Biology subjects

Korlevic, P.

Publications and source records attributed to Korlevic, P..

6 recordsLinked to original sources

bioRxiv2026

Exploring the diversity and spatial distribution of Anopheles mosquitoes and their associated Plasmodium species in Tanzania using the ANOSPP amplicon panel

Species-level identification of malaria vectors and parasites is essential for targeted vector control, surveillance, and clinical case management. However, routine surveillance often relies on morphology, species group-restricted PCR assays, and parasite-detection workflows optimised for Plasmodium falciparum, potentially masking wider vector and parasite diversity. To address this gap, we applied the previously published ANOSPP amplicon sequencing panel to Anopheles mosquitoes collected across 25 districts in mainland Tanzania between 2020 and 2023, using it to characterise vector and parasite diversity, evaluate routine species assignments, and examine how primary-vector occurrence related to national malaria endemicity patterns. Of 71,146 mosquitoes collected, 10,020 were morphologically identified as Anopheles. ANOSPP-based identification resolved 15 Anopheles taxa, including the first Tanzanian record of Anopheles funestus-like mosquitoes (n = 10) and the first resolution of Anopheles longipalpis to Type C in the country (n = 13). Using ANOSPP as the reference, morphology misclassified 6.2% of ANOSPP-analysed specimens, with Anopheles rufipes and Anopheles maculipalpis frequently misclassified, and Anopheles pretoriensis and Anopheles marshallii sensu lato completely missed. Five Plasmodium species were detected across 37 parasite-positive mosquitoes: P. falciparum, P. vivax, P. ovale, P. malariae, and P. caprae. Plasmodium caprae was detected only in Anopheles arabiensis (n = 6), representing the first record of this parasite in Tanzania and its first detection in An. arabiensis globally. Co-occurrence of An. arabiensis, An. funestus s.s., and An. gambiae s.s. was more common in higher malaria transmission strata, whereas occurrence of An. arabiensis alone predominated in very-low and low strata. These findings show that integrating ANOSPP into surveillance can substantially improve vector and parasite resolution, uncover overlooked diversity, and strengthen species-informed malaria surveillance. Author summaryEffective malaria control requires accurate data on mosquito species distributions and the parasites they carry. However, in many settings surveillance still relies mainly on morphological identification or molecular tests targeting limited vector groups, while parasite detection often focuses on Plasmodium falciparum. This limits understanding of mosquito and parasite diversity, obscuring transmission dynamics. We used the previously published ANOSPP amplicon panel to analyse Anopheles mosquitoes across Tanzania. This revealed hidden biological complexity with direct implications for malaria transmission, resolving 15 mosquito and five Plasmodium species. Notably, for the first time in Tanzania, we detected the goat-associated parasite Plasmodium caprae in Anopheles arabiensis and identified An. funestus-like, whose vectorial capacity remains unclear, and An. longipalpis Type C, implicated in malaria transmission in dryland Kenya. Interestingly, co-occurrence of all three major Tanzanian vectors aligned with higher transmission settings, whereas areas where An. arabiensis was the sole vector were mainly in lower transmission settings. These findings show that species-resolved surveillance can reveal hidden biological complexity and provide a stronger basis for locally targeted malaria control.

genomics↗

bioRxiv2025

Breaking the cold chain: solutions for room temperature preservation of mosquitoes leading to high quality reference genomes

The Earth BioGenome Project (EBP) is a global endeavour to produce reference genomes for all described eukaryotic species. The majority of described species are arthropods, which tend to be small and require taxonomic expertise to identify to species level. Therefore, the ability to collect and preserve specimens in a suitable way for long read and Hi-C data generation using very simple approaches with minimal infrastructure is certain to be important in scaling up reference genome generation. Using Anopheles mosquitoes as an insect representative we evaluate how well different preservation liquids protect high molecular weight DNA, RNA, and nuclei for Hi-C when mosquitoes are held intact versus slightly squished. We find that squished samples stored in 100% ethanol and Allprotect held at room temperature for one week result in excellent preservation of both high molecular weight DNA and nuclei for Hi-C. Other tested buffers, including RNAlater, EDTA at several pHs, and DMSO Salt Solution (DESS) performed satisfactorily for long read data generation and RNA retrieval, but less ideally for Hi-C, which may have bigger negative impacts when aiming to generate data for organisms with larger genomes. Field collections requiring dry ice or dry shippers can be logistically challenging to arrange, are notoriously expensive, and DNA degrades rapidly if ultra-cold temperature is not maintained, which is devastating given how expensive and time consuming field work can be. Here we present multiple viable options for room temperature collection and/or shipment for arthropod samples. Further exploration across a broader range of species will hopefully enable cheaper and more widely available reference genome generation globally.

genomics↗

bioRxiv2024

Genomic diversity of the African malaria vector Anopheles funestus

Anopheles funestus s.s. is a formidable human malaria vector across sub-Saharan Africa. To understand how the species is evolving, especially in response to malaria vector control, we sequenced 656 modern specimens (collected 2014-2018) and 45 historic specimens (collected 1927-1967) from 16 African countries. We find high levels of genetic variation with clear and stable continental patterns. Six segregating inversions might be involved in adaptation of local ecotypes. Strong recent signals of selection centred on canonical insecticide resistance genes are shared by multiple populations. A promising gene drive target in An. gambiae is highly conserved in An. funestus. This work represents a significant advance in our understanding of the genetic diversity and population structure of An. funestus and will enable smarter targeted malaria control.

