Modelage du génome des mammifères par la transcriptase inverse.

Abstract

Reverse-transcriptase catalyses the conversion of RNA into DNA. This operation might have played an essential role in primitive living systems role in primitive living systems and seems to have largely contributed to the evolution of complex genomes. More than 10% of a mammalian genome is composed of sequences with reverse-transcribed origin, most of which consist in repeated sequences (SINEs, LINEs). In spite of their simplicity, these sequences may play a key role in evolution by favoring illegitimate recombination. Genes depleted from intervening sequences, known as pseudogenes, can be functional. Finally, endogenous retroviruses can be involved in the regulation of neighboring genes. These hallmarks of a reverse transcription activity indicate that it has largely contributed to the fluidity of modern genomes which remains apparent in genetic pathologies.