Antarctic krill (Euphausia superba) acquire a UV-absorbing mycosporine-like amino acid from dietary algae
Antarctic krill (Euphausia superba) acquire a UV-absorbing mycosporine-like amino acid from dietary algae
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DOI：
10.1016/s0022-0981(00)00293-8
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发表时间：
2000-12-01
影响因子：
2
通讯作者：
Ritz, D
中科院分区：
文献类型：
--
作者：
Newman, SJ;Dunlap, WC;Ritz, D
我们假设，南极磷虾收购紫外线吸收类菌孢菌素氨基酸（MAAs）从饮食藻类，产生MAAs在响应紫外线（UV）照射。为了验证这一假设，我们培养了在光合有效辐射（PAR，400-750 nm）加UV照射（UVR，280-400 nm）或仅PAR下生长的南极棕囊藻培养物。藻类生长在PAR下，只产生高浓度的卟啉-334，而额外的紫外线辐射导致形成高浓度的菌孢霉素-甘氨酸：缬氨酸和较低浓度的卟啉-334。在63天内，磷虾被喂食这两种培养物中的任何一种，共8次。第三组在实验期间处于饥饿状态。在36天和63天后分析动物的MAA含量。将所有处理的剩余动物再饥饿35天，并进行分析以检查MAA保留特征。我们的研究结果是，磷虾获得不同的MAA从饮食藻类根据光照条件下生长的藻类。具体而言，磷虾喂养的藻类下生长PAR只有比饥饿的磷虾具有更高浓度的紫菜-334。相反，磷虾喂藻类PAR下生长与额外的WR有较高的身体浓度的菌孢菌素-甘氨酸：缬氨酸。在整个实验中，饥饿的磷虾中的MAA浓度保持不变。然而，长期饥饿（35天）导致某些获得性MAA水平下降。由此我们可以推断，磷虾中的MAA浓度取决于浮游植物的MAA含量，因此藻类对紫外线照射的反应。这对通过海洋营养网转移MAAs产生了影响。(C)2000 Elsevier Science BN。All rights reserved.
We hypothesised that Antarctic krill acquire UV-absorbing mycosporine-like amino acids (MAAs) from dietary algae, which produce MAAs in response to ultraviolet (UV) irradiation. To test this hypothesis, we grew cultures of Phaeocystis antarctica that had been grown under either photosynthetically active radiation (PAR, 400-750 nm) plus UV irradiation (UVR, 280-400 nm), or else PAR-only. Algae grown under PAR-only produced high concentrations of porphyra-334, whereas additional UVR caused formation of high concentrations of mycosporine-glycine:valine and lower concentrations of porphyra-334. Krill were fed with either of these two cultures on eight occasions over 63 days. A third group was starved for the duration of the experiment. Animals were analysed after 36 and 63 days for MAA content. Remaining animals from all treatments were starved for a further 35 days and analysed to examine MAA retention characteristics. Our findings are that krill acquired different MAAs from dietary algae depending on the light conditions under which the algae were grown. Specifically, krill fed algae grown under PAR-only had higher concentrations of porphyra-334 than starved krill. Conversely, krill fed algae grown under PAR with additional WR had high body concentrations of mycosporine-glycine :valine. MAA concentrations in starved krill remained static throughout the experiment. However, long term starvation (35 days) caused levels of certain acquired MAAs to decline. From this we can infer that MAA concentrations in krill are dependent on the MAA content of phytoplankton, and therefore the algae's response to UV exposure. This has implications for transfer of MAAs through marine trophic webs. (C) 2000 Elsevier Science BN. All rights reserved.