The effect of chemical mutagen on haemolymph proteins of silkworm, <i>Bombyx mori</i> L. (Lepidoptera: Bombycidae) in F¹stage

Abstract

ABSTRACT:The chemical mutagen Diethylsulphate (DES) was treated to the mulberry silkworm, NB 4 D 2 breed at the age, fifth instar fifth day with different concentrations (8mM and 10mM) by injection and spray methods. The F 1 progeny was obtained from DES treated and control sets by selfing the moths. The quantitative analysis of haemolymph proteins revealed that 8mM injection set exhibit higher levels when compared with control and treated sets. The quantitative analysis also clearly indicate the variations in the number as well as intensity of the protein bands. @JASEMThe various aspects of protein metabolism including quantitative changes in haemolymph protein synthesis and metabolic activity of specific enzymes have attracted the interest of many insect biochemists. The available results from these biochemical studies indicate that protein metabolism is of considerable importance in characterizing different stages of insect development (Chen, 1966). Haemolymph proteins play an important role in insects for transport functions, as well as for their enzyme action. The synthesis and utilization of haemolymph proteins are controlled by genetic and hormonal factors (Hurliman and Chen, 1974). Although our knowledge of insect haemolymph proteins has greatly advanced during the last decade, still only the origin and function of few major proteins are known (Riddiford and Law 1983). There is general agreement that the fat body is a main source of haemolymph proteins (Dean et al., 1985 and Keeley, 1985) and others may come from haemocytes (Hughes and Price, 1976, Katagiri, 1977). Extensive studies of blood during development in Hyalophora cecropia and Samia Cynthia have been made using starch gel electrophoresis (Lauffer, 1960). It has been reported that blood proteins fluctuate during the development of Bombyx mori (Heller, 1927). The protein concentration was found to increase seven folds during the larval life of Bombyx mori (Bito, 1927 and Florkin, 1936). Recently number of researchers worked on silkworm protein variations, qualitatively and qualitatively occurs during mutagens treatment in general and chemical mutagens in particular during larval development (Mahesh, 1997; Bashamohideen and Ameen, 1998; Mahesha et al., 2000). However studies on chemical mutagens particularly effect on haemolymph is meagre. Hence, the present investigation was attempted to study the effect of chemical mutagen on haemolymph proteins of silkworm, Bombyx mori L. during larval fifth instar stage. MATERIALS AND METHODSThe silkworm race, NB 4 D 2 a bi-voltine breed and chemical mutagen DES (Diethyl sulphate) were used for the study. The eggs were procured from private agency and incubated at temperature 25±1 o C and 70-80% relative humidity in an incubator. Block box was carried out on 8 th day to achieve uniformity in hatching. The hatched larvae were reared in environmental chamber by providing with suitable quality mulberry leaves of Morus alba (variety V 1 ). The rearing was conducted by following the method discribed by Raja Ram...