Annotation was done by the software BLAST2GO. Using the Newbler assembler software (v 2.6 Roche, IN, USA), 63,763 contiguous sequences were obtained and further assembled into 49,568 isotigs, the bioinformatic equivalent to unique RNA transcripts. curvula whole-genome sequence, a de novo assembly of the high quality clean reads was conducted. As next generation sequencing (NGS) technologies became available, a reference transcriptome for this grass was obtained through a deeper sequencing by 454 GS FLX+ Roche (INDEAR, Rosario, Argentina), leading to 2,617,197 reads (952 Mbp) with an average length of 364 bp. These genes were in silico mapped onto maize genome to identify candidates mapping to the region syntenic to the diplospory locus.
A comparative expression analysis between libraries revealed that 112 unigenes were modulated by the reproductive mode or by ploidy. ESTs were clustered and assembled in 8,864 unigenes, 79% of which were functionally categorized by BLASTX analysis against public databases, but only 38% could be classified according to Gene Ontology. Thus, initial studies were conducted on 12,295 expressed sequence tags (ESTs) generated from near-isogenic lines with different ploidy levels and reproductive modes, leading to genome coverage of 22%. Among the strategies that have been chosen to dissect apomixis regulation are transcriptome sequencing and the use bioinformatic tools. Our research group has been studying the molecular mechanisms involved in the reproductive behavior of Eragrostis curvula, an apomictic perennial grass widely naturalized in semiarid regions or Argentina. The switch from sex to apomixis is hypothesized to result from deregulation of developmental pathways leading to sexual seed development, and the trigger for deregulation involves the global genomic effects of hybridization and polyploidy.
It probably arose from a few alterations in genes controlling plant sexuality. Apomixis, clonal reproduction by seeds, is a puzzling process focused by the scientific community for many years that has interesting evolutionary implications as well as great economical and agricultural potentials, that could significantly change agricultural practices.
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