scholarly journals Genomics Reveals Widespread Ecological Speciation in Flightless Insects

2020 ◽  
Author(s):  
Graham A McCulloch ◽  
Brodie J Foster ◽  
Ludovic Dutoit ◽  
Thomas W R Harrop ◽  
Joseph Guhlin ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Species Complex ◽  
Reference Genome ◽  
Genomic Data ◽  
Ecological Speciation ◽  
Genomic Region ◽  
Wing Reduction ◽  
Genomic Analyses ◽  
Evolutionary Genomic ◽  
Repeated Evolution

Abstract Recent genomic analyses have highlighted parallel divergence in response to ecological gradients, but the extent to which altitude can underpin such repeated speciation remains unclear. Wing reduction and flight loss have apparently evolved repeatedly in montane insect assemblages, and have been suggested as important drivers of hexapod diversification. We test this hypothesis using genomic analyses of a widespread wing-polymorphic stonefly species complex in New Zealand. We identified over 50,000 polymorphic genetic markers generated across almost 200 Zelandoperla fenestrata stonefly specimens using a newly generated plecopteran reference genome, to reveal widespread parallel speciation between sympatric full-winged and wing-reduced ecotypes. Rather than the existence of a single, widespread, flightless taxon (Zelandoperla pennulata), evolutionary genomic data reveal that wing-reduced upland lineages have speciated repeatedly and independently from full-winged Z. fenestrata. This repeated evolution of reproductive isolation between local ecotype pairs that lack mitochondrial DNA differentiation suggests that ecological speciation has evolved recently. A cluster of outlier SNPs detected in independently wing-reduced lineages, tightly linked in an approximately 85 kb genomic region that includes the developmental ‘supergene’ doublesex, suggests that this ‘island of divergence’ may play a key role in rapid ecological speciation.

scholarly journals An evolutionary genomic approach reveals both conserved and species-specific genetic elements related to human disease in closely related Aspergillus fungi

Genetics ◽  
2021 ◽  
Author(s):  
Matthew E Mead ◽  
Jacob L Steenwyk ◽  
Lilian P Silva ◽  
Patrícia A de Castro ◽  
Nauman Saeed ◽  
...  
Keyword(s):  
Human Disease ◽  
Evolutionary Rate ◽  
Fungal Disease ◽  
Comparative Genomic ◽  
Genetic Elements ◽  
Genomic Approach ◽  
Evolutionary Genomic ◽  
Repeated Evolution ◽  
Species Specific ◽  
Encoding Genes

Abstract Aspergillosis is an important opportunistic human disease caused by filamentous fungi in the genus Aspergillus. Roughly 70% of infections are caused by Aspergillus fumigatus, with the rest stemming from approximately a dozen other Aspergillus species. Several of these pathogens are closely related to A. fumigatus and belong in the same taxonomic section, section Fumigati. Pathogenic species are frequently most closely related to non-pathogenic ones, suggesting Aspergillus pathogenicity evolved multiple times independently. To understand the repeated evolution of Aspergillus pathogenicity, we performed comparative genomic analyses on 18 strains from 13 species, including 8 species in section Fumigati, which aimed to identify genes, both ones previously connected to virulence as well as ones never before implicated, whose evolution differs between pathogens and non-pathogens. We found that most genes were present in all species, including approximately half of those previously connected to virulence, but a few genes were section- or species-specific. Evolutionary rate analyses identified over 1,700 genes whose evolutionary rate differed between pathogens and non-pathogens and dozens of genes whose rates differed between specific pathogens and the rest of the taxa. Functional testing of deletion mutants of 17 transcription factor-encoding genes whose evolution differed between pathogens and non-pathogens identified eight genes that affect either fungal survival in a model of phagocytic killing, host survival in an animal model of fungal disease, or both. These results suggest that the evolution of pathogenicity in Aspergillus involved both conserved and species-specific genetic elements, illustrating how an evolutionary genomic approach informs the study of fungal disease.

