Expression analysis of N19, a gene related with sexual and apomictic development in Paspalum notatum

SARTOR, M. E.; ESPINOZA, F; SEIJO G.; GONZALEZ AM; PESSINO SC

Rosario

Congreso; 40 Congreso Lationoamericano de Genética; 2012

In former expression analysis aimed at identifying genes differentially expressed in reproductive tissues of apomictic and sexual genotypes, we isolated a differentially expressed tag (experimental code N19), which kept similarity with checkpoint homologue CHK1. This candidate gene showed a high expression level, and was found upregulated in sexual plants. The objective of this work was to better characterize N19 structure and expression in reproductive tissues of apomictic and sexual plants of P. notatum. Relative expression quantitation using q-RTPCR revealed heterochronic temporal expression patterns, with minor upregulation in apomictic plant at premeiosis and meiosis, downregulation at postmeiosis and equal expression at anthesis. Spatial expression patterns were examined by using in situ RNA hybridization on reproductive tissues at meiosis and anthesis. During meiosis, the antisense probe revealed a strong signal in the teguments and nucella of the apomictic plant, but only in the area of the megaspore mother cell of the sexual plant. In anthesis, both reproductive types (apomictic and sexual) displayed a uniform expression pattern when hybridized with the antisense probe, displaying signal in teguments, egg apparatus and polar nuclei. No signal was observed with the sense probe. Rapid amplification of cDNA ends (RACE) experiments allowed the isolation of single bands, which will be sequenced in order to characterize the transcript full-length structure. Our results showed that the expression pattern of N19 actually differs between both reproductive types.