TY - JOUR
T1 - A male-specific sex marker for the endangered western sawshelled turtle (Myuchelys bellii) using in silico whole-genome subtraction
AU - Dissanayake, Duminda S.B.
AU - Streeting, Louise M.
AU - Georges, Arthur
AU - Bower, Deborah S.
N1 - Funding Information:
This study has been supported by the New South Wales Government through its Environmental Trust (Saving Our Species Partnership Grant 2015/SS/0017). Open Access funding enabled and organized by CAUL and its Member Institutions.
Publisher Copyright:
© 2022, The Author(s).
Funding Information:
We gratefully acknowledge assistance from Martin Dillon of Northern Tablelands Local Land Services and Phil Spark and Zac Petersen of North West Ecological Services for their invaluable assistance in the trapping and collection of blood samples from adult western sawshelled turtles. We acknowledge the Anaiwan people, Traditional Custodians of the lands on which this study was conducted. We also thank the landowners who allowed us access to their properties. Turtle capture and handling procedures were authorized by the New South Wales Department of Primary Industry scientific collection permit P17_0062, New South Wales Department of Planning, Industry, and Environment scientific license SL101876, and University of New England Animal Ethics Committee approval AEC17-110.
Funding Information:
This study has been supported by the New South Wales Government through its Environmental Trust (Saving Our Species Partnership Grant 2015/SS/0017). Open Access funding enabled and organized by CAUL and its Member Institutions.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/6
Y1 - 2022/6
N2 - Artificial incubation of eggs for the mass release of hatchlings is a common conservation intervention for imperilled turtle species. Programs designed to reinforce wild populations need to ensure that they are releasing appropriate male to female ratios into the wild. In many turtle species, the sex of juveniles cannot be identified using external morphology until they approach sexual maturity. For the endangered western sawshelled turtle, Myuchelys bellii, sexual dimorphism does not occur until at least 6 years of age. We aimed to develop a molecular test to identify the sex of M. bellii during the life stages where they cannot be sexed morphologically—embryos, hatchlings and small juveniles. We used in silico whole-genome subtraction of a female M. bellii (XX) from a male (XY) to identify a Y chromosome-specific sequence which we characterized and developed into a PCR sex test. Our research is the first to use a whole-genome subtraction method in-silico to successfully establish sex chromosome markers in a freshwater turtle species. Developing this technology provides an opportunity for conservation programs to ensure that populations are supplemented with a proportionate number of male and female hatchlings. Further, it allows large scale measurement of naturally occurring sex ratios in hatchlings and small juveniles, which in turn enables estimates of sex ratios within wild populations free from age-at-maturity bias. The application of sex-specific marker technology also provides an opportunity to quantify the influence of sex on behaviour, movement and survival in the segment of populations that cannot be morphologically sexed.
AB - Artificial incubation of eggs for the mass release of hatchlings is a common conservation intervention for imperilled turtle species. Programs designed to reinforce wild populations need to ensure that they are releasing appropriate male to female ratios into the wild. In many turtle species, the sex of juveniles cannot be identified using external morphology until they approach sexual maturity. For the endangered western sawshelled turtle, Myuchelys bellii, sexual dimorphism does not occur until at least 6 years of age. We aimed to develop a molecular test to identify the sex of M. bellii during the life stages where they cannot be sexed morphologically—embryos, hatchlings and small juveniles. We used in silico whole-genome subtraction of a female M. bellii (XX) from a male (XY) to identify a Y chromosome-specific sequence which we characterized and developed into a PCR sex test. Our research is the first to use a whole-genome subtraction method in-silico to successfully establish sex chromosome markers in a freshwater turtle species. Developing this technology provides an opportunity for conservation programs to ensure that populations are supplemented with a proportionate number of male and female hatchlings. Further, it allows large scale measurement of naturally occurring sex ratios in hatchlings and small juveniles, which in turn enables estimates of sex ratios within wild populations free from age-at-maturity bias. The application of sex-specific marker technology also provides an opportunity to quantify the influence of sex on behaviour, movement and survival in the segment of populations that cannot be morphologically sexed.
KW - Endangered species
KW - Sex-specific markers
KW - Turtle conservation
KW - Y chromosome
UR - http://www.scopus.com/inward/record.url?scp=85127563615&partnerID=8YFLogxK
U2 - 10.1007/s12686-022-01266-3
DO - 10.1007/s12686-022-01266-3
M3 - Article
AN - SCOPUS:85127563615
SN - 1877-7252
VL - 14
SP - 231
EP - 236
JO - Conservation Genetics Resources
JF - Conservation Genetics Resources
IS - 2
ER -