Balagopalan Unni

Analysis of genetic diversity of muga silkworm (Antheraea assamensis, Helfer; Lepidoptera: Saturniidae) using RAPD-based molecular markers.

Eleven populations of muga silkworm, Antheraea assamensis Helfer, the golden silk yarn producer of northeast India, was subjected to RAPD marker analysis in order to assess its genetic diversity. The genomic DNA extracted from muga silkworms were analysed using 50 random primers among which 36 polymorphic primers generated 309 bands. RAPD profile of the isolated DNA revealed a high level of genetic polymorphism. The average amplicons per primer was found to be 8.58, and 94.82% amplicons were polymorphic. Cluster analysis based on Jaccard’s similarity coefficients resulted in the formation of two main clusters with one population on one cluster and the remaining on the other cluster. Jaccard’s similarity coefficients ranged from 0.122 to 0.863 indicating a high level of genetic diversity within muga silkworm collection. The study concluded that, although there lays little morphological differences among the collected muga silkworm populations, the populations are highly polymorphic which might have enabled the silkworm to survive under a restricted geographical location, that is north east region of India only but under diverse climatic conditions for a long period. This study may be useful in identifying diverse genetic stocks of A. assamensis, which may be conserved on a priority basis.

Toxicological effects of arsenic exposure in a freshwater teleost fish, Channa punctatus

High concentration of arsenic in groundwater in the north-eastern states of India has become a major cause of concern. Inorganic arsenic of geological origin is found in groundwater used as drinking-water in several parts of the world. Arsenic is used in various industries and agriculture and excessive arsenic finds its way into lakes and rivers. Since arsenic is a known human carcinogen, the epidemiological studies are extremely important for this metal. Fish are ideal organisms to work with in toxicogenomics studies due to the strong power of fish models to establish biomarkers of exposure. Since, fishes respond to toxicants in a similar way as higher vertebrates, they can be used to screen for chemicals that are potentially teratogenic and carcinogenic to humans. Also fish absorbs dissolved or available metals and therefore can serve as indicator of metal pollution. The objectives of this work were to examine the toxicological effect and molecular changes caused by a heavy metal sodium arsenite (NaAsO 2 ), in Channa punctatus. When fishes were exposed to NaAsO 2 , it induced death of the fishes in a concentration-dependent manner. 100 ppm, the highest concentration tested in this study, was found to be the deadliest and it induced death of the fishes within 18 to 20 h. As the concentration lowered the survival time increased dose dependently. Liver is the target organ of arsenic toxicity. Fish liver plays an important role in uptake, accumulation, bio-transformation and excretion of arsenic. We investigated the effect of NaAsO 2 on fish liver. NaAsO 2 was found to cause liver chromosomal DNA fragmentation and expression of certain proteins. Key words: DNA Fragmentation, sodium arsenite, Channa punctatus.

Anti-Proliferative Activities of Vasicinone on Lung Carcinoma Cells Mediated via Activation of Both Mitochondria-Dependent and Independent Pathways

Vasicinone, a quinazoline alkaloid from Adhatoda vasica Nees. is well known for its bronchodilator activity. However its antiproliferative activities is yet to be elucidated. Here-in we investigated the anti-proliferative effect of vasicinone and its underlying mechanism against A549 lung carcinoma cells. The A549 cells upon treatment with various doses of vasicinone (10, 30, 50, 70 µM) for 72 h showed significant decrease in cell viability. Vasicinone treatment also showed DNA fragmentation, LDH leakage, and disruption of mitochondrial potential, and lower wound healing ability in A549 cells. The Annexin V/PI staining showed disrupted plasma membrane integrity and permeability of PI in treated cells. Moreover vasicinone treatment also lead to down regulation of Bcl-2, Fas death receptor and up regulation of PARP, BAD and cytochrome c, suggesting the anti-proliferative nature of vasicinone which mediated apoptosis through both Fas death receptors as well as Bcl-2 regulated signaling. Furthermore, our preliminary studies with vasicinone treatment also showed to lower the ROS levels in A549 cells and have potential free radical scavenging (DPPH, Hydroxyl) activity and ferric reducing power in cell free systems. Thus combining all, vasicinone may be used to develop a new therapeutic agent against oxidative stress induced lung cancer.

