Meeting Abstract
The Northern spot prawn (Pandalus platyceros) is a commercially important shrimp species in Southeast Alaska that has an interesting life history which presents challenges for its effective management. P. platyceros is protandric and demonstrates sequential hermaphroditism. As this shrimp matures, it transforms from a small functional male to a much larger functional female. During its life history, the male shrimp undergoes multiple molts as a male and at least one transitional prior to becoming a functional female. Our study objectives were to characterize the vitellogenin (Vg) gene from P. platyceros and to study its expression in male, transitional, and female shrimp tissues. Shrimp of each life history were collected during the Alaska Department of Fish and Game shrimp survey and maintained at the University of Alaska marine laboratory in flow-through sea water. Life history stages were confirmed visually from the distinct morphology of the second pleopod. The (PpVg gene was identified from the hepatopancreas using primers designed from the congeneric species, P. hypsinotus. The gene was partially sequenced using RACE PCR and cloning techniques. Spatial expression of PpVg was determined from tissues (hepatopancreas, ovary, muscle, and heart) from mature female P. platyceros. Expression of the gene was determined from total RNA extracted from the hepatopancreas and gonad of males and transitional shrimp. We found Pp Vg expression in the hepatopancreas and the gonad of the transitional and the female life history stage but not in males. Future studies will use qtPCR to measure the temporal expression or PpVg in transitional shrimp to better understand physiological changes associated with sexual differentiation.
