【作者】 文卫东；

【导师】 王建林；

【作者基本信息】 兰州大学 ， 动物学， 2010， 博士

【摘要】 为了探讨双峰驼对炎热、寒冷的荒漠、半荒漠地区生态环境适应的形态学机制,本论文对双峰驼牙齿进行了全面、细致地解剖学研究。通过对双峰驼(Camelus bactrianus)牙齿解剖学研究、牙齿与头颅相关性分析、CT图像MPR三维研究,结果表明,双峰驼牙齿的解剖学结构特殊,上颌门齿、犬齿和臼齿发育较下颌臼齿发育得好。齿体生长方向与头颅生长呈相关性,说明双峰驼在特殊环境下,牙齿在漫长的进化过程中有定向选择的趋势。对双峰驼的牙齿研究运用线性回归分析,结果具有较为明显的性别差异。二维测量结果显示,公驼多数牙齿变量的变异要大于母驼,在犬齿、门齿表现得尤为突出,异速生长的研究也显示出了公、母驼之间的差异。根据线性分析结果,对公驼,几乎所有牙齿的变量,不论是M／D向,还是B／L向,对颅骨长均表现为正的异速生长。对母驼,除I2(B/L)、P3(M/D)、P3(B/L)外,其余变量对颅骨长均呈负的异速生长。从面积变量来分析,所列指标对颅骨长在公驼表现为正的异速生长,在母驼则表现为负的异速生长。不同牙齿具有不同的生长率(b),意味着不同的食性对牙弓不同部位牙齿形态的影响不同。就牙齿变量及有关牙齿的面积与颅骨长的相关程度来看,公驼比母驼的相关关系表现得更为紧密。在母驼及公+母双峰驼,颊齿的线性型和面积对于颅骨长的异速生长指数较小。多平面重组(MPR)CT采集的单个图像,对螺旋扫描采集的立体信息集合体进行选择和重组,选择和重组依据是构成立体的体素信息,即位置信息和密度信息。以根据体素的位置信息进行任意平面的选择和重组。因牙齿位置信息和密度信息特殊,对成年双峰驼牙齿的全长、冠长、根长、冠宽、颈宽、冠厚、颈厚和头颅解剖标志点分别进行矢状、冠状、水平CT测量线性回归分析,结果为公驼I1 AL b=0.003、r=0.848,CAL b=0.003、r=0.848,P3 AL b=0.004、r=0.945, M3 CW b=-0.002、r=0.802,母驼P5 AL b=-0.384、r=0.768,NT b=-0.392、r=0.934,而公+母双峰驼M1 AL b=0.011、r=0.400,NT b=0.003、r=0.440,P<0.005存在显著意义。根据对双峰驼牙齿MPR数据和对其头颅线性与牙齿冠状、矢状、水平面上的结果进行分析,发现双峰驼牙齿具有明显的性别差异,公驼牙齿的变异程度在门齿、犬齿、前臼齿表现突出。在线性型和面积方面,公驼牙齿的异速生长均快于母驼和公驼+母驼,与二维测量结果相同。在公驼、母驼或公+母,下颌齿,变量与颅骨长的相关程度比上颌更为密切。牙齿组织的发育除遗传因素和行为因素外,同时也受动物营养条件、草地类型、年龄等因素的影响。更多还原

【Abstract】 A comprehensive investigation was conducted into the adaptation mechanisms of teeth in the Bactrian camel (Camelus bactrianus) in both warm and cold arid regions. The study analyzed morphology of the teeth, correlation analysis between the teeth and skull, CT three-dimensional MPR images and the anatomical structure of the teeth in the Bactrian camel.Two-dimensional measurements using linear regression analysis of the camel’s teeth showed gender variation, where the males teeth is larger than the females, especially in the canine and incisors. Allometric results also showed differences between female and male groups. From the linear model analysis in the male, dental variables M/D and B/L showed positive growth. In females, I2 (B/L), P3 (M/D) and P3 (B/L) showed positive growth, while the other variables showed negative growth. Indicators of skull length in males showed positive growth, while the females showed negative growth. Analysis further showed that different teeth have different growth rates (b) and different feeding habits influence the shape of teeth. Variation between tooth size and skull length show a correlation in males rather than females. In the female and male+female camel, molar teeth and size of the skull growth varied little.Multi-planar reconstruction (MPR) CT images were acquired on a single three-dimensional spiral scan. Three-dimensional measurements of density and length were used in linear regression analysis. The male results showed I1 AL b= 0.003, r= 0.848, C AL6= 0.003, r= 0.848, P3 ALb= 0.004, r= 0.945, M3 CW b=-0.002, r= 0.802, female results showed P5 AL b=-0.384, r= 0.768, NT b=-0.392, r= 0.934, while male+female results showed M1 AL b= 0.011, r= 0.400, NT b= 0.003, r= 0.440, P<0.005.Analysis of the two-dimensional and three-dimensional results indicate obvious gender growth differences, which showed male teeth growth was faster than the female and male+female groups. Other growth differences were seen in male incisor teeth, canine and premolars. A greater correlation between mandibular teeth growth and skull length was seen in male, female or male+female groups, as compared to the upper jaw teeth growth. In conclusion, the study indicates that the development of teeth is not only due to genetic factors and behavioral factors, but also by animal nutrition, grassland types, ages and other factors.更多还原