Cellular localization of bursicon using antisera against partial peptide sequences of this insect cuticle‐sclerotizing neurohormone

Abstract

Bursicon is the final neurohormone released at the end of the molting cycle. It triggers the sclerotization (tanning) of the insect cuticle. Until now, its existence has been verified only by bioassays. In an attempt to identify this important neurohormone, bursicon was purified from homogenates of 2,850 nerve cords of the cockroach Periplaneta americana by using high performance liquid chromatography technology and two-dimensional gel electrophoresis. Bursicon bioactivity was found in four distinct protein spots at approximately 30 kDa between pH 5.3 and 5.9. The protein of one of these spots at pH 5.7 was subsequently microsequenced, and five partial amino acid sequences were retrieved. Evidence is presented that two of these sequences are derived from bursicon. Antibodies raised against the two sequences labeled bursicon-containing neurons in the central nervous systems of P. americana. One of these antisera labeled bursicon-containing neurons in the crickets Teleogryllus commodus and Gryllus bimaculatus, and the moth Manduca sexta. A cluster of four bilaterally paired neurons in the brain of Drososphila melanogaster was also labeled. In addition, this antiserum detected three spots corresponding to bursicon in Western blots of two-dimensional gels. The 12-amino acid sequence detected by this antiserum, thus, seems to be conserved even among species that are distantly related.

Functional Dissection of a Neuronal Network Required for Cuticle Tanning and Wing Expansion inDrosophila

“…Recent molecular characterization of bursicon, and the availability of antibodies to its two subunits, has allowed identification of neurons that make bursicon in several insects and confirmed previous findings that some of these coexpress CCAP (Honegger et al, 2002), a peptide with cardioacceleratory activity (Tublitz and Evans, 1986;Nichols et al, 1999). In Drosophila larvae, bursicon expression is restricted to a small number of CCAP-expressing neurons in the ventral nerve cord (Honegger et al, 2002;Dewey et al, 2004;Luo et al, 2005). We have now mapped its distribution in late-stage pharate adults, a stage more relevant to its release into the hemolymph.…”

“…Bursicon also appears to be made in the brain and subesophageal ganglion (SEG) (Taghert and Truman, 1982a;Honegger et al, 2002), in which it may play a role in regulating posteclosion behavior (Baker and Truman, 2002). The cellular and molecular pathways underlying regulation of bursicon secretion at any of these sites is unknown.…”

Transcriptional expression of bursicon and novel bursicon‐regulated genes in the house fly Musca domestica

“…Using the blowfly bioassay, bursicon activity was subsequently reported in several other dipteran species including: Sarcophaga bullata (Cottrell, 1962b;Fraenkel andHsiao, 1962, 1965;Fogal and Fraenkel, Archives of Insect Biochemistry and Physiology June 2008 1969), Phormia regina (Fraenkel andHsiao, 1962, 1965), Lucilia spp (Cottrell, 1962b;Doy, 1972, 1973), and Drosophila melanogaster (Honegger et al, 2002;Dewey et al, 2004). Bursicon's presence has since been established in several other insect orders as well, including Orthoptera (Fraenkel and Hsiao, 1965;Honegger et al, 2002;Kostron et al, 1995Kostron et al, , 1996Kostron et al, , 1999Mills, 1965;Mills et al, 1965;Vincent, 1971Vincent, , 1972Srivastava and Hopkins, 1975), Hemiptera (Fraenkel and Hsiao, 1965), Coleoptera (Fraenkel and Hsiao, 1965;Kaltenhauser et al, 1995), and Lepidoptera (Fraenkel and Hsiao, 1965;Post, 1972;Post and De Jong, 1973;Reynolds, 1977;Reynolds et al, 1979;Taghert and Truman, 1982a,b;Truman, 1973).…”

Chip Is Required for Posteclosion Behavior inDrosophila

“…The neurohormone Bursicon is expressed in a subset of CCAP neurons and is responsible for initiating wing expansion and tanning and hardening of the cuticle after eclosion (Honegger et al, 2002;Dewey et al, 2004;Luan et al, 2006a). Bursicon is active as a heterodimer (Luo et al, 2005;Mendive et al, 2005), and both subunits are coexpressed in paired neurons in four abdominal segments (A1-A4) of third-instar larval/early pupal CNS.…”

“…This directed our interest to the well described posteclosion behavior of Drosophila, in which newly eclosed flies expand their wings and the cuticle becomes tanned and hard. The crustacean cardioactive peptide (CCAP)-expressing neurons of the ventral ganglion are known to regulate this behavior by secreting the neurohormone Bursicon (Honegger et al, 2002;Dewey et al, 2004;Luan et al, 2006a). Using multiple approaches to interfere with Chip function, we uncover a novel function of Chip in these neurons in the regulation of posteclosion behavior.…”