genomics↗

bioRxiv2022

Ancient dolphin genomes reveal rapid repeated adaptation to coastal waters

Parallel evolution provides among the strongest evidence of the role of natural selection in shaping adaptation to the local environment. Yet, the chronology, mode and tempo of the process of parallel evolution remains broadly debated and discussed in the field of evolutionary biology. In this study, we harness the temporal resolution of paleogenomics to understand the tempo and independence of parallel coastal ecotype adaptation in common bottlenose dolphins (Tursiops truncatus). For this, we generated whole genome resequencing data from subfossil dolphins (8,610-5,626 years BP) originating from around the formation time of new coastal habitat and compared them with data from contemporary populations. Genomic data revealed a shift in genetic affinity, with the oldest ancient sample being closer to the pelagic populations, while the younger samples had intermediate ancestry that showed greater affinity with the local contemporary coastal populations. We found coastal-associated genotypes in the genome of our highest coverage ancient sample, SP1060, providing rare evidence of rapid adaptation from standing genetic variation. Lastly, using admixture graph analyses, we found a reticulate evolutionary history between pelagic and coastal populations. Ancestral gene flow from coastal populations was the probable source of standing genetic variation present in the pelagic populations that enabled rapid adaptation to newly emerged coastal habitat. The genetic response to past climatic warming provides an understanding of how bottlenose dolphins will respond to ongoing directional climate change and shifting coastlines.

evolutionary biology↗

bioRxiv2021

A minimally morphologically destructive approach for DNA retrieval and whole genome shotgun sequencing of pinned historic Dipteran vector species

Museum collections contain enormous quantities of insect specimens collected over the past century, covering a period of increased and varied insecticide usage. These historic collections are therefore incredibly valuable as genomic snapshots of organisms before, during, and after exposure to novel selective pressures. However, these samples come with their own challenges compared to present-day collections, as they are fragile and retrievable DNA is low yield and fragmented. In this paper we tested several DNA extraction procedures across pinned historic Diptera specimens from four disease vector genera: Anopheles, Aedes, Culex and Glossina. We identify an approach that minimizes morphological damage while maximizing DNA retrieval for Illumina library preparation and sequencing that can accommodate the fragmented and low yield nature of historic DNA. We identify several key points in retrieving sufficient DNA while keeping morphological damage to a minimum: an initial rehydration step, a short incubation without agitation in a low salt Proteinase K buffer, and critical point drying of samples post-extraction to prevent tissue collapse caused by air drying. The suggested method presented here provides a solid foundation for exploring the genomes and morphology of historic Diptera collections. Significance statementLarge museum collections of pinned insects could provide important snapshots of genomes through time, but unfortunately DNA retrieval from such fragile samples often leads to severe morphological damage, especially in delicate species such as disease transmitting Diptera. In this study we have worked on a combined method that minimizes morphological damage while maximizing the retrieval of DNA from dry pinned Diptera species. We identified the importance of tissue rehydration, gentle DNA lysis buffer incubation, and critical point drying to restore collapsed tissues. We hope this approach will make it possible for more historic insect specimens to become available for genomic research while ensuring they remain intact for morphological studies.

evolutionary biology↗

bioRxiv2020

Genetic variation at the Cyp6m2 putative insecticide resistance locus in Anopheles gambiae and Anopheles coluzzii

BackgroundThe emergence of insecticide resistance is a major threat to malaria control programmes in Africa, with many different factors contributing to insecticide resistance in its vectors, Anopheles mosquitoes. CYP6M2 has previously been recognized as an important candidate in cytochrome P450-mediated detoxification in Anopheles mosquitoes. As it has been implicated in resistance against pyrethroids, organochlorines and carbamates, its broad metabolic activity makes it a potential agent in insecticide cross-resistance. Currently, allelic variation within the Cyp6m2 gene remains unknown. ResultsHere, we use Illumina whole-genome sequence data from Phase 2 of the Anopheles gambiae 1000 Genomes Project (Ag1000G) to examine genetic variation in the Cyp6m2 gene across 16 populations in 13 countries comprising Anopheles gambiae and Anopheles coluzzii mosquitoes. We find 15 missense biallelic substitutions at high frequency (defined as >5% frequency in one or more populations), that fall into five distinct haplotype groups that carry the main high frequency variants: A13T, D65A, E328Q, Y347F, I359V and A468S. We examine whether these alleles show evidence of selection either through potentially modified enzymatic function or by being linked to variants that change the transcriptional profile of the gene. Despite consistent reports of Cyp6m2 upregulation and metabolic activity in insecticide resistant Anophelines, we find no evidence of directional selection occurring on these variants or on the haplotype clusters in which they are found. ConclusionOur results imply that emerging resistance associated with Cyp6m2 is potentially driven by distant regulatory loci such as transcriptional factors rather than by its missense variants, or that other genes are playing a more significant role in conferring metabolic resistance.

genetics↗