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橘色双冠丽鱼TYR基因的克隆及其发育时序和组织表达分析 总被引：1，自引：0，他引：1
酪氨酸酶(tyrosinase,TYR)是动物体内黑色素合成信号通路中起关键性作用的限速酶,黑色素生成的速度和种类取决于TYR基因的表达量和活性水平.为了解色素相关基因与体色变化的关系,采用cDNA末端快速克隆技术(rapid-amplification of cDNA ends,RACE)技术获得橘色双冠丽鱼(Amphilophus citrinellus) TYR基因cDNA全序列,并利用qRT-PCR分析了橘色双冠丽鱼体色变化不同时期和不同组织中TYR基因的表达差异.实验获得cDNA全长序列2 683 bp,其中阅读框1 620bp,编码540个氨基酸,5'UTR区246 bp,3'UTR区817 bp.氨基酸序列和系统发育分析表明,相比与脊椎动物间的保守性,TYR蛋白序列在鱼类间的保守性更高.qRT-PCR结果表明,TYR基因在胚胎各期均有表达,受精期表达量最低,血液循环期开始急速上升;在“黑色-灰色-亮黄色”三个典型体色褪黑过程中,各组织TYR基因表达量均在黑色期呈现最高值,显著高于灰色和亮黄色期,灰色到亮黄色时期鳞片和尾鳍的TYR基因表达量逐渐降低,但差异不显著(P＞0.05),而皮肤组织的TYR基因表达量在三个体色褪黑期均显著降低(P＜0.05);亮黄色时期,TYR基因在心、肾、脑、鳔、性腺、尾鳍和眼等组织均有表达,其中眼部表达量最高,其次是鳔和尾鳍,皮肤和性腺表达量最低.橘色双冠丽鱼TYR基因在三个典型体色褪黑期表达逐渐降低,可能与红色素细胞和黄色素细胞逐渐增多以及黑色素细胞数量和分布比例发生变化相关.本研究通过了解体色变异的分子基础,为鱼类体色遗传和体色改良研究积累资料. 相似文献
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The basic biology of malignant melanoma: molecular mechanisms of disease progression and comparative aspects 总被引：2，自引：0，他引：2
Sulaimon SS Kitchell BE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(6):760-772
Malignant melanoma (MM) is a life-threatening disease characterized by a highly aggressive biologic behavior in both humans and dogs. Despite improvements in diagnosis and patient care, most deaths from MM are due to metastases that are resistant to conventional treatment modalities. To ultimately reduce the mortality associated with metastatic disease, it is necessary to better define the fundamental molecular mechanisms of malignant tumor progression. The progression of disease is a consequence of the complex interactions between malignantly transformed cells and host factors. Characterization of the stages of tumor progression and the changes occurring in highly malignant cells is important for the development of effective treatment regimens. The dys-regulated molecular mechanisms of transformed melanocytes are presently being characterized. In this review, we summarize the current understanding of the molecular phases in the progression of MM, which include genetic instability, dysregulated proliferation of melanocytes, increased invasion and metastasis, and angiogenesis. 相似文献
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针对池塘养殖牙鲆(Paralichthys olivaceus)无眼侧体色黑化消褪的现象,本研究从形态、血清和mRNA水平上对其生理学机制进行了研究.光镜观察显示,无眼侧消褪区域的黑色素细胞数量显著少于有眼侧和无眼侧黑化区域(P＜0.05),电镜观察发现,无眼侧消褪区域皮肤中黑色素颗粒模糊,黑色素细胞中色素体存在凋亡现象.无眼侧黑化区域消褪过程中,鳞片类型经历了由栉鳞—弱栉鳞—圆鳞转变的过程,栉鳞上硬棘数量也随之减少.无眼侧黑化消褪的牙鲆血清中的黑色素聚集激素(MCH)肽含量显著高于无眼侧正常和无眼侧黑化的牙鲆(P＜0.05),但无眼侧体色黑化的牙鲆血清中的黑色素细胞刺激激素(MSH)肽含量显著高于其他2种类型的牙鲆(P＜0.05).基因表达分析显示,无眼侧黑化消褪鱼垂体MCH mRNA表达水平显著高于无眼侧黑化鱼(P＜0.05),而垂体POMC1 mRNA表达水平显著低于无眼侧黑化鱼(P＜0.05),但都与无眼侧正常鱼无显著差异.研究结果可为阐释池塘养殖牙鲆无眼侧体色黑化调控机制提供理论支持. 相似文献
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AIM: To investigate the effects of platelet-derived growth factor receptor α (PDGFRα) on melanocyte apoptosis induced by hydrogen peroxide (H2O2). METHODS: Melanocyte PIGI was used as the research object. After exposed to H2O2 at different concentrations, the cell viability was detected by MTT assay. The PIGI cells were transfec-ted with empty vector pCMV6 or PDGFRα over-expression vector pCMV6-PDGFRα. The transfection efficiency was determined by RT-qPCR and Western blot. The effect of H2O2 on the viability of the PIGI cells after over-expression of PDGFRα was measured by MTT assay. The cell apoptosis was analyzed by flow cytometry. The protein levels of p38, p-p38 and cleaved caspase-3 in the cells were detected by Western