在中上层鱼类中,胚胎浮力是繁殖策略的一个值得注意的方面,与整体质量有关,生存,和进一步的发展成功。在囚禁中,早期胚胎浮力的丧失与高死亡率相关,这可能与大量细胞死亡有关。因此,这项研究的目的是评估在圈养条件下,与中上层鱼类Seriolalalandi的早期胚胎发育过程中与凋亡过程相关的基因的表达,以及它与胚胎浮力的关系。bcl2的相对表达,bax样,通过RT-qPCR评估casp9,casp8和casp3,并通过蛋白质印迹评估FasL/Fas蛋白水平,这些胚胎分为漂浮或低漂浮的胚胎的五个发育阶段。在发育的24小时内,所有检查的基因都在漂浮和低漂浮胚胎中表达。促凋亡因子bax的表达,casp9,casp8和casp3在低漂浮胚胎中以特定发育阶段的方式高于漂浮胚胎。相比之下,漂浮和低漂浮胚胎之间bcl2的表达没有差异。Fas蛋白在漂浮胚胎中被检测为一条条带,在整个发育过程中表达没有变化;然而,在低漂浮的胚胎中,在24小时胚胎中检测到三个更高强度的反应带。有趣的是,FasL仅在漂浮胚胎中24小时检测到,而在低浮动样品中,这种配体存在于所有阶段,随着发展的推进,急剧增加。细胞死亡,通过末端脱氧核苷酸转移酶介导的dUTP缺口末端标记测定法评估,与所有发育阶段的漂浮胚胎相比,低漂浮胚胎的数量大大增加,与胃阶段和在24小时观察到的最高水平。这项研究的结果表明,细胞死亡的增加,可能与内在和外在的凋亡途径有关,存在于低漂浮胚胎中,这可能解释了它们在圈养条件下的较低发育潜力。
In pelagic fish, embryo buoyancy is a noteworthy aspect of the reproductive strategy, and is associated with overall quality, survival, and further developmental success. In captivity, the loss of buoyancy of early embryos correlates with high mortality that might be related to massive cell death. Therefore, the aim of this study was to evaluate under captivity conditions the expression of genes related to the apoptosis process during the early embryonic development of the pelagic fish
Seriola lalandi, and its relationship to the buoyancy of embryos. The relative expression of bcl2, bax-like, casp9, casp8, and casp3 was evaluated by RT-qPCR and FasL/Fas protein levels by western blot in five development stages of embryos sorted as floating or low-floating. All genes examined were expressed in both floating and low-floating embryos up to 24 h of development. Expression of the pro-apoptotic factors bax, casp9, casp8, and casp3 was higher in low-floating as compared with floating embryos in a developmental stage-specific manner. In contrast, there was no difference in expression of bcl2 between floating and low-floating embryos. Fas protein was detected as a single band in floating embryos without changes in expression throughout development; however, in low-floating embryos, three higher intensity reactive bands were detected in the 24-h embryos. Interestingly, FasL was only detected at 24-h in floating embryos, whereas in low-floating samples this ligand was present at all stages, with a sharp increase as development progressed. Cell death, as evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, was highly increased in low-floating embryos as compared to floating embryos throughout all developmental stages, with the highest levels observed during the gastrula stage and at 24 h. The results of this study suggest that an increase in cell death, probably associated with the intrinsic and extrinsic apoptosis pathways, is present in low-floating embryos that might explain their lower developmental potential under captivity conditions.