A new type of heredity described in Paramecia

Considered as an obsolete theory for many years, the transmission of acquired traits has returned to the forefront of debate thanks to the development of epigenetic research1. In this context, a team from the Institut de biologie at the Ecole normale supérieure (CNRS/ENS/INSERM)2 has described how in Paramecia, mating types are transmitted from generation to generation through an unexpected mechanism. These types are not determined by the genome sequence but by small RNA sequences transmitted via the maternal cytoplasm, which specifically inactivate certain genes during development. A Paramecium can thus acquire a new mating type that will be inherited by its progeny without any genetic modification being involved. Published in Nature on May 7, 2014, this work highlights a novel mechanism that may be governed by natural selection, thus allowing the evolution of species.

Fuente : http://www.alphagalileo.org/ViewItem.aspx?ItemId=1...