Genetic diversity, phylogenetic position, and co-phylogenetic relationships of Karyolysus, a common blood parasite of lizards in the western Mediterranean

Elsevier

Available online 2 February 2023

International Journal for ParasitologyAuthor links open overlay panel, , , , , , , , Highlights•

We reassess the phylogenetic relationships and taxonomic status within the Adeleorina, a cosmopolitan order of parasites.

Karyolysus Labbé 1894 is the main blood parasite found in reptiles in the western Mediterranean and Macaronesia.

We found a lack of co-speciation signal between these parasites and their lizard hosts.

Host genera with diverging histories approximately 18 million years ago shared some parasite haplotypes.

A higher sampling effort is still needed worldwide in other large clades of Adeleorina.

Abstract

The genus Karyolysus was originally proposed to accommodate blood parasites of lacertid lizards in Western Europe. However, recent phylogenetic analyses suggested an inconclusive taxonomic position of these parasites of the order Adeleorina based on the available genetic information. Inconsistencies between molecular phylogeny, morphology, and/or life cycles can reflect lack of enough genetic information of the target group. We therefore surveyed 28 localities and collected blood samples from 828 lizards of 23 species including lacertids, skinks, and geckoes in the western Mediterranean, North Africa, and Macaronesia, where species of Karyolysus and other adeleorine parasites have been described. We combined molecular and microscopic methods to analyze the samples, including those from the host type species and the type locality of Karyolysus bicapsulatus. The phylogenetic relationship of these parasites was analyzed based on the 18S rRNA gene and the co-phylogenetic relationship with their vertebrate hosts was reconstructed. We molecularly detected adeleorine parasites in 37.9% of the blood samples and found 22 new parasite haplotypes. A phylogenetic reconstruction with 132 sequences indicated that 20 of the newly detected haplotypes clustered in a well-supported clade with another 18 sequences that included Karyolysus galloti and Karyolysus lacazei. Morphological evidence also supported that K. bicapsulatus clustered in this monophyletic clade. These results supported the taxonomic validity of the genus. In addition, we found some parasite haplotypes that infected different lizard host genera with ancient diverging histories, which suggested that Karyolysus is less host-specific than other blood parasites of lizards in the region. A co-phylogenetic analysis supported this interpretation because no significant co-speciation signal was shown between Karyolysus and lizard hosts.

Keywords

Adeleorina

Co-adaptation

Co-evolution

Karyolysus

Lacertidae

Reptiles

© 2023 The Author(s). Published by Elsevier Ltd on behalf of Australian Society for Parasitology.

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