Hepatitis C virus (HCV) is a blood borne, circular and positive single stranded virus with high spread rates. With the passage of time the frequency of HCV is increasing in different parts of the world. HCV is a major cause, which may end in liver cirrhosis and hepatocellular carcinoma. HCV has six main genotypes with many subtypes, which have variable sequence homology with each other. Symptoms can appear anytime from 2 weeks to 6 months, which include jaundice, fatigue, gray-colored stool, joint pain, belly pain, weakness, anorexia, itchy skin and dark urine. Genotyping is more significant for planning of HCV treatment period and helps to cure HCV infections. For the quantification and identification of hepatitis C virus-ribonucleic acid, many molecular techniques are performed; the most significant are HCV ELISA, quantitative HCV-RNA PCR and recombinant immunoblot assay. PCR is the major technique targeting 5 0 untranslated region (UTR). HCV can be transmitted by contaminated blood, ear and nose piercing and contaminated medical instruments. To overcome the rate of HCV, guidance should be provided to make aware the persons about risk factors, transmission and prevention. Discovery and designing of new therapies and vaccines to overcome this disease are the necessity of the present era. Four types of vaccines such as vector vaccines, peptide vaccines, DNA vaccines and recombinant protein vaccines are available in clinical trials.
The present investigation aimed to assess the concentrations of selected heavy metals in water and sediments and their bioaccumulation in tissues of freshwater mussels and their histopathological effects on the digestive gland, gills, and gonads of Anodonta cygnea. Water, sediments, and freshwater mussel samples were collected at four sites, that is, reference and polluted sites, along the Kabul River, Khyber Pakhtunkhwa. The polluted sites were receiving effluents from the industrial, agricultural, municipal, and domestic sources. The order of metals in the water was Zn > Pb > Ni > Cu > Mn > Fe > Cr > Cd, in sediments the order was Fe > Zn > Cr > Ni > Mn > Pb > Cu > Cd, and in the soft tissues the order was Fe > Zn > Mn > Pb > Cu > Cr > Ni > Cd. Histopathological alterations observed in polluted sites of Kabul River were inflammation, hydropic vacuolation, and lipofuscin pigments (in digestive gland), gill lamellar fusion, dilated hemolymphatic sinus, clumping, and generation of cilia and hemocytic infiltration (in gills), and atresia, necrosis, granulocytoma, hemocytic infiltration, and lipofuscin pigments (in gonads). The histopathological alterations in the organs of Anodonta cygnea can be considered as reliable biomarkers in biomonitoring of heavy metal pollution in aquatic ecosystems.
Genetic variations in circadian clock genes may serve as molecular adaptations, allowing populations to adapt to local environments. Here, we carried out a survey of genetic variation in Drosophila cryptochrome (cry), the fly’s dedicated circadian photoreceptor. An initial screen of 10 European cry alleles revealed substantial variation, including seven non-synonymous changes. The SNP frequency spectra and the excessive linkage disequilibrium in this locus suggested that this variation is maintained by natural selection. We focused on a non-conservative SNP involving a leucine - histidine replacement (L232H) and found that this polymorphism is common, with both alleles at intermediate frequencies across 27 populations surveyed in Europe, irrespective of latitude. Remarkably, we were able to reproduce this natural observation in the laboratory using replicate population cages where the minor allele frequency was initially set to 10%. Within 20 generations, the two allelic variants converged to approximately equal frequencies. Further experiments using congenic strains, showed that this SNP has a phenotypic impact, with variants showing significantly different eclosion profiles. At the long term, these phase differences in eclosion may contribute to genetic differentiation among individuals, and shape the evolution of wild populations.
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