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1. Presence of [His7]- corazonin in the central nervous system of a newly isolated albino strain of Schistocerca gregaria (Orthoptera: Acrididae) - mass spectrometric and immunocytochemical evidence

Creator:
Rahman, Mazibur M., Baggerman, Geert, Schoofs, Liliane, de Loof, Arnold, and Breuer, Michael
Type:
article, model:article, and TEXT
Subject:
Albinism, locusts, Schistocerca gregaria, [His7]-corazonin, neuropeptides, mass spectrometry, and immunocytochemistry
Language:
English
Description:
An inbred strain of a newly isolated spontaneous albino mutant of Schistocerca gregaria (Forsk.) was examined for the presence of the neuropeptide [His7]-corazonin by immunocytochemical and mass spectrometric methods. It was concluded that this peptide is definitely present in a limited number of neurosecretory cells in the pars lateralis as well as in the corpora cardiaca (CC). Injection of either synthetic [His7]-corazonin or of extracts of CC of the normal coloured phenotype of S. gregaria failed to induce darkening of the cuticle, while albino Locusta migratoria, used as a positive control, turned dark. The conclusion is that the cause of albinism in the new S. gregaria albino is probably due to a defect in the receptor system for [His7]-corazonin or in the biosynthetic pathway of melanin.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Thin layer chromatographic analysis of pteridine-like pigments in the migratory locust, Locusta migratoria migratorioides (Orthoptera: Oedipodidae)

Creator:
Němec, Václav, Breuer, Michael, and de Loof, Arnold
Type:
article, model:article, and TEXT
Subject:
Pterines, phase-transition, juvenile hormone, precocene, cuticle, methoprene, neem, and insect endocrinology
Language:
English
Description:
Acidic methanolic extracts of haemolymph, cuticle and eyes of larvae and adults of the migratory locust, Locusta migratoria migratorioides (R. et L.), were subjected to thin layer chromatography. The Rf-values as well as the fluorescent colour of the spots under ultraviolet illumination at 350 nm, were compared to those of 12 pteridine standards. Most of the standards showed a major spot, as well as up to 3 additional minor spots, probably due to the presence of isomers and degradation products. The extract of the haemolymph of untreated larvae and adults yielded 6 different spots. Cuticle and eyes had their own specific pattern. Application of methoprene (analogue of juvenile hormone) induced solitary phase-like pigmentation of the cuticle and green-coloured haemolyph. The content of pterin, biopterin, leucopterin, isoxanthopterin, and probably also of lumazin, increased. The melanization of the cuticle nearly completely disappeared. Similar, but weak effects were observed in neem-oil treated locusts. Application of precocene caused a number of changes in the pigment pattern of all extracts. It also induced some melanization of the cuticle in particular in larvae. Many pigment spots were observed which did not correspond to any of the 12 standard pteridines. The classical concept about the pigment composition of locust haemolymph, namely that it is restricted to melanin, carotenes and biliverdin, needs modification.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public