title: Structure and evolution of mtanga, a retrotransposon actively expressed on the Y chromosome of the African malaria vector Anopheles gambiae.
abstract: Here we report the discovery of a novel family of long terminal repeat (LTR)-retrotransposons designated mtanga-Y, specific to the Y chromosome of the African malaria vector, Anopheles gambiae. mtanga-Y elements represent the first Y-linked sequences and the first members of the Ty1-copia superfamily of retrotransposons described from this mosquito. Analysis of a full-length 4,284-bp element revealed the presence of two intact overlapping open reading frames bounded by LTRs of 119 bp. Evidence suggests that the elements are capable of retrotransposition, as transcripts and potential replication intermediates (one-LTR circles) were detected. However, the approximately 12 copies of mtanga-Y appear to be clustered rather than dispersed on the Y chromosome. Absent from the Y chromosome of four sibling species (A. arabiensis, A. quadriannulatus, A. melas, and A. merus), similar, but often defective, mtanga elements are present elsewhere in these genomes, as well as in A. gambiae. These data are consistent with a relatively recent invasion of the A. gambiae Y chromosome by an intact element. The presence of functional mtanga-Y elements suggests that the Y chromosome may be a source, not just a sink, for retrotransposons.
authors.affiliation: Department of Biological Sciences, University of Notre Dame, IN 46556, USA.
authors.forename: Cherise J B
authors.initials: CJ
authors.lastname: Rohr
authors.forename: Hilary
authors.initials: H
authors.lastname: Ranson
authors.forename: Xuelan
authors.initials: X
authors.lastname: Wang
authors.forename: Nora J
authors.initials: NJ
authors.lastname: Besansky
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D017931:DNA Primers / Q000737:chemistry; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D018626:Retroelements / Q000502:physiology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014998:Y Chromosome / Q000235:genetics*
chemical_list: D017931:DNA Primers; D018626:Retroelements