Organization and molecular cytogenetics of a satellite DNA family from Hoplias malabaricus (Pisces, Erythrinidae).
The chromosomes of the primitive South American teleost fish Hoplias malabaricus have been analyzed by classical cytogenetic (C-, AgNOR-, Hoechst 33258-, and Q-banding) techniques. A highly repetitive DNA family has been cloned and sequenced. It is a tandemly repeated sequence of about 355 bp, yielding an overall base pair composition of 67% AT with long runs of > 50% As and 70% Ts. Analysis of sequence variation has allowed the further categorization of Hoplias satellite DNA into two evolutionary related subfamilies A and B, distinguishable by characteristic insertions and deletions within this 355-bp monomer. Subfamily A satellite is found (in diverged form) at the centromeres of most H. malabaricus chromosomes. Sequence variants are clustered on specific chromosomal subsets. Subfamily B satellite is highly specific for the paracentromeric heterochromatin on one particular chromosome pair by fluorescence in situ hybridization. These results indicate that the Hoplias satellite DNA family has evolved in a concerted manner predominantly via recombination events involving homologous, rather than non-homologous chromosome regions. The clones isolated here may be useful for the molecular, genetic, and cytological analysis of the genus Hoplias.
Haaf
T
T
Department of Genetics, Stanford University School of Medicine, CA 94305.
Schmid
M
M
Steinlein
C
C
Galetti
P M
PM
Willard
H F
HF
D000818:Animals; D001483:Base Sequence; D002503:Centromere / Q000648:ultrastructure; D002871:Chromosome Banding; D016384:Consensus Sequence; D004276:DNA, Satellite / Q000032:analysis / Q000097:blood / Q000235:genetics*; D005260:Female; D005399:Fishes / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D007668:Kidney / Q000166:cytology; D008099:Liver / Q000166:cytology; D008297:Male; D008677:Metaphase; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013154:Spleen / Q000166:cytology
D004276:DNA, Satellite