Mirella da Silva Patricia, Comesaña Pilar, Fuentes José, Villalba Antonio
Centro de Investigacións Mariñas, Consellería de Pesca e Asuntos Marítimos, Xunta de Galicia, Aptdo. 13, E-36620 Vilanova de Arousa, Spain.
Fish Shellfish Immunol. 2008 May;24(5):551-63. doi: 10.1016/j.fsi.2007.11.003. Epub 2007 Nov 21.
A research project to compare productive traits (growth and mortality), disease susceptibility and immune capability between Ostrea edulis stocks was performed. This article reports the results on the immune capability and its relation with infection by the intrahaemocytic protozoan Bonamia ostreae. Four to five oyster spat families were produced from each of four European flat oyster populations (one from Ireland, one from Greece and two from Galicia, Spain) in a hatchery. The spat were transferred to a raft in the Ría de Arousa (Galicia) for on growing for 2 years. Total haemocyte count (THC) and differential haemocyte count (DHC) were estimated monthly through the second year of growing-out. Three types of haemocytes were distinguished: granulocytes (GH), large hyalinocytes (LHH) and small hyalinocytes (SHH). Significant correlations between the mean relative abundance of GH and SHH of the families and the mean prevalence of B. ostreae, the overall incidence of pathological conditions and the cumulative mortality of the families were found; these correlations supported the hypothesis that high %GH and low %SHH would enhance oyster immune ability and, consequently, would contribute to lower susceptibility to disease and longer lifespan. Infection by B. ostreae involved a significant increase of circulating haemocytes, which affected more markedly the LHH type. The higher the infection intensity the higher the %LHH. This illustrates the ability of B. ostreae to modulate the immune responses of the O. edulis to favour its own multiplication. A significant reduction of the phenoloxidase activity in the haemolymph of oysters O. edulis infected by B. ostreae was observed. Nineteen enzymatic activities in the haemolymph of O. edulis and Crassostrea gigas (used as a B. ostreae resistant reference) were measured using the kit api ZYM, Biomerieux. Qualitative and quantitative differences in enzyme activities in both haemocyte and plasma fractions between B. ostreae noninfected O. edulis from different origins were recorded. However, no clear positive association between enzyme activity and susceptibility to bonamiosis was found. The only enzyme detected in the resistant species C. gigas that was not found in the susceptible one O. edulis was beta-glucosidase (in plasma). B. ostreae infected O. edulis showed significant increase of some enzyme activities and the occurrence of enzymes that were not detected in noninfected oysters. These changes could be due to infection-induced enzyme synthesis by the host or to enzyme synthesis by the parasite.
开展了一项研究项目，比较欧洲平牡蛎种群之间的生产性状（生长和死亡率）、疾病易感性和免疫能力。本文报告了关于免疫能力及其与血细胞内原生动物包纳米虫感染关系的研究结果。在孵化场中，从四个欧洲平牡蛎种群（一个来自爱尔兰，一个来自希腊，两个来自西班牙加利西亚）中的每一个种群培育出4至5个牡蛎幼体家系。将幼体转移到加利西亚的阿罗萨河口的筏上进行养殖2年。在养殖的第二年，每月估计总血细胞计数（THC）和不同血细胞计数（DHC）。区分出三种类型的血细胞：粒细胞（GH）、大型透明细胞（LHH）和小型透明细胞（SHH）。发现家系中GH和SHH的平均相对丰度与包纳米虫的平均患病率、病理状况的总体发病率以及家系的累积死亡率之间存在显著相关性；这些相关性支持了以下假设，即高比例的GH和低比例的SHH会增强牡蛎的免疫能力，从而有助于降低疾病易感性和延长寿命。包纳米虫感染导致循环血细胞显著增加，对LHH类型的影响更为明显。感染强度越高，LHH的比例越高。这说明了包纳米虫调节欧洲平牡蛎免疫反应以利于自身繁殖的能力。观察到被包纳米虫感染的欧洲平牡蛎血淋巴中的酚氧化酶活性显著降低。使用生物梅里埃公司的api ZYM试剂盒测量了欧洲平牡蛎和太平洋牡蛎（用作抗包纳米虫的参照）血淋巴中的19种酶活性。记录了来自不同来源的未感染包纳米虫的欧洲平牡蛎在血细胞和血浆部分的酶活性的定性和定量差异。然而，未发现酶活性与包纳米虫病易感性之间存在明显的正相关。在抗性物种太平洋牡蛎中检测到而在易感物种欧洲平牡蛎中未检测到的唯一一种酶是β-葡萄糖苷酶（在血浆中）。被包纳米虫感染的欧洲平牡蛎显示出一些酶活性显著增加，并且出现了在未感染牡蛎中未检测到的酶。这些变化可能是由于宿主感染诱导的酶合成或寄生虫的酶合成所致。
