Meeting Abstract

8-4  Thursday, Jan. 5 09:15 - 09:30  Sexual Differentiation during the Life History of a Protandric Shrimp LEVY, T*; MANOR, R; TAMONE, SL; AFLALO, ED; SAGI, A; Ben-Gurion University of the Negev, Beer-Sheva; Ben-Gurion University of the Negev, Beer-Sheva; University of Alaska Southeast, Juneau; Ben-Gurion University of the Negev, Beer-Sheva; Ben-Gurion University of the Negev, Beer-Sheva toml@post.bgu.ac.il http://lifeserv.bgu.ac.il/wb/sagia/pages/lab-members.php#Tom_Levy

Crustacea is an ancient arthropod group which exhibits diverse types of reproductive strategies. Crustacean species whose reproduction type is deviated from the common gonochoristic scheme, such as the Northern spot shrimp Pandalus platyceros, present a unique opportunity for studying the controlling mechanism(s) behind sexual differentiation. P. platyceros is a protandric hermaphrodite decapod crustacean, native to the North Pacific Ocean, in which the three life stages occur consecutively: at early stage of life each animal functions as a male, then it exhibits a transitional stage followed by its transformation into a functional female. Given that each P. platyceros transforms from a functional male (producing sperm) to a functional female (producing eggs), this shrimp provides a model to study the changing morphology of the gonads and the role of the prominent masculine androgenic gland (AG) and the masculine insulin-like androgenic gland hormone (IAG) during its interesting life-cycle. In this study, P. platyceros specimens of the three developmental stages: male, transitional and female, were collected from Alaska. The gonads and the AG were characterized histologically in each stage. Moreover, the IAG gene was sequenced and its spatial and temporal expression described during the life history of the shrimp. Our results shed light on changes in the reproductive system, as well as the control of the masculine endocrine system during the shift from maleness to femaleness in a protandric species in which sexual differentiation is not limited to early developmental stages but occurs also during adulthood.