DNA analysis of natural fiber rope.

When rope is found at a crime scene, the type of fiber is currently identified through its microscopic characteristics. However, these characteristics may not always unambiguously distinguish some types of rope from others. If rope samples contain cells from the plants of origin, then DNA analysis may prove to be a better way to identify the type of rope obtained from a crime scene. The objective of this project was to develop techniques of DNA analysis that can be used to differentiate between ropes made from Cannabis sativa L. (hemp), Agave sisalana Perrine (sisal), Musa textilis Née (abaca, "Manila hemp"), Linum usitatissimum L. (flax), and Corchorus olitorus L. (jute). The procedures included extracting the DNA from the rope, performing polymerase chain reaction (PCR) using the extracted DNA as a template, and analyzing the DNA products. A primer pair for PCR, chosen from within a chloroplast gene for the large subunit of ribulose bisphosphate carboxylase/oxygenase, was designed to be specific for plant DNA and complementary to the genes from all five plants. The resulting PCR fragments were approximately 771 base pairs long. The PCR fragments, distinguished through base sequence analysis or restriction enzyme analysis, could be used to identify the five different rope types. The procedure provides a useful addition to visual methods of comparing rope samples.

Wheat VIN3-like PHD finger genes are up-regulated by vernalization.

The term 'vernalization' describes the acceleration of the transition between the vegetative and reproductive stages after exposing plants to an extended period of low temperature. In Arabidopsis, vernalization promotes flowering by silencing the flowering repressor gene FLOWERING LOCUS C (FLC). Mitotically stable repression of FLC is the result of chromatin modifications mediated by the Vernalization-INsensitive 3 (VIN3) and VIN3-Like (VIL) proteins. In this study, we identified and characterized three VIL genes in diploid wheat (Triticum monococcum L.), named TmVIL1, TmVIL2, and TmVIL3. Similar to Arabidopsis VIN3, all three wheat VIL proteins carry three conserved domains including a plant homeodomain finger motif (PHD), a fibronectin type III domain (FNIII), and a VIN3 interacting domain (VID). Genetic mapping placed TmVIL1, TmVIL2, and TmVIL3 loci in the centromeric regions of chromosome 5, 6, and 1, respectively. The chromosome location of TmVIL1 is close to that of the vernalization gene VRN-D5, but more precise mapping information is required to validate this relationship. Transcription of the wheat VIL genes was up-regulated by vernalization, with a peak after 4-6 weeks of cold treatment. When transferred back to warm conditions, transcript levels of the wheat VIL genes returned to pre-vernalization levels. In addition, the transcript levels of wheat VIL genes are affected by photoperiod. This study indicates that wheat VIL genes have retained a similar structure and transcriptional regulation as their Arabidopsis VIN3/VIL homologues, suggesting that they might have retained some of their functions.