Garrido-Ramos M A, Jamilena M, Lozano R, Ruiz Rejón C, Ruiz Rejón M
Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Spain.
Cytogenet Cell Genet. 1994;65(4):233-7. doi: 10.1159/000133637.
A highly repetitive DNA sequence family from the genome of Sparus aurata has been cloned and characterized. The family is composed of repeat units of 186 bp in length, and it accounts for 2% of the fish genome. Data from Southern blots and in situ hybridization demonstrate that repeating units are tandemly arranged at the centromeres of all the chromosomes in this species. The repetitive sequence is AT rich (67%) and is characterized by short stretches of consecutive AT base pairs and by short direct and inverted repeats. Sequence analysis of six cloned monomers of the family reveals some variation among clones at random positions and also distinguishes two subfamilies of repeats that differ in a highly divergent block of 31 bp. These two subfamilies do not seem to be located in separate domains but occur together in the centromere of each chromosome pair. The presence of this repeat family in the genome of other Sparidae species, some of which are relatively distant from S. aurata, indicates that this repetitive sequence could be an important component of the centromere in this fish family.
已克隆并鉴定了来自金头鲷基因组的一个高度重复DNA序列家族。该家族由长度为186 bp的重复单元组成，占鱼类基因组的2%。Southern印迹和原位杂交数据表明，重复单元在该物种所有染色体的着丝粒处串联排列。该重复序列富含AT（67%），其特征是有短的连续AT碱基对片段以及短的正向和反向重复序列。对该家族六个克隆单体的序列分析揭示了克隆之间在随机位置存在一些差异，并且还区分出两个重复亚家族，它们在一个31 bp的高度分歧区域有所不同。这两个亚家族似乎并非位于不同区域，而是共同存在于每对染色体的着丝粒中。其他鲷科物种的基因组中也存在这个重复家族，其中一些与金头鲷亲缘关系相对较远，这表明这个重复序列可能是该鱼类家族着丝粒的重要组成部分。
