Content deleted Content added
Rockpocket (talk | contribs) added development diagram |
Rockpocket (talk | contribs) m →Xanthophores and erythrophores: wikify |
||
Line 6:
=== Xanthophores and erythrophores ===
Originally termed ''lipophores'' due to their fat-soluble content, chromatophores that contain large amounts of [[yellow]] [[pteridine]] pigments were renamed xanthophores and those with an excess of [[red]]/[[Orange (colour)|orange]] [[carotinoid]]s termed erythrophores. <ref name=Cytology>Bagnara JT. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=5337298&query_hl=1&itool=pubmed_docsum Cytology and cytophysiology of non-melanophore pigment cells.] ''Int Rev Cytol''. 1966; 20:173-205. </ref> Soon after, it was discovered that pterinosome and carotinoid [[Vesicle (biology)|vesicles]] are found within the same cell, and that the manifest colour depends on the ratio of red and yellow pigments. <ref name=Xiphophorus> Matsumoto J. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=5885426&query_hl=4&itool=pubmed_docsum Studies on fine structure and cytochemical properties of erythrophores in swordtail, ''Xiphophorus helleri''.] ''J Cell Biol''. 1965; 27:493-504. </ref> Thus the distinction between these chromatophore types is essentially arbitrary. The capacity to biosynthesise pteridines from [[guanosine triphosphate]] ''[[de novo]]'' is a feature common to most chromatophores, but xanthophores appear to have supplemental biochemical pathways that result in an excess accumulation of yellow pigment. In contrast, carotinoids are metabolised from the diet and transported to erythrophores. Thus normally green frogs reared on a diet of [[carotene]]-restricted [[Cricket (insect)|crickets]] display an erythrophore specific defect, resulting in a blue appearance.
[[Image:C Calyptratus female.jpg|thumb|left|260px|A [[veiled chameleon]], ''Chamaeleo calyptratus''. Structural green and blue colours are generated by overlaying chromatophore types to reflect filtered light. A process known as [[Rayleigh scattering]].]]
| |||