Four young researchers clamber from a boat onto a teetering raft, sending ripples across calm water that gleams like polished chrome in the October morning sun. The raft is the size of a king-sized bed and all of the students wear life jackets strapped over bulky wool sweaters or bright jackets. Katie Pocock and Tamara Russell maneuver\u00a0a winch over a hole in the middle of the raft. They throw their weight onto the crank and haul up the first of several cages that hang in the cerulean water. Kayla Mohns cuts the zip ties that were holding the cage closed, revealing the captives within: hundreds of shiny blue-black mussels, frilly blushing scallops, and gnarly Pacific oysters.<\/p>\n
While Pocock, Russell, and Mohns get busy selecting samples to take back to the lab, the fourth researcher, Caitlin Smith, is setting up an impromptu wet lab in the damp cabin of the boat moored alongside the raft. She sets out a box of syringes and a rack of test tubes, and picks up a mussel the size of a key fob. She\u2019s extracting hemocytes from the mussel, or as she says, \u201cpretty much mussel blood.\u201d She saws a notch in the mussel with a metal file, then uncaps a syringe and slides the needle into the gap, feeling for the hemocyte-rich adductor muscle. Then, her hands steady and careful as the boat gently rocks, she draws back the plunger, and the barrel fills with clear fluid, chock-full of RNA. Jackpot. She squirts the sample into a tube, caps it, and moves on to the next mussel.<\/p>\n
Smith wants RNA because this \u201cmessenger molecule\u201d is a snapshot of which genes are being expressed in the animal at that moment. \u201cDNA is just kinda like what codes for the organism, where the RNA is showing how the organism is reacting to its environment,\u201d Smith says. If the mussel is hot or hungry or horny, that message can be found floating in the needle\u2019s barrel.<\/p>\n