GPR143在绵羊皮肤组织中的表达及定位分析

G蛋白偶联受体143(G-protein coupled receptor143, GPR143)在黑素体的生物合成中起重要作用,本文旨在研究GPR143基因在不同毛色绵羊皮肤组织中的差异表达及定位,探索GPR143基因与毛色形成的相关性。通过qRT-PCR方法和免疫印迹方法分别检测不同毛色绵羊皮肤组织中GPR143基因mRNA水平和蛋白水平的表达差异;运用免疫荧光法对不同毛色绵羊皮肤组织中的GPR143基因进行定位并对结果进行光密度值分析。qRT-PCR结果显示,GPR143基因在黑色绵羊皮肤组织中mRNA相对表达量为白色绵羊的7.84倍,二者差异极显著(P<0.01);免疫印迹结果显示,黑色绵羊皮肤组织中GPR143蛋白表达量是白色绵羊的1.3倍,二者差异显著(P<0.05)。免疫荧光结果显示,GPR143蛋白的主要表达部位为绵羊皮肤组织毛囊外根鞘和表皮层,经光密度值分析后发现,GPR143在黑色绵羊皮肤毛囊外根鞘和表皮层的表达量显著高于白色绵羊。本研究结果表明不同毛色绵羊皮肤组织均能表达GPR143基因,但黑色绵羊皮肤组织中该基因的mRNA和蛋白水平都显著高于白色绵羊,说明GPR143的mRNA和蛋白在黑色绵羊皮肤组织中表达上调,在白色绵羊皮肤组织中表达下调。GPR143基因可能通过调控MITF水平和黑素体的数量、大小、运动和成熟进而参与绵羊毛色的形成过程。     

Electron microscopical studies of Strongyloides ratti infective larvae: loss of the surface coat during skin penetration

Previous indications using radiolabelled larvae that Strongyloides ratti free-living infective larvae lose a surface coat during penetration of the skin were further investigated by transmission electron microscopy of the cuticle of S. ratti infective larvae in the free-living stage, after penetration of mouse skin, and after migration to the lungs. These studies demonstrated the presence of a faint electron-dense surface coat external to the epicuticle on free-living worms which was absent from larvae recovered from the skin and lungs. When free-living infective larvae were incubated in 10% CO2 at 37 C and then examined with phase-contrast microscopy, worms were observed in the process of losing this coat. These observations confirm the hypothesis that S. ratti infective larvae lose a surface coat during penetration of the skin.     

Slc7a11基因在不同被毛颜色哈萨克羊皮肤组织中的表达分析

Slc7a11基因属于溶质转运家族,编码胱氨酸/谷氨酸xCT转运载体,经证实该基因调控黑色素与伪黑色素的转换。文章利用实时荧光定量PCR技术分析Slc7a11基因在3种不同毛色哈萨克绵羊羔羊皮肤组织中的mRNA转录水平,构建原核表达载体,诱导表达融合蛋白,并对包涵体蛋白进行纯化,免疫新西兰大白兔制备抗血清,最后检测不同毛色皮肤中该蛋白的表达水平。结果表明,Slc7a11基因在3种毛色皮肤中的表达水平有显著差异,棕色被毛皮肤中表达水平最高,其次是黑色,在白色中表达最少。利用纯化的融合蛋白制备多克隆抗体,发现sxCT蛋白在棕色被毛中表达最高,其次是黑色,白色最低,因此,Slc7a11基因可能与哈萨克绵羊毛色表型有相关性。     

Seasonal coat changes in grazing Red deer (Cervus elaphus)

Seasonal change in the coat of four male and four female Red deer (Cervus elaphus) was studied in coat and skin samples taken monthly for two years. Changes in coat length were measured, the times of moult recorded, and the cycle of follicle activity determined from histological preparations.     

