Takeet Michael I, Fagbemi Benjamin O, Peters Sunday O, DeDonato Marcos, Yakubu Abdul-Mojeed, Wheto Mathew, Imumorin Ikhide G
Animal Genetics and Genomics Laboratory, International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853 USA.
Department of Veterinary Microbiology and Parasitology, Federal University of Agriculture, Abeokuta, Abeokuta, Nigeria.
J Parasit Dis. 2017 Jun;41(2):433-441. doi: 10.1007/s12639-016-0822-1. Epub 2016 Aug 13.
(sub-genus Duttonella) is largely responsible for non profitable livestock production in sub-Sahara Africa. In Nigeria, no study has addressed the molecular characteristic of except Y486. Hence, we characterized and assessed the genetic diversity among detected in naturally infected cattle in Nigeria using internal transcribed spacer 1 (ITS1) of ribosoma DNA (rDNA) and diagnostic antigen gene (DAG) sequences. The length of ITS1 and DAG sequences range from 215-220 to 257-338 bp, respectively and the mean G-C contents were 60 and 61.5 %. Homology search revealed 93-99 and 95-100 % homologies to DAG and ITS1 sequences from GenBank. Aligned sequences revealed both ITS1 rDNA and DAG to be less polymorphic but DAG sequences of the Y486 strain and its clone showed marked variation from autochthonous strains. Phylogenetic analysis yielded tree that grouped ITS1rDNA gene and DAG sequences into two main clades each. Considering the ITI1 rDNA sequences, clade A contained autochthonous within which the South American sequences clustered, clade B contained the sequences of from East Africa. Analysis of DAG revealed that the clade A contains autochthonous sequences but clade B contained the Y486 and its clones. In conclusion, the diagnostic antigen gene sequences of the detected in this study may have undergone considerable gene recombination through time and suggests that more than one strain of exist among cattle population in Nigeria.
（达顿氏虫亚属）在很大程度上导致了撒哈拉以南非洲地区畜牧业生产无利可图。在尼日利亚，除了Y486菌株外，尚无研究涉及[具体虫种]的分子特征。因此，我们利用核糖体DNA（rDNA）的内部转录间隔区1（ITS1）和诊断抗原基因（DAG）序列，对在尼日利亚自然感染牛体内检测到的[具体虫种]进行了特征分析并评估了其遗传多样性。ITS1和DAG序列的长度分别为215 - 220 bp至257 - 338 bp，平均G - C含量分别为60%和61.5%。同源性搜索显示，与GenBank中[具体虫种]的DAG和ITS1序列的同源性分别为93 - 99%和95 - 100%。比对后的序列显示，ITS1 rDNA和DAG的多态性均较低，但Y486菌株及其克隆的DAG序列与本地菌株存在明显差异。系统发育分析得到的树状图将[具体虫种]的ITS1 rDNA基因和DAG序列分别分为两个主要分支。考虑ITS1 rDNA序列，分支A包含本地[具体虫种]，其中南美序列聚集在一起，分支B包含来自东非的[具体虫种]序列。对DAG的分析表明，分支A包含本地[具体虫种]序列，而分支B包含Y486及其克隆。总之，本研究中检测到的[具体虫种]的诊断抗原基因序列可能随时间发生了相当程度的基因重组，这表明尼日利亚牛群中存在不止一种[具体虫种]菌株。
