Villalba Antonio, Coimbra Raquel M, Pampín Marina, Iglesias David, Costas Damián, Mariño Carlos, Blanco Andrés, Vera Manuel, Domínguez Marta, Cacabelos Eva, Abella Emilio, Incera Mónica, Otero Rosa Fernández, Martínez Paulino
Centro de Investigacións Mariñas (CIMA), Consellería do Mar, Xunta de Galicia Vilanova de Arousa Spain.
Departamento de Ciencias de la Vida Universidad de Alcalá Alcalá de Henares Spain.
Evol Appl. 2023 Oct 17;16(11):1789-1804. doi: 10.1111/eva.13601. eCollection 2023 Nov.
The common cockle is a valuable bivalve species inhabiting the Atlantic European coasts. The parasite has devastated cockle beds in the southern Galician (NW Spain) rias since 2012. Previous data suggested that cockles from Ría de Arousa acquired some resilience to this parasite through natural selection after consecutive annual marteiliosis outbreaks and candidate markers associated with marteiliosis resilience were identified using population genomics and transcriptomics approaches. Here, a common garden experiment was performed using a naïve stock (from Ría de Muros-Noia) and an affected stock (from Ría de Arousa) to test this hypothesis. Breeders from both stocks were used to produce seed cohorts at hatchery, which were pre-grown in a raft (outdoor nursery stage) and deployed in two shellfish beds affected by marteiliosis in Ría de Arousa (growing-out stage). In both beds, the naïve stock showed high marteiliosis prevalence and was fully depleted in a short period, while the affected stock barely showed evidence of marteiliosis. A set of 45 SNPs putatively associated with marteiliosis resilience were fitted for MassARRAY genotyping to check their role in the differential resilience detected between both stocks. Though no significant differentiation was found between the naïve and the affected stocks with neutral markers, 28 SNPs showed significant divergence between them, suggesting that these SNPs were involved in directional selection during eight generations (to the most) of marteiliosis pressure (long-term selection). Furthermore, signals of selection were also detected in the naïve stock along the marteiliosis outbreak in the growing-out stage (short-term selection) and six SNPs, all shared with the long-term evaluation, showed consistent signals of differentiation according to the infection severity. Some of these SNPs were located within immune genes pertaining to families such as proteasome, ubiquitin, tumor necrosis factor, and glutathione S-transferase. These resilience-associated markers will be useful to recover cockle production in Galicia.
鸟蛤是一种有价值的双壳类物种，栖息在欧洲大西洋沿岸。自2012年以来，这种寄生虫已对西班牙西北部加利西亚南部里亚斯的鸟蛤养殖场造成了严重破坏。先前的数据表明，在连续多年爆发马尔太虫病后，阿罗萨里亚斯的鸟蛤通过自然选择获得了对这种寄生虫的一定抵抗力，并且利用群体基因组学和转录组学方法鉴定出了与马尔太虫病抵抗力相关的候选标记。在此，进行了一项共同花园实验，使用了一个未受影响的种群（来自穆罗斯-诺亚里亚斯）和一个受影响的种群（来自阿罗萨里亚斯）来验证这一假设。两个种群的亲贝在孵化场用于培育幼体群体，这些幼体先在筏式养殖中预先培育（室外育苗阶段），然后被放置在阿罗萨里亚斯两个受马尔太虫病影响的贝类养殖场（养成阶段）。在这两个养殖场中，未受影响的种群显示出高马尔太虫病患病率，并在短时间内全部死亡，而受影响的种群几乎没有显示出马尔太虫病的迹象。一组假定与马尔太虫病抵抗力相关的45个单核苷酸多态性（SNP）被用于MassARRAY基因分型，以检查它们在两个种群间检测到的不同抵抗力中的作用。尽管使用中性标记在未受影响和受影响的种群之间未发现显著差异，但有28个SNP在它们之间显示出显著差异，这表明这些SNP在八代（最多）马尔太虫病压力（长期选择）期间参与了定向选择。此外，在养成阶段马尔太虫病爆发期间，在未受影响的种群中也检测到了选择信号（短期选择），并且六个SNP，均与长期评估结果相同，根据感染严重程度显示出一致的差异信号。其中一些SNP位于与蛋白酶体、泛素、肿瘤坏死因子和谷胱甘肽S-转移酶等家族相关的免疫基因内。这些与抵抗力相关的标记将有助于恢复加利西亚的鸟蛤产量。
