Sutherland, Ben J.G. and Rico, Ciro and Audet, Céline and Bernatchez, Louis (2017) Sex Chromosome Evolution, Heterochiasmy, and Physiological QTL in the Salmonid Brook Charr Salvelinus fontinalis. G3: Genes, Genomes, Genetics, 7 . pp. 2749-2762. ISSN 2160-1836
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Abstract
Whole-genome duplication (WGD) can have large impacts on genome evolution, and much
remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex
determination system and whether this has an impact on increasing the diversity of sex determination
mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can
result in sequestration of genes into nonrecombining sex chromosomes. Sex chromosome development
itself may involve sex-specific recombination rate (i.e., heterochiasmy), which is also poorly understood. The
family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and
subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex
determining gene is known, and many species have nonhomologous sex chromosomes, putatively due to
transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis
and compare sex chromosome identities across the lineage (eight species and four genera). Although
nonhomology is frequent, homologous sex chromosomes and other consistencies are present in distantly
related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also
characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with
paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the
overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the
male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome
contains a large interspecific inversion, although its status between males and females remains unknown.
Finally, we identify quantitative trait loci (QTL) for 21 unique growth, reproductive, and stress-related
phenotypes to improve knowledge of the genetic architecture of these traits important to aquaculture
and evolution.
| Item Type: | Journal Article |
|---|---|
| Additional Information: | This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Uncontrolled Keywords: | heterochiasmy, salmon, sex chromosomes, QTL, whole-genome duplication, Genetics of Sex |
| Subjects: | Q Science > QH Natural history > QH301 Biology Q Science > QH Natural history > QH426 Genetics |
| Divisions: | Faculty of Science, Technology and Environment (FSTE) > School of Marine Studies |
| Depositing User: | Fulori Nainoca - Waqairagata |
| Date Deposited: | 13 Aug 2017 23:34 |
| Last Modified: | 13 Aug 2017 23:34 |
| URI: | https://repository.usp.ac.fj/id/eprint/10060 |
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