A mutation degree model for the identification of transcriptional regulatory elements

Cascading cis-cleavage on transcript from trans-acting siRNA-producing locus 3

The production of small RNAs (sRNAs) from phased positions set by microRNA-directed cleavage of trans-acting-siRNA-producing locus (TAS) transcript has been characterized extensively; however, the production of sRNAs from non-phased positions remains unknown. We report three cis-cleavages that occurred in TAS3 transcripts in Vitis vinifera, by combining high-throughput sRNA deep sequencing information with evolutional conservation and genome-wide RNA degradome analysis. The three cis-cleavages can be deciphered to generate an orderly cleavage cascade, and can also produce distinct phasing patterns. Each of the patterns, either upstream or downstream of the cis-cleaved position, had a set of sRNAs arranged in 21-nucleotide increments. Part of the cascading cis-cleavages was also conserved in Arabidopsis thaliana. Our results will enhance the understanding of the production of sRNAs from non-phased positions that are not set by microRNA-directed cleavage.

An efficient approach to identify Ginkgo biloba cultivars by using random amplified polymorphic DNA markers with a manual cultivar identification diagram strategy

Cultivar identification is a key step to avoid the formation of homonyms and synonyms of Ginkgo biloba. In this study, a new approach based on combinational utilization of polymorphic bands produced from 6 different random amplified polymorphic DNA (RAPD) primers was developed for identifying 42 Ginkgo cultivars, and a manual cultivar identification diagram that consisted of polymorphic bands produced from different RAPD primers was reported. To check the reliability and efficiency of the cultivar identification diagram, 5 randomly chosen cultivars were further tested, and the workability of the diagram was verified. This new approach will be very helpful for Ginkgo cultivar discrimination and protection, and will also be beneficial for the nursery industry for early identification of Ginkgo seedlings.