López-Hernández Danimar, de Melo Alan Lane, Pinto Hudson Alves
Department of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, P.O. Box 486, 30123-970, Belo Horizonte, Minas Gerais, Brazil.
J Parasitol. 2023 Mar 1;109(2):129-134. doi: 10.1645/22-87.
Species of the family Reniferidae are trematodes found in the oral cavity and esophagus of snakes from Nearctic and Neotropical regions. Although Renifer heterocoelium has been reported in different snake species from South America, the snails involved in its transmission remain unknown. In this study, a xiphidiocercaria emerged from the physid snail Stenophysa marmorata from Brazil and was subjected to morphological and molecular study. The general morphology, including the shape of the stylet and arrangement of penetration glands, resembles that described for reniferid trematodes from North America. Phylogenetic analysis on the basis of nuclear sequences (28S ribosomal deoxyribonucleic acid gene [1,072 base pairs {bp}] and internal transcribed spacer region [ITS, 1,036 bp]) supports identifying this larva as a member of the family Reniferidae, very possibly a species of the genus Renifer. In the 28S analysis, low molecular divergences were found to Renifer aniarum (1.4%) and Renifer kansensis (0.6%), but also concerning other 2 reniferid species, i.e., Dasymetra nicolli (1.4%) and Lechriorchis tygarti (1.0%). Regarding ITS, the divergences between this Brazilian cercaria and R. aniarum or L. tygarti were 1.9% and 8.5%, respectively. In the case of the mitochondrial marker cytochrome oxidase subunit 1 (797 bp), our Reniferidae gen. sp. differs 8.6-9.6% from Paralechriorchis syntomentera, the only reniferid with sequences available for comparison. We discuss the probable conspecificity of the larval stages here reported with R. heterocoelium, the reniferid species reported in South America.
雷尼吸虫科的物种是在新北区和新热带区蛇类的口腔和食道中发现的吸虫。尽管已在南美洲的不同蛇类物种中报道过异腔雷尼吸虫，但参与其传播的蜗牛仍不为人知。在本研究中，一种尾蚴从巴西的大理石纹窄口螺中逸出，并对其进行了形态学和分子学研究。其总体形态，包括口针的形状和穿刺腺的排列，与北美雷尼吸虫科吸虫所描述的相似。基于核序列（28S核糖体脱氧核糖核酸基因[1072个碱基对{bp}]和内转录间隔区[ITS，1036 bp]）的系统发育分析支持将这种幼虫鉴定为雷尼吸虫科的成员，很可能是雷尼属的一个物种。在28S分析中，发现与尼亚雷尼吸虫（1.4%）和堪萨斯雷尼吸虫（0.6%）的分子差异较小，但与其他两种雷尼吸虫科物种，即尼氏粗盘吸虫（1.4%）和泰氏裂盘吸虫（1.0%）的差异也较小。关于ITS，这种巴西尾蚴与尼亚雷尼吸虫或泰氏裂盘吸虫之间的差异分别为1.9%和8.5%。在线粒体标记细胞色素氧化酶亚基1（797 bp）的情况下，我们的雷尼吸虫科属种与可用于比较序列的唯一雷尼吸虫科物种——共肠副裂盘吸虫的差异为8.6 - 9.6%。我们讨论了此处报道的幼虫阶段与在南美洲报道的异腔雷尼吸虫可能的同种性。
