Plant & Animal Genomes XVI Conference

January 12-16, 2008
Town & Country Convention Center
San Diego, CA

Characterization And Physical Mapping Of Genes Candidate For Apomixis

Emidio Albertini¹ , Gianpiero Marconi¹ , Lorenzo Raggi¹ , Francesco Angeloni^{1, 2} , Silvio Collani¹ , Gianni Barcaccia³ , Hans DeJong² , Mario Falcinelli¹

¹  Plant Biology, Agroenvironmental and Animal Biotechnology Department, University of Perugia, Italy

²  Laboratory of Genetics, Wageningen University, 6703 BD Wageningen, The Netherlands

³  Environmental Agronomy and Crop Science Department, University of Padova, Legnaro, Italy

By applying the cDNA-AFLP method to developmentally staged inflorescences, we selected some mRNAs differentially expressed between apomictic and sexual genotypes of P. pratensis at the time of flowering. In particular some genes were chosen for further temporal and spatial characterization. We created 2 full-length cDNA libraries (1 from an apomictic and 1 from a sexual genotypes) and isolated the full-length of 6 genes (APOSTART, PpSERK, PpMET, PpARM, PpRAB and PpMOB1). Here we focus on the expression pattern of 11 APOSTART members/alleles which was investigated through Real-time PCR. Since several APOSTART members showed to be flower-specific, our aim was that of isolating the relative promoter(s). Genome walking strategies failed since it seems that in the 5’-end of the gene resides a retrotransposon region which did not allowed to walk upstream the gene. We, then, decided to create 3 genomic libraries (2 from apomictic and 1 from a sexual genotypes). The isolation and bioinformatic characterization of APOSTART genomic clones is reported and discussed. In addition, since the BLAT analysis of sequences revealed that homologous of APOSTART and of the other 5 selected genes are tightly linked in a small chromosome region of Arabidopsis, M. truncatula and rice, we aimed at physically mapping cosmid clones carrying these candidate genes in P. pratensis to verify if the linkage is maintained. Moreover, the spatial distribution of APOSTART transcripts within reproducing organs was determined by an high number of independent in situ hybridization experiments.