Identification and Structural Characterization of Interneurons of the Drosophila Brain by Monoclonal Antibodies of the Würzburg Hybridoma Library

Abstract

Several novel synaptic proteins have been identified by monoclonal antibodies (mAbs) of the Würzburg hybridoma library generated against homogenized Drosophila brains, e.g. cysteine string protein, synapse-associated protein of 47 kDa, and Bruchpilot. However, at present no routine technique exists to identify the antigens of mAbs of our library that label only a small number of cells in the brain. Yet these antibodies can be used to reproducibly label and thereby identify these cells by immunohistochemical staining. Here we describe the staining patterns in the Drosophila brain for ten mAbs of the Würzburg hybridoma library. Besides revealing the neuroanatomical structure and distribution of ten different sets of cells we compare the staining patterns with those of antibodies against known antigens and GFP expression patterns driven by selected Gal4 lines employing regulatory sequences of neuronal genes. We present examples where our antibodies apparently stain the same cells in different Gal4 lines suggesting that the corresponding regulatory sequences can be exploited by the split-Gal4 technique for transgene expression exclusively in these cells. The detection of Gal4 expression in cells labeled by mAbs may also help in the identification of the antigens recognized by the antibodies which then in addition to their value for neuroanatomy will represent important tools for the characterization of the antigens. Implications and future strategies for the identification of the antigens are discussed.

Synaptic organization of the Drosophila antennal lobe and its regulation by the Teneurins

“…The major structural components of the T-bar include Bruchpilot (Brp) and Rim-binding protein ( Wagh et al, 2006 ; Liu et al, 2011 ), with Brp encoding the ‘table-top’ of the T-bar and Rim-binding protein comprising the ‘pedestal’ ( Figure 1A ). Widely used monoclonal antibodies (nc82) against Brp ( Blanco Redondo et al, 2013 ) label synaptic neuropil and discrete puncta corresponding to active zones ( Wagh et al, 2006 ). However, these antibodies cannot distinguish synapses formed by a given class of neurons in complex CNS circuits.…”