Gene expression analysis at the onset of aposporous apomixis in Paspalum notatum

Apomixis is a route of asexual reproduction through seeds, that progresses in the absence of meiosis and fertilization to generate maternal clonal progenies. Gametophytic apomicts are usually polyploid and probably arose from sexual ancestors through a limited number of mutations in the female reproductive pathway. A differential display analysis was carried out on immature inflorescences of sexual and apomictic tetraploid genotypes of Paspalum notatum, in order to identify genes associated with the emergence of apospory. Analysis of approximately 10,000 transcripts led to the identification of 94 high-quality differentially expressed sequences. Assembling analysis, plus validation, rendered 65 candidate unigenes, organized as 14 contigs and 51 singletons. Thirty-four unigenes were isolated from apomictic plants and 31 from sexual ones. A total of 45 (69.2 ) unigenes were functionally categorized.