| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1999: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
|
|---|
| Research Abstract |
It has been reported that EL mice had absence of all third molars, and there was no significant difference in that incidence between the sexes. A genetic factor affecting the appearance of absence of the third molars in EL mice was studied using two strains of mice and their genetic crosses : EL/sea mice, MSM/Msf mice which have no hypodontia, F1 hybrid, F2 intercross and backcross mice. Based on these genetic crosses, it was concluded that the appearance of absence of the third molars in strain EL mice was recessively influenced by autosomal genetic factor(s). To search the candidate linkages, individual genotyping of both 10 F2 intercross and 7 F2 backcross mice with absence of the third molars was performed using the 58 informative markers. A high score in the xィイD12ィエD1-test for F2 sample was found at D3Mit17, 38 and 194 on chromosome 3 (xィイD12ィエD1=22.6, p<0.0001), while a high score in the xィイD12ィエD1-test for N2 sample was found at D3Mit17, 38 and 194 on chromosome 3 (xィイD12ィエD1=3.2, p<0.05). Based on these results, we propose that a candiate gene for the cause of absence of the third molars in EL mice would be existed on the middle region (44 〜 49 cM) of mouse chromosome 3.
|
