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1997 (1)
1994 (1)
1Author    Gerhard StarneckerRequires cookie*
 Title    Involvement of Cyclic Adenosine Monophosphate in the Regulation of Pupal Color Adaptation of the Butterfly, Inachis io  
 Abstract    In the butterfly Inachis io, a pupal melanization reducing factor (PMRF) which is located throughout the entire central nervous system controls the intensity of pigmentation of pupal cuticle depending on the background color of the pupation site. PMRF does not only reduce melanization but, in addition, enhances lutein incorporation in a dose-dependent manner to form pupae with yellow color on bright backgrounds. The present paper reports on the effects on pupal pigmentation caused by cyclic nucleo­ tides and phosphodiesterase (PDE) inhibitors which prevent degradation of cyclic nucleo­ tides. The injection of cAMP did not alter pupal coloration whereas its membrane-permeable analog dibutyryl-cAMP mimicked dose-dependently PMRF activity. Thus, pupae of reduced melanization and, in addition, enhanced yellow coloration were formed. Tliis indicates that an increased intracellular cAMP level is capable of mediating PMRF effect. Also, the injec­ tion of the PDE inhibitor isobutylmethylxanthine (IBM X) caused dose-dependently pupae of reduced melanization and enhanced lutein incorporation. Theophylline (another PDE inhibitor) was only slightly effective (23% inhibition of mela­ nization) at the highest dose compared to IBMX. The injection of cGMP and its analog dibutyryl-cGMP exhibited no melanization reducing effect. Extracts of abdominal ganglia (AG) which contained PM RF activity caused significantly brighter pupae when injected in combination with IBM X. However, this stimulation by IB M X became no longer effective at higher AG doses. Therefore, the present results are suggestive of an involvement of cAMP as a second messenger in the action of PMRF on pupal color adaptation. 
  Reference    Z. Naturforsch. 52c, 255—258 (1997); received November 28/December 17 1996 
  Published    1997 
  Keywords    Neurohormone, Cyclic Nucleotide, Color Adaptation, Polyphenism, Lepidoptera 
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 TEI-XML for    default:Reihe_C/52/ZNC-1997-52c-0255.pdf 
 Identifier    ZNC-1997-52c-0255 
 Volume    52 
2Author    G. S. Tarn Eck Er3, P.B K Och3, S. M. Atsum Otob, T. M. Itsui5, D. BiickmRequires cookie*
 Title    Localization of the Pupal Melanization Reducing Factor of Inachis io (L.) and Comparison with Melanization and Reddish Coloration Hormone  
 Abstract    In Inachis io, a pupal melanization reducing factor (PMRF) which controls morphological color adaptation is located in the brain, suboesophageal ganglion, thoracic ganglia, and all abdominal ganglia. Higher PM RF am ounts were extracted from abdominal ganglia than from the anterior ganglia. No PMRF activity could be found in the Corpora cardiaca-Corpora allata complex, in segmentally branching nerves of abdominal ganglia and their connectives. Extracts from brain-thoracic ganglia and abdominal ganglia complex of I. io contained also a factor with melanization and reddish coloration hormone (MRCH) activity in Pseudaletia separata and with pherom one biosynthesis activating neuropeptide (PBAN) activity in Bom-byx mori. However, injection of synthetic Pseudaletia pheromonotropin (Pss-PT) (= Pss-MRCH) into prepupae of I. io did not yield a melanization reducing effect. Therefore, PMRF and the PBAN/M RCH related neuropeptides seem to be different molecules. The PBAN-like factor from I. io is possibly related to the myotropins and pyrokinins of insects. 
  Reference    Z. Naturforsch. 49c, 476—482 (1994); received March 22 1994 
  Published    1994 
  Keywords    Neurohorm one, Color Adaptation, Pupal Melanization Reducing Factor, Inachis io 
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 TEI-XML for    default:Reihe_C/49/ZNC-1994-49c-0476.pdf 
 Identifier    ZNC-1994-49c-0476 
 Volume    49