Sex, Death and Secret Identities
Roles for genetics in conservation
Alyssa Mitchell
What is Conservation Genetics?• Integrative• Variation• Intra & inter population
Effective Population Size• Adaptability is related to variability• Hunted to near extinction• 20-30 left• 175 000 now• Ne = 60• What does
this mean for them?
Breeding• Inbreeding• Mating vs breeding• Blanding’s Turtles are promiscuous, but
only about 5% of males are producing offspring!
Hybrids• Increase in variation• Dilute deleterious alleles• Florida panthers got a little help from
Texas cougars
Cryptic Species• How do we know??• In this case, all it takes is a
karyotype!
Population Distinction• Who meets?• Who mates?• And who cares???
Microsatellites• Simple-sequence tandem repeats• Highly variable & mutable• Locus-specific• Highly heterozygous• Biparental nuclear variation• CACACACACACACACACACACACACA…
Mitochondrial DNA• Many genes are highly conserved• (Usually) Uniparental & matrilineal
variation• Species ID & phylogeny• Operation Shrew Poo!
Nova Scotian Shrews• Nova Scotia is home to seven species
of shrews, most of which are sympatric.
• Sorex cinereus is the common shrew, found in most of the province, including some islands.
• Sorex fumeus is knownas the smokey shrew,and smells worse thanany other!
Nova Scotian Shrews
• Sorex dispar is a talis slope specialist• Sorex hoyi is the American pygmy
shrew & among the smallest land mammals in the world
• Blarina brevicauda is a short-tailed shrew with a venomous saliva that seems to have anti-cancer properties.
Sorex Palustrius• American water shrew• One of the
only species todive & foragein water.
• Not endangeredoverall
Sorex maritimensis• Maritime shrew• Endemic• Likely endangered• Recently elevated to species status
The Goal• To determine the distribution of these
two species of shrews in Nova Scotia• Data points few & far between
General Characteristics of Shrews
• Very low body weight for land mammals
• High metabolism• Easily stressed• Can be scared to death• Most active at night
Obstacles to Research• Trapping• Identifying• Holding in
captivity
Dr. Churchfield to the Rescue
• Dr. J Sara Churchfield’s Water Shrew Survey
• UK Mammal Society• Amassed volunteers & collected
scats• Used scat morphology• Volunteers submitted
reports
Fecal DNA & Molecular Markers
• Two students developed some species-specific primers & an RFLP-based protocol
• Mitochondrial DNA : more copies, well-known cytochrome b gene
Fecal DNA & Molecular Markers
• What happened??• DNA quality• New protocol!
BamHI cuts Sorex palustris only
XbaI cuts Sorex maritimensis only
Much easier to amplify
100 & 200 bp fragments indicate that a cut site has been recognized
Forensics• What is it, and where did it come
from?• CSI: Whale
Captive Breeding• Avoid inbreeding• Encourage specific alleles
Success!
• Out of danger• ID a threat• Increase genetic variation