BIOG275 - Module 2 Mapping, Linked Traits, and Recombination

recombination types

phenotypes reflecting a new combination of alleles that occurred during gamete formation

syntenic

describes the relationship of two or more loci located on the same chromosome

parental types

phenotypes that reflect a previously existing parental combination of alleles that is retained during gamete formation

linked traits

on the same chromosome; there will be more of the parental type than of the recombinant type

parental classes

combinations of alleles present in the original parental generation.

recombinant classes

reshuffled combinations of alleles that were not present in the parental generation

physical markers

cytologically visible abnormalities that make it possible to keep track of specific chromosome parts from one generation to the next

genetic markers

genetic loci identifiable through phenotypic variants that can serve as points of reference in determining whether particular progeny are the result of recombination

recombination frequency (RF)

the percentage of recombinant progeny; can be used as an indication of the physical distance separating any two loci on a chromosome

centimorgan (cM) or map units (m.u.)

1 is equal to a 1% chance that a marker at one genetic locus will be separated from a marker at a second locus due to crossing-over in a single generation

NCO

a meiosis that occurs with no crossovers between a particular gene pair

locus

a designated location on a chromosome; sometimes refers to a gene

chromosomal interference

the phenomenon of crossovers not occurring independently

coefficient of confidence (C)

the ratio between the actual frequency of double crossovers observed in an experiment and the number of double crossovers expected on the basis of independent probabilities

recombination hotspots

small DNA regions where the frequency of recombination is much higher than average

linkage group

genes on the same chromosome

interference (I)

1-C

DCO

double crossover