Lef-1基因在棕色和白色羊驼皮肤差异表达

本实验旨在研究Lef-1在不同毛色羊驼皮肤中的表达和定位,探索其与毛色间的关系.采用实时荧光定量PCR、Western blotting以及免疫组织化学方法,研究白色和棕色羊驼皮肤中的mRNA、蛋白表达水平和定位.实时荧光定量PCR结果显示,Lef-1在棕色羊驼皮肤组织相对基因表达量是3.3727±0.1989,在白色羊驼皮肤组织是1.0003±0.0227; Western blotting结果显示,在羊驼皮肤组织总蛋白中存在分子量约44 KD与兔抗Lef-1多克隆抗体发生免疫阳性反应的蛋白条带,棕色羊驼平均蛋白表达量显著高于白色羊驼;免疫组织化学结果显示,在棕色羊驼皮肤组织中多表达在毛球部、表皮也有分布,在白色羊驼皮肤组织中多表达在表皮,在棕色和白色羊驼皮肤组织中外根鞘都有较强表达.结果显示Lef-1在棕色和白色羊驼皮肤的定位和含量存在差异,提示Lef-1可能影响了羊驼被毛颜色的形成.     

Studies on water vapor pressure gradient from external air through clothing to the skin in relation to external humidity and clothing conditions

Using a hygrometric capsule method developed by the authors, water vapor pressure was measured at each layer of clothing as well as at the skin surface on a human subject under actual wearing conditions. The pattern of vapor pressure gradient from the skin surface through clothing to the external air was examined in relation to the ambient vapor pressure and ths sort of textiles worn. The following findings were obtained. 1) Water vapor pressure gradient was greater between coat and external air than that between coat and underwear. The gradient became steeper again between underwear and the skin. 2) Under given clothing conditions, vapor pressure at each layer of clothing as well as at the skin varied according to the ambient humidity. However, the pattern of vapor pressure gradient from the skin through clothing to the external air was not greatly influenced by the external humidity. 3) The pattern of vapor pressure gradient from the skin through clothing to the external air was not greatly influenced by the external humidity. 3) The pattern of vapor pressure gradient through the clothing as a whole differed according to the kinds of textiles used for coat and underwear.     

Simulation of sensible and latent heat losses from wet-skin surface and fur layer

A simulation model that simultaneously calculates heat and mass transfer from a wetted skin surface and fur layer of a cow is presented. The model predicts evaporative, convective and radiant heat losses for different levels of skin and fur wetness, air velocity, air temperature and relative humidity. In the model, fur layer (hair coat) properties such as fur thickness and hair density assumed are that of summer conditions. Evaporative cooling from wet-skin surface and hair coat is the dominant mode of heat mitigation mechanism in stressful hot environments and is further enhanced by increased air velocity. Evaporative cooling is, however, depressed by increased relative humidity because of deficit of water-vapor concentration between the skin surface and ambient air.     

豫医无毛小鼠分离近交系的建立及其遗传纯度测定

采用强迫杂合性史妹酱方式培育携带无毛突变基因的分离近交系,然后用生化标记法,皮肤移植实验和毛色基因测试法对其进行遗传监测。并对其基本生物学特性进行了研究。结果育成了具有独特生物学特性的豫医无毛小鼠分离近交系,现已达30代,生化标记法测定的9条染色体上13个生化标记位点全部纯合;同系异体间皮肤移植100天后,未见排斥现象,为同系组织遗传性;与DBA/2交配进行的毛色基因测试,杂交的F1代相同,全部为野生色,基因型为AABBccDD ,表明豫医无毛小鼠已成为一个达到国际标准的新品系。     

