The evolution and genetics of being sinister: from chiral shells to chiral cells
Lab rotation project description
The student will receive training in the basic techniques necessary to the project. In the lab, this is likely to include an introduction to some of the core techniques of molecular biology, including DNA extraction, PCR and DNA sequencing, as well as experiments in manipulating embryos. Subsequently, the student will be introduced to bioinformatic and phylogenetic methods, necessary to understand the relationship between the different populations and species. Depending upon the time of year of the rotation, local field work may also be possible.
LR1, LR2 and LR3
Linked PhD Project Outline
|While our bodies are bilaterally symmetric on the outside, the internal organs exhibit consistent, directional asymmetries in their position or anatomy, such that left/right positional errors are an important class of human birth defect, and in later life, numerous diseases affect seemingly symmetric organs in a lateralised fashion. However, while invariant left/right asymmetry appears to be the rule in nearly all animals, until recently it has not been clear if the path to asymmetry is conserved, or how/why the left/right axis is consistently set up in the same direction (e.g. heart to the left).
In a recent breakthrough published in Current Biology (26: 654-660), the Davison lab and collaborators in Scotland, Germany and the USA identified the one in a billion base pair change that determines mirror image development (“chirality”) in the pond snail, finally identifying the first described locus that reverses the whole body structure of an animal. As we also showed that the same gene is similarly involved in setting up asymmetry in the frog, then our work that began in snails ultimately revealed one of the earliest common symmetry-breaking steps across the whole of the Bilateria. The next stage of the project is to ‘unravel’ symmetry breaking at the molecular and cellular level, in particular to find the set of genes that first establish asymmetry, and ultimately, to define general rules for how this is translated into creating left-right asymmetric snail shells and vertebrate bodies. In this exciting and fast-moving, but quite flexible project, the student will seek to understand why snails routinely vary in their chirality, unlike any other animal group, and how this asymmetry is set up. According to need and specific interests, the student will use the pond snail system, perhaps undertake field work in other countries, and conduct genetic and genomic research, from both developmental and evolutionary perspectives.