What is congenic marker?

Congenic strains are produced by repeated backcrosses to an inbred (background) strain, with selection for a particular marker from the donor strain (Snell 1978, Flaherty 1981).

What is the designation for offspring from the first backcross to generate a congenic strain?

In the derivation of any new congenic strain, the first cross is always an outcross, and the offspring are considered members of the F1 generation. The second cross is always a backcross, and the offspring are considered members of the N2 generation.

What is inbred and outbred?

Inbreeding refers to mating of related individuals. It results in a decline in survival and reproduction (reproductive fitness), known as inbreeding depression, in most species of plants and animals. Outbreeding refers to matings between individuals from different populations, subspecies, or species.

What is recombinant strain?

A recombinant inbred strain or recombinant inbred line (RIL) is an organism with chromosomes that incorporate an essentially permanent set of recombination events between chromosomes inherited from two or more inbred strains.

What is congenic animals?

In genetics, two organisms that differ in only one locus and a linked segment of chromosome are defined as congenic. Similarly, organisms that are coisogenic differ in one locus only and not in the surrounding chromosome.

How do you make a congenic mouse?

Backcrossing to Generate Congenic Mice Repeatedly mating the donor to the recipient strain and selecting for offspring with the desired mutation, typically through genotyping, removes ~50% of the donor genome with each successive generation.

How many backcross generations are there?

two-generation
Backcrossing is a two-generation breeding protocol that starts by generating hybrid F1 mice between two inbred strains (preferably distantly related), one of them carrying the mutation of interest.

Can inbreeding be reversed?

Management. Introducing alleles from a different population can reverse inbreeding depression. Different populations of the same species have different deleterious traits, and therefore their cross breeding will not result in homozygosity at most loci in the offspring.

What’s the benefit of inbreeding?

Inbreeding is done to develop purelines. It increases the homozygosity and helps in the accumulation of superior genes. Inbreeding also helps in eliminating less desirable genes.

How are RILs produced?

An RIL is formed by crossing two inbred strains followed by repeated selfing or sibling mating to create a new inbred line whose genome is a mosaic of the parental genomes (Figure 1).

What is recombinant inbred strains of mice?

RECOMBINANT INBRED STRAINS. Recombinant inbred (RI) strains are generated by outcrossing two progenitor strains and then intercrossing these F1 hybrids to produce F2 progeny, as illustrated in Figure 11-2. Then pairs of sister–brother F2 mice are selected at random to serve as founders for each RI strain.

What is consomic and congenic strain?

Congenic Strain. Congenic and consomic strains are marker-assisted backcross breeding strategies to isolate a homologous chromosome (consomic) or chromosomal segment (congenic) from one inbred strain onto the genetic background of another.

How many generations of backcrossing are needed for congenic strain development?

Generally, 10 generations of backcrossing is considered the standard for congenic strain development. Theoretically, with each backcross, the mutant stock acquires 50% of the inbred backcross partner’s DNA sequences.

Is h2-t18b/snj a congenic strain?

A.BY-H2 b H2-T18b/SnJ is a congenic strain. See also the Rules for Nomenclature of Mouse and Rat Strains .

What is the difference between congenic and Coisogenic?

Not to be confused with congeners – see conspecificity. In genetics, two organisms that differ in only one locus and a linked segment of chromosome are defined as congenic. Similarly, organisms that are coisogenic differ in one locus only and not in the surrounding chromosome.