Recent genetic exchanges and admixture shape the genome and population structure of the zoonotic pathogen Cryptosporidium parvum

Corsi, GI; Tichkule, S; Sannella, AR; Vatta, P; Asnicar, F; Segata, N; Jex, AR; van Oosterhout, C; Cacci&#242;, SM

Author(s): Corsi, GI; Tichkule, S; Sannella, AR; Vatta, P; Asnicar, F; Segata, N; Jex, AR; van Oosterhout, C; Cacciò, SM;
Details: Publication Year 2023-05,Volume 32,Issue #10,Page 2633-2645
Journal Title: Molecular Ecology
Abstract: Cryptosporidium parvum is a globally distributed zoonotic pathogen and a major cause of diarrhoeal disease in humans and ruminants. The parasite's life cycle comprises an obligatory sexual phase, during which genetic exchanges can occur between previously isolated lineages. Here, we compare 32 whole genome sequences from human- and ruminant-derived parasite isolates collected across Europe, Egypt and China. We identify three strongly supported clusters that comprise a mix of isolates from different host species, geographic origins, and subtypes. We show that: (1) recombination occurs between ruminant isolates into human isolates; (2) these recombinant regions can be passed on to other human subtypes through gene flow and population admixture; (3) there have been multiple genetic exchanges, and most are likely recent; (4) putative virulence genes are significantly enriched within these genetic exchanges, and (5) this results in an increase in their nucleotide diversity. We carefully dissect the phylogenetic sequence of two genetic exchanges, illustrating the long-term evolutionary consequences of these events. Our results suggest that increased globalisation and close human-animal contacts increase the opportunity for genetic exchanges between previously isolated parasite lineages, resulting in spillover and spillback events. We discuss how this can provide a novel substrate for natural selection at genes involved in host-parasite interactions, thereby potentially altering the dynamic coevolutionary equilibrium in the Red Queens arms race.
Publisher: Wiley
Keywords: Cryptosporidium parvum; evolution; gene flow; population admixture; recombination; whole genome sequencing
Research Division(s): Population Health And Immunity
PubMed ID: 35652748
Publisher's Version: https://doi.org/10.1111/mec.16556
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2022-06-17 09:28:43

Last Modified: 2023-06-09 10:43:04