Variation of coat color in house mice throughout Asia

Coat color variation due to melanin pigment synthesis in house mice Mus musculus in Asia is described and found to be consistent with Gloger's rule, which states that individuals of endothermic animals are darker in humid habitats than those in drier habitats. Three properties of coat color (hue, value and chroma) were measured, and a lightness variable was derived from a principal components analysis using 428 skin specimens representing three subspecies from 85 localities. Dorsal coat color ranged from yellow through brown to black, whereas ventral coat color ranged from white to black. Dorsal coat color varied less than the ventral color. In our samples, the variation in coat color in natural populations was far less than that observed in the laboratory. We found a significant correlation between the lightness variable of dorsal coat color and precipitation. Dark coat color was observed in more humid and closed habitats (darker background color), and pale coat color in drier, more open habitats (lighter background color). This result might imply the role of concealment as a selective force affecting dorsal coat color that was observed in house mice. We also discussed other selective forces that could affect the coat color variation in house mice, such as resistance to bacterial degradation and thermoregulation. In addition, the color spectra of the dorsal pelage among the three subspecies were different, the major distinction being the environmental background color of the habitats in which they are distributed.     

Tyrosinase Depletion Prevents the Maturation of Melanosomes in the Mouse Hair Follicle

The mechanisms that lead to variation in human skin and hair color are not fully understood. To better understand the molecular control of skin and hair color variation, we modulated the expression of Tyrosinase (Tyr), which controls the rate-limiting step of melanogenesis, by expressing a single-copy, tetracycline-inducible shRNA against Tyr in mice. Moderate depletion of TYR was sufficient to alter the appearance of the mouse coat in black, agouti, and yellow coat color backgrounds, even though TYR depletion did not significantly inhibit accumulation of melanin within the mouse hair. Ultra-structural studies revealed that the reduction of Tyr inhibited the accumulation of terminal melanosomes, and inhibited the expression of genes that regulate melanogenesis. These results indicate that color in skin and hair is determined not only by the total amount of melanin within the hair, but also by the relative accumulation of mature melanosomes.     

Solar heating of mammals: Observations of hair transmittance

The transmission of solar radiation through animal coats by diffuse scattering is well known, but the part played by hair structure has not been examined. Transmittance of light through single guard hairs of 6 marine and 5 terrestrial mammals was measured through a microscope and values ranging from 0.29 to 0.94 were found. The hair transmittance was negatively correlated with pigmentation and medullation. Stepwise regression analysis indicates that solar heating at skin level is correlated with both hair transmittance and coat reflectance besides being coupled with coat thickness.     

Coping with Heat: Function of The Natal Coat of Cape Fur Seal (Arctocephalus Pusillus Pusillus) Pups in Maintaining Core Body Temperature

Cape fur seal (Arctocephalus pusillus) pups spend the first weeks of life exclusively or mainly ashore. They are exposed to intense solar radiation and high temperatures for long time periods, which results in temperatures up to at least 80°C on their black natal coat. To test the hypothesis that the natal coat has a crucial function in coping with these extreme conditions, we investigated the insulating properties of the natal coat in six captive newborn Cape fur seals during the first 50 days after birth. The natal fur differs from the adult fur not only in colour, but also in density, structure, and water repellence. We measured temperature on the fur surface and within the fur, as well as skin and rectal temperature under varying environmental conditions, comparable to the species'' habitat. Experiments were designed to not influence the spontaneous behaviour of the pups. Rectal temperature was constant as long as the pups stayed dry, even during long-lasting intense solar radiation for up to 3 h. Skin temperature remained close to rectal temperature as long as the fur was dry, while with wet fur, skin temperature was significantly reduced as well. Our results show that the natal coat provides an effective insulation against overheating. The severely reduced insulation of wet natal fur against cold supports the assumption that the natal fur is an adaptation to the pups'' terrestrial phase of life.     

