Project Details
Projekt Print View

Phylogenetics of early vertebrate genomes: an approach to understanding genomic innovations as sources of phenotypic evolution

Subject Area Evolution, Anthropology
Term from 2009 to 2014
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 150795574
 
Final Report Year 2015

Final Report Abstract

This research project was conducted in a highly interdisciplinary manner in the interface of molecular phylogenetics, genome informatics, and developmental biology. The goal was to reinforce sequence information for cyclostomes and chondrichthyans and characterize available resources for phylogenetic reconstruction of the process of genome evolution. Achieving these goals was largely supported by the International Sea Lamprey Genome Analysis Project, but the sequence resources derived from that project as well as those for other key species, such as hagfish and Southern Hemisphere lampreys, have remained insufficient. With all these limitations, first, existing information for chondrichthyans was processed to clarify divergence times between the major chondrichthyan lineages, namely, between rays/skates, sharks and chimaeras. Second, lamprey genomes were revealed to have accumulated unique modifications during evolution. This includes massive invasion of Tc1-like transposable elements possibly because of its horizontal transfer from Salmonidae fishes and acquisition of unique patterns of codon usage bias and amino acid composition in protein-coding regions in their genomes. It is of great interest to examine if these genomic characteristics have been maintained in hagfish and Southern Hemisphere lampreys. The whole genome analysis also facilitated an identification of 224 gene families whose members do not exist in any invertebrates but do exist in both sea lamprey and jawed vertebrates. In addition, molecular phylogenetic analyses on individual regulatory gene families were performed to contribute to identification and phylogenetic characterization of developmental regulatory genes to better understand the evolution of morphogenetic and physiological programs at the molecular level. Further investigation on the origin of vertebrates and subsequent evolutionary processes is expected to be performed on the basis of more complete sequence resources covering elasmobranchs, hagfishes and Southern Hemisphere lampreys.

Publications

 
 

Additional Information

Textvergrößerung und Kontrastanpassung