title: Digital transcriptome analysis of putative sex-determination genes in papaya (Carica papaya).
abstract: Papaya (Carica papaya) is a trioecious plant species that has male, female and hermaphrodite flowers on different plants. The primitive sex chromosomes genetically determine the sex of the papaya. Although draft sequences of the papaya genome are already available, the genes for sex determination have not been identified, likely due to the complicated structure of its sex-chromosome sequences. To identify the candidate genes for sex determination, we conducted a transcriptome analysis of flower samples from male, female and hermaphrodite plants using high-throughput SuperSAGE for digital gene expression analysis. Among the short sequence tags obtained from the transcripts, 312 unique tags were specifically mapped to the primitive sex chromosome (X or Y(h)) sequences. An annotation analysis revealed that retroelements are the most abundant sequences observed in the genes corresponding to these tags. The majority of tags on the sex chromosomes were located on the X chromosome, and only 30 tags were commonly mapped to both the X and Y(h) chromosome, implying a loss of many genes on the Y(h) chromosome. Nevertheless, candidate Y(h) chromosome-specific female determination genes, including a MADS-box gene, were identified. Information on these sex chromosome-specific expressed genes will help elucidating sex determination in the papaya.
authors: Okinawa Prefectural Agricultural Research Center, Itoman, Japan.
authors: Naoya
authors: N
authors: Urasaki
authors: Kazuhiko
authors: K
authors: Tarora
authors: Ayano
authors: A
authors: Shudo
authors: Hiroki
authors: H
authors: Ueno
authors: Moritoshi
authors: M
authors: Tamaki
authors: Norimichi
authors: N
authors: Miyagi
authors: Shinichi
authors: S
authors: Adaniya
authors: Hideo
authors: H
authors: Matsumura
mesh_terms: D001483:Base Sequence; D029441:Carica / Q000235:genetics*; D032461:Chromosomes, Plant / Q000235:genetics*; D035264:Flowers / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D015203:Reproducibility of Results; D012730:Sex Chromosomes / Q000235:genetics*; D019849:Sex Determination Processes / Q000235:genetics*
chemical_list: D026161:MADS Domain Proteins