Journal: BMC Biology

Article Title: Morphological and Transcriptomic Analysis of a Beetle Chemosensory System Reveals a Gnathal Olfactory Center

doi: 10.1186/s12915-016-0304-z

Figure Lengend Snippet: Sensilla types and distribution on Tribolium castaneum antennae I. a Chemosensory sensilla are restricted to the distal three segments (9–11) of the T. castaneum antenna, which is composed of scape ( S ), pedicel ( P ), and flagellum, and the last labial palp ( LP ) and maxillary palp ( MP ) segment. CLSM-stack voltex projection of a transgenic beetle head (ventral view, green : partial Orco - Gal4/UAS -tGFP; yellowish eye, brownish cuticle: autofluorescence). b – b '' SEM images of the club segments with close-up of segments 9 ( b ') and 11 ( b ''). Single sensilla: CLSM maximum intensity projection overlays ( c – h ) of antibody-enhanced EF1 - B -DsRed reporter signal ( magenta , c '– h ') and cuticle autofluorescence ( green , c ''– h ''). c '''– h ''' SEM analysis. Mechanoreceptive sensilla: SCam are small, smooth, and dome-shaped sensilla restricted to segment 11 (Additional file : Figure S3a); SCha – previously described as spines – are longitudinally corrugated, connected to a neuron at the socket ( c '; blue ), jointed ( c '''; arrow ), and solid ( c ''''; arrowhead ). d – d '''' SpaB – in T. brevicornis called sensilla squamiformium – resemble modified (slightly thicker tip) SCha restricted to segment 11 (Additional file : Figure S3b). e – e '''' mSTri (structurally similar to SCha but smaller more hair-like appearance) have previously been described in other species [ , ]. CLSM analysis showed joint-like structures at the base ( c – e , c ''– e '', open squares ) of the mechanoreceptive sensilla and SEM revealed a small gap at their base ( c ''' –e ''', arrow ). Chemoreceptive sensilla: f – f ''' cSTri are hair-like structures restricted to segment 11 (Additional file : Figure S3d) with a rounded tip and a smooth transition of the base; g – g '''' SBas are smooth-surfaced pegs with rounded tips and smooth transitions at the base ( g '''; arrow ). h – h ''' SCoe are short and corrugated, and their transition into the antennal cuticle shows a typical elevation ( b '', h '''). All chemoreceptive sensilla ( f , g , f '– h ') house dendritic branches of CSNs labeled by DsRed. The close-up in c ' shows a non-CSN fiber entering only the base of a SCha labeled with phalloidin ( blue ). Chemoreceptive sensilla show a smooth transition into the antennal cuticle ( f '''– h ''', arrow ). Whereas all mechanoreceptive sensilla are solid cuticular structures (fractured in c ''''– e ''''), chemoreceptive SBas appear hollow (fractured in g ''''). CLSM confocal laser-scanning microscopy, CSN chemosensory neuron, cSTri chemosensilla trichoidea, LP labial palp, MP maxillary palp, mSTri mechanosensilla trichoidea, P pedicel, S scape, SBas sensilla basiconica, SCam sensilla campaniformes, SCha sensilla chaetica, SCoe sensilla coeloconica, SEM scanning electron microscopy, SpaB spaculate bristle

Article Snippet: For mechanoreceptive mSTri , we identified about 37 on the apical side of segment 11 (Fig. '') and four in lateral corners of segments 9 and 10 ( f , f ', g , g ', and Additional file : Figure S3c, h). h Voltex projection based on a CLSM image stack of the tenth segment from the EF1 - B -DsRed line displaying CSNs ( orange ) and autofluorescence of the cuticle ( green ).

Techniques: Transgenic Assay, Modification, Labeling, Confocal Laser Scanning Microscopy, Electron Microscopy

Journal: BMC Biology

Article Title: Morphological and Transcriptomic Analysis of a Beetle Chemosensory System Reveals a Gnathal Olfactory Center

