Meiotic chromosome behaviour reflects levels of sequence divergence in Sus scrofa domestica satellite DNA.
We present a general model for the evolution of chromosome-specific satellite DNA subfamilies. Sus scrofa domestica has a bimodal karyotype with two autosomal subsets of 12 meta-/submetacentric (Mc) and 6 acrocentric (Ac) chromosome types (Mc and Ac "subgenomes"). We show that the centromeric heterochromatin is characterised by two distinct satellite DNA families designed Mc1 and Ac2. Mc1 is a diverse satellite family of the Mc subgenome of which certain members with a 100 bp repeat unit are found to occur at the pericentromeric regions of each Mc autosome, while others are chromosome-specific, e.g. clone Mc pAv1.5, a higher order repeat variant, which hybridises specifically to chromosome 1. Ac2 is a homogeneous satellite occurring at the subterminal pericentromeric regions of all Ac autosomes. DNA sequence analyses showed that all clones investigated are built up from a 14 bp repeat unit which is highly conserved. In situ hybridisation to meiotic pachytene nuclei revealed a distinct spatial arrangement of the Ac2 centromeric satellite.
Jantsch
M
M
Department of Cytology and Genetics, University of Vienna, Austria.
Hamilton
B
B
Mayr
B
B
Schweizer
D
D
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002871:Chromosome Banding; D016384:Consensus Sequence; D004276:DNA, Satellite / Q000737:chemistry*; D014644:Genetic Variation; D006570:Heterochromatin / Q000648:ultrastructure; D007621:Karyotyping; D008540:Meiosis; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D013552:Swine / Q000235:genetics*; D014998:Y Chromosome / Q000648:ultrastructure*
D004276:DNA, Satellite; D006570:Heterochromatin