Monday, 8 October 2012

Last minute checks

Last quick checks before the exam on biotechnology...

Daughter design: One possible population structure when studying the QTLs of dairy cows. Genotype and markers are assessed on daughters of sires heterozygous for the markers. (Weller, Kashi, Soller 1990)

Epistasis: The function of one gene is affected by many other genes, also known as modifier genes.

Granddaughter design: One possible population structure when studying the QTLs of dairy cows.  Marker genotype is determined on sons of heterozygous sires and quantitative trait value measured on daughters of the sons. (Weller, Kashi, Soller 1990)

Interval: The chromosomal area or distance between two genetic markers. Can be measured by calculating recombination frequencies without interference in several cross- and backcross breeding. For a certain map location the function is
yij = mj + eij
where yij is the value of the trait for the animal i, mj is the mean effect of animals with genotype j, and eij is random error (Anderson, McRae, Visscher  2006).

Pleiotrophy:  One gene influences many phenotypic ("visible") traits. Examples of phenotypic traits are color and height.

QTL-mapping: Mapping of quantitative trait loci has four phases:
  1. Measuring the quantitative traits to be researched
  2. Analyzing the genotype of the animals to be researched
  3. Building the connection maps
  4. Finding statistically significant connections between desired traits and connection map
Mapping can be done either by studying a population or by cross-breeding two different lines of animals, and often inbred lines are used.

PS. Lastly, this is precisely my problem when studying:

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