Gene Duplication :: GUEST :: Heather Machado
Heather Machado (former research associate) will visit from Stanford to talk to the students about the project they will be doing. This is work she initiated while working in the Renn lab.
The diverse and rapid adaptive radiation of African Great Lake cichlids has occurred despite a rather unexceptional amount of genetic diversity in sequence. The fact that this tendency to speciate is not evenly distributed throughout the clade suggests the involvement of underlying genomic elements. Gene duplications provide one source of functionally diverse genomic elements that may lead to phenotypic diversity on which natural selection can act. Multiple independent comparisons between radiated lineages and their non-radiated relatives are important to identify such elements.
Using aCGH on the current A. burtoni cDNA microarray we find a 38% – 49% increase in gene duplicates for three species representing radiated lineages of Lake Malawi (M. estherae, P. similis, R "chilingali") relative to the total number identified in a related species from a non-radiated lineage (A. tweddlei).
These patterns, and the specific candidates, provide a tantalizing suggestion that gene duplication plays a functional role in these radiations. These duplicated genes may underlie adaptive phenotypes and be integral to the process of evolutionary adaptive radiation.
Students will read :
abbreviated version of the grant proposal
and Machado et al (in prep)
Gene Duplication in an African Cichlid Adaptive Radiation
In lab for the following 3 weeks, students will perform array based Comparative Genomic Hybridizations for 4 species from lake Tanganyika.. Analysis of those experiments will be used as a second comparison to test the hypothesis that gene duplication is associated with adaptive radiation.