| First Author | Harris BS | Year | 2016 |
| Journal | MGI Direct Data Submission | Mgi Jnum | J:235201 |
| Mgi Id | MGI:5795728 | Citation | Harris BS, et al. (2016) A new mutation named smaller size. MGI Direct Data Submission |
| abstractText | A recessive mutation that causes homozygotes to be 25-50% smaller in body size than wild type siblings arose spontaneously in the CByJ.Cg-hml/GrsrJ strain at The Jackson Laboratory. This mutation was simply called smaller size (smsz). Homozygotes of both sexes are fertile and live a normal lifespan. A routine histology screen showed no lesions at 33 weeks of age in one affected female and one control male examined. Auditory brainstem response of one homozygote at 5 months of age found normal hearing compared with a control. Cataracts were found in some, but not all, heterozygotes and homozygotes assessed at approximately 18 weeks of age. The average litter size varied from 5.44 pups per litter in heterozygote x heterozygote crosses, 4.45 in heterozygote x homozygote crosses, and 3.74 in homozygote x wildtype crosses, with approximately 30% of the crosses (4 of 13) being sterile. This colony produced far fewer than the expected ratio of homozygotes only approximately 5% affected progeny in both heterozygote x homozygote and heterozygote x heterozygote crosses. A mapping intercross to CAST/EiJ yielded only one small mouse in nearly 250 mice in the F2 population, whereas a mapping intercross to 129S1/SvImJ had a slightly improved, but still very low, yield of affected mice in the F2 population. No map position has been determined to date due to the difficulty in obtaining an adequate number of affected mice on any background. |
