Brenig B
Institute of Veterinary Medicine, University of Göttingen, Germany.
Anim Genet. 1999 Apr;30(2):120-5. doi: 10.1046/j.1365-2052.1999.00450.x.
Interspersed elements are ubiquitous in the genomes of higher eukaryotes and account for over a third of the genomic DNA (Smit 1996). In swine the short interspersed elements, SINEs or PREs (porcine repetitive elements), have been found in a number of introns and 3' untranslated regions of different genes. However, compared to human Alu repeats the number of available PRE DNA sequences is still limited. In this study we have compared 85 PREs selected from DNA sequence database entries. The PREs were aligned and for each nucleotide position the relative frequencies of the four bases were calculated. A consensus sequence was derived from the first base usage. Similar to studies of SINEs in other species, the analysis showed that most mutations in PREs occur at CpG dinucleotide hot spots. The position variability for the two most frequent bases shows a bimodal distribution. The analysis suggests that the porcine SINEs can be divided into three major subfamilies sharing conserved nucleotide similarities.
散布元件在高等真核生物基因组中普遍存在，占基因组DNA的三分之一以上（斯密特，1996年）。在猪中，短散布元件，即SINEs或PREs（猪重复元件），已在不同基因的多个内含子和3'非翻译区中被发现。然而，与人类Alu重复序列相比，可用的PRE DNA序列数量仍然有限。在本研究中，我们比较了从DNA序列数据库条目中选取的85个PREs。对这些PREs进行了比对，并计算了每个核苷酸位置上四种碱基的相对频率。根据第一个碱基的使用情况得出了一个共有序列。与其他物种中SINEs的研究相似，分析表明PREs中的大多数突变发生在CpG二核苷酸热点。两个最常见碱基的位置变异性呈现双峰分布。分析表明，猪SINEs可分为三个主要亚家族，它们具有保守的核苷酸相似性。
