We analyzed 6 heterozygous Htt KI lines expressing CAG repeats of 20, 80, 92, 11151 (link), 14052 (link), and 17512 (link). For each one of the 6 lines, male heterozygous (HET) mice were crossed with C57BL/6J female mice at Jackson Laboratory (Bar Harbor, ME). For each line, animals born within 3-4 days from litters having 4 to 8 pups were identified by ear tags, tail sampled for genotyping and weaned at around 3 weeks of age. HET mice were selected based on the CAG repeat to allow a Gaussian distribution of CAG repeats in the experimental cohort to avoid skewed distributions. Best Gaussian fit was judged by eye. Body weight cut off: experimental animals had to weigh more than 11 g (females) and more than 13 g (males) by 5 weeks of age. Animals presenting any anomaly were excluded. Unacceptable anomalies were cataracts, malocclusion, missing/small eye, ear infection, unreadable or missing tag. Mice were housed in cages enriched with two play tunnels, a plastic bone and enviro-dri® (Shepherd Specialty Papers). Animal cage changes occurred weekly. The cages were maintained on a 12:12 light/dark cycle. Water and food were freely available at all times.
This study was carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals, NRC (2010). The protocols were approved by the Institutional Animal Care and Use Committee of PsychoGenics, Inc., an AAALAC International accredited institution (Unit #001213).
This study was carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals, NRC (2010). The protocols were approved by the Institutional Animal Care and Use Committee of PsychoGenics, Inc., an AAALAC International accredited institution (Unit #001213).