doi: 10.1186/s12915-016-0304-z

Figure Lengend Snippet: Sensilla types and distribution on Tribolium castaneum antennae II. a – e SEM images of SBas with one to five prongs. f , f ' SEM image of the tenth segment of the antenna with a close-up of the lateral corner ( f ') containing SCoe , SBas , and mSTri . g , g ' SEM image of the ninth segment with a close-up of the lateral corner ( g' ) showing SCoe and mSTri . Chemoreceptive SCoe were previously described as “minute spicule-like sensilla trichoidea” , are relatively rare (Additional file : Figure S3e), and located besides the lateral corners of segments 9 and 10 ( f ', g ') mostly at the apical side of segment 11 (Fig. ''). Chemoreceptive SBas are arranged in an axial ring at the distal margins of all three club segments ( f, g , Fig. ''). For mechanoreceptive mSTri , we identified about 37 on the apical side of segment 11 (Fig. '') and four in lateral corners of segments 9 and 10 ( f , f ', g , g ', and Additional file : Figure S3c, h). h Voltex projection based on a CLSM image stack of the tenth segment from the EF1 - B -DsRed line displaying CSNs ( orange ) and autofluorescence of the cuticle ( green ). The dendrites of the CSNs converge into the SBas (on average, six per prong), while the axons unite at the center of the segment and join the antennal nerve ( AN ). i – i '' Overlay of the signals of the DsRed reporter ( magenta , i ') and the Orco antibody ( green , i '') together with DAPI staining ( light blue ) in the EF1 - B -DsRed line, demonstrating a high level of colocalization between DsRed and Orco in segments 9 and 10, but not in 11, where some DsRed-immunoreactive CSNs are spared (compare with Additional file : Figure S1a). AN antennal nerve, CLSM confocal laser-scanning microscopy, CSN chemosensory neuron, mSTri mechanosensilla trichoidea, Orco odorant receptor co-receptor, SBas sensilla basiconica, SCoe sensilla coeloconica, Seg segment, SEM scanning electron microscopy

Article Snippet: For mechanoreceptive mSTri , we identified about 37 on the apical side of segment 11 (Fig. '') and four in lateral corners of segments 9 and 10 ( f , f ', g , g ', and Additional file : Figure S3c, h). h Voltex projection based on a CLSM image stack of the tenth segment from the EF1 - B -DsRed line displaying CSNs ( orange ) and autofluorescence of the cuticle ( green ).

Techniques: Staining, Confocal Laser Scanning Microscopy, Electron Microscopy

Journal: BMC Biology

Article Title: Morphological and Transcriptomic Analysis of a Beetle Chemosensory System Reveals a Gnathal Olfactory Center

doi: 10.1186/s12915-016-0304-z

Figure Lengend Snippet: Orco-immunoreactive sensory neurons in the maxillary palp. a Voltex projection of a CLSM-stack showing antibody enhanced reporter expression of the EF1 - B -DsRed line ( a ', orange ) and Orco-immunoreactive cells ( a '', green ) in a halved maxillary palp. b – b '' Single optical section of ( a ) showing partial colocalization of Orco immunoreactivity and the reporter expression of the EF1 - B -DsRed line ( magenta ). Dotted lines in ( b ) highlight reporter-expressing cells that are not Orco-immunoreactive. CLSM confocal laser-scanning microscopy, Orco odorant receptor co-receptor

Article Snippet: For mechanoreceptive mSTri , we identified about 37 on the apical side of segment 11 (Fig. '') and four in lateral corners of segments 9 and 10 ( f , f ', g , g ', and Additional file : Figure S3c, h). h Voltex projection based on a CLSM image stack of the tenth segment from the EF1 - B -DsRed line displaying CSNs ( orange ) and autofluorescence of the cuticle ( green ).

Techniques: Expressing, Confocal Laser Scanning Microscopy

Journal: BMC Biology

Article Title: Morphological and Transcriptomic Analysis of a Beetle Chemosensory System Reveals a Gnathal Olfactory Center

doi: 10.1186/s12915-016-0304-z

Figure Lengend Snippet: Antennal lobe tracts. Maximum intensity projection of a CLSM image stack after dye injection into the AL ( magenta ) revealed three antennal lobe tracts – the medial ( mALT ), mediolateral ( mlALT ), and the lateral antennal lobe tract ( lALT ) – as well as the calyx ( CA ) and the lateral horn ( LH ). In the CA , most fibers from the mALT form microglomeruli ( inset obtained from another preparation). The staining in the optical lobe is an artifact caused by diffusion of the dye during application. Phalloidin counterstaining in green. AL antennal lobe, ALT antennal lobe tracts, CA calyx, CLSM confocal laser-scanning microscopy, lALT lateral antennal lobe tract, LH lateral horn, mALT mediolateral lobe tract, mlALT mediolateral lobe tract

Article Snippet: For mechanoreceptive mSTri , we identified about 37 on the apical side of segment 11 (Fig. '') and four in lateral corners of segments 9 and 10 ( f , f ', g , g ', and Additional file : Figure S3c, h). h Voltex projection based on a CLSM image stack of the tenth segment from the EF1 - B -DsRed line displaying CSNs ( orange ) and autofluorescence of the cuticle ( green ).

Techniques: Injection, Staining, Diffusion-based Assay, Confocal Laser Scanning Microscopy