P1.64 Wednesday, Jan. 4 Myostatin and limb regenerate growth in the blackback land crab, Gecarcinus lateralis MARSHALL, KL*; CHANG, ES; MYKLES, DL; Colorado State Univ.; UC Davis Bodega Marine Lab; Colorado State Univ. email@example.com
Decapod crustaceans can regenerate appendages lost to injury and predation. Autotomy of at least 5 walking legs stimulates a precocious molt, as animals must molt to restore a full complement of functional appendages. Regeneration of a claw or walking leg occurs in two stages. In intermolt animals, a small basal regenerate, or limb bud (LB), forms from the proliferation and differentiation of stem cells. Basal LBs remain small (R index 8-10) until premolt, during which LBs grow to an R index of 22-23. If a LB (R < 15) is autotomized, remaining LBs stop growing and premolt is delayed for 2-3 weeks until a secondary LB forms and grows to the size of the lost LB. In mammals, myostatin (Mstn) is a negative regulator of skeletal muscle growth and acts by suppressing protein synthesis. A Mstn-like factor may have a similar function in G. lateralis. In claw muscle, a decrease in Gl-Mstn mRNA is correlated with increased protein synthesis. We hypothesize that Mstn controls LB growth. Real-time polymerase chain reaction will be used to quantify Gl-Mstn expression in LBs. The hypothesis predicts that that Gl-Mstn levels in growing LBs would be lower than levels is limb buds displaying suspended growth. Preliminary results showed a low level of Gl-Mstn expression in growing limb buds. This is in agreement with the hypothesis. Future research will focus on comparing Gl-Mstn expression levels in growing limb buds to levels in limb buds that have ceased growing due to limb bud autotomy. Supported by NSF (IBN-0618203).