The extent of introgression between incipient Clarkia species is determined by temporal environmental variation and mating system

Introgression is pervasive across the tree of life but varies across taxa, geography, and genomic regions. However, the factors modulating this variation and how they may be affected by global change are not well understood. Here, we used 200 genomes and a 15-y site-specific environmental dataset to investigate the effects of environmental variation and mating system divergence on the magnitude of introgression between a recently diverged outcrosser-selfer pair of annual plants in the genus Clarkia. These sister taxa diverged very recently and subsequently came into secondary sympatry where they form replicated contact zones. Consistent with observations of other outcrosser-selfer pairs, we found that introgression was asymmetric between taxa, with substantially more introgression from the selfer to the outcrosser. This asymmetry was caused by a bias in the direction of initial F1 hybrid formation and subsequent backcrossing. We also found extensive variation in the outcrosser's admixture proportion among contact zones, which was predicted nearly entirely by interannual variance in spring precipitation. Greater fluctuations in spring precipitation resulted in higher admixture proportions, likely mediated by the effects of spring precipitation on the expression of traits that determine premating reproductive isolation. Climate-driven hybridization dynamics may be particularly affected by global change, potentially reshaping species boundaries and adaptation to novel environments.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:121

Enthalten in:

Proceedings of the National Academy of Sciences of the United States of America - 121(2024), 12 vom: 19. März, Seite e2316008121

Sprache:

Englisch

Beteiligte Personen:

Sianta, Shelley A [VerfasserIn]
Moeller, David A [VerfasserIn]
Brandvain, Yaniv [VerfasserIn]

Links:

Volltext

Themen:

Environmental variation
Introgression
Journal Article
Mating system
Speciation
Temporal variation

Anmerkungen:

Date Completed 13.03.2024

Date Revised 27.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1073/pnas.2316008121

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM369565819