肤色、黑色素皮质素受体1和紫外线

近期的研究表明,哺乳动物黑素细胞中黑色素皮质素受体1（MC1R）对调节棕黑色素和红黄色素的合成起关键的作用。MC1R基因的变异与动物的皮毛、人的皮肤和头发颜色差异密切相关。对小鼠的遗传学研究显示,MC1R是独特的、双功能控制受体。它由α-促黑色素皮质激素激活,其拮抗物为agouti蛋白,二者的共同作用导致哺乳动物表皮颜色的变异。另外,人类皮肤的色素沉着是决定于皮肤对外辐射的反应,以及由此引发皮肤癌的重要因素。MC1R变异与黑色素癌易感性相关。 Genotype,Melanocortin 1 Receptor and Ultrviolet Radiation Lü Xue-mei,SHI Peng,ZHANG Ya-ping Lab of Cellular & Molecular Evolution,Kunming Institute of Zoology,the Chinese Academy of Sciences,Kunming 650223,China Abstract:Recent work on the melanocortin 1 receptor (MC1R) suggests that MC1R plays a central role in regulation of eumelanin (brwon/black melanins) and phaeomelanin (red/yellow melanins) synthesis within the mammalian melanocyte.In the mouse,genetic studies show that the MC1R appears to be a unique,bifunctionally controlled receptor,activated by α–MSH and antagonized by agouti,both of which contribute to the variability seen in mammalian coat color.Variants of this receptor are associated with different animal's coat,human skin and hair colors.In addition,cutaneous pigmentation is a major determinant of the cutaneous response to ultraviolet radiation,and consequently of the risk of developing skin cancer.MC1R variants are a risk factor for melanoma susceptibility. Key words：Melanocortin-1 receptor gene; MC1R variants; ultraviolet radiation; skin and hair colors; skin cancer     

A model of evaporative cooling of wet skin surface and fur layer

(1) A theoretical model that simultaneously solves heat and mass transfer in a wet skin surface and fur layer that occurs when an animal is cooled by blowing air over its wetted skin surface and hair coat is presented. (2) The model predicts evaporative and convective heat losses for different levels of wetness, air velocity, ambient temperature, relative humidity and fur properties. (3) Model predictions provide insight about evaporative and convective cooling processes of cows in stressful hot environments.     

Uncv (uncovered): a new mutation causing hairloss on mouse chromosome 11.

A pair of mutant mice with a first sparse coat appeared spontaneously in the production stock of BALB/c mice with a normal coat. After being sib-mated, they produced three phenotypes in their progeny: mice with normal hair, mice with a first sparse coat and then a fuzzy coat, and uncovered mice. Genetic studies revealed the mutants had inherited an autosomal monogene that was semi-dominant. By using 11 biochemical loci--Idh, Car2, Mup1, Pgm1, Hbb, Es1, Es10, Gdc, Ce2, Mod1 and Es3--as genetic markers, two-point linkage tests were made. The results showed the gene was assigned to chromosome 11. The result of a three-point test with Es3 and D11Mit8 (microsatellite DNA) as markers showed that the mutation was linked to Es3 with the recombination fraction 7.89 +/- 2.19%, and linked to D11Mit8 with the recombination fraction 26.30 +/- 3.57%. The recombination fraction between Es3 and D11Mit8 was 32.90 +/- 3.81%. It is suggested that the mutation is a new genetic locus that affected the skin and hair structure of the mouse. The mutation was named uncovered, with the symbol Uncv. Further studies showed the mutation affected not only the histology of skin and hair but also the growth and reproductive performance of the mice. The molecular characterization of the Uncv locus needs to be further studied.     

Schistosoma mansoni: topochemical features of cercariae, schistosomula, and adults

