The Developmental-Genetic Basis for Integration and Canalization in the Vertebrate Skeleton

点击翻译按钮获取中文摘要

Development and evolution interact in complex ways. Development is shaped by natural selection, but developmental processes also generate the phenotypic variation which is the raw material for evolution. How this happens matters because developmental processes structure variation in ways that influence how evolution occurs. In particular, development produces relationships among traits that thus tend to vary together and thus co-evolve. It also modulates the amount of phenotypic variation that is expressed relative to underlying genetic variation. These two phenomena, called integration and canalization, are at the crux of the complex relationship between development and evolution. We propose to exploit a unique genetic resource, the Collaborative Cross Project, to dissect the genetics and development of integration and canalization. This resource has a crucial advantage. This is that it consists of a large and genetically diverse assemblage of mouse strains, called RIXs, that are genetically identical and can be reproduced indefinitely. In addition, the RIX mice are highly heterozygous and are thus much more like natural populations than other laboratory mice. Because these mice can be reproduced indefinitely, when we find genetic variants that cause variation of interest, we can generate more such mice for further study into the mechanisms that produce that variation. We combine the genetics of these mice with transcriptomics, which is the study of gene expression patterns, to unravel the complex genetic networks that underlie both integration and canalization. This work will significantly advance our understanding of how development and evolution interact to shape the morphology of the vertebrate skeleton. This understanding also has practical application because artificial selection through animal breeding often produces side-effects that are determined by developmental connections between the trait that is selected on and other traits. Understanding how these connections occur through development can lead to selection strategies that overcome them.