The word pronucleuses is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 22
Highest Scoring Words With Friends™ Play In The Letters pronucleuses
:
Seven Letter Word Alert: (68 words)
censers, censors, censure, cloners, closers, closeup, closure, consuls, corpses, coulees, counsel, coupler, couples, courses, creoles, cresols, cupless, cuprene, cupules, elopers, enclose, encores, ensouls, ensures, espouse, leprous, lupuses, necrose, nucleus, openers, percuss, persons, peruses, poseurs, pouncer, pounces, process, pulsers, punless, pursues, reclone, reclose, recluse, recoups, recuses, reopens, reposes, repulse, rescope, rescues, resoles, screens, scruple, secerns, secures, slopers, sources, spleens, sporule, spruces, sucrose, surplus, unclose, uncross, uncurls, uncurse, unreels, uprouse