The teguments of developing and mature cercariae, recently transformed, and 1-wk-old schistosomula and adult worms were examined for the ultrastructural location of macromolecular carbohydrates and polyelectrolytes. The surface of mature cercariae within sporocysts and cercariae released from the snail is covered by a filamentous coat which reacts with cytochemical reagents for the demonstration of vicinal glycols, but neither the coat nor the surface of the tegument plasmalemma binds cationic colloidal iron at low pH.Upon penetrating mammalian skin, the cercaria sheds its surface coat; the tegument surface of newly transformed schistosomula, older schistosomula and adult worms stains en bloc with acidic colloidal iron, as does the tegument plasmalemma of mature cercariae if the overlying filamentous coat is first removed by physicochemical means. The cercarial coat thus serves to mask anionic groups at the surface of the tegument plasmalemma which become functionally exposed after penetration of the mammalian host. The distribution of colloidal iron binding sites coincides with those for the carbohydrate-complexing phytohemmagglutnin, concanavalin A, which suggests that these membrane-fixed anions are acid mucopolysaccharides, glycoproteins or glycolipids. Carbohydrate-containing material was also localized within membrane-bound vesicles of the tegument matrix and perikarya of developing cercariae and postcercarial schistosomes, suggesting that surface mucosubstances contributing to the tegument glycocalyx of these worms are elaborated, at least in part, by the tegument itself.     

Consequences of skin color and fur properties for solar heat gain and ultraviolet irradiance in two mammals

Summary In animals with fur or feather coats, heat gain from solar radiation is a function of coat optical, structural, and insulative characteristics, as well as skin color and the optical properties of individual hairs or feathers. In this analysis, I explore the roles of these factors in determining solar heat gain in two desert rodents (the Harris antelope squirrel,Ammospermophilus harrisi, and the round-tailed ground squirrel,Spermophilus tereticaudus). Both species are characterized by black dorsal skin, though they contrast markedly in their general coat thickness and structure. Results demonstrate that changes in coat structure and hair optics can produce differences of up to 40% in solar heat gain between animals of similar color. This analysis also confirms that the model of Walsberg et al. (1978) accurately predicts radiative heat loads within about 5% in most cases. Simulations using this model indicate that dark skin coloration increases solar heat gain by 5%. However, dark skin significantly reduces ultraviolet transmission to levels about one-sixth of those of the lighter ventral skin.Symbols and abbreviations: (unless noted, all radiation relations refer to total solar radiation) absorptivity of individual hairs - _C absorptivity of the coat - backward scattering coefficient [reflectivity] of individual hairs - _C reflectivity of coat - _S reflectivity of skin - forward scattering coefficient [transmissivity] of individual hairs - _C transmissivity of coat - _S transmissivity of the skin - transmissivity of the coat and skin - transmissivity of the coat to ultraviolet radiation - _S transmissivity of the skin to ultraviolet radiation - [(1 – )² – ²] - h _C coat thermal conductance [W/m²-°C] - h _E coat surface-to-environment thermal conductance [W/m²-°C] - I probability per unit coat depth that a ray will be intercepted by a hair [m^–1] - K volumetric specific heat of air at 20°C [1200 J/m³-°C] - l _C coat thickness [m] - l _H hair length [m] - d hair diameter [m] - n hair density per unit skin area (m^–2] - Q _ABS heat load on animal's skin from solar radiation [W/m²] - Q _I solar irradiance at coat surface [W/m²] - r _E external resistance to convective and radiative heat transfer [s/m] - r _C coat thermal resistance [s/m]     

Red-eyed dilution (rd), a novel coat-color mutant gene in the musk shrew (Suncus murinus, Insectivora).

A novel coat-color mutant was found in the musk shrew (Suncus murinus). Mutant shrews were characterized by light-gray coat, pinkish skin and red eyes. Mating experiment demonstrated that the mutant character was controlled by a single autosomal recessive gene. The gene could be traced back to at least four heterozygous carriers captured in Naha city, Okinawa in 1983. The name, red-eyed dilution, was proposed for this mutant character with the gene symbol rd. Linkage analysis proved no close relationship of the rd locus with the cr (cream coat color) and ch (curly hair) loci. The red-eyed dilution shrews (+/+, rd/rd) could easily be distinguished from the cream coat shrews with dark-red eyes (cr/cr, +/+) and the double homozygotes exhibiting light-cream coat with pink eyes (cr/cr, rd/rd). The rd gene has been maintained in the OKI line about at 75% of its frequency in every generation. We have started to develop a new line triple-homozygous for the cr, ch and rd genes.