标题：VARIATION OF ESTERASE ISOZYME BANDING PATTERN IN PENAEUS MONODON WITH REFERENCE TO TISSUE SPECIFICITY, MALATHION TOXICITY AND ALLELE FREQUENCY DISTRIBUTION
摘要：The electrophoretic banding pattern of esterase isozymes were examined in five different tissues of black tiger shrimp (Penaeus monodon) after staining with and naphthyl acetates where altogether five esterase bands (Est-1, Est-2, Est-3, Est-4 and Est-5) were observed. Single esterase band (Est-1) was observed in the dorsal (anterior) and tail (base of telson) muscle while two, four and five bands were found in ventral muscle (Est-1 and Est-4), nerve cord (Es-1, Est-2, Est-3 and Est-4) and eye (Es-1, Est-2, Est-3, Est-4 and Est-5) in order. When the nerve and eye tissue were treated with different doses of malathion, fluctuation in esterase activity in terms of intensity variation as well as switch on or off of certain allele was observed. Allele frequency distribution was counted from eye and nerve tissue of sampled population (n=50) where variation in the number of bands was observed. Most of the sampled eyes contained three or four esterase bands (40% and 46% respectively) while nerve tissues showed two or three bands (48% and 36% respectively). Each locus (band) was found to be polymorphic in nature. Polymorphism of Est-1 from both tissues was tested for Hardy-Weinberg Equilibrium (HWE) and found them within HWE.
