Molecular Biology and Evolution, Vol 2, 411-419, Copyright © 1985 by Society for Molecular Biology and Evolution
B Widegren, U Arnason and G Akusjarvi
A tandemly organized, highly repetitive DNA component of the killer whale
was sequenced. The length of the repeat was 1,579 bp. This unit, which
characterizes all delphinids, shows stringent hybridization homology with a
1,740-bp repeat that is characteristic of all other cetacean families. The
1,579-bp component comprises approximately 15% of the killer-whale genome,
in which it is repeated 4-5 X 10(5) times. Computer analysis of the
sequence showed no linear repetition within the component. This indicates
that the 1,579-bp unit has not evolved by amplification of shorter repeats.
Several inverted repeats of substantial length were found in the 1,579-bp
unit. The most conspicuous of these was a 72-bp sequence that deviated from
matching in only three positions. The 72-bp sequence occurs within an open
reading frame 330 bp in length. Transcriptional activity was registered in
the cloned repeat in a cell-free system. The length of the transcript was
approximately 340 nucleotides. The chromosomal localization of the 1,579-bp
repeat was determined by in situ hybridization. The repeat was present in
eight of 21 autosomal pairs and was found in almost all C-band-positive
(constitutive heterochromatin) regions of the karyotype.
ORIGINAL ARTICLE
Characteristics of a conserved 1,579-bp highly repetitive component in the killer whale, Orcinus orca
Department of Genetics, University of Lund, Sweden.
![]()
CiteULike
Connotea
Del.icio.us What's this?