Figure 5
cam-1 is expressed andfunctions in the guidepost cellPVT. (A) PVP and PVQ neuronsin a L4 larva were visualized withhdIs26[Podr-2::CFP; Psra-6::dsRed2]that expresses CFP in PVPs anddsRed in PVQs. (B) Expression ofPcam-1::
cam-1::GFP in the sameworm. (C) Overlay of A and Bshows that
cam-1 is stronglyexpressed in PVQs and barely detectable in PVPs. (D) oyIs14[Psra-6::GFP]; otIs37[Punc-47(del)::GFP] in aL2 larva shows expression of GFPin PVT and PVQs. (E) Expression ofPcam-1::
cam-1::mCherry in the sameworm. (F) Overlay of D and E showsthat
cam-1 is expressed in PVT andPVQs. The images in A-C were acquired with a Zeiss LSM700inv laserscanning confocal microscope witha 203 objective. For images in D-F,we used an Axioscope 2, 403 objective. (G) Expression of lim-6int3::GFP in an embryo at the commastage. Expression is seen in AVL,DVB, RIS, and PVT (white arrow).(H) Differential interference contrast (DIC) image of the same embryo as in G. (I) lim-6int3_short::GFP is only expressed in PVT(white arrow). (J) DIC image ofthe same embryo as in I. Bar,100 um. Quantification of crossover defects of PVP (K) and PVQ (L)in nontransgenic
cam-1(
gm122)mutants compared to
cam-1 mutants carrying transgenes containing
cam-1 cDNA expressed fromeither its own promoter Pcam-1(multiple tissue), a hypodermisspecific promoter (Pelt-3), a promoter expressed in PVP (Podr-2), apromoter expressed in PVQ (Psra-6),or from a promoter containingelements that drive expressionspecifically in PVT (lim-6int_short).Green bars show crossover anteriorto the AVG neuron (head), blue barsbetween the AVG and PVT (middle),and red bars posterior to PVT. Thenumber of animals scored for eachgenotype is indicated above eachbar. At least two independent,nonintegrated transgenic lineswere generated for each construct. ** P , 0.01 (Fisher's exact test).