title: Quantitative variation of LINE-1 sequences in five species and three subspecies of the subgenus Mus and in five Robertsonian races of Mus musculus domesticus.
abstract: The quantitative variation of a conserved region of the LINE-1 ORF2 sequence was determined in eight species and subspecies of the subgenus Mus (M. m. domesticus, M. m. musculus, M. m. castaneus, M. spicilegus, M. spretus, M. cervicolor, M. cookii, M. caroli) and five Robertsonian races of M. m. domesticus. No differences in LINE-1 ORF2 content were found between all acrocentric or Robertsonian chromosome races, whereas the quantitative variation of the LINE-1 ORF2 sequences detected among the eight taxa partly matches with the clades into which the subgenus is divided. An accumulation of LINE-1 ORF2 elements likely occurred during the evolution of the subgenus. Within the Asiatic clade, M. cervicolor, cookii, and caroli show a low quantity of LINE-1 sequences, also detected within the Palearctic clade in M. m. castaneus and M. spretus, representing perhaps the ancestral condition within the subgenus. On the other hand, M. m. domesticus, M. m. musculus and M. spicilegus showed a high content of LINE-1 ORF2 sequences. Comparison between the chromosomal hybridization pattern of M. m. domesticus, which possesses the highest content, and M. spicilegus did not show any difference in the LINE-1 ORF2 distribution, suggesting that the quantitative variation of this sequence family did not involve chromosome restructuring or a preferential chromosome accumulation, during the evolution of M. m. domesticus.
authors.affiliation: Dipartimento di Biologia Animale, Università degli Studi di Pavia, Piazza Botta, 9-10, 27100, Pavia, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Rebuzzini
authors.forename: Riccardo
authors.initials: R
authors.lastname: Castiglia
authors.forename: Solomon G
authors.initials: SG
authors.lastname: Nergadze
authors.forename: George
authors.initials: G
authors.lastname: Mitsainas
authors.forename: Pavel
authors.initials: P
authors.lastname: Munclinger
authors.forename: Maurizio
authors.initials: M
authors.lastname: Zuccotti
authors.forename: Ernesto
authors.initials: E
authors.lastname: Capanna
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Redi
authors.forename: Silvia
authors.initials: S
authors.lastname: Garagna
mesh_terms: D000818:Animals; D001483:Base Sequence; D002875:Chromosomes / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics*; D008297:Male; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D013045:Species Specificity