Download Genetic structure web

DNA sampling of Little Penguin
(Eudyptula minor) colonies in
south-eastern Australia
Rebecca Overeem1, Amanda Peucker1,
Peter Dann2 & Chris Burridge1 3
1Deakin
University, Warrnambool Campus, Victoria, Australia
Island Nature Parks, Cowes, Victoria, Australia
3Otago University, Dunedin, New Zealand
2Phillip
Cartoon: Vic Nelson
Little Penguin
(Eudyptula minor)
•
World’s smallest penguin
•
33cm in height
•
Weight ~ 1kg
•
First breed at 2-3 years
•
Average lifespan of
6-7 years
VICTORIA
Melbourne
•
•
•
•
Endemic to southern Australia and New Zealand
Distributed from Fremantle in Western Australia to
northern New South Wales and Tasmania
40 000 breeding pairs in Victoria
Phillip and Gabo Islands contain the largest colonies
Conservation Priority
• Human induced pressure
• Potentially limited movement between
colonies
• Phenotypic variation: potential that
individual colonies are locally adapted
Aim
•
Determine exchange of reproductive individuals among colonies
– H0: Little Penguin colonies exist in a meta-population structure
Southern Ocean
Melbourne
Approach
•
Survey variation of:
– microsatellite loci
– mtDNA
Methods
•
Seven sites
– 50 adults per site
Granite Island
St Kilda
Gabo Island
London Bridge
Phillip Island
Kangaroo Island
Middle Island
Southern Ocean
Molecular Methods
Microsatellites
– Nuclear DNA
– Repeating units of 1-6 bp
– Distributed throughout the genome
•
17 loci screened for polymorphism
– Roeder et al. 2002 Adelie Penguin (4 loci)
– Akst et al. 2002 Galapagos & Magellanics (6 loci)
– Schlosser et al. 2003 Humboldt Penguin (7 loci)
Molecular Methods continued
Mitochondrial DNA
– Genetic information contained in the
mitochondria
– Maternally inherited
– Rapid rate of evolution
650bp segment of the control region sequenced,
employing primers of Roeder et al. 2002
6 variable nucleotides identified, 3 PCR-RFLPs
developed
Results
Microsatellites
•
17 loci screened
– 5 polymorphic
• Akst et al. 2002 (B3-2, G3-11, G2-2)
• Roeder et al. 2002 (AM13)
• Schlosser et al. 2003 (Sh1Ca9)
•
All in agreement with Hardy-Weinberg equilibrium except
G2-2 at Kangaroo Island
•
Genotypes independent across loci
•
Only Kangaroo Island distinguished from some other
colonies
•
No relationship between genetic divergence and geographic
distance
0.40
0.35
0.30
0.25
FST
0.20
Results
Mitochondrial DNA
0.15
0.10
0.05
0.00
-0.05
0
200
400
600
800
1000
1200
1400
Distance (km)
•
PCR-RFLPs screened
•
All colonies polymorphic
•
Kangaroo and Granite Islands distinct from the Victorian colonies
•
Almost significant relationship between genetic divergence and
geographic distance (Mantel test P-value = 0.054)
1600
Pairwise population comparisons
Southern Ocean
Further Study
•
Extend microsatellite and mtDNA research to incorporate
– a broader geographic range (TAS, NSW, WA, NZ)
– more microsatellite loci
Acknowledgements
•
Staff and students at Deakin University, Warrnambool campus
– Colleagues in the Molecular Ecology and Biodiversity Laboratory
•
Staff at Phillip Island Nature Park
•
This study was partially funded by:
- Deakin University (RLO-Scholarship)
- Holsworth Wildlife Research Fund (RLO)
- Norman Wettenhall Foundation (RLO)
- Australian Research Council (AJP-Scholarship)
- Phillip Island Nature Parks (AJP)
•
Field assistants