title: Genome sequence comparison reveals a candidate gene involved in male-hermaphrodite differentiation in papaya (Carica papaya) trees.
abstract: The sex type of papaya (Carica papaya) is determined by the pair of sex chromosomes (XX, female; XY, male; and XY(h), hermaphrodite), in which there is a non-recombining genomic region in the Y and Y(h) chromosomes. This region is presumed to be involved in determination of males and hermaphrodites; it is designated as the male-specific region in the Y chromosome (MSY) and the hermaphrodite-specific region in the Y(h) chromosome (HSY). Here, we identified the genes determining male and hermaphrodite sex types by comparing MSY and HSY genomic sequences. In the MSY and HSY genomic regions, we identified 14,528 nucleotide substitutions and 965 short indels with a large gap and two highly diverged regions. In the predicted genes expressed in flower buds, we found no nucleotide differences leading to amino acid changes between the MSY and HSY. However, we found an HSY-specific transposon insertion in a gene (SVP like) showing a similarity to the Short Vegetative Phase (SVP) gene. Study of SVP-like transcripts revealed that the MSY allele encoded an intact protein, while the HSY allele encoded a truncated protein. Our findings demonstrated that the SVP-like gene is a candidate gene for male-hermaphrodite determination in papaya.
authors.affiliation: Department of Bioscience and Textile Technology, Shinshu University, Ueda, Nagano, 386-8567, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ueno
authors.forename: Naoya
authors.initials: N
authors.lastname: Urasaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Natsume
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tarora
authors.forename: Ayano
authors.initials: A
authors.lastname: Shudo
authors.forename: Ryohei
authors.initials: R
authors.lastname: Terauchi
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsumura
mesh_terms: D029441:Carica / Q000235:genetics*; D032461:Chromosomes, Plant / Q000235:genetics; D017343:Genes, Plant; D056726:Genetic Association Studies; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D012730:Sex Chromosomes / Q000235:genetics; D019849:Sex Determination Processes