Analysis of BAC clones containing homologous sequences on the end of the Xq arm and on chromosome 7 in the dioecious plant Silene latifolia.
Silene latifolia is a model dioecious plant with morphologically distinguishable XY sex chromosomes. The end of the Xq arm is quite different from that of the Yp arm, although both are located at opposite ends of their respective chromosomes relative to a pseudo-autosomal region. The Xq arm does not seem to originate from the same autosome as the Yp arm. Bacterial artificial chromosome clone #15B12 has an insert containing a 130-kb stretch in which a 313-bp satellite DNA is repeated 420 times. PCR with a single primer revealed that this 130-kb stretch consists of three reversals of the orientation of the satellite DNA. A non-long terminal repeat retroelement and two sequences that share homology with an Oryza sativa RING zinc finger and a putative Arabidopsis thaliana protein, respectively, were found in the sequences that flank the satellite DNA. Fluorescence in situ hybridization carried out using this low-copy region of #15B12 as a probe confirmed that these sequences originated from the X chromosome and that homologous sequences exist at the end of chromosome 7. The region distal to DD44X on the Xq arm is postulated to have recombined with a region containing satellite DNA on chromosome 7 during the process of sex chromosome evolution.
Ishii
Kotaro
K
Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8562, Japan.
Amanai
Yasuhito
Y
Kazama
Yusuke
Y
Ikeda
Miho
M
Kamada
Hiroshi
H
Kawano
Shigeyuki
S
D001483:Base Sequence; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics*; D032461:Chromosomes, Plant / Q000235:genetics*; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D029751:Silene / Q000235:genetics*; D016615:Telomere / Q000235:genetics
D018744:DNA, Plant