Komparativ genomik: evolution av neuronala och endokrina genfamiljer hos ryggradsdjur
Tidsperiod: 2013-01-01 till 2015-12-31
Projektledare: Dan Larhammar
Budget: 2 100 000 SEK
The origin of vertebrates was preceded by two dramatic genomic events, namely whole genome doublings or tetraploidizations. This generated numerous additional genes that have facilitated the evolution of many novel functions in vertebrates. We use comparisons of sequences and chromosomal locations of genes as two complementary methods to sort out the evolution of complex gene families to find out when and how new functions arose. We have previously shown how genes involved in important mechanisms such as neurotransmission, pain, reward, and appetite regulation were duplicated in the tetraploidizations. This approach is used to study the evolution of colour vision by analyzing the many gene families involved in visual signal transduction. We have completed studies of the three transducin gene families and we are finalizing studies of the opsins (the light receptors) and phosphodiesterases that relay the signal. We now proceed to additional gene families to resolve how they facilitated specialization of rods and the different types of colour vision cones by analyzing gene expression in the zebrafish retina which is much more avanced than that of mammals. In parallel, we analyze the origin of many neuroendocrine peptides and receptors involved in appetite regulation, pain, and other processes. This work has general importance for our understanding of the evolution of novel and specialized functions and will enhance our understanding of the shaping of vertebrate genomes.