sentence: 12 This hypothesis is supported by the presence of intracellular Verm staining in the tracheal cells of certain SJ mutants including Atp α , lachesin / bulbous ( lac ) , sinuous ( sinu ) 12 and varicose ( vari ) .13 Such intracellular Verm staining , however , is not detectable in the wun mutant2 or in other SJ mutants including kune kune ( kune ) ,14 coracle ( cora ) 11 and nervana 2 ( nrv2 ) .15 In contrast , Serp is not reported to be intracellular in any mutant backgrounds including lac ,12 13 vari13 and kune.14These differing observations may reflect differences in the affinity of the antibodies used and on the precise embryonic stage examined , particularly if intracellularly accumulating Serp or Verm becomes a target for degradation .