title: The Y chromosome-specific STS marker MS2 and its peripheral regions on the Y chromosome of the dioecious plant Silene latifolia.
abstract: Sex determination in Silene latifolia uses the XX/XY system. The recent evolution of dioecy in S. latifolia provides a unique opportunity to study the early stages of Y chromosome evolution. However, the current Y chromosome map still contains many large gaps with no available markers. In this study, a sequence tagged site (STS) marker, MS2, was isolated and mapped to the same locus as L8 on the Y chromosome. To investigate the peripheral regions of MS2, a bacterial artificial chromosome (BAC) library was constructed from a male plant, and the BAC clone containing MS2 (MS2-9d12F) was isolated from 32 640 clones with an average insert size of 115 kb. A 109-kb insert of the BAC clone was analyzed. BLASTX analysis showed 11 sequences similar to some known proteins, most of which are retrotransposon-like elements. The ORF Finder predicted 9 ORFs within MS2-9d12F. RT-PCR analyses revealed that only 4 of the 9 predicted ORFs are expressed in both male and female plants. These 4 ORFs are candidates for genes having counterparts on both the X and Y chromosomes. Dot-matrix plot analysis and a BLASTN search revealed LTR-like sequences close to the retrotransposon-like elements and high similarity to 3 known genomic sequences of S. latifolia. These results suggest an accumulation of retrotransposons and segmental duplications in peripheral regions of MS2 during the early stage of sex chromosome evolution.
authors: Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8562, Japan.
authors: Kotaro
authors: K
authors: Ishii
authors: Ryuji
authors: R
authors: Sugiyama
authors: Megumi
authors: M
authors: Onuki
authors: Yusuke
authors: Y
authors: Kazama
authors: Sachihiro
authors: S
authors: Matsunaga
authors: Shigeyuki
authors: S
authors: Kawano
mesh_terms: D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D032461:Chromosomes, Plant; D018744:DNA, Plant / Q000737:chemistry; D019143:Evolution, Molecular; D017343:Genes, Plant; D005819:Genetic Markers; D023281:Genomics; D017404:In Situ Hybridization, Fluorescence; D018626:Retroelements; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D016324:Sequence Tagged Sites; D019849:Sex Determination Processes; D029751:Silene / Q000235:genetics*; D020079:Terminal Repeat Sequences
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers; D018626:Retroelements