TY - JOUR
T1 - Transition in sexual system and sex chromosome evolution in the tadpole shrimp Triops cancriformis
AU - Mathers, T. C.
AU - Hammond, R. L.
AU - Jenner, R. A.
AU - Hänfling, B.
AU - Atkins, J.
AU - Gómez, A.
N1 - Funding Information:
This work was part of TCM’s PhD project ‘The genetics and evolutionary dynamics of reproductive mode in tadpole shrimps’ funded by a NERC CASE Studentship (NE/G012318/1). We are grateful to Dani Boix, for sending us multiple sediment samples from Espolla Lake, and Thorid Zierold for her support and help when sampling German populations. RAD library preparation and Illumina sequencing was funded by a NERC-NBAF grant (NBAF400) and carried out at the NERC Biomolecular Analysis Facility at Edinburgh. We thank Karim Gharbi, Cathlene Eland, Urmi Trivedi and Tim Cezard at The GenePool for help with a pilot RAD library construction, bioinformatics analysis and sequencing. We thank Dave Lunt, Amir Szitenberg, Dan Jeffries and Steve Moss from the Evolution Group at Hull, for help with setting up bioinformatics analysis. AG was funded by an Advanced NERC fellowship (NE/B501298/1). Nicholas Perrin, Chiara Benvenuto, Lori Lawson-Handley, Steve Weeks and two anonymous reviewers gave valuable suggestions on an earlier version of the manuscript.
Publisher Copyright:
© 2015 Macmillan Publishers Limited All rights reserved.
PY - 2015/7/11
Y1 - 2015/7/11
N2 - Transitions in sexual system and reproductive mode may affect the course of sex chromosome evolution, for instance by altering the strength of sexually antagonistic selection. However, there have been few studies of sex chromosomes in systems where such transitions have been documented. The European tadpole shrimp, Triops cancriformis, has undergone a transition from dioecy to androdioecy (a sexual system where hermaphrodites and males coexist), offering an excellent opportunity to test the impact of this transition on the evolution of sex chromosomes. To identify sex-linked markers, to understand mechanisms of sex determination and to investigate differences between sexual systems, we carried out a genome-wide association study using restriction site-associated DNA sequencing (RAD-seq) of 47 males, females and hermaphrodites from one dioecious and one androdioecious population. We analysed 22.9 Gb of paired-end sequences and identified and scored >3000 high coverage novel genomic RAD markers. Presence-absence of markers, single-nucleotide polymorphism association and read depth identified 52 candidate sex-linked markers. We show that sex is genetically determined in T. cancriformis, with a ZW system conserved across dioecious and androdioecious populations and that hermaphrodites have likely evolved from females. We also show that the structure of the sex chromosomes differs strikingly, with a larger sex-linked region in the dioecious population compared with the androdioecious population.
AB - Transitions in sexual system and reproductive mode may affect the course of sex chromosome evolution, for instance by altering the strength of sexually antagonistic selection. However, there have been few studies of sex chromosomes in systems where such transitions have been documented. The European tadpole shrimp, Triops cancriformis, has undergone a transition from dioecy to androdioecy (a sexual system where hermaphrodites and males coexist), offering an excellent opportunity to test the impact of this transition on the evolution of sex chromosomes. To identify sex-linked markers, to understand mechanisms of sex determination and to investigate differences between sexual systems, we carried out a genome-wide association study using restriction site-associated DNA sequencing (RAD-seq) of 47 males, females and hermaphrodites from one dioecious and one androdioecious population. We analysed 22.9 Gb of paired-end sequences and identified and scored >3000 high coverage novel genomic RAD markers. Presence-absence of markers, single-nucleotide polymorphism association and read depth identified 52 candidate sex-linked markers. We show that sex is genetically determined in T. cancriformis, with a ZW system conserved across dioecious and androdioecious populations and that hermaphrodites have likely evolved from females. We also show that the structure of the sex chromosomes differs strikingly, with a larger sex-linked region in the dioecious population compared with the androdioecious population.
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U2 - 10.1038/hdy.2015.10
DO - 10.1038/hdy.2015.10
M3 - Article
C2 - 25757406
AN - SCOPUS:84930868717
SN - 0018-067X
VL - 115
SP - 37
EP - 46
JO - Heredity
JF - Heredity
IS - 1
ER -