BDC331Conservation Genetics

2015

Mr. Adriaan EngelbrechtDepartment of Biodiversity and Conservation Biology

New Life Sciences Building Core 2, Room 4.100

adengelbrecht@uwc.ac.za

Module outline

• Introduction into molecular genetics

• Traditional and molecular characters in genetic studies

• DNA sequencing

• Techniques for acquiring molecular data

• Interpretation of data derived from genetic studies

• The use of molecular data in Conservation biology

DNA the double Helix of life• Nucleotide

– a deoxyribose sugar, and – a phosphate group that - bridge between deoxyribose sugars – a nitrogen-containing pyrimidine or purine base

• Purines– Adenine – Guanine

• Pyrimidines– Cytosine– Thymine

• 1’ carbon has base• 3’ carbon has phosphate group• 5’ carbon has phosphate group

56

6

What does it do?• Protein synthesis needs transcription and

translation– via mRNA - tRNA – The Central Dogma

And this occurs via a

set of RULES:

The Genetic Code

The genetic code• Three mRNA nucleotides = Codon• Codon (reading frame) produces 1 amino acid

Or to start (AUG) or stop (UAA, UAG, UGA)

1. It is degenerate (amino acids can be

produced by more than one codon)

2. It is unambiguous (each codon = one

amino acid)

3. It is universal (all organisms with a specific

codon will produce the same amino acid!!!)http://www.youtube.com/watch?v=zwibgNGe4aY

http://www.youtube.com/watch?v=5MQdXjRPHmQ

http://www.youtube.com/watch?v=0SCjhI86grUhttp://www.youtube.com/watch?v=GhHOjC4oxh8

The drivers of genetic variation

• Gene flow

• Sex

• Mutations

Mutations• Point mutations (Base substitutions)

– missense – one amino acid for another– conditional – environmental dependent – nonsense – stop codon– silent – subtle or non expressive

• Frame shifts– Insertions – Deletions

• Chromosomal deficiencies– Translocations– Inversions– Duplications

• Aneuploidy– Monosomy– Trisomy– Quatrosomy

Mutation rate in Human mtDNAIs 0.00003 per base per 20 year generationHuman genomic DNA ?~0.0000000011 per site per generation

Plants

So what?

Mutations are the ultimate source of genetic variation

-Only mutations produce new alleles!!!

What are the sources?- DNA replication errors- Meiosis- Chromosomal breakages - Mutagens (such as radiation or chemicals!!!!)

http://www.youtube.com/watch?v=hOfRN0KihOU

http://www.youtube.com/watch?v=0SCjhI86grU

http://www.youtube.com/watch?v=GhHOjC4oxh8

Conservation genetics

Evolutionary genetics Taxonomic uncertainty

Species biology Population structure & fragmentationIntrogression

Small populations

Mutation accumulation

inbreeding

Genetic diversity loss

Extinction

Genetic management

Reproductive fitness

MU identification

Wild captivereintroduction

Genetic adaptation to captivity

Frankham et al. 2002