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

Chromosomal behaviour in cultured cells of Dioscorea foribunda Mart. and Gall. (2n=36) was studied progressively from the time of initiation to one year old cul-tures maintained in different hormonal regimes. Cytological analysis of the cultured cells revealed a heterogenous population of dividing cells with both euploid and aneuploid chromosome numbers in all cases. Gradual polyploidization with in-creasing age of the callus has been recorded. Multipolar anaphase, budded cell with chromosomes migrating from mother cell to the daughter bud and multi-nucleate cells were observed.

Chromosomal Behaviour in Cultured Cells of Dioscorea floribunda

A series of 200 normal serum samples obtained from healthy blood donors belonging to different religious communities and casters were examined for transferrin phenotypes by vertical polyacrylamide gel electrophoresis. Of these, 196 showed the common CC phenotype, while 4 showed CD phenotype, without any correlation with the caste or community. In another study involving 102 cases of malignancy, no relationship was observed between th transferrin phenotype and the type of malignancy, except in the case of Hodgkin's disease, which showed B2C phenotype.

Transferrin patterns in the Eastern India in normal and malignant cases.

Fenfluramine (Fen), an amphetamine-derivative widely used in the treatment of obesity, has been evaluated in vivo in the bone marrow cells of Swiss albino mice for assessing its clastogenic potentials. Concentrations of 0.75, 1.50 and 5.0 mg Fen/kg body weight (b.w.) were administered orally for the study. Long-term treatment for 21 days showed dose-dependent significant increase in chromosomal aberrations on the 8th day. A significant decrease in aberration levels was seen in the late treatment period. Caffeine alone produced dose-and duration-dependent clastogcnicity at doses of 2.0, 4.0 and 6.0 mg/kg b.w. when given by gavage. Using caffeine post-treatment (4.0 and 6.0 mg/kg b.w.) 2h after Fen application, a strong synergism could be seen in the late treatment period as shown by the dose-response curves and by statistical analysis using the principle of least squares. The results support the hypouhesis that prolonged Fen application induces dose-dependent increase in post-replication repair and...

Potentiation by caffeine of the frequencies of chromosomal aberrations induced by chronic exposure to fenfluramine in mice.

Estimation of cadmium in biological tissues by atomic absorption spectrophotometer--a new reagent.

Publisher Summary
This chapter presents a study of plant chromosomes from tissue culture. Tissue culture technique allows the cultivation of cells, tissues, and organs in vitro in natural medium or in artificial medium, but reproducing as far as is practicable the conditions in vivo. Tissue culture allows a complete analysis of the sequence of reactions from the initial stage, and also of the chromosomal mechanism involved in the operation. In the study of cytogenetics in relation to plant breeding, tissue, and embryo, culture has acquired the status of a routine technique in the laboratory. The importance of tissue culture lies principally in its capacity to secure rapid propagation of disease-free clones and of embryo culture in the production of interspecific hybrids and overcoming the incompatibility barrier. In the in vivo condition, the presence of plasmodesma and other living factors, which cannot necessarily be reproduced exactly in vitro, help in the process of transport and uptake of food between cell and cell; therefore, under cultural conditions, the access of food at intracellular sites is a problem, which needs constant attention. There are essentially two methods for protoplast isolation based on the principle whether the enzymes are to be put simultaneously or sequentially. For chromosome analysis, it is desirable to centrifuge the protoplasts and take the sediment with nuclei.

Archana Sharma

Papers

Chromosomal Behaviour in Cultured Cells of Dioscorea floribunda

Transferrin patterns in the Eastern India in normal and malignant cases.

Potentiation by caffeine of the frequencies of chromosomal aberrations induced by chronic exposure to fenfluramine in mice.

Estimation of cadmium in biological tissues by atomic absorption spectrophotometer--a new reagent.

Study of plant chromosomes from tissue culture