Fitness consequences and ancestry loss in the Apennine brown bear after a simulated genetic rescue intervention.

Autor: Maroso F; Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.; Department of Biology, University of Padova, Padova, Italy., Padovani G; Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy., Muñoz Mora VH; Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy., Giannelli F; Department of Life and Environmental Science, Marche Polytechnic University, Ancona, Italy., Trucchi E; Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.; Department of Life and Environmental Science, Marche Polytechnic University, Ancona, Italy., Bertorelle G; Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
Jazyk: angličtina
Zdroj: Conservation biology : the journal of the Society for Conservation Biology [Conserv Biol] 2023 Dec; Vol. 37 (6), pp. e14133. Date of Electronic Publication: 2023 Sep 28.
DOI: 10.1111/cobi.14133
Abstrakt: Reduction in population size, with its predicted effects on population fitness, is the most alarming anthropogenic impact on endangered species. By introducing compatible individuals, genetic rescue (GR) is a promising but debated approach for reducing the genetic load unmasked by inbreeding and for restoring the fitness of declining populations. Although GR can improve genetic diversity and fitness, it can also produce loss of ancestry, hampering local adaptation, or replace with introduced variants the unique genetic pools evolved in endemic groups. We used forward genetic simulations based on empirical genomic data to assess fitness benefits and loss of ancestry risks of GR in the Apennine brown bear (Ursus arctos marsicanus). There are approximately 50 individuals of this isolated subspecies, and they have lower genetic diversity and higher inbreeding than other European brown bears, and GR has been suggested to reduce extinction risks. We compared 10 GR scenarios in which the number and genetic characteristics of migrants varied with a non-GR scenario of simple demographic increase due to nongenetic factors. The introduction of 5 individuals of higher fitness or lower levels of deleterious mutations than the target Apennine brown bear from a larger European brown bear population produced a rapid 10-20% increase in fitness in the subspecies and up to 22.4% loss of ancestry over 30 generations. Without a contemporary demographic increase, fitness started to decline again after a few generations. Doubling the population size without GR gradually increased fitness to a comparable level, but without losing ancestry, thus resulting in the best strategy for the Apennine brown bear conservation. Our results highlight the importance for management of endangered species of realistic forward simulations grounded in empirical whole-genome data.
(© 2023 The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.)
Databáze: MEDLINE
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