THE GENETIC BASIS OF MORPHOLOGICAL VARIATION IN THE SKULL OF THE GRAY SHORT-TAILED POSSUM, MONODELPHIS DOMESTICA

描述（由申请人提供）：本研究项目的长期目标是通过使用有袋动物模型来提高我们对哺乳动物颅面骨骼遗传基础的理解。有袋动物已经成为几种人类疾病的有价值的模式生物，如皮肤癌和眼癌、高胆固醇血症和脊髓损伤。这项研究将其应用扩展到颅面研究，主要有两个原因。首先，我们对这一哺乳动物次纲物种形态变异的遗传基础知之甚少。其次，德州生物医学研究所（TBRI）的约翰·范德伯格博士长期以来一直维持着一个非常有用的圈养家养单角兽繁殖种群，其中包括已知血统和几个准近交系的个体。因此，本研究项目将利用该灰短尾负鼠圈养繁殖种群，对灰短尾负鼠颅骨形态变异进行遗传分析。在这项分析中，新的DNA测量技术将用于生成分子标记，其变异将与颅骨形态的个体差异相关，通过使用3D数字化设备进行测量。然后，将使用针对复杂谱系的统计方法确定导致颅面形态个体差异的数量性状位点。关于形态变异的发育决定因素的假设也将被测试。这项工作将增加我们对哺乳动物颅面骨骼遗传基础的稀疏理解。它还将使我们能够识别影响颅面骨骼的几个基因组区域。其中一些基因组区域可能为我们提供有趣的候选基因，为这种模式物种开辟新的研究途径。这项工作也将有助于我们了解颅面融合进化的遗传和个体发生机制。

DESCRIPTION (provided by applicant): The long-term objective of this research project is to enhance our understanding of the genetic underpinnings of the mammalian craniofacial skeleton through the use of a marsupial model. Marsupials have already become a valuable model organism for several human conditions, such as skin and eye cancer, hypercholesterolemia and spinal cord injury. This research expands their use to include craniofacial research, for two main reasons. First, little is known about the genetic underpinnings of morphological variation in species from this mammalian infraclass. Second, Dr. John VandeBerg from the Texas Biomedical Research Institute (TBRI) has for long maintained an extremely useful captive breeding population of Monodelphis domestica, containing individuals with known pedigrees and several quasi-inbred lines. Therefore, this research project will take advantage of this captive breeding population of the gray short-tailed opossum and carry out a genetic analysis of cranial morphological variation in this species. In this analysis, novel DNA surveying techniques will be used to generate molecular markers whose variation will be correlated to individual differences in cranial morphology, measured through the use of 3D digitizing equipment. Quantitative trait loci contributing to individual differences in craniofacial morphology will then be identified using statistical methods tailored t complex pedigrees. Hypotheses about the developmental determinants of morphological variation will also be tested. This work will increase our sparse understanding of the genetic underpinnings of the mammalian craniofacial skeleton. It will also allow us to identify several genomic regions that affect the craniofacial skeleton. Some of these genomic regions may provide us with interesting candidate genes that will open up new research avenues for this model species. This work will also contribute to our understanding of the genetic and ontogenetic mechanisms for the evolution of craniofacial integration.