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.

Heterosis and Expressivity of Apospory in Tetraploid Bahiagrass Hybrids

“…This phenomenon was repeatedly observed in hybrids from crosses between sexual and apomictic tetraploid genotypes of bahiagrass that were segregating for reproduction mode and was attributed to the presence of a lethal genetic factor with incomplete penetrance associated with the apospory‐controlling locus (Martínez et al, 2001; Stein et al, 2004; Acuña et al, 2011). Furthermore, there is evidence indicating that the low transmission of apospory in bahiagrass is related to the presence of an inversion in the chromosomal region where the apospory‐controlling locus is located (Stein et al, 2004; Podio et al, 2012). Equal proportions of sexual and aposporic hybrids were observed in Family E (Table 2).…”

Apomixis in plant reproduction: a novel perspective on an old dilemma

“…From an evolutionary point of view, we expect that relatively young and simple genetic systems of apomixis determination should include a narrow euchromatic region where genetic recombination between apomeiosis and parthenogenesis loci, and their linked genes, is possible (Table 1), as in Poa (Barcaccia et al 2000; Albertini et al 2001), Taraxacum (van Dijk and Bakx-Schotman 2004), Hypericum (Schallau et al 2010), Erigeron (Noyes and Rieseberg 2000), Hieracium (Catanach et al 2006), and Panicum maximum (Kaushal et al 2008). In contrast, a degenerate heterochromatic block carrying apomixis factors should represent evolutionarily advanced genetic systems of apomixis determination with large non-recombining regions surrounding the apomixis locus (Table 1) as in Pennisetum / Cenchrus (Ozias-Akins et al 1998; Roche et al 1999), Brachiaria (Pessino et al 1998), Paspalum (Labombarda et al 2002; Stein et al 2007; Podio et al 2012), and Tripsacum (Grimanelli et al 1998). Just recently, Conner et al (2013) found recombination between apospory and parthenogenesis loci in C. ciliaris (Table 1).…”

Molecular markers and their application for DNA fingerprinting and genetic diversity studies in Coffea species Marka molekuler dan penerapannya untuk studi sidik jari DNA dan keragaman genetik pada spesies Coffea

“…Random genomic clones are a poor choice as hybridization probes because, plant genomes containing a large percentage of repeated sequences, they will generate a number of hybridization bands that are difficult to analyze. Therefore the two primary sources of probes for RFLP are cDNA clones and PstI-derived genomic clones representing respectively expressed genes and non-methylated ones (Podio et al, 2012).…”