Gene Flow Between Populations With Highly Divergent Mitogenomes in the Australian Stingless Bee, Tetragonula hockingsi .

Autor: Law G; School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia., da Silva CRB; School of Biological Sciences Monash University Melbourne Victoria Australia.; School of Natural Sciences Macquarie University Sydney New South Wales Australia., Vlasich-Brennan I; School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia., Taylor BA; Department of Entomology Purdue University West Lafayette Indiana USA., Harpur BA; Department of Entomology Purdue University West Lafayette Indiana USA., Heard T; School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia., Nacko S; Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia., Riegler M; Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia., Dorey JB; School of Earth, Atmospheric, and Life Sciences University of Wollongong Wollongong New South Wales Australia., Stevens MI; Earth & Biological Sciences South Australian Museum Adelaide South Australia Australia.; School of Biological Sciences University of Adelaide Adelaide South Australia Australia., Lo N; School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia., Gloag R; School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2024 Nov 13; Vol. 14 (11), pp. e70475. Date of Electronic Publication: 2024 Nov 13 (Print Publication: 2024).
DOI: 10.1002/ece3.70475
Abstrakt: Coadaptation of mitochondrial and nuclear genes is essential for proper cellular function. When populations become isolated, theory predicts that they should maintain mito-nuclear coadaptation in each population, even as they diverge in genotype. Mito-nuclear incompatibilities may therefore arise when individuals from populations with divergent co-evolved mito-nuclear gene sets are re-united and hybridise, contributing to selection against inter-population hybrids and, potentially, to speciation. Here, we explored genetic divergence and gene flow between populations of a stingless bee ( Tetragonula hockingsi ) that have highly divergent mitogenomes. We identified three distinct populations across the species' 2500 km range on the east coast of Queensland (Australia): 'Cape York', 'Northern', and 'Southern'. The mitogenomes of each population showed > 12% pairwise nucleotide divergence from each other, and > 7% pairwise amino acid divergence. Based on nuclear SNPs from reduced representation sequencing, we identified at least two zones of gene flow between populations: a narrow natural zone between Northern and Southern populations (coinciding with a biogeographic barrier, the Burdekin Gap), and an artificial zone at the southern edge of the species' distribution, where Cape York, Northern, and Southern mito-lineages have been brought together in recent decades due to beekeeping. In the artificial hybrid zone, we also confirmed that males of all three mito-lineages were attracted to the mating aggregations of Southern queens, consistent with inter-population hybridisation. Populations of T. hockingsi thus appear to be in the 'grey zone' of the speciation continuum, having strong genetic differentiation but incomplete reproductive isolation. Among the nuclear SNPs most differentiated between Northern and Southern populations, several were associated with genes involved in mitochondrial function, consistent with populations having co-diverged mito-nuclear gene sets. Our observations suggest that coadapted sets of mitochondrial and nuclear genes unique to each population of T. hockingsi may play a role in maintaining population boundaries, though more study is needed to confirm the fitness costs of mito-nuclear incompatibilities in hybrid individuals.
Competing Interests: The authors declare no conflicts of interest.
(© 2024 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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