Origin of human chromosome 2: an ancestral telomere-telomere fusion.
We have identified two allelic genomic cosmids from human chromosome 2, c8.1 and c29B, each containing two inverted arrays of the vertebrate telomeric repeat in a head-to-head arrangement, 5'(TTAGGG)n-(CCCTAA)m3'. Sequences flanking this telomeric repeat are characteristic of present-day human pretelomeres. BAL-31 nuclease experiments with yeast artificial chromosome clones of human telomeres and fluorescence in situ hybridization reveal that sequences flanking these inverted repeats hybridize both to band 2q13 and to different, but overlapping, subsets of human chromosome ends. We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2.
Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510.
J W
JW
IJdo
A
A
Baldini
D C
DC
Ward
S T
ST
Reeders
R A
RA
Wells
D001483:Base Sequence; D005075:Biological Evolution; D002478:Cells, Cultured; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2; D003001:Cloning, Molecular; D003360:Cosmids; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D015698:Genomic Library; D006801:Humans; D007621:Karyotyping; D008214:Lymphocytes / Q000166:cytology / Q000502:physiology; D008677:Metaphase; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012091:Repetitive Sequences, Nucleic Acid; D016615:Telomere / Q000502:physiology*
D015342:DNA Probes; D004247:DNA