Jogahara Takamichi, Oda Sen-Ichi, Kawai Tatsushi, Hanamura Hajime, Koyasu Kazuhiro
Laboratory of Animal Management and Resources, Graduate School of Bio-Agricultural Sciences, Nagoya University, Nagoya, Japan.
Arch Oral Biol. 2008 Jul;53(7):617-21. doi: 10.1016/j.archoralbio.2008.01.013. Epub 2008 Mar 7.
Wild populations of Suncus murinus from Nagasaki were thought to be extinct, although specimens from Nagasaki are kept at the National Science Museum, Tokyo. Variation in the number of teeth, including both congenital and postnatal absence, was observed in 25 of 85 individuals. All 25 abnormal individuals were checked using a micro-CT unit to document the presence or absence of embedded teeth and any traits of postnatal absence. Four of these had congenitally absent teeth, whereas the rest showed signs of postnatal absence. There was no significant difference in the ratio of length of tooth group P(4)M(3) against palatal length between individuals with congenital absent teeth and normal ones. Because S. murinus in captivity shows a high rate of periodontal disease, we suggest that the high rate of postnatal absence of teeth in the wild population is due to oral diseases such as periodontal disease or other traumatic factors.
长崎的野生短尾鼩种群曾被认为已经灭绝，不过东京国立科学博物馆保存着来自长崎的标本。在85只个体中的25只身上观察到了牙齿数量的变异，包括先天性和后天性缺齿。对所有25只异常个体使用微型CT设备进行检查，以记录埋伏牙的有无以及任何后天缺齿的特征。其中4只存在先天性缺齿，其余则显示出后天缺齿的迹象。先天性缺齿个体与正常个体之间，齿列P(4)M(3)长度与腭长的比例没有显著差异。由于圈养的短尾鼩显示出较高的牙周病发病率，我们认为野生种群中较高的后天缺齿率是由牙周病等口腔疾病或其他创伤因素导致的。
