CELL SURFACE ALTERATIONS BY TAXOL ASSOCIATED WITH ABNORMAL MORPHOGENESIS IN THE CHICK EMBRYO

The anticancer drug taxol brings about its biological effects by altering the stability of microtubules. We have examined the effects of taxol on early morphogenesis in chick embryos culturedin vitro. Taxol induced various abnormalities in the developing nervous system, heart and somites as well as general retardation of development. SEM studies revealed that taxol treatment leads to dramatic alterations in the embryonic cell surfaces. Time-course experiments demonstrated that the action of taxol is very rapid and becomes evident within a few minutes at the ultrastructural level. Taxol thus throws embryonic cell adhesion and motility out of balance. This appears to be the major cause of abnormal morphogenesis in taxol-treated embryos.     

Formation of successive cambia and stem anatomy of Sesuvium sesuvioides (Aizoaceae)

Mature stems of Sesuvium sesuvioides (Fenzl) Verdc. were found to be composed of successive rings of xylem alternating with phloem. Repeated periclinal divisions in the parenchyma outside the primary phloem gave rise to conjunctive tissue and the lateral meristem that differentiate into the vascular cambium on its inner side. After the formation of the vascular cambium, the lateral meristem external to it became indistinct as long as the cambium was functional. As the cambium ceased to divide, the lateral meristem again became apparent prior to the initiation of the next cambial ring. The cambium was exclusively composed of fusiform cambial cells with no rays. In the young saplings, the number of cambial cylinders in the axis varied from the apex to the base, indicating formation of several rings within the year. In each successive ring of the lateral meristem, small segments differentiated into the vascular cambium and gave rise to vessels, axial parenchyma, fibres and fibriform vessels towards the inside, and secondary phloem on the outer side. In the old stems, non‐functional phloem of the innermost rings was replaced by a new set of sieve tube elements formed by periclinal divisions in the cambial segments associated with the non‐functional phloem. In some places the cambial segments completely differentiate into derivatives leaving no cambial cells between the xylem and phloem. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 548–555.     

Computerized Optimization of the Relative Growth of Callus Cultures of Orange Fruit Tissues7

The induction and growth of callus cultures from different partsof the fruit of Coorg mandarin orange (Citrus reticulata, Blanco)and the hormonal combinations that can maximize the growth witha basal MS medium, have been explored using Response SurfaceMethodology. The relative growth, protein, peroxidase pattern,and GC fingerprinting of volatiles have been studied. Calluscultures from juice vesicles were found to be more similar totheir explant counterpart than those from albedo, for all propertiesstudied. Key words: Callus culture, Citrus, albedo, juice vesicles, response surface methodology, growth optimization     

Rethinking inheritance,yet again: inheritomes,contextomes and dynamic phenotypes

Journal of Genetics -     

Histochemical localization of glycogen and some representative enzymes of glycolytic cycle in the cheliped muscle of Scylla serrata (Forskal) (Brachyura: Decapoda)

Glycogen, phosphorylase, aldolase, a-glycerophosphate dehydrogenase, lactic dehydrogenase and glucose-6-phosphate dehydrogenase were localized histochemically in the cheliped muscle of Scylla serrata (Forskal) in normal, destalked, destalked receiving eyestalk extract injection and intact injected with eyestalk extract.