Heteroplasmy due to coexistence of mtCOI haplotypes from different lineages of theThrips tabacicryptic species group

2017 ◽  
Vol 107 (4) ◽  
pp. 534-542 ◽  
Author(s):  
S.J. Gawande ◽  
S. Anandhan ◽  
A.A. Ingle ◽  
Alana Jacobson ◽  
R. Asokan
Keyword(s):  
Flow Cytometry ◽  
Mitochondrial Dna ◽  
Real Time Pcr ◽  
Copy Number ◽  
Species Complex ◽  
Species Group ◽  
Thrips Tabaci ◽  
Mitochondrial Cytochrome ◽  
Quantitative Real Time Pcr ◽  
Putative Species

AbstractHeteroplasmy is the existence of multiple mitochondrial DNA haplotypes within the cell. Although the number of reports of heteroplasmy is increasing for arthropods, the occurrence, number of variants, and origins are not well studied. In this research, the occurrence of heteroplasmy was investigated inThrips tabaci, a putative species complex whose lineages can be distinguished by their mitochondrial DNA haplotypes. The results from this study showed that heteroplasmy was due to the occurrence of mitochondrial cytochrome oxydase I (mtCOI) haplotypes from two differentT. tabacilineages. An assay using flow cytometry and quantitative real-time PCR was then used to quantify the per cell copy number of the two mtCOI haplotypes present in individuals exhibiting heteroplasmy from nine geographically distant populations in India. All of theT. tabaciindividuals in this study were found to exhibit heteroplasmy, and in every individual the per cell copy number of mtCOI from lineage 3 comprised 75–98% of the haplotypes detected and was variable among individuals tested. There was no evidence to suggest that the presense of lineage-specific haplotypes was due to nuclear introgression; however, further studies are needed to investigate nuclear introgression and paternal leakage during rare interbreeding between individuals from lineages 2 and 3.

scholarly journals The distributions of the six species constituting the smooth newt species complex (Lissotriton vulgaris sensu lato and L. montandoni) – an addition to the New Atlas of Amphibians and Reptiles of Europe

2018 ◽  
Vol 39 (2) ◽  
pp. 252-259 ◽  
Author(s):  
Ben Wielstra ◽  
Daniele Canestrelli ◽  
Milena Cvijanović ◽  
Mathieu Denoël ◽  
Anna Fijarczyk ◽  
...  
Keyword(s):  
Species Complex ◽  
Genomic Data ◽  
Genetic Data ◽  
Sister Species ◽  
Contact Zones ◽  
Distribution Maps ◽  
Smooth Newt ◽  
Lissotriton Vulgaris ◽  
Constituent Species ◽  
Distribution Ranges

Abstract The ‘smooth newt’, the taxon traditionally referred to as Lissotriton vulgaris, consists of multiple morphologically distinct taxa. Given the uncertainty concerning the validity and rank of these taxa, L. vulgaris sensu lato has often been treated as a single, polytypic species. A recent study, driven by genetic data, proposed to recognize five species, L. graecus, L. kosswigi, L. lantzi, L. schmidtleri and a more restricted L. vulgaris. The Carpathian newt L. montandoni was confirmed to be a closely related sister species. We propose to refer to this collective of six Lissotriton species as the smooth newt or Lissotriton vulgaris species complex. Guided by comprehensive genomic data from throughout the range of the smooth newt species complex we 1) delineate the distribution ranges, 2) provide a distribution database, and 3) produce distribution maps according to the format of the New Atlas of Amphibians and Reptiles of Europe, for the six constituent species. This allows us to 4) highlight regions where more research is needed to determine the position of contact zones.

scholarly journals Phylogenetic Position and Generic Placement of The Socorro Wren (Thryomanes Sissonii)

The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Juan E. Martínez Gómez ◽  
Brian R. Barber ◽  
A. Townsend Peterson
Keyword(s):  
Mitochondrial Dna ◽  
Dna Sequences ◽  
Species Complex ◽  
Taxonomic Classification ◽  
Phylogenetic Position ◽  
Base Pairs ◽  
House Wren ◽  
Taxonomic History ◽  
Socorro Island ◽  
Nd2 Gene

Abstract Since early in its taxonomic history, placement of the Socorro Wren (Thryomanes sissonii) has been an object of contention. Of particular interest is its current placement in the genus Thryomanes, which makes that genus ditypic and leads to an odd biogeographic scenario for the Socorro Wren's colonization of Socorro Island. We assessed its phylogenetic position by analyzing 516 base pairs of mitochondrial DNA sequences from the ND2 gene of this species and 14 additional wren taxa. Contrary to its present placement, the Socorro Wren is nested phylogenetically within the House Wren species complex, being placed as sister to the clade Troglodytes aedon + T. musculus. The current hypothesis (i.e. sister to Thryomanes bewickii) is strongly invalidated by our analysis. Our analyses indicate that the most appropriate taxonomic classification for the Socorro Wren is Troglodytes sissonii. Posición Filogenética y Ubicación Genérica de Thryomanes sissonii

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