blot. DCDHF-DA was used to estemate the generation of reactive oxygen species (ROS) in the cells. RESULTS: The viability of PIGI cells decreased after exposed to H2O2 (P<0.05), and the half maximal inhibitory concentration of H2O2 was 0.7 mmol/L. Transfection with PDGFRα over-expression vector successfully induced high expression of PDGFRα at mRNA and protein levels in the PIGI cells, and increased the viability of the cells with H2O2 treatment (P<0.05). Over-expression of PDGFRα decreased the apoptotic rate of PIGI cells treated with H2O2 (P<0.05), and the level of ROS in the cells (P<0.05). The protein levels of cleaved caspase-3 and p-p38 were also decreased (P<0.05). CONCLUSION: PDGFRα inhibits the apoptosis of melanocytes induced by H2O2, partially reverses the growth inhibition of melanocytes by H2O2, and decreases the ROS level. The mechanism may be related to regulating the protein levels of p-p38 and cleaved caspase-3 in the cells. 相似文献
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Protective Effects of Sunscreens on Sunburn and Suntan Reactions in Cross-bred Mexican Hairless Dogs
Résumé— Les réponses cutanées à l'exposition solaire (radiations UV: 290–400 nm) et l'effet protecteur de deux sortes d'écrans solaires vis-à-vis des coups de soleil et du bronzage ont étéétudié chez des chiens nus descendants de chiens nus Méxicains par trois méthodes (colorimétrie, comptage des mélanocytes DOPA positifs et histologie cutanée). Après la premiére exposition aux UV, alors qu'aucune modification de couleur de la peau (érythème) n'était constatée, les modifications histologiques étaient patentes. Ensuite, après une exposition prolongée, les modifications de couleur étaient nettes (bronzage) et corrélées avec le nombre de mélanocytes DOPA-positifs. Après le troisième jour d'exposition, les mélanocytes étaient retrouvés dans tout l'épiderme des sites non protégés par les écrans solaires et aucune modification de la couleur ni des nombres de mélanocytes n'a été observé dans les zones protégées par les écrans solaires. Histologiquement, seules des modifications mineures ont été notées après 3 à 6 jours d'irradiation UV et il existait des diférences significatives selon la valeur de protection des différents écrans solaires. Par conséquent les écrans solaires protègent efficacement la peau de chiens nus des coups de soleil et du bronzage induits par les expositions solaires. [Kimura, T., Doi, K. Protective effects of sunscreens on sunburn and suntan reactions in cross-bred Mexican hairless dogs (Effet protectuer des écrans solaires vis-à-vis du bronzage et des coups de soleil chez les chiens nus méxicains et croisés). Resumen— Se estudiaron las respuestas cutáneas a la exposición solar (radiación UV 290–400 nm) y los efectos protectores de dos tipos de pantallas solares sobre las quemaduras y bronceados solares en descendientes pelones de perros Pelones Mejicanos utilizando tres métodos distintos [colorimetría, histología y contaje de melanocitos positivos a la dihidroxifenilalanina (DOPA)]. Después de la primera exposición a la radiación UV no se detectó cambio en la coloración de la piel (eritema) aunque si se observaron alteraciones histológicas. Posteriormente, tras sucesivas exposiciones, los cambios de coloración se hicieron visibles (bronceado) y se halló correlación con el número de melanocitos DOPA-positivos. En el tercer dia de exposición, se detectaban melanocitos en toda la epidermis de las