In Silico Prediction of SSRs and Functional Annotation of ESTs from Catharanthus Roseus

Catharanthus roseus (periwinkles) belongs to the Apocynaceae family with great anti-cancer, anti-diabetic, andhepatoprotective values. Due to the large number of active molecules accumulated in these plants, they are ofparticular concern, especially in the pharmaceutical sector. The availability of ESTs gave the genetic algorithmof the plant to differentiate between the species accessions at the genetic level. The high-throughput method usedfor mining and detection of microsatellites (SSRs) embedded in ESTs gave a new insight for molecular markers’development. 19899 ESTs were retrieved, examined by NCBI EST dB and assembled 2692 to get full-lengthcontigs sequences. 338 microsatellites (SSR) loci were predicted with an average of SSR per 9.33 kb of ESTthough MISA-web tools out of 2692 contigs. Furthermore, trinucleotide, a well-known SSR was examined andfound to be the most favorable repeats' type (26.62%) followed by dinucleotide (24.22), mononucleotide (48.22%),and hexanucleotide (0.3%) types. The highest frequency of (A/T)n was reported in this finding followed by(AAG)n. The simple sequence repeats (SSR) extracted from C. roseus EST's data were used as molecular toolsfor genetic characterization in the present study. These predicted SSRs can be significantly used for constructingthe genetic maps and also for differentiating the accession between the species.

Enzyme Based Asparagine Biosensor for the Detection of Asparagine Levels in Leukemic Samples.

Plants have been used for the treatment of different diseases since 1100 BC. Catharanthus roseus is one of the medicinally important plants showing anti-tumor, anti-mutagenic and anti-microbial effects. L-asparaginase is extracted by C. roseus and is used for the development of biosensors. L-asparaginase breaks down asparagine into aspartic acid and ammonia, thus killing the tumor cells due to asparagine starvation. In the present study the L-asparaginase was extracted from C. roseus and immobilized in different matrixes such as agar, soil, clay and k-carrageenan. Out of the various immobilization techniques k-carrageenan gave the fastest response time, so it was choosen for the development of asparagine biosensor. In the leukemic blood samples the asparagine concentration was 10-2 to 10-3 M whereas in normal blood samples it was 10-5 to 10-6 M. The developed biosensor gave the fast response and were sensitive and reliable.