TY - JOUR
T1 - Sex-linked and autosomal microsatellites provide new insights into island populations of the tammar wallaby
AU - MACDONALD, Anna
AU - FitzSimmons, Nancy
AU - Chambers, B.
AU - Renfree, M. B.
AU - SARRE, Stephen
N1 - Funding Information:
This work was supported by an Australian Research Council Discovery Grant (DP0211687) awarded to SDS and NNF. Professor Geoff Shaw, Dr Danielle Hickford and Dr Terry Fletcher assisted with sample collection and Rachel Walsh assisted with DNA extractions. We thank three anonymous reviewers, Niccy Aitken, William Sherwin, Marion Höhn, Dennis McNevin and participants in an Institute for Applied Ecology Science Writers’ Workshops for helpful comments on earlier versions of this manuscript.
PY - 2014/3
Y1 - 2014/3
N2 - The emerging availability of microsatellite markers from mammalian sex chromosomes provides opportunities to investigate both male- and female-mediated gene flow in wild populations, identifying patterns not apparent from the analysis of autosomal markers alone. Tammar wallabies (Macropus eugenii), once spread over the southern mainland, have been isolated on several islands off the Western Australian and South Australian coastlines for between 10 000 and 13 000 years. Here, we combine analyses of autosomal, Y-linked and X-linked microsatellite loci to investigate genetic variation in populations of this species on two islands (Kangaroo Island, South Australia and Garden Island, Western Australia). All measures of diversity were higher for the larger Kangaroo Island population, in which genetic variation was lowest at Y-linked markers and highest at autosomal markers (θ=3.291, 1.208 and 0.627 for autosomal, X-linked and Y-linked data, respectively). Greater relatedness among females than males provides evidence for male-biased dispersal in this population, while sex-linked markers identified genetic lineages not apparent from autosomal data alone. Overall genetic diversity in the Garden Island population was low, especially on the Y chromosome where most males shared a common haplotype, and we observed high levels of inbreeding and relatedness among individuals. Our findings highlight the utility of this approach for management actions, such as the selection of animals for translocation or captive breeding, and the ecological insights that may be gained by combining analyses of microsatellite markers on sex chromosomes with those derived from autosomes.
AB - The emerging availability of microsatellite markers from mammalian sex chromosomes provides opportunities to investigate both male- and female-mediated gene flow in wild populations, identifying patterns not apparent from the analysis of autosomal markers alone. Tammar wallabies (Macropus eugenii), once spread over the southern mainland, have been isolated on several islands off the Western Australian and South Australian coastlines for between 10 000 and 13 000 years. Here, we combine analyses of autosomal, Y-linked and X-linked microsatellite loci to investigate genetic variation in populations of this species on two islands (Kangaroo Island, South Australia and Garden Island, Western Australia). All measures of diversity were higher for the larger Kangaroo Island population, in which genetic variation was lowest at Y-linked markers and highest at autosomal markers (θ=3.291, 1.208 and 0.627 for autosomal, X-linked and Y-linked data, respectively). Greater relatedness among females than males provides evidence for male-biased dispersal in this population, while sex-linked markers identified genetic lineages not apparent from autosomal data alone. Overall genetic diversity in the Garden Island population was low, especially on the Y chromosome where most males shared a common haplotype, and we observed high levels of inbreeding and relatedness among individuals. Our findings highlight the utility of this approach for management actions, such as the selection of animals for translocation or captive breeding, and the ecological insights that may be gained by combining analyses of microsatellite markers on sex chromosomes with those derived from autosomes.
KW - STR
KW - X chromosome
KW - Y chromosome
KW - marsupial
KW - sex-linked microsatellite
UR - http://www.scopus.com/inward/record.url?scp=84894040339&partnerID=8YFLogxK
U2 - 10.1038/hdy.2013.109
DO - 10.1038/hdy.2013.109
M3 - Article
SN - 0018-067X
VL - 112
SP - 333
EP - 342
JO - Heredity
JF - Heredity
IS - 3
ER -