DNA isolation from dry and fresh samples of polysaccharide-rich plants

DNA extraction is difficult in a variety of plants because of the presence of metabolites that interfere with DNA isolation procedures and downstream applications such as DNA restriction, amplification, and cloning. The chemotypic heterogeneity among species may not permit optimal DNA yield with a single protocol; thus, even closely related species may require different isolating protocols. Here we describe a modified procedure based on the hexadecyltrimethylammonium bromide (CTAB) method to isolate DNA from tissues containing high levels of polysaccharides. The procedure is applicable to both dry and fresh tissues and was tested on chickpea seeds, soybean, and wheat leaves. This method solved the problems of DNA degradation, contamination, and low yield due to binding and/or coprecipitation with starches and polysaccharides. The isolated DNA proved amenable to PCR amplification and restriction digestion.     

Studies on the host-parasite interaction and role of esterases during biting of the Indian cattle leech, Poecilobdella granulosa.

Histochemical localization of acetylcholinesterase and butyrylcholinesterase in the salivary glands has unfolded the significant fact that salivary glands are of two types, one being enzymatically negative and the other showing positive activity. Activity of these enzymes has been linked with the operation of glandular dynamics, particularly concerning the synthetic and secretory processes. The enzymes have been seen localized in the core of jaw. Contrary to it they are absent in the papillary and interpapillary zones of the jaw. Absence of esterases in the papillary and interpapillary ductules has been correlated with its possible non-involvement in the synthesis of vasodilating and anticoagulating materials. The experiments on effect of biting on host tissue give a faint indication of vascular dilation due to bite. Likewise, experiments on enzymatic state of a salivary gland after leech-bite reveal that the diminution of the reactive coverage area in the salivary glands reaches its maximum in the case of ATPase, indicating thereby its more involvement in salivary functions than those of esterases and acid phosphatase.     

Some allied dematiaceae-dictyosporae from India

Summary In this paperTetracoccosporium andDictyoarthrinium are treated.T. cupulatum, D. lilliputeum andD. microsporum are described new, apart from the typeD. sacchari. A key to the known species ofDictyoarthrinium is proposed.Tetracoccosporium, is a maiden report for India.     

Histoenzymatic pattern of adenosine triphosphatase in the different components of the alimentary canal in some common earthworms and its possible physiological significance

The present contribution incorporates an account of the distribution of adenosine triphosphatase and its functional role in various regions of the alimentary canal of Pheretima posthuma and Barogaster annandalei. The main areas, showing adenosine triphosphatase activity in P. posthuma are sub-epithelial blood vessels in pharynx, peri-oesophageal blood vessels in oesophagus, columnar epithelial cells of gizzard and in the areas outside the typhlosole and around the supra-intestinal excretory ducts. In B. annandalei the epithelial cells of gizzard show significant enzymatic localization. In addition to this, enzymatic activity has also been found in the deeply embedded blood vessels of buccal region, peri-oesophageal vasculature, sub-epithelial vasculature of typhlosole and intestine, and in the adjoining chloragogen cells. Physiological significance of the enzymatic pattern has been discussed.     

The Unusual Transmembrane Partition of the Hexameric Channel of the Hepatitis C Virus

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