| Summary: | Island gigantism has evolved repeatedly in birds and many mammals. Yet little is known about the genetics underlying this ecological rule. We have collected giant wild mice from the Faroe Islands, which are among the largest wild mice in the world and are often 50% heavier than continental mice. In addition, the Faroese mice exhibit significant directional asymmetry in skull development. I will first discuss the origin of these mice, which turns out to be an inter-subspecific hybrid between Mus musculus domesticus and Mus musculus musculus. We have retraced its evolutionary origin to the early days of colonization of the Faroe Islands. Then I will discuss our on-going efforts to uncover the genetic underpinnings of their large body size. From our labora- tory colony we have established a large (>800) F2 intercross panel with a reference-inbred line (SM/J for “small”). For each individual we have gathered a wealth of phenotypes, including growth curves from biweekly measurements, organ weight and plasma growth hormone levels. To dissect the genetic basis of body size variation, we have generated a high-resolution genetic map from our intercross panel (>2 markers per cM) using restriction-site associated DNA sequenci- ng (RADseq). The rich set of genotype–phenotype data allows us to generate a detailed genetic blueprint for body size in a wild mouse population. I will discuss preliminary results arising from this mapping panel. In addition I will discuss pilot results in applying an automated atlas-based image registration pipeline on whole-body 3-dimensional X-ray reconstructions collected from these mice. Applied across the whole panel we may be able to test the genetic validity of various eco- logical rules regarding climate adaptations like Allen’s Rule, Bergmann’s Rule or the Island Rule for the first time. The large size of the intercross panel and the wealth of phenotyping information make this a unique wild mouse genetic resource to investigate the evolutionary genetics of complex traits in evolution ...
|
|---|