Many animals have a variety of pigment patterns, even within a species, and these patterns may be one of the driving forces of speciation. Recent molecular genetic studies on zebrafish have revealed that interaction among pigment cells plays a key role in pattern formation, but the mechanism of pattern formation is unclear. The zebrafish jaguar/obelix mutant has broader stripes than wild-type f...

Melanophores of the angelfish, Pterophyllum scalare, were studied in an attempt to demonstrate the existence of actin in these cells although microfilaments had previously not been found. By use of a variety of procedures, including immunofluorescence microscopy of intact and detergent-extracted cells, transmission electron microscopy, high voltage electron microscopy of whole-mount preparation...

T HAS been shown by grafting potential melanophores from one embryo to I another of a genetically different breed of fowl or species of bird that the color or color pattern produced in the host feather is invariably like that of the donor breed or species (RAWLES 1939; WILLIER and RAWLES 1940). In other words, the coloration or color pattern produced seems to depend upon the genotypic constitut...

The effects of purified red drum somatolactin on pigment movement in red drum scales were studied in vitro and in vivo. The integument became pale within 2 min following an intramuscular injection of somatolactin (1 nmol/g body weight) in fish held in a black-background aquarium, and gradually regained its black coloration during the subsequent 30 min. No melanosome aggregation was observed in ...

In two earlier papers21 23 it was reported that when melanoblasts of the Barred Plymouth Rock embryo were grafted into an embryo of a non-barred breed such as the N. H. Red, Black Minorca, and White Leghorn, two definite types of black and white barred patterns were produced in the host contour feathers. The black bands were wider and darker in one type than in the other. These pigmentation dif...

Hypotheses on general olfaction can be divided into two broad groups: those that predict the existence of olfactory-specific olfactory receptor proteins and those that do not. Recently, much attention has been paid to the discovery of an odorant-stimulated adenylate cyclase in purified olfactory cilia. This finding has, for the most part, been accepted as evidence that the former hypotheses are...

Microtubular organization in the melanophores of the angelfish, Pterophyllum scalare, has been studied by serial thin sectioning. The course of microtubules has been followed in sets of transverse serial sections taken from the centrosphere and a segment of a cell process, respectively. Microtubules arise from a prominent zone in the cell center, the central apparatus, which is composed of nume...