Rojas Isis, Cárcamo Claudia B, Defranchi Yohana, Jeno Katherine, Rengel José, Araya Michael, Tarnok María Elena, Aguilar Luis, Álvarez Gonzalo, Schmitt Paulina, Brokordt Katherina
Doctorado en Acuicultura, Programa Cooperativo Universidad de Chile, Pontificia Universidad Católica de Valparaíso, Universidad Católica del Norte, Coquimbo 1781421, Chile.
Laboratorio de Fisiología Marina (FIGEMA), Departamento de Acuicultura, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo 1780000, Chile.
Animals (Basel). 2023 Apr 20;13(8):1416. doi: 10.3390/ani13081416.
Massive mortalities in farmed larvae of the scallop have been associated with pathogenic outbreaks. An energetic trade-off between development-associated demands and immune capacity has been observed. Given that highly unsaturated fatty acids (HUFAs) are essential nutrients for larval development, we evaluated the effect of diets based on microalgae low and high in HUFAs (LH and HH, respectively) on the energetic condition and the immune response of scallop larvae. The results showed that the HH diet increased cellular membrane fluidity in veliger larvae. The routine respiration rate was 64% higher in the HH-fed veligers than in the LH-fed veligers. Additionally, the metabolic capacity tended to be higher in the HH-fed veligers than in the LH-fed veligers after the challenge. After the challenge, the HH-fed veligers presented higher transcript induction of (immune receptor) and (immune effector) genes, and the HH-fed pediveligers presented higher induction of (antimicrobial immune effector) gene, than the LH-fed larvae. Furthermore, the HH-fed veligers controlled total proliferation (maintaining near basal levels) after the bacterial challenge, while the LH-fed veligers were not able to control this proliferation, which increased three-fold. Finally, the HH-fed larvae showed 20-25% higher growth and survival rates than the LH-fed veligers. Overall, the results indicated that the administration of a HH diet increases cell membrane fluidity and energy metabolic capacity, which in turn enhances immunity and the ability to control proliferation. The administration of microalgae high in HUFAs would be a promising strategy for improving scallop larval production efficiency.
养殖扇贝幼虫的大规模死亡与致病性疫情有关。人们观察到在发育相关需求和免疫能力之间存在能量权衡。鉴于高度不饱和脂肪酸（HUFAs）是幼虫发育的必需营养素，我们评估了基于低HUFA和高HUFA微藻（分别为LH和HH）的饲料对扇贝幼虫能量状况和免疫反应的影响。结果表明，HH饲料增加了面盘幼虫的细胞膜流动性。喂食HH的面盘幼虫的常规呼吸率比喂食LH的面盘幼虫高64%。此外，在受到挑战后，喂食HH的面盘幼虫的代谢能力往往高于喂食LH的面盘幼虫。受到挑战后，与喂食LH的幼虫相比，喂食HH的面盘幼虫的（免疫受体）和（免疫效应器）基因的转录诱导更高，喂食HH的匍匐幼虫的（抗菌免疫效应器）基因的诱导更高。此外，喂食HH的面盘幼虫在细菌挑战后控制了总增殖（维持在接近基础水平），而喂食LH的面盘幼虫无法控制这种增殖，其增殖增加了三倍。最后，喂食HH的幼虫的生长和存活率比喂食LH的面盘幼虫高20-25%。总体而言，结果表明，给予HH饲料可增加细胞膜流动性和能量代谢能力，进而增强免疫力和控制增殖的能力。给予富含HUFA的微藻将是提高扇贝幼虫生产效率的一个有前景的策略。
