Meeting Abstract
P2.96 Wednesday, Jan. 5 Long-term effects of eyestalk ablation and multiple limb autotomy on myostatin expression in skeletal muscle of Carcinus maenas. LACHOWIEZ, C. A.*; CHO, I.G.; MACLEA, K.S.; CHANG, E.S.; MYKLES, D.L.; colorado State U.; Colorado State U.; UC Davis Bodega Marine Lab; Colorado State U. culachow@rams.colostate.edu
Myostatin (Mstn) is a negative regulator of muscle growth in vertebrates. A Mstn-like protein expressed in crustacean muscle may suppress protein synthesis. In land crab (Gecarcinus lateralis), eyestalk ablation (ESA) and multiple limb autotomy (MLA) induce molting, and both treatments decrease Gl-Mstn in skeletal muscle that is correlated with a large increase in global protein synthesis. This study examined the effects of ESA and MLA on Mstn expression in the European green crab (C. maenas). Adults occur as two color morphs that differ in growth and reproduction. Green morphs molt more often than the red morphs, which are larger and put more energy into reproduction. Expression of Cm-Mstn and elongation factor 2 (Cm-EF2), a “housekeeping” gene, in the thoracic and claw muscles was quantified by real-time PCR (qPCR) in two separate experiments. In the first experiment, red morphs were divided into 4 treatment groups (intact control, ESA, MLA, and ESA + MLA) and muscles were harvested after 2 months. In the second experiment, green morphs were divided into 3 treatment groups (intact control, ESA, & MLA) and muscles were harvested after 3 months. Red morphs were resistant to ESA and MLA, as none of the animals entered premolt. ESA and MLA also no effect on green morphs, although some of the intact animals molted spontaneously during the experiment. In both morphs, there was little effect of any of the long-term treatments on Cm-Mstn and Cm-EF2 mRNA levels in both muscles. These data indicate that C. maenas, unlike G. lateralis, is refractory to molt induction by ESA or MLA, resulting in minimal effects on Mstn expression. Supported by an REU supplement to NSF grant IBN-0618203.
