Sex, Death and Secret Identities

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Sex, Death and Secret Identities Roles for genetics in conservation Alyssa Mitchell

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Sex, Death and Secret Identities. Roles for genetics in conservation Alyssa Mitchell. What is Conservation Genetics?. Integrative Variation Intra & inter population. Effective P opulation S ize. Adaptability is related to variability Hunted to near extinction 20-30 left 175 000 now - PowerPoint PPT Presentation

Transcript of Sex, Death and Secret Identities

Page 1: Sex, Death and Secret Identities

Sex, Death and Secret Identities

Roles for genetics in conservation

Alyssa Mitchell

Page 2: Sex, Death and Secret Identities

What is Conservation Genetics?• Integrative• Variation• Intra & inter population

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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?

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Breeding• Inbreeding• Mating vs breeding• Blanding’s Turtles are promiscuous, but

only about 5% of males are producing offspring!

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Hybrids• Increase in variation• Dilute deleterious alleles• Florida panthers got a little help from

Texas cougars

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Cryptic Species• How do we know??• In this case, all it takes is a

karyotype!

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Population Distinction• Who meets?• Who mates?• And who cares???

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Microsatellites• Simple-sequence tandem repeats• Highly variable & mutable• Locus-specific• Highly heterozygous• Biparental nuclear variation• CACACACACACACACACACACACACA…

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Mitochondrial DNA• Many genes are highly conserved• (Usually) Uniparental & matrilineal

variation• Species ID & phylogeny• Operation Shrew Poo!

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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!

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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.

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Sorex Palustrius• American water shrew• One of the

only species todive & foragein water.

• Not endangeredoverall

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Sorex maritimensis• Maritime shrew• Endemic• Likely endangered• Recently elevated to species status

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The Goal• To determine the distribution of these

two species of shrews in Nova Scotia• Data points few & far between

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General Characteristics of Shrews

• Very low body weight for land mammals

• High metabolism• Easily stressed• Can be scared to death• Most active at night

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Obstacles to Research• Trapping• Identifying• Holding in

captivity

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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

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Fecal DNA & Molecular Markers

• Two students developed some species-specific primers & an RFLP-based protocol

• Mitochondrial DNA : more copies, well-known cytochrome b gene

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Fecal DNA & Molecular Markers

• What happened??• DNA quality• New protocol!

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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

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Forensics• What is it, and where did it come

from?• CSI: Whale

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Captive Breeding• Avoid inbreeding• Encourage specific alleles

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Success!

• Out of danger• ID a threat• Increase genetic variation