lecture 25 pt 2 Gene Mapping and Recombination

Flashcards covering gene mapping, recombination frequency, and allele arrangements.

Gene Map/Linkage Map

Indicates the relative distance between genes based on the calculation of the number or percentage of recombinants.

Recombination Frequency

The percentage of recombinants among the progeny which can be converted into map units, where 1% recombination equals one map unit or one centimorgan.

Centimorgan (cM)

A unit of measure for genetic distance, equivalent to 1% recombination frequency.

Cis Arrangement

When dominant alleles of two genes are on the same homolog and recessive alleles are on the other homolog (e.g., AB/ab).

Trans Arrangement

When each homolog carries one dominant and one recessive allele for two genes (e.g., Ab/aB).

Recombination Frequency Calculation

Sum of recombinant progeny divided by total progeny, often expressed as a percentage. Note: values should not exceed 50%.

Parental Combination of Alleles

The arrangement of alleles on a chromosome that is identical to the arrangement in one of the parents; non-recombinant.

Recombinant Progeny

Progeny that have a different combination of alleles than either parent, resulting from crossing over during meiosis; indicate gene distance.