Flavonoids are nearly ubiquitous in plants and are recognized as the pigments responsible for the colors of leaves, especially in autumn. They are rich in seeds, citrus fruits, olive oil, tea, and red wine. They are low molecular weight compounds composed of a three-ring structure with various substitutions. This basic structure is shared by tocopherols (vitamin E). Flavonoids can be subdivided according to the presence of an oxy group at position 4, a double bond between carbon atoms 2 and 3, or a hydroxyl group in position 3 of the C (middle) ring. These characteristics appear to also be required for best activity, especially antioxidant and antiproliferative, in the systems studied. The particular hydroxylation pattern of the B ring of the flavonoles increases their activities, especially in inhibition of mast cell secretion. Certain plants and spices containing flavonoids have been used for thousands of years in traditional Eastern medicine. In spite of the voluminous literature available, however, Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional. Suggestions are made where such possibilities may be worth pursuing.

The Effects of Plant Flavonoids on Mammalian Cells:Implications for Inflammation, Heart Disease, and Cancer

The biochemistry and medical significance of the flavonoids.

Tetraodon nigroviridis is a freshwater puffer fish with the smallest known vertebrate genome. Here, we report a draft genome sequence with long-range linkage and substantial anchoring to the 21 Tetraodon chromosomes. Genome analysis provides a greatly improved fish gene catalogue, including identifying key genes previously thought to be absent in fish. Comparison with other vertebrates and a urochordate indicates that fish proteins have diverged markedly faster than their mammalian homologues. Comparison with the human genome suggests ∼900 previously unannotated human genes. Analysis of the Tetraodon and human genomes shows that whole-genome duplication occurred in the teleost fish lineage, subsequent to its divergence from mammals. The analysis also makes it possible to infer the basic structure of the ancestral bony vertebrate genome, which was composed of 12 chromosomes, and to reconstruct much of the evolutionary history of ancient and recent chromosome rearrangements leading to the modern human karyotype.

/pdf/genome-duplication-in-the-teleost-fish-tetraodon-qw9iuo5jxx.pdf

Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype

Copper toxicity, oxidative stress, and antioxidant nutrients.

Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we
report a high-quality draft sequence of the N. crassa genome. The approximately 40-megabase genome encodes about 10,000
protein-coding genes—more than twice as many as in the fission yeast Schizosaccharomyces pombe and only about 25% fewer
than in the fruitfly Drosophila melanogaster. Analysis of the gene set yields insights into unexpected aspects of Neurospora biology
including the identification of genes potentially associated with red light photobiology, genes implicated in secondary metabolism,
and important differences in Ca21 signalling as compared with plants and animals. Neurospora possesses the widest array of
genome defence mechanisms known for any eukaryotic organism, including a process unique to fungi called repeat-induced
point mutation (RIP). Genome analysis suggests that RIP has had a profound impact on genome evolution, greatly slowing the
creation of new genes through genomic duplication and resulting in a genome with an unusually low proportion of closely related
genes.

/pdf/the-genome-sequence-of-the-filamentous-fungus-neurospora-2jw3s2832k.pdf

The genome sequence of the filamentous fungus Neurospora crassa

Analyses of the structure and behaviour of chromosomes and estimation of 4C nuclear DNA in both male and female plants of Coccinia indica and Trichosanthes dioica were made. In male and female plants of T. dioica had identical chromosome numbers. There was remarkable similarity between sexes in chromosome morphology, number of secondary constrictions and total chromosome length, as well as the amount of 4C DNA. In absence of any detectable chromosomal differences it may be argued that the sex determination in this species is principally controlled at the autosomal level. The karyotypes of male and female individuals were not markedly different in C. indica, except for the sex chromosomes. The total chromosome length was slightly more in male as compared to female plant. There was a corresponding difference in 4C DNA values. The differences in chromosome size between sexes of C. indica reflected additional chromatin rather than differential condensation. The heterochromatic nature of long sex chromosome was also indicated in its staining behaviour. The total chromosome length, average chromosome length and the 4C nuclear DNA values of both males and females of annual T. dioica were comparatively higher than those of the related perennial, C. indica.

Chromosome Studies and Nuclear DNA in Relation to Sex Difference and Plant Habit in Two Species of Cucurbitaceae.

Single dose treatment with stannic chloride (4 micrograms/ml) on human lymphocytes in vitro revealed a significant increase of chromosomal aberrations. These showed a distinct relationship with the donor's age. Single and isochromatid breaks including gaps, premature chromosome condensation, irregular staining, stretching of the centromere and interchange, i.e. quadriradial exchange of chromosome arms, and also aneuploidy, were observed.

Effects of stannic chloride on human leucocytes in vitro.

Chromosome Painting is emerging as a powerful tool in the exact localization of different gene sequences of chromosomes at the microscopic level. It is principally based on molecular hybridization in situ with sequence specific probes on chromosomes. Different strategies have been adopted for the preparation of probes, hybridization and visualization. The impact of this method lies in identification of genes for desired characters in the chromosomes, including those of genetic disorders, in cancer research, in transgenesis and in studies on biodiversity and evolution.

Chromosome painting – principles, strategies and scope

The occurrence of different types of hemoglobin variants in India has been well-documented in urban populations and in certain tribal areas. Beta-thalassaemia and hemoglobins D, E, H, S, and rare variants like Hb Lepore, have been found in varying percentages. There is a higher incidence of Hb E in the Eastern region and of Hb D in certain Northern populations. The association of Hb E with beta thalassaemia G6PD deficiency has been established. The relationship with other environmental factors, like malaria, is not yet clear.

Hemoglobin variants in India

The potential of chlorophyllin in reducing clastogenicity was studied against two concentrations of each of three potent metallic clastogens (cesium chloride, mercuric chloride and cobalt chloride) in bone marrow cells of mice in vivo. The respective salts and chlorophyllin were administered orally to mice by gavaging in different combinations. Simultaneous administration of chlorophyllin with both concentrations of each salt reduced the clastogenic effects in the order Cs > Hg > Co. Chlorophyllin could not decrease the clastogenic effects when administered 2 h before the salts.

Archana Sharma

Papers

Chromosome Studies and Nuclear DNA in Relation to Sex Difference and Plant Habit in Two Species of Cucurbitaceae.

Effects of stannic chloride on human leucocytes in vitro.

Chromosome painting – principles, strategies and scope

Hemoglobin variants in India

Comparative efficacy of chlorophyllin in reducing cytotoxicity of some heavy metals