טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentFeder Martin
SubjectModularity of gene duplicate expression in the
Caenorhabditis elegans founder-cells
DepartmentDepartment of Biology
Supervisor Professor Itai Yanai
Full Thesis textFull thesis text - English Version


Abstract

Gene duplicates represent an important source of genic redundancy in the gene pool of a species. The mechanism of duplication can lead to the evolution of new forms of cellular activity. Temporal and spatial control of gene expression is essential to metazoan development. Here we investigate the patterns of evolutionary development for duplicate gene activity through an analysis of Caenorhabditis elegans embryonic founder cell lineages. We explore expression profiles during the nematode's embryonic development constructed through applying the CEL-Seq sequencing method over early developing embryos, focusing on separated blastomere founder cells.

We find that duplicates are less frequently expressed during early development and are also less often ubiquitously expressed. In contrast, we also find that duplicated transcription factors are variably expressed across times and stages, most significantly in the AB lineage, while most non-duplicate transcription factors express in the terminal somatic cells and the E and C lineages. Furthermore, comparing novel versus ancient duplicates we demonstrate increasing divergence in spatio-temporal expression profile with evolutionary time. While the expression patterns of novel genes evolves gradually, ancient gene duplications are rarer and activity diverges abruptly. Finally, we report evidence that gene function may evolve over both space and time. Our results lead us to hypothesize that functional shifts across lineages may be made possible through the evolution of transcription factor duplicates.