Genetic and Epigenetic Impacts of L1 Retrotransposition in Mouse and Man

Abstract

An interesting fact the Human Genome Sequencing Project revealed is that just around newlinetwo percent of the genome consists of genes, while the rest of it consists of repetitive newlinesequences and a group of diverse elements called transposons, which are mobile genetic newlineelements (Lander et al., 2001). This was also found to be by and large true in case of other newlinemammalians genomes as well (Waterston et al., 2002). In fact, transposable elements are newlinepresent in almost every eukaryotic organism whose genome has been sequenced so far (with newlinerare exception such as that of Ashbya gossypii, a filamentous fungus) (Huang et al., 2012). newlineTransposons have come a long way from being called selfish DNA or parasite (Orgel and newlineCrick, 1980; Yoder et al., 1997), to being recognized as an important player in the mammalian newlinegenomes (Rebollo et al., 2012), playing roles in altering the genome landscape and evolution newline(Hedges and Batzer, 2005) and in normal biological processes such as bringing about newlinephenotype variation (Akagi et al., 2013) and cellular diversity (Thomas et al., 2012), as well as newlineabnormalities such as cancers (Rodic and Burns, 2013). Approximately half of each newlinesequenced mammalian genome is comprised of various classes of transposable elements newline(TEs), mobilized by different mechanisms and accumulated over evolutionary time (Akagi et newlineal., 2013; Lander et al., 2001; Levin and Moran, 2011; Waterston et al., 2002).