研究重點

本實驗室致力於探討海洋動物面臨氣候變遷（海洋酸化及溫度變化）與極端環境因子波動衝擊下，海洋生物如何進行有效地進行生理調節機制以適應環境。本團隊運用次世代基因體學、代謝體學、行為表徵、以及表觀遺傳等研究方法，結合臺灣四面環海的絕佳海洋生物學研究優勢，以臺灣海域的頭足類動物（軟絲、花枝、章魚）、硬骨魚（吳郭魚、青鱂魚）、甲殼類動物（烏龜怪方蟹、大閘蟹）、以及棘皮類動物（海膽、陽隧足）為研究物種，進行綜合性比較生理學研究。以求突破過往海洋生物研究的知識與傳統，準確且深入地探討海洋動物生態學表徵背後的生理學意義。

Our team specially focuses on the impacts of environmental perturbations (e.g. ocean acidification and temperature variations) on both embryos and adults of aquatic animals. Integration of molecular genome databases, physiological approaches and biochemical techniques, we try to take advantage of molecular approaches coupled with eco-physiological studies for exploring deeper and practical biological significances behind superficial appearances.

 

 

海水表層的酸化情形往往伴隨著暖化現象的產生，可能會對於在此海域區段棲息的動物個體造成自小分子到大整體全面性的系統生理影響。而在此棲息的狹溫性動物在同時面臨高溫高碳酸刺激擾動下的生理衝擊，至今仍鮮為人知。
本實驗室利用生物外表型模組觀測、即時生理參數檢測、次世代高速定序分析、行為表徵、表觀遺傳、以及基因表現相分析等研究方法，以全方位Eco – Evo - Devo-（生態 - 演化 - 發育）的生物網絡思維，研究海洋環境酸鹼值及溫度波動對於海洋運動型生物如頭足類動物（萊氏擬烏賊及章魚）、甲殼類動物(烏龜怪方蟹)、與硬骨魚類（青鱂魚）胚胎及成體的生理衝擊影響。

Acidification of surface seawater will be accompanied by warming which may significantly affect an organisms thermal window for physiological processes from the molecular to the systemic level. To date there is still a gap in knowledge regarding the effects of environmental hypercapnia within and beyond the limits of the thermal tolerance of marine organisms, which may significantly alter their capacity to acclimate to CO₂ induced acid-base disturbances.

We are focusing on the biometric analysis regarding phenotypes, physiological parameters and gene expressions of marine athletic animals such as teleosts (medaka), crustaceans (hydrothermal vent crab) and cephalopods (squid and octopus) with low variations of ambient pH (0.4~0.7 units) and temperature . Embryonic development and adult responses are both examining subjects for the global challenging issue.

 

 

深海熱泉支持著獨特的生態系統，其中包含了從微生物到脊椎動物豐富的生物多樣性。為了要在如此極端的環境生存，生物發展出特殊的形態和生理機制，以適應高溫、高硫、低氧、高二氧化碳和低酸鹼值的棲地。台灣北方的龜山島的淺海熱泉即是這類生物的代表棲地。龜山島熱泉的是一個高溫(76-116℃)、極度酸化(pH 1.5-2.5)的海底熱泉系統；此外，此處的排水含有大量的硫化物。在如此特殊的環境中，只有少數物種可以生存。例如在噴口附近的烏龜怪方蟹(Xenograpsus testudinatus)，是唯一生存於此的後生動物。
對甲殼類動物而言，鰓是參與細胞外離子與酸鹼平衡的主要器官，鰓表面的離子調節上皮所具有的離子主動/被動運輸機制在演化則相當的保守。在本團隊最近的研究中，我們找到烏龜怪方蟹主要的酸價與硫的排除通道。與脊椎動物相似，烏龜怪方蟹的鰓表皮細胞上有眾多的膜通道蛋白，這些通道幫浦在怪方蟹所有的鰓對上都有存在，並維持了烏龜怪方蟹的酸鹼平衡功能。此外，龜山島熱泉對生物的生理挑戰不僅是酸鹼調節，同時也包括了如何克服環境硫化氫的毒性。我們認為，在熱泉系統中的甲殼類應該具有比其他物種更好的控制硫化物與酸鹼恆定性。此外，日本九州鹿兒島南方海域也存在著與龜山島相似的淺海熱泉，在鹿兒島的熱泉生態系也發現與烏龜怪方蟹相似的種類。然而，此海域環境酸鹼值卻明顯低於龜山島海域。藉由比較在這兩個不同環境下生活的怪方蟹是否有不同的適應機制，可望了解酸鹼或硫化物調控的次主動運輸幫浦蛋白的演化關係。酸鹼與離子調節機制對甲殼類來說，不僅是一個物種演化的現象，在物種與生態的永續維持也至關重要。

