不同毛色豚鼠的TYR及MC1R基因多态性及组织表达分析  

Polymorphism and Tissue Expression Analysis of TYR and MC1R Genes in Guinea Pigs with Different Coat-Color Phenotypes

作　　者：汤银根 冯亚仙 钟敏 卫振 汪洌 刘迪文 TANG Yingen;FENG Yaxian;ZHONG Min;WEI Zhen;WANG Lie;LIU Diwen(Zhejiang Hongrun Biotechnology Co.,Ltd.,Tongxiang 314512,China;Laboratory Animal Center,Zhejiang University,Hangzhou 310013,China)

机构地区：[1]浙江宏润生物科技有限公司,桐乡314512 [2]浙江大学实验动物中心,杭州310013

出　　处：《实验动物与比较医学》2025年第1期21-29,共9页Laboratory Animal and Comparative Medicine

基　　金：浙江省基础公益研究计划项目“通过重测序和FISH定位建立豚鼠SSR遗传检测方法的研究”(LTGD24C040001)。

摘　　要：目的为定位豚鼠优势性状基因筛选遗传标志,探索豚鼠酪氨酸酶(tyrosinase,TYR)、黑素皮质素1受体(melanocortin 1 receptor,MC1R)基因多态性及其mRNA表达水平与毛色表型的关系。方法选择自主培育的普通级豚鼠57只,依据毛色分为白(22只)、花(22只)和黑(13只)3组。腹腔注射过量戊巴比妥钠对豚鼠施行安乐死后,取背部皮肤,提取组织中DNA。通过克隆测序,检测各组豚鼠TYR、MC1R基因外显子编码序列(coding sequence,CDS)的多态性,采用实时荧光定量PCR方法检测两个基因在皮肤组织中的mRNA表达,进而探讨两基因与豚鼠毛色的关系。结果在TYR外显子Ⅰ的CDS区域发现1个单核苷酸多态性(single nucleotide polymorphism,SNP)位点,其碱基A被G替换。所有白色豚鼠的TYR基因呈G/G基因型;深色(花、黑)豚鼠无G/G基因型,多数为A/A型,少数为A/G型;黑色豚鼠的A/A基因型频率高于花色豚鼠。MC1R基因外显子有2760 bp序列缺失,标记为-基因;非缺失样本标记为N基因。大部分白色豚鼠的MC1R基因呈-/-基因型;花色豚鼠以-/N为主;黑色豚鼠以N/N为主,-/N次之。白色豚鼠的TYR基因表达水平较高,花色豚鼠较低,黑色豚鼠居中,但三者无显著性差异(P>0.05)。白色豚鼠的MC1R基因表达水平非常低,花色及黑色豚鼠均极显著高于白色豚鼠(P<0.01),黑色豚鼠又显著高于花色豚鼠(P<0.05)。结论豚鼠TYR与MC1R基因协同调控毛色。TYR基因的G位点突变可能导致豚鼠白化,MC1R基因的N位点改变影响毛色的深浅。Objective To explore the polymorphism of tyrosinase(TYR)and melanocortin 1 receptor(MC1R)genes and their mRNA expression levels in relation to coat-color phenotypes in guinea pigs,providing genetic markers for locating dominant traits in guinea pigs.Methods A total of 57 self-bred ordinary-level guinea pigs were selected and divided into three groups based on coat color:white(n=22),variegated(n=22)and black(n=13).The guinea pigs were euthanized with an overdose of pentobarbital sodium via intraperitoneal injection.DNA was then extracted from the dorsal skin tissue.Polymorphism in the coding sequence(CDS)of the exons of the TYR and MC1R genes in each group was detected by cloning and sequencing.The mRNA expression of the two genes in skin tissues was detected by real-time fluorescent quantitative PCR to investigate the relationship between these genes and guinea pig coat color.Results A single nucleotide polymorphism(SNP)site was found in the CDS region of TYR exonⅠ,where the base A was replaced by G.All white guinea pigs had the G/G genotype for TYR,while no deep-colored(variegated and black)guinea pigs exhibited the G/G genotype for TYR.Most deep-colored guinea pigs had the A/A genotype,and a few had A/G genotype.The A/A genotype frequency in black guinea pigs was higher than in variegated guinea pigs.A 2760 bp sequence deletion was identified in the exon of the MC1R gene,marked as the−gene,with non-deleted samples marked as N gene.Most white guinea pigs had the−/−genotype for MC1R,variegated guinea pigs mainly had the−/N genotype,and black guinea pigs mainly had the N/N genotype,with a few showing the−/N.The TYR gene expression level was higher in white guinea pigs,lower in variegated guinea pigs,and intermediate in black guinea pigs,but there was no significant difference among the three groups(P>0.05).The MC1R gene expression level in white guinea pigs was extremely low,while both variegated and black guinea pigs showed significantly higher levels than white guinea pigs(P<0.01).Black guinea pigs s

关 键 词：豚鼠 基因多态性 基因表达 毛色 酪氨酸酶 黑素皮质素1受体 

分 类 号：Q95-33[生物学—动物学] R-332[医药卫生]