Adipokinetic hormone promotes infection with entomopathogenic fungus Isaria fumosorosea in the cockroach Periplaneta americana

A hypertrehalosaemic neuropeptide from the corpora cardiaca of the blowfly Phormia terraenovae has been isolated by reversed-phase h.p.l.c., and its primary structure was determined by pulsed-liquid phase sequencing employing Edman chemistry after enzymically deblocking the N-terminal pyroglutamate residue. The C-terminus was also blocked, as indicated by the lack of digestion when the peptide was incubated with carboxypeptidase A. The octapeptide has the sequence pGlu-Leu-Thr-Phe-Ser-Pro-Asp-Trp-NH2 and is clearly defined as a novel member of the RPCH/AKH (red-pigment-concentrating hormone/adipokinetic hormone) family of peptides. It is the first charged member of this family to be found. The synthetic peptide causes an increase in the haemolymph carbohydrate concentration in a dose-dependent fashion in blowflies and therefore is named ‘Phormia terraenovae hypertrehalosaemic hormone’ (Pht-HrTH). In addition, receptors in the fat-body of the American cockroach (Periplaneta americana) recognize the peptide, resulting in carbohydrate elevation in the blood. However, fat-body receptors of the migratory locust (Locusta migratoria) do not recognize this charged molecule, and thus no lipid mobilization is observed in this species.

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Efficacy of an autodisseminator of an entomopathogenic fungus, Isaria fumosorosea, to suppress Asian citrus psyllid, Diaphorina citri, under greenhouse conditions

Biological Control ◽

10.1016/j.biocontrol.2015.04.014 ◽

2015 ◽

Vol 88 ◽

pp. 37-45 ◽

Cited By ~ 13

Author(s):

Joseph M. Patt ◽

Andrew Chow ◽

William G. Meikle ◽

Carlos Gracia ◽

Mark A. Jackson ◽

...

Keyword(s):

Entomopathogenic Fungus ◽

Asian Citrus Psyllid ◽

Diaphorina Citri ◽

Isaria Fumosorosea

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The effect of alkanes on the physiology and metabolism of the entomopathogenic fungus,Isaria fumosorosea

Biocontrol Science and Technology ◽

10.1080/09583157.2014.896876 ◽

2014 ◽

Vol 24 (8) ◽

pp. 847-859

Author(s):

Shaukat Ali ◽

Muhammad Hamid Bashir ◽

Shunxiang Ren ◽

Zhen Huang

Keyword(s):

Entomopathogenic Fungus ◽

Isaria Fumosorosea

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The detection of AKH/HrTH-like peptides inAscaridia galliandAscaris suumusing an insect hyperglycaemic bioassay

Parasitology ◽

10.1017/s0031182000076046 ◽

1994 ◽

Vol 108 (4) ◽

pp. 479-485 ◽

Cited By ~ 5

Author(s):

T. R. B. Davenport ◽

L. A. Eaves ◽

T. K. Hayes ◽

D. L. Lee ◽

R. E. Isaac

Keyword(s):

High Performance ◽

Periplaneta Americana ◽

Reversed Phase ◽

Parasitic Nematodes ◽

Ascaridia Galli ◽

Adipokinetic Hormone ◽

Blaberus Discoidalis ◽

Peptide Fraction ◽

Wet Weight ◽

Dose Dependent

SUMMARYEvidence for the presence of adipokinetic hormone/hypertrehalosaemic hormone (AKH/HrTH)-like peptides in the parasitic nematodesAscaridia galliandAscaris suumhas been obtained using insect bioassays which measure hyperglycaemic responses to peptides belonging to the AKH/HrTH family of insect hormones. A peptide fraction extracted from heads and tails ofAscaridia gallievoked a dose-dependent hyperglycaemic response when injected into the cockroach,Periplaneta americana. Maximal bioactivity was obtained with material that was equivalent to 38 mg (wet weight) of nematode. Bioactivity appeared to be highest in extracts from heads and tails of both male and female worms and could be fractionated into at least three peaks of hyperglycaemic activity by reversed-phase high-performance liquid chromatography. An extract from heads and tails ofA. suumalso evoked a hyperglycaemic response when injected into the cockroach,Blaberus discoidalis. The bioactivity was inactivated on incubation with pure endopeptidase 24.11, confirming the peptidic nature of the bioactive material. These results provide evidence for the existence of peptides related to the insect AKH/HrTH family of peptides in parasitic nematodes.

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