The mechanisms that generate this diversity determine nervous system development and pathology. Since the discovery of the Hox genes in 1984, our knowledge of embryonic development has improved tremendously. However, we have a more limited understanding of how Hox genes function at the cellular level, particularly in the nervous system. As a consequence, it is very valuable to be able to examine and manipulate the expression of these genes in individual, identified neurons whose properties are well known. For these reasons, we are studying the Hox genes in the leech Hirudo medicinalis , an organism well suited for neurobiological research.
Leeches have a simple nervous system with large, hardy neurons that are easy to study.
The goal of our research is to examine the functions of Hox genes in the development of the central nervous system. Some of these genes have been cloned, allowing us to raise antibodies against their proteins and study their expression. The Lox genes are expressed in different but overlapping subsets of neurons within the central nervous system of the embryo, where they may act in a combinatorial way to determine neuronal identities. We are currently examining the normal patterns of expression of Lox genes in the nervous system, as well as the effects of experimentally altering their expression in neurons. Part of this work is carried out as a collaboration with Eduardo Macagno of Columbia University.