Biological Sciences, Washington State University Vancouver, 14204 NE Salmon Creek Avenue, Vancouver, WA 98686, USA.
Genome. 2010 Jan;53(1):79-82. doi: 10.1139/g09-074.
Very little information is currently available regarding the sites of integration of transgenes in genetically engineered fish. We examined the chromosomal location of growth hormone gene constructs containing GH1 in three different strains of transgenic coho salmon produced by microinjection into pronuclei of fertilized eggs. The constructs were labeled and used as probes in fluorescence in situ hybridization experiments on chromosome preparations from the M77, MT5750A, and H3D0474 strains of transgenic coho salmon. The constructs were localized at 1-3 different sites in different strains. In the M77 strain the construct was found at a single centromeric site on a medium-sized metacentric chromosome, while in the MT5750A strain, the construct was found at a single telomeric site on the short arm of chromosome pair 21, a subtelocentric chromosome with a large band of repetitive DNA on the short arm. In the H3D0474 strain, the construct was found at telomeric sites on the long arms of three metacentric chromosomes that appear to represent one pair of homologous chromosomes and one chromosome containing the homeologous long arm (recently duplicated chromosome arm) corresponding to the long arm of the first pair. This suggests transfer of the construct may have occurred by homologous and homeologous crossing over. All of the constructs incorporated at restricted sites characterized by the presence of tandem DNA repeats.
目前有关转基因鱼中外源基因整合位点的信息还很少。我们通过微注射法将含有 GH1 的生长激素基因构建体导入到受精鱼卵的原核中，从而得到了三种不同的转基因银大麻哈鱼品系。利用这些构建体作为探针，通过荧光原位杂交实验，对来自 M77、MT5750A 和 H3D0474 转基因银大麻哈鱼品系的染色体标本进行了分析。结果表明，这些构建体在不同的品系中定位于 1-3 个不同的位点。在 M77 品系中，该构建体位于一条较大的着丝粒区的中着丝粒染色体的一个单一着丝粒区；而在 MT5750A 品系中，该构建体位于第 21 对染色体短臂的一个单一端粒区，该染色体是一个亚端着丝粒染色体，其短臂上带有大量重复 DNA 带。在 H3D0474 品系中，该构建体位于三个着丝粒区的端粒区，这些染色体可能代表一对同源染色体和一条含有与其同源长臂（最近复制的染色体臂）相对应的长臂的染色体。这表明该构建体的转移可能是通过同源和异源交叉发生的。所有的构建体都整合到了具有串联 DNA 重复序列的限定性位点上。