Isolation, purification, and characterization of staphylocoagulase, a blood coagulating protein from Staphylococcus sp. MBBJP S43

Staphylocoagulase, a protein produced by S. aureus, play major role in blood coagulation and investigations are in advance to discover more staphylocoagulase producing species. The present study demonstrates the identification of a coagulase producing bacteria and isolation, purification and characterization of the protein. The bacteria was identified using 16S rDNA sequencing and phylogenetic investigation, classified the bacteria as Staphylococcus sp. MBBJP S43 with Genbank accession number KX907247. Tube test and Chromozym TH assay were used to study enzyme activity and comparison was made with five standard coagulase positive strains. The SEM images of the fibrin threads provide evidence of coagulation. The optimum temperature for enzyme activity was 37°C and pH of 6.5-7.5. Glucose and lactose as a carbon source and ammonium chloride as nitrogen source greatly influenced the bacterial growth. Staphylocoagulase has been purified to homogeneity (766 fold) by 80% (NH4)2SO4 precipitation, Sephadex G-75 gel filtration, DEAE anion exchange chromatography, and HPLC using C18 column. SDS PAGE revealed the molecular weight of the protein to be approximately 66kD and FTIR spectra of the purified protein demonstrated the presence of α helical structure. Present study revealed that the Staphylococcus sp. MBBJP S43 strain is a potential staphylocoagulase producing bacteria.

Role of Environmental Pollutants in Liver Physiology: Special References to Peoples Living in the Oil Drilling Sites of Assam

The populations residing near polluted sites are more prone to various types of diseases. The important causes of air pollution are the suspended particulate matter, respirable suspended particulate matter, sulfur dioxide and nitrogen dioxide. As limited information is available enumerating the effect of these pollutants on liver physiology of the population living near the polluted sites; in the present study, we tried to investigate their effect on liver of the population residing near the oil drilling sites since birth. In this study, a randomly selected 105 subjects (46 subjects from oil drilling site and 61 subjects from control site) aged above 30 years were taken under consideration. The particulate matter as well as the gaseous pollutants, sulfur dioxide and nitrogen dioxide, were analyzed through a respirable dust sampler. The level of alkaline phosphatase, alanine transaminase and aspartate transaminase enzymes in serum were measured by spectrophotometer. The generalized regression model studies suggests a higher concentration of respirable suspended particulate matter, suspended particulate matter and nitrogen dioxide lowers the alkaline phosphatase level (p<0.0001) by 3.5 times (95% CI 3.1-3.9), 1.5 times (95% CI 1.4 - 1.6) and 12 times (95% CI 10.74 -13.804), respectively in the exposed group. The higher concentration of respirable suspended particulate matter and nitrogen dioxide in air was associated with increase in alanine transaminase level (p<0.0001) by 0.8 times (95% CI 0.589-1.049) and by 2.8 times (95% CI 2.067-3.681) respectively in the exposed group. The increase in nitrogen dioxide level was also associated with increase in aspartate transaminase level (p<0.0001) by 2.5 times (95% CI 1.862 – 3.313) in the exposed group as compared to control group. Thus, the study reveals that long-term exposure to the environmental pollutants may lead to liver abnormality or injury of populations living in polluted sites.

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and random amplified polymorphic DNA (RAPD) based genetic variation studies in eri silkworm ( Samia cynthia ricini Lepidoptera: Saturniidae)

Four strains of eri, Samia cynthia ricini Lepidoptera: Saturniidae that can be identified morphologically and maintained at North East Institute of Science and Technology, Jorhat were characterized based on their protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and DNA by random amplified polymorphic DNA (RAPD) technique. Fiber yield was highest in Gs strain. SDS-PAGE profile showed 11 prominent bands in the strains with molecular weight ranging from 35 to 200 kDa together with 28 minor bands with molecular weight ranging from 33 to 210 kDa. Two polypeptides of molecular weight 90 and 110 kDa were absent in both Y and Ys. Eight random primers and one universal primer used for RAPD analysis generated a total of 79 bands, of which 49 were polymorphic. In both SDS-PAGE and RAPD, the UPGMA based dendrogram showed two clusters: cluster 1 included Gs and G, whereas Y and Ys was grouped in cluster 2 by SDS-PAGE analysis but RAPD analysis grouped Ys and G in cluster 1 and Gs and Y in cluster 2. The range of genetic diversity observed among the strains affirms the potentiality of RAPD technique for identification and selection of distant parents for silkworm hybridization for high silk yield. Key words: Genetic variation, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), random amplified polymorphic DNA (RAPD), silkworm, cocoon.