The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners.
As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.
i
Genomic evidence for inbreeding depression and purging of deleterious genetic variation in Indian tigers
-
2021
-
-
Source: Proceedings of the National Academy of Sciences, 118(49)
[PDF-1.70 MB]
Details:
-
Journal Title:Proceedings of the National Academy of Sciences
-
Personal Author:
-
NOAA Program & Office:
-
Description:Increasing habitat fragmentation leads to wild populations becoming small, isolated, and threatened by inbreeding depression. However, small populations may be able to purge recessive deleterious alleles as they become expressed in homozygotes, thus reducing inbreeding depression and increasing population viability. We used whole-genome sequences from 57 tigers to estimate individual inbreeding and mutation load in a small–isolated and two large–connected populations in India. As expected, the small–isolated population had substantially higher average genomic inbreeding (FROH = 0.57) than the large–connected (FROH = 0.35 and FROH = 0.46) populations. The small–isolated population had the lowest loss-of-function mutation load, likely due to purging of highly deleterious recessive mutations. The large populations had lower missense mutation loads than the small–isolated population, but were not identical, possibly due to different demographic histories. While the number of the loss-of-function alleles in the small–isolated population was lower, these alleles were at higher frequencies and homozygosity than in the large populations. Together, our data and analyses provide evidence of 1) high mutation load, 2) purging, and 3) the highest predicted inbreeding depression, despite purging, in the small–isolated population. Frequency distributions of damaging and neutral alleles uncover genomic evidence that purifying selection has removed part of the mutation load across Indian tiger populations. These results provide genomic evidence for purifying selection in both small and large populations, but also suggest that the remaining deleterious alleles may have inbreeding-associated fitness costs. We suggest that genetic rescue from sources selected based on genome-wide differentiation could offset any possible impacts of inbreeding depression.
-
Keywords:
-
Source:Proceedings of the National Academy of Sciences, 118(49)
-
DOI:
-
ISSN:0027-8424;1091-6490;
-
Format:
-
Publisher:
-
Document Type:
-
License:
-
Rights Information:CC BY-NC-ND
-
Compliance:Library
-
Main Document Checksum:
-
Download URL:
-
File Type:
