title: Sequence characterization, in silico mapping and cytosine methylation analysis of markers linked to apospory in Paspalum notatum.
abstract: In previous studies we reported the identification of several AFLP, RAPD and RFLP molecular markers linked to apospory in Paspalum notatum. The objective of this work was to sequence these markers, obtain their flanking regions by chromosome walking and perform an in silico mapping analysis in rice and maize. The methylation status of two apospory-related sequences was also assessed using methylation-sensitive RFLP experiments. Fourteen molecular markers were analyzed and several protein-coding sequences were identified. Copy number estimates and RFLP linkage analysis showed that the sequence PnMAI3 displayed 2-4 copies per genome and linkage to apospory. Extension of this marker by chromosome walking revealed an additional protein-coding sequence mapping in silico in the apospory-syntenic regions of rice and maize. Approximately 5 kb corresponding to different markers were characterized through the global sequencing procedure. A more refined analysis based on sequence information indicated synteny with segments of chromosomes 2 and 12 of rice and chromosomes 3 and 5 of maize. Two loci associated with apomixis locus were tested in methylation-sensitive RFLP experiments using genomic DNA extracted from leaves. Although both target sequences were methylated no methylation polymorphisms associated with the mode of reproduction were detected.
authors.affiliation: Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Zavalla, Santa Fe, Argentina. ; Instituto de Botánica del Nordeste, Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste, Corrientes, Argentina.
authors.forename: Maricel
authors.initials: M
authors.lastname: Podio
authors.forename: María P
authors.initials: MP
authors.lastname: Rodríguez
authors.forename: Silvina
authors.initials: S
authors.lastname: Felitti
authors.forename: Juliana
authors.initials: J
authors.lastname: Stein
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Martínez
authors.forename: Lorena A
authors.initials: LA
authors.lastname: Siena
authors.forename: Camilo L
authors.initials: CL
authors.lastname: Quarin
authors.forename: Silvina C
authors.initials: SC
authors.lastname: Pessino
authors.forename: Juan Pablo A
authors.initials: JP
authors.lastname: Ortiz