1. Retina pigment epithelium cells and iris pigment cells are placed in an identical medium. 2. The differentiation into two different parts, as well as the pigment strains of the migrating pigment epithelium cells, is lost. The normally highly specialized cuticular structures disappear. The cells begin to move and assume a spindle shape, thus losing their original hexagonal shape. 3. The migra...

Many mutants that disrupt zebrafish embryonic pigment pattern have been isolated, and subsequent cloning of the mutated genes causing these phenotypes has contributed to our understanding of pigment cell development. However, few mutants have been identified that specifically affect development of the adult pigment pattern. Through a mutant screen for adult pigment pattern phenotypes, we identi...

* Arbeitsgruppe Sehphysiologie. Abteilung für Biologie. Ruhr-Universität. D-4630 Bochum, Bundesrepublik Deutschland ** D epartm ent of Physiology, Karolinska Institute, S-10401 Stockholm, and D epartm ent of Occupational Neuromedicine, National Board of Occupational Safety and H ealth, S-17184 Solna, Sweden Z. Naturforsch. 42c, 973—976 (1987); received October 13, 1986/March 18. 1987 Screening ...

The retinal pigment epithelium is an important part of the vertebrate eye, particularly in studying the causes and possible treatment of age-related macular degeneration. The retinal pigment epithelium is difficult to access in vivo due to its location at the back of the eye, making experimentation with age-related macular degeneration treatments problematic. An alternative to in vivo experimen...

The fitness of male guppies (Poecilia reticulata) highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the bla...

Staphylococcus aureus mutants lacking pigment, or expressing only low levels of pigment, were more sensitive to oleic acid than were the parent strain and mutants making more pigment than the parent. One class of mutants (colour index 5), although possessing significant levels of pigment, were nevertheless quite sensitive to oleic acid. This suggested that only certain carotenoids in the biosyn...

Genes which affect pigment elaboration may do so by autonomous action within the developing pigment cells or by way of tissue interactions leading to pigment cell differentiation. The site of action of the periodic albinism (ap) gene was investigated by substituting presumptive neural ectoderm of gastrulae of one genotype with uncommitted ectoderm of different genotype. Retinal pigment cells an...

Pigment-based chemotaxonomy is a widely utilized tool to determine the biomass of phytoplankton classes from pigment biomarkers. The CHEMTAX approach sensitive initial estimates pigment-to-chlorophyll (Chl a) ratios for required, even though these are modified by process. We present an alternative chemotaxonomic method that utilizes simulated annealing with steepest descent algorithm derive cla...

The role of pigment particle size, pigment volume concentration and dispersion in gloss loss of paint lms on weathered surfaces is unclear. Because reproducibile and cost e ective data is di cult to obtain, an approach based on computer simulation and modelling is a promising supplementary tool. We describe the simulation of a painted surface consisting of pigment particles of known size, pigme...

A bacterium capable of producing a deep blue pigment was isolated from the environment and identified as Pantoea agglomerans. The pigment production characteristics of the bacterium under various conditions were studied. The optimal agar plate ingredients for pigment production by the bacterium were first studied: the optimal ingredients were 5 g/liter glucose, 10 g/liter tryptic soy broth, and...