Investigation of Inductive Mechanisms in Arthropod Germ Line Specification: Analysing The Role of Dpp Signaling

Harvard University, Cambridge MA

Investigators

Abstract

Germ cells are the cells responsible for making eggs and sperm in all multicellular, sexually reproducing animals. Because they are one of the most important cell types, it is important to understand not only the genes that control their development, but also their evolutionary history. Early multicellular animals probably did not have a dedicated group of germ cells, but rather used stem cells to make eggs and sperm. This means that the development of a dedicated group of cells responsible for reproduction can be considered an evolutionary novelty. This problem will be examined with comparative developmental genetics. Probably the first genetic program used to specify germ cells was that used in mice, which involves signalling between cells. Fruit flies use a completely different genetic program, raising the question of whether or not the fruit fly program is representative of all arthropods (insects, crustaceans, millipedes, centipedes, spiders and scorpions), or is specific to flies. Genes will be isolated from both the mouse and the fly and their expression and function will be studied to determine whether the inductive signals used in mice are also used in crickets and spiders. This project will help to bridge a gap in our current understanding of the evolutionary origins of germ cells, as almost nothing is known about germ cell origin in arthropods besides fruit flies. It may also provide the first demonstration of an inductive mechanism for germ cell specification in invertebrate animals. The project will provide training for a postdoc, a graduate student and undergraduate students. The PI is committed to providing a positive role model for women and under-represented minorities in academic science.