Vitellogenin (Vg) is the precursor of yolk protein,which functions as a nutritive resource that is important for embryonic growth and gonad development.In this study,the cDNA encoding the Vg gene from the oriental river prawn Macrobrachium nipponense was cloned using expressed sequence tag (EST) analysis and the rapid amplification of cDNA ends (RACE) approach.The transcript encoded 2536 amino acids with an estimated molecular mass of 286.810 kDa.