大黄鱼耐低温性状相关微卫星标记的筛选

鱼类的耐低温性状是一种重要的经济性状。为了初步分析大黄鱼的耐低温性状, 文章采用15对荧光微卫星标记, 以SSR-PCR方法对大黄鱼低温耐受组和正常对照组F₁代共40个个体进行了耐低温性状遗传差异分析。结果显示, 标记LYC0002在两组样品中共扩增出5个等位基因(片段大小分别为112 bp、110 bp、108 bp、106 bp和104 bp), 其中LYC00021_{12 bp}等位基因在低温耐受组的出现频率达60%, 而在正常对照组中的频率为零, 表明该等位基因对大黄鱼的温度敏感特性有较明显的偏好性, 可能与某种耐低温基因存在一定的连锁关系。此外, 对LYC0002_{106 bp、}LYC0002_{108 bp}、LYC0002_{110 bp} 和 LYC0002_{112 bp} 4个等位基因分别进行了回收、克隆及测序。序列比对结果显示, LYC0002_{112 bp}等位基因含有10个(CA)重复单元, 而其他3个等位基因依次缺失1个(CA)重复单元, 说明LYC0002在本研究样本中的突变方式为微卫星逐步突变模型(Stepwise mutation model, SMM)。

Screening of microsatellite markers associated with cold tolerance of large yellow croaker (Pseudosciaena crocea R.)

Cold tolerance is one of the major economic characters in fish. In order to discuss the cold tolerance of large yellow croaker (Pseudosciaena crocea R.), fifteen fluorescent dye-labeled microsatellite markers were applied to detect genetic differences between F₁ offsprings of cold tolerance group and normal group of large yellow croaker by SSR-PCR. Each group contained 20 randomly and separately sampled individuals. As a result, marker LYC0002 five alleles (LYC0002_{104 bp}, LYC0002_{106 bp}, LYC0002_{108 bp}, LYC0002_{110 bp}, and LYC0002_{112 bp}) were amplified with marker LYC0002 in both groups and 60% (12/20) of individuals had allele LYC0002_{112 bp} in cold tolerance group exclusively, which indicated that this allele is probably sensitive to temperature and associated with gene for cold tolerance. In addition, four alleles (LYC0002_{106 bp}, LYC0002_{108 bp}, LYC0002_{110 bp}, and LYC0002_{112 bp}) were sequenced individually. Sequence alignments showed that LYC0002_{112 bp} allele contains 10 (CA) repeats, the remaining three alleles lacked one (CA) one by one, corresponding to the stepwise mutation model (SMM) of microsatellite.