Neuroendocrine regulation of corpus allatum activity in Manduca sexta: The endocrine basis for starvation-induced supernumerary larval moult

Bhaskaran, G.; Jones, Grace

doi:10.1016/0022-1910(80)90113-4

Journal of Insect Physiology

1980

DOI: 10.1016/0022-1910(80)90113-4

|View full text |Cite

Neuroendocrine regulation of corpus allatum activity in Manduca sexta: The endocrine basis for starvation-induced supernumerary larval moult

G. Bhaskaran

Grace Jones

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

1980

2003

Publication Types

Select...

Article7

Relationship

Self Cite2

Independent5

Authors

Journals

Cited by 55 publications

(33 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In M. sexfa, starvation causes the induction of supernumerary molts and this effect can be prevented by cautery of the M-NSC (Bhaskaran and Jones, 1980) implicating the role of the M-NSC cells in activating the larval CA. In Galleria mellonellu, implantation of a fourth-instar larval brain into a fifth-instar larva results in a supernumerary molt in intact but not in allotectomized larvae (Granger and Sehnal, 1974).…”

mentioning

confidence: 99%

Molecular Characterization and Expression Analysis of Manduca sexta Allatotropin

Taylor¹,

Bhatt²,

Horodyski³

1996

European Journal of Biochemistry

View full text Add to dashboard Cite

Juvenile hormones (JH) are a class of regulatory sesquiterpenoids that control metamorphosis in immature insects and reproduction in adult insects. The regulation of JH synthesis by the corpora allata (CA), a pair of endocrine glands with nervous connections to the brain, is achieved by a complex interplay of stimulatory and inhibitory factors mediated in part by the brain. The neuropeptide, allatotropin (Mas AT), was recently isolated and sequenced from the brain of the tobacco hornworm Manduca sexta. Mas AT is a 13-residue amidated peptide that activates JH synthesis in adult, but not larval, lepidopteran CA. A 23-nucleotide degenerate oligonucleotide was designed based on the peptide sequence and was used to isolate the Mas AT genomic clone. The Mas AT gene is expressed as three mRNAs which differ from one another by alternative splicing. These mRNAs are predicted to encode three distinct prohormones, each containing Mas AT. A restriction fragment from the genomic clone was then used to isolate the cDNA clone. In situ hybridization and immunohistochemistry studies show that Mas AT is expressed in both the central and enteric nervous systems. Cells expressing Mas AT were identified in the brain, frontal ganglion and terminal ganglion.

show abstract

mentioning

confidence: 99%

Molecular Characterization and Expression Analysis of Manduca sexta Allatotropin

Taylor¹,

Bhatt²,

Horodyski³

1996

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…The nature of the succeeding molt shows whether or not the implanted CA were comparable to day 0 CA in activity. This assay actually measures the response of CA to allatotropin secreted by the host brain (9,15). Hence, the failure of implanted CA to induce supernumerary molting in the assay animals would indicate that the CA were unable to increase JH production to a level that is required for promoting a larval molt.…”

mentioning

confidence: 99%

“…Evidence suggests that the neurosecretory centers in the brain (and perhaps in other ganglia) influence the activity of CA through hormones either transported directly to the CA by axons (allatal nerves) or released into the blood. These hormones may be stimulatory (8,9) or inhibitory (10,11). Direct neural control has been demonstrated in some insects and is mainly inhibitory in nature (12,13).…”

mentioning

confidence: 99%

“…Allatectomy, nerve severance, cautery of neurosecretory cells, and implantation techniques have been described (9).…”

mentioning

confidence: 99%

“…Larvae were reared on an artificial diet at 270C and 60% relative humidity on a 16:8 light:dark 24-hr cycle (lights-off at midnight). Larvae of identical age were collected and staged as described (9,15). Under our laboratory conditions, a majority of fourth-instar larvae show head-capsule slippage (a sign of the impending larval molt) on day 3 and ecdyse to fifth-instar larvae on day 4.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Neuroendocrine regulation of corpus allatum activity in Manduca sexta : Sequential neurohormonal and nervous inhibition in the last-instar larva

Bhaskaran

Jones

1980

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

The inactivation of corpora allata (CA) in the last-instar larva of the tobacco hornworm Manduca sexta was studied using in vivo assay methods that test the capacity of the glands to induce an extra larval molt. Results indicate that the CA are inactivated by a two-step process. In the first step, a neurohormonal inhibition occurs by day 1 after ecdysis, resulting in a decrease in the ability of the glands to respond to allatotropin. The inhibitory hormone appears to be secreted by the medial neurosecretory cells in the brain and remains in the hemolymph only for a short period of <2 days. The second step of inactivation occurs by day 3; it is neurally mediated and essentially terminates juvenile hormone secretion. Neither the neurohormonal nor the neural inhibition is reversible under the conditions used in our larval assays. The timing of the two stages of inhibition coincides with the two periods of reduction in hemolymph juvenile hormone titer; this suggests that the regulation of corpus allatum activity plays an important role in reducing the juvenile hormone titer during the last larval instar-a prerequisite for the transformation of the larva into the pupa.Metamorphosis in insects is controlled by the level of juvenile hormone (JH) in the hemolymph at the time of initiation of a molt by ecdysone. Thus in holometabolous insects, a high JH titer leads to a larval molt and a low titer leads to a pupal molt; in the absence of JH the insect molts into an adult (1-3). Although it has been known for a long time that the corpora allata (CA) secrete JH, very little is known about the mechanism of regulation of CA activity in the immature stages. A number of earlier studies have indicated that the CA become inactive in the final larval instar (4-7) and that this inactivation is not autonomous but is regulated by the brain in response to changes in external and internal milieu (1, 2). Evidence suggests that the neurosecretory centers in the brain (and perhaps in other ganglia) influence the activity of CA through hormones either transported directly to the CA by axons (allatal nerves) or released into the blood. These hormones may be stimulatory (8, 9) or inhibitory (10,11). Direct neural control has been demonstrated in some insects and is mainly inhibitory in nature (12, 13). Thus, the mechanism of regulation of CA appears to differ between various species of insects.It has been postulated for the tobacco hornworm Manduca sexta L. that when last-instar larvae attain a critical weight, an unidentified abdominal factor triggers the brain to stop allatotropin secretion and instead to release through the allatal nerves a CA-inhibiting factor, allatohibin (14). Shortly thereafter the brain secretes prothoracicotropic hormone, which stimulates the prothoracic glands to secrete ecdysone. Thus, a molt is initiated in the virtual absence of JH and larvae undergo pupation.Because experimental evidence for the preceding hypothesis is fragmentary, the purpose of this study was to determine whether the change in CA ac...

show abstract

Expression of theManduca sexta allatotropin gene in cells of the central and enteric nervous systems

Bhatt

Horodyski

1999

J. Comp. Neurol.

View full text Add to dashboard Cite

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Neuroendocrine regulation of corpus allatum activity in Manduca sexta: The endocrine basis for starvation-induced supernumerary larval moult

Cited by 55 publications

References 21 publications

Molecular Characterization and Expression Analysis of Manduca sexta Allatotropin

Molecular Characterization and Expression Analysis of Manduca sexta Allatotropin

Neuroendocrine regulation of corpus allatum activity in Manduca sexta : Sequential neurohormonal and nervous inhibition in the last-instar larva

Expression of theManduca sexta allatotropin gene in cells of the central and enteric nervous systems

Contact Info

Product

Resources

About