Extreme variation in recombination rate and genetic diversity along the Sylvioidea neo-sex chromosome
Ponnikas, Suvi LU ; Sigeman, Hanna LU ; Lundberg, Max LU and Hansson, Bengt LU
(2022)
In Molecular Ecology
31(13).
p.3566-3583
- Abstract
Recombination strongly impacts sequence evolution by affecting the extent of linkage and the efficiency of selection. Here, we study recombination over the Z chromosome in great reed warblers (Acrocephalus arundinaceus) using pedigree-based linkage mapping. This species has extended Z and W chromosomes (“neo-sex chromosomes”) formed by a fusion between a part of chromosome 4A and the ancestral sex chromosomes, which provides a unique opportunity to assess recombination and sequence evolution in sex-linked regions of different ages. We assembled an 87.54 Mbp and 90.19 cM large Z with a small pseudoautosomal region (0.89 Mbp) at one end and the fused Chr4A-part at the other end of the chromosome. A prominent feature in our data was an... (More)
Recombination strongly impacts sequence evolution by affecting the extent of linkage and the efficiency of selection. Here, we study recombination over the Z chromosome in great reed warblers (Acrocephalus arundinaceus) using pedigree-based linkage mapping. This species has extended Z and W chromosomes (“neo-sex chromosomes”) formed by a fusion between a part of chromosome 4A and the ancestral sex chromosomes, which provides a unique opportunity to assess recombination and sequence evolution in sex-linked regions of different ages. We assembled an 87.54 Mbp and 90.19 cM large Z with a small pseudoautosomal region (0.89 Mbp) at one end and the fused Chr4A-part at the other end of the chromosome. A prominent feature in our data was an extreme variation in male recombination rate along Z with high values at both chromosome ends, but an apparent lack of recombination over a substantial central section, covering 78% of the chromosome. The nonrecombining region showed a drastic loss of genetic diversity and accumulation of repeats compared to the recombining parts. Thus, our data emphasize a key role of recombination in affecting local levels of polymorphism. Nonetheless, the evolutionary rate of genes (dN/dS) did not differ between high and low recombining regions, suggesting that the efficiency of selection on protein-coding sequences can be maintained also at very low levels of recombination. Finally, the Chr4A-derived part showed a similar recombination rate as the part of the ancestral Z that did recombine, but its sequence characteristics reflected both its previous autosomal, and current Z-linked, recombination patterns.
(Less)
- author
- Ponnikas, Suvi
LU
; Sigeman, Hanna
LU
; Lundberg, Max
LU
and Hansson, Bengt
LU
- organization
- publishing date
- 2022-07
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- evolutionary rates, genetic variation, great reed warbler, linkage map, neo-sex chromosome, recombination
- in
- Molecular Ecology
- volume
- 31
- issue
- 13
- pages
- 18 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:85131313023
- pmid:35578784
- ISSN
- 0962-1083
- DOI
- 10.1111/mec.16532
- language
- English
- LU publication?
- yes
- id
- 6c67066c-22a9-4987-910d-21a0f79e6192
- date added to LUP
- 2022-09-06 10:46:49
- date last changed
- 2024-06-27 20:18:01
@article{6c67066c-22a9-4987-910d-21a0f79e6192,
abstract = {{<p>Recombination strongly impacts sequence evolution by affecting the extent of linkage and the efficiency of selection. Here, we study recombination over the Z chromosome in great reed warblers (Acrocephalus arundinaceus) using pedigree-based linkage mapping. This species has extended Z and W chromosomes (“neo-sex chromosomes”) formed by a fusion between a part of chromosome 4A and the ancestral sex chromosomes, which provides a unique opportunity to assess recombination and sequence evolution in sex-linked regions of different ages. We assembled an 87.54 Mbp and 90.19 cM large Z with a small pseudoautosomal region (0.89 Mbp) at one end and the fused Chr4A-part at the other end of the chromosome. A prominent feature in our data was an extreme variation in male recombination rate along Z with high values at both chromosome ends, but an apparent lack of recombination over a substantial central section, covering 78% of the chromosome. The nonrecombining region showed a drastic loss of genetic diversity and accumulation of repeats compared to the recombining parts. Thus, our data emphasize a key role of recombination in affecting local levels of polymorphism. Nonetheless, the evolutionary rate of genes (dN/dS) did not differ between high and low recombining regions, suggesting that the efficiency of selection on protein-coding sequences can be maintained also at very low levels of recombination. Finally, the Chr4A-derived part showed a similar recombination rate as the part of the ancestral Z that did recombine, but its sequence characteristics reflected both its previous autosomal, and current Z-linked, recombination patterns.</p>}},
author = {{Ponnikas, Suvi and Sigeman, Hanna and Lundberg, Max and Hansson, Bengt}},
issn = {{0962-1083}},
keywords = {{evolutionary rates; genetic variation; great reed warbler; linkage map; neo-sex chromosome; recombination}},
language = {{eng}},
number = {{13}},
pages = {{3566--3583}},
publisher = {{Wiley-Blackwell}},
series = {{Molecular Ecology}},
title = {{Extreme variation in recombination rate and genetic diversity along the Sylvioidea neo-sex chromosome}},
url = {{http://dx.doi.org/10.1111/mec.16532}},
doi = {{10.1111/mec.16532}},
volume = {{31}},
year = {{2022}},
}