full issue - Association of Biotechnology and Pharmacy

Current Trends in Biotechnology and PharmacyVol. 5 (2) 1157-1162 April 2011. ISSN 0973-8916 (Print), 2230-7303 (Online)1158silk worm pupa has also human nutritional values(13, 14). In this regard, Babu et al. (2) tried toenhance spinning rate in Mysore and NB 4D 2varieties of silk worm B. Mori. However,information on the effect of dietary glysupplementation on cocoon and pupa productionis seldom available. It is note worthy to mentionhere that glycine has the principal function as aprecursor to proteins. Synthesis of the centralC 2N subunit of all purines needs glycine asprecursor. D-aminolevulinic acid, the keyprecursor of porphyrins, is biosynthesized fromglycine and succinyl-CoA in higher eukaryotes.This amino acid is also acts as a building block tonumerous natural products. On the other hand,gly supplementation found to have organ specificroles in animals (15, 16). The organ specific roleof dietary gly is also found to be functionallyrelated with age or different life stages of theanimals. Kanafi et al. (17) summarized thatadditional dietary supplementation of vitamins andother biological nutrients influence the growth ofthe silk worms. They found that the dietarysupplementations of the above nutrients causebetter cocoon production in the silk worms as afunction of weather, larval condition, variety ofworms etc. Therefore, it was hypothesized thatdietary L-glycine may have specific role on thesilk gland growth and cocoon production in B.mori. To answer this hypothesis, this study wasintended to find out the role of dietary alpha glysupplementation on pupa and cocoon productionof the Nistari variety of the silk moth Bombyxmori. Additionally, the effect was also checkedwith larvae and silk gland growth of the worm.Materials and MethodsChemicals and feeds: Fresh mulberry leaveswere supplied by Department of Sericulture,Sikharchandi Mulberry Centre, Bhubaneswar,India. Double distilled (DW) water was used forall treatment purposes. Nistari variety of B. moriseeds were collected from Eri Seed Station,Khurda of Odisha, India. L- gly was procuredfrom Sigma chemicals, USA.Experimental protocol: The eggs weremaintained in the laboratory condition and allowedto hatch on sterilized plastic trays. The larvaewere then transferred carefully with fine brushonto the tender mulberry leaves kept on sterilizedbamboo baskets which were covered withmosquito net (1 mm pore size). Larvae weresupplied with tender leaves twice a day. Notreatment was imposed up to IV th instar. Thelarvae from the above stock were divided intonine groups with 25 healthy, equal weighed (0.2± 0.02 g) larvae in each. The treatment scheduleis given in Table 1.In each basket, three equal weighedfresh mulberry leaves (~12.5 g) were smearedwith 2.5 ml of 2% or 3% gly solution (dissolved inDW) in both dorsal and ventral surfaces of theleaves and dried under shade to remove moisterand then fed to the larvae. In control groups, 2.5Table 1. Treatment schedule for the experiment. Groupname symbol- percent (0, 1, 2) of gly (G) once(1) or twice (2) treatment from the 1 st (I) or 2 nd(II) day of V th instar.SN Group Glycine No. of Starting dayname (%) feeding/day of treatment1 0G1I 0 once 1 st2 0G2I 0 twice 1 st3 0G2II 0 twice 2 nd4 2G1I 2 once 1 st5 2G2I 2 twice 1 st6 2G1II 2 once 2 nd7 2G2II 2 twice 2 nd8 3G1I 3 once 1 st9 3G2I 3 twice 1 st10 3G1II 3 once 2 nd11 3G2II 3 twice 2 ndBiswaranjan Paital et al