Sollars - Genetic Recombination & Linkage Analysis Flashcards
Molecular Basic for Law of Independent Assortment
Genes act separately form one another during meiosis; existence of different chromosomes and recombinatio events between genes on the same chromosome.
Locus
Postion that a gene occurpies in a chromosome or within a segment of genomic DNA
Parental Gamete
Same genotype at loci of interest as those that formed the individual
Recombinant Gamete
Gametes produced by an indiviual that differ in genotype at the loci of interest
What stage of the cell cycle is the molecular basis for Mendel’s Second Law?
Chromosome assortment during M1
Chiasmata
Sites of genetic exchange
Syntenic Genes
Genes on same chromosome
When does the Law of Independent Assortment fail?
Genes are close together on the same chromosome; e.g they segregate together during meiosis and a reduced number of recombinant gametes are formed
Complete (Tight) Linkage
No recombinant genotypes are observed
Linkage Disequilibrium
Nonrandom distribution into the gametes of a population of the alleles of genes that reside on the same chromosome.
Greater degree of linkage the less random the distribution of alleles is.
Haplotype
Symbolic representation of a specififc combination of linked alleles on a chromosome
Partial Linkage
Recombinant classes observed, but less than total parental classes
What do you need to know to determine % recombinants?
1) Phase of alleles in questione–e.g. is it a recombinant, or a parental?
2) Number of recombinant gametes–or more likely, population of a known genotype
Coupling
Repulsion
Alleles of two genes are on the same chromosome
Alleles of two genes are on homologues
What will have more recombination in partially linked genes–those close or far?
Far
