Lecture 35 - Population Genetics

Question 1

What are some phenotypic variation that we can detect in the molecular level?

Answer 1

• chromosomal differences (length, etc)
• immunological marker (eg., blood groups)
• mini-satellites
• microsatellites - STR
• SNP (Single Nucleotide Polymorphism)

Question 2

Differ between minisatellites, microsatellites, and SNP.

Answer 2

Mini-satellites: tandem repeat of 15-100 bases

Microsatellites: Short tandem repeats (STR) of 2-9 bases - can have several alleles according to how many repeats

Single nucleotide polymorphism - 1 base change; can only have two alleles at a locus

Question 3

Differ between multi locus and single locus probing of VNTR.

Answer 3

VNTR (Variable Number of Tandem Repeats) is located in the non-coding regions of the genome. A multi locus probe involves the usage of primers that locate mini-satellite regions (which can be found in multiple chromosomes throughout the genome). In a single locus probe, primers used only find tandem regions unique to one locus (hence also one chromosome), which maybe microsatellite or mini-satellites.

Question 4

Mention and explain the method of the detection of SNPs.

Answer 4

• DNA sequencing: sequencing the bases of DNA
• restriction cutting sites: SNP may result in the loss or gain of restriction enzyme recognition sequences which may lead to the detectable RFLP