Evolutionary Biology
Several projects are under development in the lab to answer essential questions in the field of new gene origination:

Functional and evolutionary study of young retrogenes

We have recently determined the age of 4 young genes in Drosophila, they are between 3 and 15 million years old (Betran et al. 2002). We are pursuing the functional and evolutionary characterization of these young genes. This should provide information on the significance of the acquisition of these new genes by the Drosophila genome. Expression will be studied, and mutants will be generated to describe the function of those genes. In addition, the study of polymorphism and divergence at the DNA level should provide bases to infer if these new acquisitions fixed in the species by drift or positive selection and if these genes are acquiring a new function.

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De novo formation of promoter regions

In Drosophila the vast majority of retrogenes that move from X to autosome expresses in male germ line (Betrán et al. 2002). These new retrogenes have to recruit a completely novel promoter from the insertion site. How new promoter regions are recruited is a major question in biology that can only be addressed if there is enough knowledge about changes in expression pattern and phylogenetic information for the promoter region before and after the change (Betrán and Long 2003). P element transformation technology and green fluorescent protein as a reporter gene are been used in D. melanogaster to study the promoter regions.

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Patterns on the formation of new genes: where do new duplicate genes go?

This objective has two aspects I want to explore using bioinformatics:

[1] In D. melanogaster, we continue the study of the pattern of new gene acquisition and explore the existence of other (non retroposed) duplicate genes in relation to sex chromosome evolution to reveal the generality of the observed pattern for Drosophila retrogenes.

[2] In other organisms, we study the repeatability of the observed patterns across taxa to uncover the generality of the phenomena of gene relocation with respect to sex chromosomes. We concentrate on studying the convenient retroposition mechanism to reveal mobilizations (Betrán et al. 2002) in sequenced genomes with heteromorphic (Humans, D. pseudoobscura and A. gambiae) or XO sex determination (C. elegans).

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Genes domesticated from transposable elements

In collaboration with Cedric Fechotte, we are studying genes domesticated from transposable elements in Drosophila. Recently, we identified seven distinct genes distributed across the Drosophila genus that encode proteins related to PIF transposases, but lack the hallmarks of transposons. In one instance the recruitment of the transposase gene was accompanied by the co-recruitment of the adjacent second PIF gene, which raises the hypothesis that both proteins now function in the same pathway.

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