Doctoral Dissertation Improvement: Understanding Gene Dosage Imbalance and Biological Mechanisms Responsible for Craniofacial Variability and Variation

点击翻译按钮获取中文摘要

This research advances knowledge and understanding of how chromosomal changes affect biological processes that produce craniofacial phenotypic variation through comparisons of Down Syndrome individuals with their siblings. Conclusions will generate testable hypotheses (in animal models) about how some transitions in primate cranial evolution (e.g. size/shape changes, tooth number, shape, size, and eruption pattern changes, and brain size changes) have occurred through changes in patterns of facial development and integration. Data come from working with the National Down Syndrome Congress, Special Olympics of Pennsylvania, Centre County Down Syndrome Society, and Down Syndrome Buddy Walks. Members of the lab, at all educational levels (e.g., undergraduates, graduate students, post-docs,) are trained to collect 3D data and frequently volunteer at these events. These interactions have educated the research team about how Down syndrome organizations work and have educated members of the Down syndrome community about how the research might be beneficial in the long term. These experiences have strengthened the commitment to explain the research goals in a manner that is easily accessible to non-scientists.Craniofacial characteristics are used to infer phylogenetic relationships between human ancestors and to estimate sex, ethnicity, and age in fossils, skeletal populations, and forensic anthropology. This project examines both normal and abnormal craniofacial variation to eventually understand contemporary human variation and the evolutionary variation found in our fossil record by understanding how chromosomal changes affect developmental processes of phenotypic production. Regarding the specific chromosomal change that causes Down Syndrome, the morphometric analyses of craniofacial morphology in this study will determine: 1) how levels of phenotypic variance are modified; 2) how developmental stability changes; 3) how patterns of variation are altered; and 4) how this particular chromosomal alteration compatible with life affects development to produce phenotypic variation.