Figure 1.
Uptake of fluorescent dyes by neurons of Heterodera schachtii.
After 16 h exposure to 1 mM of A) FITC B) Alexa Fluor 488 and C) bisbenzimide fluorescence was observed in J2 of H. schachtii using epillumination excitation under standard conditions. Images A) and B) are lateral views and C) a dorsal view. Key: c, cephalic framework; (showing autofluoresence); a, amphidial pouch; d, tract of amphidial dendrites; n, nerve ring; g, region of the lateral and ventral ganglia. Scale bars are 10 µm.
Figure 2.
Schematic representation of the anterior region of a cyst nematode.
The representation highlights the amphidial structures and neurons and omits oesophageal glands for clarity.
Figure 3.
Neuronal uptake of Alexa Fluor 488-labelled nAChRbp by Heterodera schachtii.
A) After 16 hours incubation in 183 µM peptide-dye conjugate the peptide was detected in J2 of H. schachtii by epifluorescence as in Figure 1. B) After a similar incubation in labelled peptide the region of neuronal cell bodies posterior to the nerve ring was observed using confocal microscopy. C) Epifluorescent detection of the labelled peptide 48 h after removal of the H. schachtii from the peptide solution. All images are lateral views of the nematodes. Key: c, cephalic framework; s, stomatostylet (both showing autofluorescence); a, amphidial pouch; d, tract of amphidial dendrites; n, nerve ring; g, region of the lateral and ventral ganglia. The scale bar is 10 µm and the dorsal side is that nearer to the scale bar.
Figure 4.
Neuronal uptake of Alexa Fluor 488-labelled nAChRbp by a hermaphrodite of Caenorhabditis elegans.
After 18 h incubation in 300 µM peptide-dye conjugate the peptide was detected by epifluoresence as in Figure 1. A) posterior region of the pharynx and B) detail of boxed area showing fluorescence in the region of the lateral ganglia where the dye-filling neuronal cell bodies of this nematode occur. In contrast to the tylenchids this nematode ingests the fluorescent peptide causing intense fluorescence in the lumen of the pharynx. The scale bar is 15 µm; nematode anterior uppermost.
Figure 5.
Simultaneous uptake of Alexa Fluor 488-labelled nAChRbp and bisbenzimide by a J2 of Heterodera schachtii.
J2 of H. schachtii were incubated for 16 h in 183 µM nAChRbp labelled with Alexa Fluor 488 together with 1 mM bisbenzimide. The fluorophores were visualised by different excitation and emission wavelengths. Images correspond to a region 5–30 µm posterior to the nerve ring. A) Green fluorescence of the labelled peptide. C) Blue fluorescence of bisbenzimide. B) Combined image of A) and C). Key: p, process of a neuron; nu, nucleus. The scale bar is 5 µm and the images are left lateral views with the anterior uppermost.
Figure 6.
Neuronal uptake of Alexa Fluor 488-labelled nAChRbp by J2s of Globodera pallida.
J2 of G. pallida were incubated in 281 µM nAChRbp labelled with Alexa Fluor 488 for varying periods of 1–16 h and the labelled peptide was then visualised by epifluorescence. Images with one amphidial pouch visualised are lateral views and those with two amphidial pouches visualised are dorsal or ventral views. The scale bar of 10 µm applies to all images.
Figure 7.
Neuronal uptake of four different concentrations of labelled nAChRbp by J2s of Globodera pallida.
J2 of G. pallida were incubated for 16 h in 4 µM, 10 µM, 40 µM or 281 µM nAChRbp labelled with Alexa Fluor 488. The peptide was visualised by epifluorescence. The scale bar of 10 µm applies to all images.
Table 1.
Effect of nAChRbp on the ability J2 Globodera pallida to respond chemotactically to root exudate.