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Coat Color (coat + color)

Distribution by Scientific Domains

Life Sciences	85%

Selected Abstracts

Bioluminescent imaging of reporter gene expression in the lungs of wildtype and model mice following the administration of PEG-stabilized DNA nanoparticles

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 9 2010
Assem G. Ziady
Abstract DNA nanoparticles (DNPs) formed by compacting DNA with polyethyleneglycolylated poly- L -lysine are a nonviral vector shown to be safe and efficacious in animals and humans. To extend our capabilities of assessing the efficacy and duration of expression achieved by DNPs, we tested the utility of bioluminescent imaging (BLI) of transgene expression in wildtype and cystic fibrosis (CF) mouse models. We tested the effect of route of administration, mouse coat color, anesthesia, dose, and promoter sequence on the level and duration of expression. Furthermore, we investigated the correlation between imaging and direct analysis of luciferase expression in lung homogenates. We found that intratracheal instillation, and the use of deep and prolonged anesthesia with avertin produced significantly higher expression compared with intranasal administration, and the use of lighter anesthesia with isoflurane. Although similar expression was observed for both dark and light coat animals, imaging signal intensity was attenuated in mice with dark fur. Furthermore, good correlation between imaging and direct homogenate analysis was observed for single dose (r = 0.96), and dose response studies in wildtype (r = 0.82) and CF mice (r = 0.87). Finally, we used imaging to track gene expression over a 56-day time course. We found that the human ubiquitin B promoter gives stable transgene expression up to 49 days following nanoparticle administration, while expression with the cytomegalovirus promoter diminished after 2 days and returned to background levels by day 14. Taken together, our results demonstrate that BLI is an effective and useful modality for measuring gene expression conferred by DNPs in the lung. Microsc. Res. Tech. 73:918,928, 2010. © 2010 Wiley-Liss, Inc. [source]

9- cis Retinal Increased in Retina of RPE65 Knockout Mice with Decrease in Coat Pigmentation,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 6 2006
Jie Fan
The protein RPE65 is essential for the generation of the native chromophore, 11- cis retinal, of visual pigments. However, the Rpe65 knockout (Rpe65 -1- ) mouse shows a minimal visual response due to the presence of a pigment, isorhodopsin, formed with 9- cis retinal. Isorhodopsin accumulates linearly with prolonged dark-rearing of the animals. The majority of Rpe65 -/- mice have an agouti coat color. A tan coat color subset of Rpe65 -/- mice was found to have an enhanced visual response as measured by electroretinograms. The enhanced response was found to be due to increased levels of 9- cis retinal and isorhodopsin pigment levels. Animals of both coat colors reared in cyclic light have minimal levels of regenerated pigment and show photoreceptor degeneration. On dark-rearing, pigment accumulates and photoreceptor degeneration is decreased. In the tan Rpe65 -/- mice, the level of photoreceptor degeneration is less than in the agouti animals, which have an increased pigment and decreased free opsin level. Therefore, photoreceptor damage correlates with the amount of the apoprotein present, supporting findings that the activity from unregenerated opsin can lead to photoreceptor degeneration. [source]

The location of heart melanocytes is specified and the level of pigmentation in the heart may correlate with coat color

PIGMENT CELL & MELANOMA RESEARCH, Issue 4 2008
Ichiro Yajima
Summary Melanocytes are mainly found in the skin and more rarely in other parts of the body, including the heart. We analyzed the localization of heart melanocytes and their levels of pigmentation in a series of mutant mice presenting different numbers of melanocytes and pigmentation in the skin. We found that melanocytes were localized in the valves (mitral, tricuspid, and aortic) and septa (ventricular and atrial). Moreover, the numbers of melanocytes in the heart appears to reflect that of the skin. Mice having a high or low level of pigmented cells and/or melanin in valves and septa have similar lifespan. In this respect, melanocytes found in the valves and septa of the heart are probably not essential in a healthy and non-stressful environment. [source]

Variation of the melanocortin 1 receptor gene in the macaques

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 8 2008
Kazuhiro Nakayama
Abstract Melanocortin 1 receptor (MC1R), a G-coupled seven-transmembrane receptor protein, plays a key role in the regulation of melanin synthesis in mammals. Sequence variation of the MC1R gene (MC1R) has been associated with pigmentation phenotypes in humans and in several animal species. The macaques (genus Macaca) are known to show a marked inter-specific variation in coat color although the causative genetic variation remains unclear. We investigated nucleotide sequences of the MC1R in 67 individuals of 18 macaque species with different coat color phenotypes including black and agouti. Twenty-eight amino acid replacements were identified in the macaques, but none of these amino acid replacements could explain the black coat color of Macaca silenus and the Sulawesi macaque species. Our molecular evolutionary analysis has revealed that nonsynonymous substitution/synonymous substitution (dN/dS) ratio of the MC1R has not been uniform in the macaque groups and, moreover, their coat color and dN/dS ratio were not related. These results suggest that the MC1R is unlikely to be responsible for the coat color variation of the macaques and functions of MC1R other than pigmentation might be associated with the different selective pressures on the MC1R in macaques. Am. J. Primatol. 70:778,785, 2008. © 2008 Wiley-Liss, Inc. [source]

Phylogeny of lion tamarins (Leontopithecus spp) based on interphotoreceptor retinol binding protein intron sequences

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2001
Nicholas I. Mundy
Abstract The evolutionary relationships of the lion tamarins (Leontopithecus) were investigated using nuclear interphotoreceptor retinol binding protein (IRBP) intron sequences. Phylogenetic reconstructions strongly support the monophyly of the genus, and a sister relationship between the golden lion tamarin, Leontopithecus rosalia, and the black lion tamarin, L. chrysopygus, to the exclusion of the golden-headed lion tamarin, L. chrysomelas. The most parsimonious evolutionary reconstruction suggests that the ancestral lion tamarin and the common ancestor of L. rosalia and L. chrysopygus had predominantly black coats. This reconstruction is not consistent with a theory of orthogenetic evolution of coat color that was based on coat color evolution in marmosets and tamarins. An alternative reconstruction that is consistent with metachromism requires that ancestral lion tamarins had agouti hairs. Am. J. Primatol. 54:33,40, 2001. © 2001 Wiley-Liss, Inc. [source]