zonas desprotejidas pero no se observó ningún cambio de coloración ni aumento de melanocitos en las zonas protejidas por pantallas solares. Histológicamente sólo se detectaron ligeros cambios en la piel protejida al cabo de 3 y 6 dias de radiación UV y existian diferencias entre zonas protejidas con pantallas de diferentes valores SPF. Concluimos que las pantallas solares protegieron la piel de los perros pelones de las quemaduras y bronceado solares. [Kimura, T., Doi, K. Protective effects of sunscreens on sunburn and suntan reactions in cross-bred Mexican hairless dogs (Effectos protectores de las pantallas solares sobre las quemaduras y bronceados solares en perros Pelones Mejicanos cruzados). Zusammenfassung— Es wurden die Hautreaktionen auf Sonnenbestrahlung (UV-Strahlen von 290–400 nm) und die Schutzwirkung von 2 Arten von Sonnenschutzmitteln auf Sonnenbrand und Verfärhungsreaktionen bei haarlosen Abkümmlingen von Mexikanischen Nackthunden mittels dreier Methoden untersucht (Colorimeter, Dihydroxyphenylalanin (DOPA)-positiver Melanozytenzählung und Hauthistologie). Nach der ersten Exposition gegenüber UV-Strahlung konnten histologiesche Veränderungen festgestellt werden, obwohl keine Veränderung der Hautfarbe (Erythem) sichtbar war. Bei der darauffolgenden Exposition traten Farbveränderungen auf (Verfärbungen) und korrelierten mit den Veränderungen der Zahl der festgestellten DOPA-positiven Melanozyten. Am dritten Tag der Exposition konnten Melanozyten in der Epidermis an nicht durch Sonnenschutz bedeckten Stellen festgestellt werden, während an den son-nengeschützten Stellen weder Farbveränderungen noch Melanozytenvermehrung stattfanden. Histologisch konnten auch nach 0 bis 6 Tagen Bestrahlung nur geringgradige Veränderungen in der behandelten Haut ermittell werdem. Es bestanden Unterschiede zwischen Stellen mit Sonneschutzmitteln verschiedener Lichtschutzfaktoren. Sonnenschutzmittel schützen also die Haut von haarlosen. Hurden gegen Sonnenbrand und Verfärbungereaktionen, die durch Sonnenbestrahlung ausgelöst wird. [Protective effects of sunscreens on sunburn and suntan reactions in cross-bred Mexican hairless dogs (Auswirkung von Sonnenschutzmitteln auf Sonnenbrand und Ver färbungsreaktionen bei Mischlingen von Mexikanischen Nackthunden). Abstract— Skin responses to solar exposure (UV radiation: 290–400 nm) and protective effects of two kinds of sunscreens on sunburn and suntan reactions were examined in hairless descendants of Mexican hairless dogs using three methods [colorimeter, dihydroxyphenylalanin (DOPA)-positive melanocyte count and skin histology]. After the first exposure to UV irradiation, while skin color change (erythema) was not detected, histologic changes were apparent. Thereafter, with subsequent exposure, color changes were apparent (tanning) and correlated with changes in numbers of DOPA-positive melanocytes detected. By the third day of exposure, melanocytes were detected throughout the epidermis in sites unprotected by sunscreens but no color change nor increase in melanocytes was noted in sunscreen-protected sites. Histologically, only minor changes were noted in treated skin after 3 and 6 days of UV irradiation, and there were differences between sites treated with sunscreens of different SPF values. Thus, sunscreens effectively protected the skin of hairless dogs from sunburn and suntan reactions induced by solar exposure. 相似文献
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