◽  
1999 ◽  
Vol 153 (4) ◽  
pp. 1683-1699 ◽  
Author(s):  
Stuart J Macdonald ◽  
David B Goldstein
Keyword(s):  
Genetic Analysis ◽  
Sibling Species ◽  
Reproductive Traits ◽  
Drosophila Simulans ◽  
Directional Selection ◽  
Posterior Lobe ◽  
Sex Comb ◽  
Tooth Number ◽  
Comb Tooth ◽  
Shape And Size

Abstract A quantitative trait locus (QTL) genetic analysis of morphological and reproductive traits distinguishing the sibling species Drosophila simulans and D. sechellia was carried out in a backcross design, using 38 markers with an average spacing of 8.4 cM. The direction of QTL effects for the size of the posterior lobe was consistent across the identified QTL, indicating directional selection for this trait. Directional selection also appears to have acted on testis length, indicating that sexual selection may have influenced many reproductive traits, although other forms of directional selection cannot be ruled out. Sex comb tooth number exhibited high levels of variation both within and among isofemale lines and showed no evidence for directional selection and, therefore, may not have been involved in the early speciation process. A database search for genes associated with significant QTL revealed a set of candidate loci for posterior lobe shape and size, sex comb tooth number, testis length, tibia length, and hybrid male fertility. In particular, decapentaplegic (dpp), a gene known to influence the genital arch, was found to be associated with the largest LOD peak for posterior lobe shape and size.

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