Mice homozygous for this recessive mutation are recognizable by 2.5 - 3 weeks of age by their smaller body size, gaunt torso, frailty, and constant quivering which is most obvious from the nose to the abdominal-thoracic area. Mutants also show poor ability to hold onto an edge with either their fore- or hindlimbs. Adult mutants may chatter excessively. Some homozygous mutants die before weaning; others survive through adulthood but they are unreliable breeders. twithas been mapped between the flanking markers D14Mit44 and D14Mit175 in the B band of Chr 14 at 22.9 Mb and 27.9 Mb, respectively.
The twitter mutation arose spontaneously in 1999 on a D.B6Ei/2Ei background that was at N10F17 and held by Dr. Eva Eicher. The twitter mutation was maintained by sibling mating for several generations then backcrossed once to a DBA/2J-Myo5ad+2J/Myo5ad/J that was homozygous for Myo5ad then intercrossed again for several generations. In 2004 this strain reached N10F18+F2N1F8. In 2005 embryos were generated for cryopreservation from DBA/2J females and homozygous mutant males.
When using the twitter mouse strain in a publication, please cite the originating article(s) and include JAX stock #004416 in your Materials and Methods section.