Chapter 7: Linkage, Recombination, And Eukaryotic Gene Mapping

Front 1

Linked Genes

Back 1

Genes located on the same chromosome.

Front 2

Linkage Group

Back 2

Genes located together on the same chromosome.

Front 3

Nonrecombinant (Parental) Gamete

Back 3

Contains only the original combinations of genes present in the parents.

Front 4

Nonrecombinant (Parental) Progeny

Back 4

Possesses the original combinations of traits possessed by the parents.

Front 5

Recombinant Gamete

Back 5

Possesses new combinations of genes.

Front 6

Recombinant Progeny

Back 6

Possesses new combinations of traits formed from recombinant gametes.

Front 7

Recombination Frequency

Back 7

Proportion of recombinant progeny produced in a cross.

Front 8

Coupling (cis) Configuration

Back 8

Arrangement in which two or more wild-type genes are on one chromosome and their mutant alleles are on the homologous chromosome.

Front 9

Repulsion (trans) Configuration

Back 9

Arrangement in which each chromosome contains one wild-type (dominant) gene and one mutant (recessive) gene.

Front 10

Interchromosomal Recombination

Back 10

Recombination among genes on different chromosomes.

Front 11

Intrachromosomal Recombination

Back 11

Recombination among genes located on the same chromosome.

Front 12

Genetic Map

Back 12

Map of the relative distances between genetic loci, markers, or other chromosome regions determined by rates of recombination; measured in percent recombination or map units.

Front 13

Physical Map

Back 13

Map of physical distances between loci, genetic markers, or other chromosome segments; measured in base pairs.

Front 14

Map Unit

Back 14

Unit of measure for distances on a genetic map; 1 map unit equals 1% recombination.

Front 15

CentiMorgan (cM)

Back 15

Another name for map unit.

Front 16

Morgan

Back 16

100 map units.

Front 17

Two-Point Testcross

Back 17

Cross between an individual heterozygous at two loci and an individual homozygous for recessive alleles at those loci.

Front 18

Three-Point Testcross

Back 18

Cross between an individual heterozygous at three loci and an individual homozygous for recessive alleles at those loci.

Front 19

Interference

Back 19

Degree to which one crossover interferes with additional crossovers.

Front 20

Coefficient of Coincidence

Back 20

Ratio of observed double crossovers to expected double crossovers.

Front 21

Mapping Function

Back 21

Relates recombination frequencies to actual physical distances between genes.

Front 22

Lod (Logarithm of Odds) score

Back 22

Logarithm of the ratio of the probability of obtaining a set of observations, assuming a specified degree of linkage, to the probability of obtaining the same set of observations with independent assortment; used to assess the likelihood of linkage between genes from pedigree data.

Front 23

Genetic Marker

Back 23

Any gene or DNA sequence used to identify a location on a genetic or physical map.

Front 24

Linkage Analysis

Back 24

Gene mapping based on the detection of physical linkage between genes, as measured by the rate of recombination, in progeny from a cross.

Front 25

Genomewide Association Studies

Back 25

Studies that look for nonrandom associations between the presence of a trait and alleles at many different loci scattered across a genome—that is, for associations between traits and particular suites of alleles in a population.

Front 26

Haplotype

Back 26

A specific set of linked genetic variants or alleles on a single chromosome or on part of a chromosome.

Front 27

Linkage Disequilibrium

Back 27

Nonrandom association between genetic variants within a haplotype.

Front 28

Single-nucleotide Polymorphism (SNP)

Back 28

Single-base-pair differences in DNA sequence between individual members of a species.

Front 29

Deletion Mapping

Back 29

Technique for determining the chromsomal location of a gene by studying the association of its phenotype or product with particular chromosome deletions.

Front 30

Somatic-cell Hybridization

Back 30

Fusion of different cell types.

Front 31

Cell Line

Back 31

Genetically identical cells that divide indefinitely and can be cultured in the laboratory.

Front 32

Heterokaryon

Back 32

Cell possessing two nuclei derived from different cells through cell fusion.