An inbred strain that was separated from an inbred ancestor before F40, or separated by greater than 100 generations from a common inbred ancestor, or possesses a known genetic characteristic (mutat [..]

  A mutant allele that antagonizes the function of another gene and acts in a semi-dominant manner.

  The cross-shaped exchange configuration between non sister chromatids of homologous chromosomes that is visible during prophase I of meiosis.

A nucleotide sequence coding for a single polypeptide.

The superiority of hybrids over either inbred parent; a.k.a. hybrid vigor.

Biochemical process involving addition of methyl groups to DNA, silencing a gene or cluster of genes. 

 Association for Assessment and Accreditation of Laboratory Animal Care International.  A voluntary accreditation program for laboratory animal facilities and programs.

American Association for Laboratory Animal Science.

  Biochemical process involving addition of acetyl groups to DNA, favoring gene expression. 

Chromosome pattern in which the centromere is assymetrically toward one end and the telomeres are at the ends (in contrast to telocentric and metacentric). Mice do not have acrocentric chromosomes.