Conservation of a satellite DNA sequence (SATB) in the tilapiine and haplochromine genome (Pisces: Cichlidae)

Genome. 1993 Feb;36(1):187-94. doi: 10.1139/g93-025.

Abstract

We have cloned and sequenced a 1900-bp EcoRI fragment (SATB) from the tilapiine fish Oreochromis niloticus. The SATB sequence is highly reiterated in the tilapiine genome and organized in long tandem arrays. A 760-bp HindIII fragment, an internal component of SATB, has also been cloned and sequenced from the related tilapiine species Oreochromis hornorum. Hybridization of the radiolabelled 760-bp HindIII repeat detected the presence of the SATB repeat in the genomes of several tilapiine species as well as the haplochromine species Haplochromis (Protomelas) similis. The 760-bp HindIII fragment did not hybridize to genomic DNA of Etroplus maculatus (an Asian cichlid) or to that of Cichlasoma meeki (a South American cichlid). The SATB repeat sequence is 56% AT and constitutes 0.2-5% of the tilapiine genome depending on the species examined. Four imperfect 21-bp direct repeat sequences are present within the cloned 1900-bp EcoRI repeat. Alignment of the four direct repeats from the O. niloticus cloned 1900-bp DNA and the two homologous direct repeats from the O. hornorum 760-bp HindIII repeat revealed a core motif of 11 bp that exhibits 100% sequence identity between all of the direct repeats. The conservation of this motif in the SATB repeat suggests that this sequence may be under selective constraint.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Conserved Sequence*
  • DNA, Satellite / genetics*
  • Molecular Sequence Data
  • Perches / classification
  • Perches / genetics*
  • Phylogeny
  • Repetitive Sequences, Nucleic Acid
  • Sequence Homology, Nucleic Acid
  • Species Specificity

Substances

  • DNA, Satellite

Associated data

  • GENBANK/L20583
  • GENBANK/L20584
  • GENBANK/S57287
  • GENBANK/S57288
  • GENBANK/X61610
  • GENBANK/X68165
  • GENBANK/X68166
  • GENBANK/Z22859
  • GENBANK/Z22860
  • GENBANK/Z22861