Mladineo Ivona, Bušelić Ivana, Hrabar Jerko, Vrbatović Anamarija, Radonić Ivana
Laboratory of Aquaculture, Institute of Oceanography and Fisheries, Setaliste Ivana Metrovica 63, 21000 Split, Croatia.
Laboratory of Aquaculture, Institute of Oceanography and Fisheries, Setaliste Ivana Metrovica 63, 21000 Split, Croatia.
Mol Biochem Parasitol. 2017 Mar;212:46-54. doi: 10.1016/j.molbiopara.2017.01.003. Epub 2017 Jan 23.
Recombinant genotypes of A. simplex sensu stricto (s.s.) and A. pegreffii, two species of Anisakis simplex complex found in sympatric waters of the Mediterranean Sea, are believed to be a product of interspecific hybridisation and/or DNA introgression. In contrast, such events within an allopatric area as the Adriatic Sea are unlikely to occur and therefore observed recombination should be assessed more closely. We have genotyped 525 anisakids collected from migratory and non-migratory fish of the southern part of the Adriatic Sea, inferring its omniparentage at nuclear (ITS locus) and matrilineage at mitochondrial locus (cox2). The aim was to address the presence and cause of the recombination within the population and to test its genetic structure under admixture theory. Population parameters, i.e. prevalence, and mean abundance and intensity of anisakids were also evaluated to contribute for future epidemiological risk assessments. As a result, we have inferred the presence of A. pegreffii, A. typica and A. ziphidarum in the Adriatic, lacking type species A. simplex s.s. at both nuclear and mitochondrial locus. A. pegreffii population shows a high level of admixture and heterogeneity and a recent demographic expansion from a small population size. We argue that the observed recombinant genotypes in the Adriatic are a product of ancestral polymorphism and consequent remote genetic introgression.
在同域分布于地中海海域的简单异尖线虫狭义种（A. simplex sensu stricto，s.s.）和佩氏异尖线虫（A. pegreffii）这两种简单异尖线虫复合体的重组基因型，被认为是种间杂交和/或DNA渐渗的产物。相比之下，在亚得里亚海等异域分布区域内不太可能发生此类事件，因此应对观察到的重组进行更深入的评估。我们对从亚得里亚海南部洄游性和非洄游性鱼类采集的525条异尖线虫进行了基因分型，推断其在核基因座（ITS位点）的双亲遗传和线粒体基因座（cox2）的母系遗传。目的是探讨种群内重组的存在情况和原因，并根据混合理论检验其遗传结构。还评估了种群参数，即异尖线虫的患病率、平均丰度和感染强度，为未来的流行病学风险评估提供参考。结果，我们推断在亚得里亚海存在佩氏异尖线虫、典型异尖线虫（A. typica）和齐氏异尖线虫（A. ziphidarum），在核基因座和线粒体基因座均未发现狭义简单异尖线虫。佩氏异尖线虫种群表现出高度的混合性和异质性，且近期经历了从小种群规模开始的种群扩张。我们认为在亚得里亚海观察到的重组基因型是祖先多态性和随之而来的远距离基因渐渗的产物。
