Genome-Wide Stochastic Adaptive DNA Amplification at Direct and Inverted DNA Repeats in the Parasite Leishmania

• DOI: 10.1371/journal.pbio.1001868
• Publication Date: 2014-05-20T20:18:00Z
• Authors: Jean-Michel Ubeda; Frédéric Raymond; Angana Mukherjee; Marie Plourde; Hélène Gingras; Gaétan Roy; Andréanne Lapointe; Philippe Leprohon; Barbara Papadopoulou; Jacques Corbeil; Marc Ouellette
• Keywords: Extrachromosomal DNA; Amplicon; Repeated sequence; Inverted repeat

Gene amplification of specific loci has been described in all kingdoms life. In the protozoan parasite Leishmania, product is usually part extrachromosomal circular or linear amplicons that are formed at level direct inverted repeated sequences. A bioinformatics screen revealed sequences widely distributed Leishmania genome and repeats chromosome-specific, conserved among species, generally present low copy number. Using sensitive PCR assays, we provide evidence continuously being rearranged these sequences, which serve as a functional platform for constitutive stochastic (and deletion) genomic segments population. This process adaptive number advantageous elements increases upon selective pressure reversible when selection removed. We also mechanistic insights on formation through RAD51 recombinase-dependent -independent mechanisms, respectively. The whole thus stochastically subpopulations with changes used strategy to respond changing environment.