Biology subjects

Karagodin, D. A.

Publications and source records attributed to Karagodin, D. A..

4 recordsLinked to original sources

bioRxiv2024

Discovery and characterization of chromosomal inversions in the arboviral vector mosquito Aedes aegypti

Chromosomal inversions play a fundamental role in evolution and have been shown to regulate epidemiologically important traits in malaria mosquitoes. However, they have never been characterized in Aedes aegypti, the major vector of arboviruses, because of the poor structure of its polytene chromosomes. In this study, we applied a Hi-C proximity ligation approach to identify chromosomal inversions in 25 strains of Ae. aegypti, acquired from its worldwide distribution, as well as in one strain of Ae. mascarensis. The study identified 21 multi-megabase inversions with uneven distributions along the three chromosomes. All chromosomal inversions, including one specific for Ae. mascarensis, were polymorphic. Nevertheless, geographic origin separated the strains into two clusters carrying African and non-African inversions suggesting their potential association with Ae. aegypti subspecies. Some of the inversions colocalized with chemoreceptor genes and quantitative trait loci associated with pathogen infection, implicating the potential role of inversions in host choice and disease transmission.

evolutionary biology↗

bioRxiv2022

Patterns of genetic differentiation imply distinct evolutionary histories of the sibling mosquito species Anopheles messeae and Anopheles daciae in Eurasia

Detailed knowledge of phylogeography is important for control of mosquito species involved in transmission of human infectious diseases. Anopheles messeae is a geographically widespread and genetically diverse dominant vector of malaria in Eurasia. A closely related sibling species, An. daciae, was distinguished from An. messeae based on a few nucleotide differences in its ribosomal DNA. However, the mechanisms of speciation and their evolutionary histories are poorly understood. Here, we performed a large-scale population genetics analysis of 3694 mosquitos from Eurasia to understand the species divergence, diversity, and population structure using the Internal Transcribed Spacer 2 of ribosomal DNA for species identification and frequencies of 11 polymorphic chromosomal inversions as genetic markers. The study revealed striking differences in the geographical distribution of the sibling species. The largest genetic differences between An. messeae and An. daciae were detected in the X sex chromosome suggesting that this chromosome plays a role in speciation. The frequencies of autosomal inversions differed significantly between the species, strongly supporting a restricted gene flow. The clinal variability of some inversion frequencies was revealed in both species implicating their possible involvement in climate adaptations. Statistical analysis of inversion polymorphism clearly distinguished two clusters associated with the two species and demonstrated much higher genetic diversity within An. messeae. Overall, the frequencies of hybrids in all locations were extremely low with the exception of several southeastern populations, where putative hybrids were abundant. Thus, the pattern of genetic differentiation implies dramatic differences in geographic distribution, population structure, and evolutionary histories of the sibling species An. messeae and An. daciae.

evolutionary biology↗

bioRxiv2022

Phylogenomics revealed migration routes and adaptive radiation timing of Holarctic malaria vectors of the Maculipennis group

BackgroundUnderstanding the evolutionary relationships between closely related taxa is important for mosquitoes that transmit human diseases. Six out of 41 dominant malaria vectors in the world belong to the Maculipennis group, which is subdivided into two North American subgroups (Freeborni and Quadrimaculatus), and one Eurasian (Maculipennis) subgroup. Although previous studies considered the Nearctic subgroups as ancestral, details about their relationship with the Palearctic subgroup, and their migration times and routes from North America to Eurasia remain controversial. The Eurasian species An. beklemishevi is currently included in the North American Quadrimaculatus subgroup adding to the uncertainties in mosquito systematics. ResultsTo reconstruct historic relationships between the North American and Eurasian mosquitoes, we conducted a phylogenomic analysis of 11 Palearctic and 2 Nearctic species based on 1271 orthologous genes using their transcriptomic or genomic sequences. The analysis indicated that the Palearctic species An. beklemishevi clusters together with other Eurasian species and represents a basal lineage among them. Also, An. beklemishevi is related more closely to An. freeborni, which inhabits the Western United States, rather than to An. quadrimaculatus, a species from the Eastern United States. The time-calibrated tree suggests a migration of mosquitoes in the Maculipennis group from North America to Eurasia about 20-25 million years ago through the Bering Land Bridge. A Hybridcheck analysis demonstrated highly significant signatures of introgression events between allopatric species An. labranchiae and An. beklemishevi. The analysis also identified ancestral introgression events between An. sacharovi and its Nearctic relative An. freeborni despite their current geographic isolation. ConclusionsOur phylogenomic analyses reveal migration routes and adaptive radiation timing of Holarctic malaria vectors and strongly support inclusion of An. beklemishevi into the Maculipennis subgroup. The vectorial capacity and the ability to diapause during winter evolved multiple times in Maculipennis evolution. Detailed knowledge of the evolutionary history in the Maculipennis subgroup will help us better understand the current and future patterns of malaria transmission in Eurasia.

evolutionary biology↗

bioRxiv2020

Improved reference genome of the arboviral vector Aedes albopictus

The Asian tiger mosquito Aedes albopictus is globally expanding and has become the main vector for human arboviruses in Europe. Here we present AalbF2, a dramatically improved assembly of the Ae. albopictus genome that has revealed widespread viral insertions, novel microRNAs and piRNA clusters, the sex determining locus, new immunity genes, and has enabled genome-wide studies of geographically diverse Ae. albopictus populations and analyses of the developmental and stage-dependent network of expression data. Additionally, we built the first physical map for this species with 75% of the assembled genome anchored to the chromosomes. These up-to-date resources of the genome provide a foundation to improve understanding of the adaptation potential and the epidemiological relevance of this species and foster the development of innovative control measures. One Sentence SummaryLong-read and Hi-C-based de novo assembly of the arboviral vector Aedes albopictus genome fosters deeper understanding of its biological features.

genomics↗