Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by mis...Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by missense mutations of tyrosinase. Albino mutations in Tyr have been identified in various animals, including human, mouse, rat, rabbit, cattle, cat, and ferret, but not in gerbil. We created two new gerbil strains: MON/Num/a (inbred agouti phenotype) and MON/Num/c (albino phenotype). Here, we report that four nucleotide substitutions in the Tyr gene caused two missense mutations in amino acids in the albino gerbil: a G-to-A mutation at position 204 in exon 1 caused R77H, and A-to-G at position 1392 and G-to-T at position 1393 in exon 5 caused Q473R. The substitution at position 1408 in exon 5 was silent. These missense mutations are conserved in all albino phenotypes we tested. Therefore, we suggest that these mutations are responsible for albinism in gerbil.展开更多
在水稻品种宜香B中发现了一个白化转绿叶突变体,经过多代自交获得了稳定的白化转绿叶色突变体。该突变体在4叶期前叶色为黄绿色,之后逐渐变绿,从苗龄4周到12周,突变体/野生型叶绿素含量比值从34.5%逐渐升高到99.4%。遗传分析表明该突变...在水稻品种宜香B中发现了一个白化转绿叶突变体,经过多代自交获得了稳定的白化转绿叶色突变体。该突变体在4叶期前叶色为黄绿色,之后逐渐变绿,从苗龄4周到12周,突变体/野生型叶绿素含量比值从34.5%逐渐升高到99.4%。遗传分析表明该突变受1对隐性核基因控制,暂命名为gra。利用微卫星标记将gra初步定位于第10染色体标记RM596和RM5620之间,进一步利用极端个体定位法把gra精细定位于标记RM25522和RM25535之间。gra基因距RM25522和RM25535标记的遗传距离均为0.05 c M,其物理距离约为136 kb。展开更多
本文综述了禾谷类作物花药培养中,花粉植株白化现象的主要研究结果和新近进展。讨论了解释花粉白苗发生机理的各种观点。根据我们实验室的研究结果,提出了核基因通过控制质体 DNA 缺失发生的时期,频率和程度而影响白苗发生的观点,以及...本文综述了禾谷类作物花药培养中,花粉植株白化现象的主要研究结果和新近进展。讨论了解释花粉白苗发生机理的各种观点。根据我们实验室的研究结果,提出了核基因通过控制质体 DNA 缺失发生的时期,频率和程度而影响白苗发生的观点,以及控制大麦花粉白苗发生的综合措施。展开更多
文摘Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by missense mutations of tyrosinase. Albino mutations in Tyr have been identified in various animals, including human, mouse, rat, rabbit, cattle, cat, and ferret, but not in gerbil. We created two new gerbil strains: MON/Num/a (inbred agouti phenotype) and MON/Num/c (albino phenotype). Here, we report that four nucleotide substitutions in the Tyr gene caused two missense mutations in amino acids in the albino gerbil: a G-to-A mutation at position 204 in exon 1 caused R77H, and A-to-G at position 1392 and G-to-T at position 1393 in exon 5 caused Q473R. The substitution at position 1408 in exon 5 was silent. These missense mutations are conserved in all albino phenotypes we tested. Therefore, we suggest that these mutations are responsible for albinism in gerbil.
基金This work was supported by Program for New Century Excellent Talents in University (No. NCET-04-0907) and Program for In-novative Research Team in University (No.IRT0453).
文摘在水稻品种宜香B中发现了一个白化转绿叶突变体,经过多代自交获得了稳定的白化转绿叶色突变体。该突变体在4叶期前叶色为黄绿色,之后逐渐变绿,从苗龄4周到12周,突变体/野生型叶绿素含量比值从34.5%逐渐升高到99.4%。遗传分析表明该突变受1对隐性核基因控制,暂命名为gra。利用微卫星标记将gra初步定位于第10染色体标记RM596和RM5620之间,进一步利用极端个体定位法把gra精细定位于标记RM25522和RM25535之间。gra基因距RM25522和RM25535标记的遗传距离均为0.05 c M,其物理距离约为136 kb。
文摘目的:研究乳腺癌生成过程中,Wnt家族成员表达的变化规律。方法:收集自发乳腺癌小鼠42只,记录其详细资料。采用基因芯片筛选正常TA2小鼠乳腺组织和自发乳腺癌TA2小鼠乳腺癌组织中的差异表达基因,随后用Real-time PCR进行验证,并检测TA2小鼠乳腺癌形成过程中相关基因表达的变化。结果:TA2自发乳腺癌小鼠平均见瘤年龄为(336.706±85.05)d,平均分娩次数为(3.767±1.79)次。分娩次数最多者为7次,其平均见瘤年龄只有251.5 d。TA2小鼠基因芯片结果发现Wnt家族成员中,Wnt1、Wnt10b、Wnt5a、Wnt5b在正常乳腺组织和乳腺癌组织中表达具有差异。Real time PCR的结果证实了以上结果,并发现Wnt1、Wnt10b、Wnt5a在癌前病变和乳腺癌组织中表达高于正常乳腺组织,而Wnt5b在乳腺癌组织中表达低于正常乳腺组织。结论:Wnt1、Wnt5a、Wmt10b在TA2小鼠乳腺癌生成过程中起促进作用,而Wnt5b的作用可能是抑制小鼠乳腺癌的生成。
