Genetics and Molecular Biology of Mouse Pigmentation

Jackson, Ian J.; Budd, Peter S.; Horn, Jacqueline M.; Johnson, Ray; Raymond, Sophie; Steel, Karen P.

doi:10.1111/j.1600-0749.1994.tb00024.x

Cited by 55 publications

(31 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the footpad, they are present at the epidermal-dermal border adjacent to the sweat glands. Tyrosinase catalyzes the hydroxylation of tyrosine to form DOPA, which is freely diffusible (Jackson et al, 1994;Spritz and Hearing, 1994;del Marmol and Beermann, 1996). DOPA levels are 100-fold higher in the hairy skin of pigmented pups than in albino pups at P15 and 10-fold higher in the plasma of pigmented wild-type animals at P7 and p15 than in albino animals (G. Eisenhofer, personal communication), suggesting that tyrosinase in melanocytes is an important source of DOPA in skin and in plasma.…”

Section: Discussionmentioning

confidence: 99%

“…Tyrosinase is expressed at high levels in melanocytes. To determine where tyrosinase is localized in footpad skin and to identify melanocytes, we took advantage of the fact that in addition to hydroxylating tyrosine, tyrosinase catalyzes the oxidation of DOPA to dopaquinone, which forms an insoluble black reaction product (Gurr, 1958;Jackson et al, 1994;Spritz and Hearing, 1994;del Marmol and Beermann, 1996). A tyrosinase reaction product was present in melanocytes localized at the intersection of the epidermis and dermis in footpads of pigmented mice (Fig.…”

Section: Catecholamines Are Required For the Development Of Secretorymentioning

confidence: 99%

See 1 more Smart Citation

Catecholamines Are Required for the Acquisition of Secretory Responsiveness by Sweat Glands

et al. 2000

View full text Add to dashboard Cite

The sympathetic innervation of sweat glands undergoes a developmental change in transmitter phenotype from catecholaminergic to cholinergic. Acetylcholine elicits sweating and is necessary for development and maintenance of secretory responsiveness, the ability of glands to produce sweat after nerve stimulation or agonist administration. To determine whether catecholamines play a role in the development or function of this system, we examined the onset of secretory responsiveness in two transgenic mouse lines, one albino and the other pigmented, that lack tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis. Although both lines lack TH, their catecholamine levels differ because tyrosinase in pigmented mice serves as an alternative source for catecholamine synthesis (Rios et al., 1999). At postnatal day 21 (P21), 28 glands on average are active in interdigital hind footpads of albino TH wild-type mice. In contrast, fewer than one gland is active in albino TH null mice, which lack catecholamines in gland innervation. Treatment of albino TH null mice with DOPA, a catecholamine precursor, from P11 to P21 increases the number of active glands to 14. Pigmented TH null mice, which have faint catecholamine fluorescence in the developing gland innervation, possess 12 active glands at P21, indicating that catecholamines made via tyrosinase, albeit reduced from wild-type levels, support development of responsiveness. Gland formation and the appearance of cholinergic markers occur normally in albino TH null mice, suggesting that catecholamines act directly on gland cells to trigger their final differentiation and to induce responsiveness. Thus, catecholamines, like acetylcholine, are essential for the development of secretory responsiveness.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Catecholamines Are Required For the Development Of Secretorymentioning

confidence: 99%

Catecholamines Are Required for the Acquisition of Secretory Responsiveness by Sweat Glands

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Le récepteur est la cible de deux protéines : l'a-MSH (a-melanocyte-stimulating hormone) et son antagoniste : la protéine Agouti codée au locus du même nom (aussi notée ASIP pour Agouti SIgnaling Protein). L'activation du récepteur par l'a-MSH onduit à la synthèse d'eumélanine tandis que l'inactivation par Agouti conduit à la synthèse de phéomélanine (Jackson et al 1994;Lu et al 1994). Des expériences d'hybridation in situ avec un anticorps reconnaissant la protéine Agouti ont mis en évidence son expression au niveau des mélanocytes des follicules pileux en suggérant une action paracrine (Lu et al 1994;Matsunaga et al 2000).…”

Section: Phénotype Non Pangaréunclassified

Identification de mutations à l’origine de différents phénotypes chez les ânes

Legrand¹,

Abitbol²

2016

bavf

View full text Add to dashboard Cite

Publiées depuis le début des années 1990, de nombreuses observations décrivent l'effet de mutations ponctuelles affectant les gènes responsables des différentes couleurs de la robe du cheval. Par contre, à ce jour, aucune étude n'a encore été consacrée à l'espèce asine, bien que celle-ci, en dépit de sa grande proximité phylogénique, présente des phénotypes très différents de ceux du cheval.

show abstract

“…The main candidate locus targeted was melanocortin 1-receptor (MC1R), a member of the G protein-coupled superfamily that acts as a pigment switch in the production of melanin. When activated by α-melanocyte-stimulating hormone, it signals the production of eumelanin (black/brown pigment) via cyclic adenosine monophosphate; in the absence or inhibition of stimulation, pheomelanin (red/yellow pigment) is synthesized (Jackson et al, 1994). In mice, dominant mutations that disable the binding of α-melanocyte-stimulating hormone lead to constitutive activity (constant signaling of eumelanin synthesis) and predominantly black coat color (Jackson, 1997).…”

Section: Introductionmentioning

confidence: 99%

Molecular evolution of the pigmentation gene melanocortin-1 receptor in rodents

Gonçalves

Paixão‐Côrtes²,

Freitas³

2013

Genet. Mol. Res.

View full text Add to dashboard Cite

ABSTRACT. Adaptive variation in the melanocortin 1-receptor gene (MC1R), a key locus in melanogenesis, has been identified in some species of rodents. However, in others, MC1R has no causative role in pigmentation phenotypes despite their coat color variation. In this study, we characterized the rates and patterns of MC1R nucleotide and amino acid sequence evolution and, particularly, selective pressures in the separated domains of the protein using a comparative analysis of 43 species representing three major lineages of rodents with variable coat colors. We found high amino acid variation (44% of sites) throughout the protein. Most substitutions were observed in extracellular and transmembrane domains; the intracellular segment was conserved across species. Pairwise non-synonymous substitutions did not vary significantly in different domains among the rodent lineages -i.e., variation was not associated with phylogenetic distance. Phylogenybased likelihood analysis suggested that purifying selection has mostly shaped the evolutionary course of MC1R. However, a high proportion of sites (27%) were under relaxation of functional constraints (ω = 0.38), and four sites (3, 14, 26, and 251) clearly evolved under positive selection (ω ≅ 2.9). Thus, our data indicate a high proportion of sites evolving under relaxed evolutionary constraints, which might indicate the evolvability of the system in the generation of adaptive changes in specific taxa in rodent lineages.

show abstract

Genetics and Molecular Biology of Mouse Pigmentation

Cited by 55 publications

References 45 publications

Catecholamines Are Required for the Acquisition of Secretory Responsiveness by Sweat Glands

Catecholamines Are Required for the Acquisition of Secretory Responsiveness by Sweat Glands

Identification de mutations à l’origine de différents phénotypes chez les ânes

Molecular evolution of the pigmentation gene melanocortin-1 receptor in rodents

Contact Info

Product

Resources

About