Isolation and characterization of X chromosome-derived DNA sequences from a dioecious plant Melandrium album.
A number of X chromosome DNA sequences have been isolated from a dioecious plant, Melandrium album (syn. Silene latifolia), using chromosome microdissection followed by degenerate oligonucleotideprimed polymerase chain reaction (DOP-PCR) amplification. Six DNA clones were selected and further characterized by DNA/DNA hybridization techniques to check their copy numbers, sex-specific methylation patterns, species specificity and positions on chromosomes. These clones were moderately to highly repetitive (approximately 10(3)-10(5) copies per haploid genome) and none of them gave a positive signal on Northern blots. One of the clones yielded a sex-specific methylation pattern: its abundant non-methylated CCGG island was found only in males. All the clones also hybridized to two closely related dioecious Melandrium species (M. rubrum and M. dicline). Nucleotide sequences of two X-derived clones showed a number of internal short direct repeats; one of them strikingly resembled a plant conservative telomere sequence (TTTAGGG). None of the clones hybridized to the X chromosome only, but all were localized at the telomeric heterochromatic regions (DAPI C-bands) of both arms of a vast majority of M. album chromosomes using the fluorescence in situ hybridization (FISH) technique. However, the non-homologous arm of the Y chromosome (contrary to the arm homologous to the X chromosome, possessing the pseudoautosomal region) showed neither a DAPI C-banding-stained heterochromatin nor a FISH signal with any of the DNA probes tested, thus indicating its evolutionary diversification.
Bůzek
J
J
Institute of Genetics and Molecular and Cellular Biology, Strasbourg, France.
Koutníková
H
H
Houben
A
A
Ríha
K
K
Janousek
B
B
Siroký
J
J
Grant
S
S
Vyskot
B
B
D001482:Base Composition; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002871:Chromosome Banding; D003001:Cloning, Molecular; D019175:DNA Methylation; D015342:DNA Probes; D018744:DNA, Plant / Q000235:genetics / Q000302:isolation & purification; D006570:Heterochromatin / Q000648:ultrastructure; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018749:RNA, Plant / Q000235:genetics / Q000302:isolation & purification; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA; D012728:Sex Chromatin; D013045:Species Specificity; D014960:X Chromosome / Q000235:genetics* / Q000648:ultrastructure; D014998:Y Chromosome / Q000235:genetics / Q000648:ultrastructure
D015342:DNA Probes; D018744:DNA, Plant; D006570:Heterochromatin; D018749:RNA, Plant