Expansion of frozen hybrids in the guppy ectoparasite, Gyrodactylus turnbulli.
Mol Ecol
; 30(4): 1005-1016, 2021 02.
Article
in En
| MEDLINE
| ID: mdl-33345416
ABSTRACT
Hybridization is one of the major factors contributing to the emergence of highly successful parasites. Hybrid vigour can play an important role in this process, but subsequent rounds of recombination in the hybrid population may dilute its effects. Increased fitness of hybrids can, however, be frozen by asexual reproduction. Here, we identify invasion of a 'frozen hybrid' genotype in natural populations of Gyrodactylus turnbulli, a facultatively sexual ectoparasitic flatworm that causes significant damage to its fish host. We resequenced genomes of these parasites infecting guppies from six Trinidad and Tobago populations, and found surprisingly high discrepancy in genome-wide nucleotide diversity between islands. The elevated heterozygosity on Tobago is maintained by predominantly clonal reproduction of hybrids formed from two diverged genomes. Hybridization has been followed by spread of the hybrids across the island, implying a selective advantage compared with native genotypes. Our results thus highlight that a single outcrossing event may be independently sufficient to cause pathogen expansion.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Parasites
/
Trematoda
/
Poecilia
/
Fish Diseases
Type of study:
Prognostic_studies
Limits:
Animals
Country/Region as subject:
Caribe ingles
/
Trinidad y tobago
Language:
En
Journal:
Mol Ecol
Journal subject:
BIOLOGIA MOLECULAR
/
SAUDE AMBIENTAL
Year:
2021
Document type:
Article
Affiliation country:
Poland