The Proteomic Response of the Carcinus maenas Y-organ Over the Course of the Molt Cycle

<p>Molting in arthropods is a complex process governed by regulatory mechanisms that have evolved and adapted over millennia to allow these animals to grow, despite being confined by a hardened exoskeleton. We isolated the molt-regulating Y-organs (YO) from the common shore crab <em>Carcinus maenas</em> at molt stages B, C_1-3, C₄, and D₀ to assess how changes in protein abundances might underline the unique physiology of each of these stages. We found that changes in protein abundance were most notable in the postmolt stages (B and C_1-3), where an increase in energy metabolism and the reactive oxygen species stress (ROS) response proteins was observed. An increase in triosephosphate isomerase and transketolase suggest that the postmolt YO is participating in triglycerides storage and is also actively recycling excess ribose sugars manufactured during the YO’s previously activated state. We also propose as mechanism through which ROS-induced release of cyclophilin A may contribute to YO atrophy during postmolt through the remodeling of structural proteins such as collagen. We support the standing observation of YO atrophy during postmolt by drawing attention to hemolymph protein abundances, especially those of cryptocyanin isoforms, which dropped precipitously in intermolt (C₄) and remained at low abundances into early premolt (D₀). Finally, though our evidence is preliminary, we propose that future investigations into the YO proteome address the significance of the protein glutamate dehydrogenase. Glutamate dehydrogenase, a key enzyme involved in the formation of glutamate, represents a potential nutrient-sensing checkpoint that might be involved in YO activation. Historically, most attention has gone to the acute molt stages, where signaling mechanisms involved in the activation of the YO have been the focus. Here, we present data suggesting that other regulatory mechanism may be governing the atrophy the postmolt YO. A better understanding of crustacean physiology has the potential to benefit ecosystems and economies worldwide.</p>

Name thesis:degree_name

MS in Biological Sciences

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2015

Author dc:creator

• Hamer, Mark S

Contributors dc:contributor

• Lars Tomanek

• Carcinus maenas
• crustacean growth
• Y-organ
• Proteomics
• Molting
• ROS
• Integrative Biology

Identifier

10.15368/theses.2015.6

OAI identifier oai:identifier

oai:digitalcommons.calpoly.edu:theses-2456