Khan Imad, Afshan Kiran, Shah Saba, Akhtar Samreen, Komal Maria, Firasat Sabika
Department of Animal Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
Acta Parasitol. 2020 Mar;65(1):225-236. doi: 10.2478/s11686-019-00155-4. Epub 2019 Dec 17.
Little is known about the genetic and morphological characters of Paramphistomum epiclitum. For the first time in Pakistan, adult flukes were morphologically characterized and the sequence variation in the nuclear ribosomal DNA (rDNA) region, including the first internal transcribed spacers (ITS1) and the 5.8S gene of the Paramphistomum epiclitum were studied.
Adult amphistomes were examined by light microscopy and sequences of ITS1 and 5.88S rDNA genes were obtained.
Twenty adult flukes were measured, 13.17 ± 1.19 mm in length and 5.28 ± 1.34 mm in width. Seventeen adult flukes were sequenced and high sequence variability was observed in 5' end of ITS1 region. The 5.8S and 3' end of ITS1 sequences had 100% identity among the samples. A comparative analysis revealed that different types and numbers of repeats were found within each ITS1 region. The 3' end of ITS1 region from P. epiclitum showed 98% homology with P. cervi from China and formed a subclade with genetic distance of 0.1663. The 5.8S gene showed 100% identity within Paramphistomidae family and formed a sub-clade with P. epiclitum, P. leydeni, P. cervi and Cotylophoron cotylophorum species isolated from China, India and Uruguay.
This work provides new information on morphological identity and genetics of P. epiclitum from Pakistan.
关于微小片形吸虫的遗传和形态特征，我们所知甚少。在巴基斯坦首次对成虫进行了形态学鉴定，并研究了微小片形吸虫核糖体DNA（rDNA）区域的序列变异，包括第一个内部转录间隔区（ITS1）和5.8S基因。
通过光学显微镜检查成虫，并获得ITS1和5.8S rDNA基因的序列。
测量了20条成虫，体长13.17±1.19毫米，体宽5.28±1.34毫米。对17条成虫进行了测序，在ITS1区域的5'端观察到高度的序列变异性。样本中5.8S和ITS1序列的3'端具有100%的同一性。比较分析表明，每个ITS1区域内发现了不同类型和数量的重复序列。微小片形吸虫ITS1区域的3'端与来自中国的鹿片形吸虫显示出98%的同源性，并形成了一个遗传距离为0.1663的亚分支。5.8S基因在片形科内具有100%的同一性，并与从中国、印度和乌拉圭分离出的微小片形吸虫、莱登片形吸虫、鹿片形吸虫和杯殖吸虫物种形成一个亚分支。
这项工作提供了关于来自巴基斯坦的微小片形吸虫形态特征和遗传学的新信息。
