The majority of minicircle DNA in Crithidia fasciculata strain CF-C1 is of a single class with nearly homogeneous DNA sequence.
The majority of minicircle DNA in Crithidia fasciculata strain CF-C1 is of a single class with nearly homogeneous DNA sequence.
复制标题
Crithidia fasciculata 菌株 CF-C1 中的大多数小环 DNA 属于单一类别，具有几乎均质的 DNA 序列。
作者：
L. Birkenmeyer;H. Sugisaki;D. Ray
在束状锥虫Crithidia fasciculata的动质体内发现的DNA微环，像大多数其他动质体物种一样，在序列上是异质的。用各种限制性内切酶切割动质体DNA所产生的小环DNA片段的模式已被用来证明这种异质性。在这里，我们描述了一个菌株的Crithidia fasciculata中，超过90%的DNA小环表现出一个共同的模式的限制性内切酶切割位点。这一主要的微环DNA类内的切割位点的地图提出了七个限制性内切酶与六核苷酸识别序列。在更精细水平上的序列同质性反映在由具有四核苷酸识别位点的限制性酶产生的小环DNA消化模式中。主要小环类的多个克隆的部分DNA序列分析显示在核苷酸水平上几乎完全同源。在Crithidia中存在一种近乎同质的DNA微环，这将有助于研究它们在这种生物中的复制。
DNA minicircles found within the kinetoplast of the trypanosomatid Crithidia fasciculata, like those of most other kinetoplastid species, are heterogeneous in sequence. The pattern of minicircle DNA fragments generated by cleavage of kinetoplast DNA with various restriction enzymes has been used to demonstrate this heterogeneity. Here we describe a strain of Crithidia fasciculata in which more than 90% of the DNA minicircles exhibit a common pattern of restriction enzyme cleavage sites. A map of cleavage sites within this major minicircle DNA class is presented for seven restriction enzymes with hexanucleotide recognition sequences. Sequence homogeneity at an even finer level is reflected in minicircle DNA digestion patterns generated by restriction enzymes with tetranucleotide recognition sites. Partial DNA sequence analysis of multiple clones from the major minicircle class shows nearly complete homogeneity at the nucleotide level. The existence of a near homogeneous complement of DNA minicircles in Crithidia should facilitate the study of their replication in this organism.