Novoa B, Posada D, Figueras A
Instituto de Investigaciones Marinas, CSIC, Vigo, Spain.
J Fish Dis. 2005 Jun;28(6):331-8. doi: 10.1111/j.1365-2761.2005.00634.x.
Marteilia refringens is a protozoan parasite causing a disease notifiable to the Office International des Epizooties (OIE) and its distribution has implications for the transfer of live animals. The internal transcribed spacer-1 (ITS-1) from Marteilia clones contains polymorphism. Digestion with HhaI reveals two different restriction profiles, previously referred as 'O' (Marteilia from oyster or Marteilia refringens) and 'M' (Marteilia from mussels or Marteilia maurini). The aim of the present work was to determine whether the two previously described Marteilia molecular types (O and M) exist in the Iberian Peninsula and the strictness of the association with their bivalve host species. The sequence variability in the ITS-1 of Marteilia species was studied in mussels, Mytilus galloprovincialis, and flat oysters, Ostrea edulis, from different geographical locations in Spain, to establish the existence and the distribution of different species or molecular types. Although there were two distinct evolutionary lineages that corresponded more or less strictly with the 'M' and 'O' types, it was evident from the estimated phylogeny that some 'O' types have switched to 'M' type, and vice versa. Moreover, 'O' types were found in mussels and 'M' types were found in oysters, which suggests that there have been several cross-species transmissions of Marteilia between mussels and oysters.
折射马尔太虫是一种原生动物寄生虫，可引发一种须向国际兽疫局（OIE）通报的疾病，其分布情况对活体动物的运输有影响。来自马尔太虫克隆体的内部转录间隔区1（ITS-1）存在多态性。用HhaI酶切可揭示两种不同的限制性图谱，之前分别称为“O”型（来自牡蛎的马尔太虫或折射马尔太虫）和“M”型（来自贻贝的马尔太虫或毛利马尔太虫）。本研究的目的是确定伊比利亚半岛是否存在之前描述的两种马尔太虫分子类型（O型和M型），以及它们与双壳贝类宿主物种关联的严格程度。对来自西班牙不同地理位置的贻贝（加利福尼亚贻贝）和扁牡蛎（食用牡蛎）中马尔太虫物种的ITS-1序列变异性进行了研究，以确定不同物种或分子类型的存在及分布情况。尽管存在两个明显的进化谱系，它们或多或少与“M”型和“O”型严格对应，但从估计的系统发育来看，很明显一些“O”型已转变为“M”型，反之亦然。此外，在贻贝中发现了“O”型，在牡蛎中发现了“M”型，这表明马尔太虫在贻贝和牡蛎之间发生了多次跨物种传播。
