Kumar Susheel, Kaur Harpreet
Parasitology Laboratory, Department of Zoology, Panjab University, Chandigarh, India.
Syst Parasitol. 2025 May 14;102(3):36. doi: 10.1007/s11230-025-10235-x.
This study presents morphological, molecular and phylogenetic analyses of two species of the genus Avitellina, A. sudanea and A. centripunctata parasitic in sheep and goats and sampled in the region of the City of Chandigarh, North India. Three molecular markers were used: mitochondrial cytochrome c oxidase subunit 1 (cox1), nuclear small subunit ribosomal RNA (SSU rDNA) and internal transcribed spacer 1-5.8S rRNA (ITS1-5.8S rDNA) genes. Morphological analysis revealed differences in key structures, including paruterine organ shape and testis arrangement. Molecular analysis revealed that A. sudanea showed no exact match but significant similarity with other species: A. lahorea and A. centripunctata, exhibiting 91.39% and 85.89-86.52% (SSU rDNA), 96.27 and 94.31% (cox1), 94.19 and 94.41% (ITS1-5.8S rDNA) sequence similarity, respectively. The Maximum Likelihood phylogenetic trees based on DNA sequences of SSU rRNA, cox1 and ITS1 placed these species in a separate clade, which was distinct from anoplocephalids (sensu stricto) and supported the thysanosomatids as a distinct taxon at the family level. The evolutionary divergence based on base substitution rates confirmed substantial interspecific genetic distinctions, with high divergence values of 0.12 (cox1), 0.25 (SSU rDNA) and 0.11 (ITS1-5.8S rDNA) between A. sudanea and A. centripunctata. This study provides the first molecular characterization of A. sudanea, confirming its genetic distinctiveness and taxonomic status as a valid species. Our findings highlight the necessity for more molecular studies on Avitellina tapeworms using robust genetic tools to ensure accurate taxonomic delineation within the genus.
本研究对寄生于绵羊和山羊体内、采自印度北部昌迪加尔市地区的苏丹阿维太利绦虫（Avitellina sudanea）和中点阿维太利绦虫（A. centripunctata）这两种阿维太利绦虫属物种进行了形态学、分子生物学和系统发育分析。使用了三种分子标记：线粒体细胞色素c氧化酶亚基1（cox1）、核糖体小亚基RNA（SSU rDNA）和内部转录间隔区1 - 5.8S rRNA（ITS1 - 5.8S rDNA）基因。形态学分析揭示了关键结构的差异，包括子宫旁器形状和睾丸排列。分子分析表明，苏丹阿维太利绦虫与其他物种：拉霍雷阿维太利绦虫（A. lahorea）和中点阿维太利绦虫没有完全匹配，但有显著相似性，在SSU rDNA上分别表现出91.39%和85.89 - 86.52%、在cox1上分别为96.27%和94.31%、在ITS1 - 5.8S rDNA上分别为94.19%和94.41%的序列相似性。基于SSU rRNA、cox1和ITS1的DNA序列构建的最大似然系统发育树将这些物种置于一个单独的分支中，该分支与狭义无钩绦虫不同，并支持将蒂萨诺体绦虫作为科级的一个独特分类单元。基于碱基替代率的进化分歧证实了种间存在显著的遗传差异，苏丹阿维太利绦虫和中点阿维太利绦虫之间的分歧值较高，cox1为0.12、SSU rDNA为0.25、ITS1 - 5.8S rDNA为0.11。本研究首次对苏丹阿维太利绦虫进行了分子特征描述，证实了其遗传独特性和作为一个有效物种的分类地位。我们的研究结果强调了使用强大的遗传工具对阿维太利绦虫进行更多分子研究的必要性，以确保该属内准确的分类界定。
