Yolk protein profiles of three prawn (Macrobrachium) species during reproductive cycle.

Ovarian yolk protein (vitellin) of adult freshwater prawns Macrobrachium malcolmsonii, M. rosenbergii and M. lamarreii was characterized, and relationship between the gonadosomatic index (GSI) and the appearance of specific polypeptides in their ovary during different stages (early-mature, mature and spent) of reproductive cycle was studied. Mature ovaries of all the three species showed increased GSI values, compared to the respective early-mature ovaries. Protein profiles at the three stages of ovarian maturation were analysed by SDS-PAGE. Polypeptides of low molecular mass (20 to 70 kDa) were prominent in the early-mature ovary, whereas in mature ovary, 89 and 100 kDa polypeptides were predominant. Immunodiffusion studies, using antiserum raised against purified vitellin from mature ovary of M. malcolmsonii indicated antigenic similarities of vitellins among the three species.