Mechanisms of ion and acid-base regulation in aquatic animals have become a research focus especially in primitive teleosts and tetrapods. During colonization from open sea to freshwater habitats, maintenance of ionic gradients and even active ion transport are essential for cellular homeostasis and further adaptation to terrestrial life. While in the case of teleosts, progress in molecular physiology research has enabled a detailed understanding of epithelial ionocyte function.
For internal pH homeostasis, the epithelial ionocytes have to secret H⁺ from the blood, which is acidified due to the metabolic/respiratory acidosis or the impacts of environmental pH fluctuations. Recent molecular physiological studies proposed that the Na⁺ uptake/acid secretion mechanisms in teleosts epithelium ionocytes are homologous to those in proximal tubular cells of mammalian kidneys. Through the functioning of membrane-bound carbonic anhydrase (CA), ambient HCO₃^- and H⁺ secreted by the apical Na⁺/H⁺ exchanger (NHE, in SW organisms) or V-type H⁺-ATPase (VHA, in FW organisms) react to form CO₂ and H₂O outside of apical membranes of epithelium ionocytes, and this enables the passive diffusion of CO₂ into ionocytes. Then the cytosolic CA hydrates CO₂ to form HCO₃^- and H⁺. In addition, VHA may electrically link to absorption via the epithelial Na⁺ channel (ENaC) for epithelium apical Na⁺. Through the investigation of epithelial ion transport machinery in primitive a diverse aquatic animals such hagfish, lamprey, sturgeon and shark, we can explore the homeostasis mysteries behind fish terrestrialization.

 

 

低溫緊迫或酸化波動已知會使誘發水生動物複雜的基因相變化及生化反應，並在一些重要器官強化粒線體的活性以提高代謝機制。然而粒線體提升呼吸作用的同時可能會導致生物體的傷害，

包括活性氧化物質（ROS）的形成累積、粒線體內膜氫離子的溢漏增加、以及脂質過氧化反應的產生。其中粒線體ROS過量累積已知會造成細胞面臨氧化壓力。因此，我們透過了解水生動物適應性代謝調節、轉錄體與代謝體資料庫建構、以及行為表徵的模式建立，綜合探討極端環境溫度變動下，水生動物個體內生理調節的變化，並進行細胞抗氧化相關機制的觀察。這些發現對於往後進一步研究並發展出應用於水生動物養殖產業的實際可行的策略，提供了重要的素材。

Environmental perturbation, such as cold stress and hypercapnia, triggers a complex program of gene expressions and biochemical responses in different tissues of aquatic animals. In several vital organs increments of mitochondrial properties enhance the metabolic capacity. Nevertheless, raising the mitochondrial respiration rates may lead to deleterious consequences, including reactive oxygen species (ROS) formation, proton leak increment and lipid peroxidation. Among them, mitochondrial ROS overproduction usually results in cellular oxidative stress. Therefore, an antioxidant mechanism through HIF (hypoxia-induced factor) regulations, PPAR (peroxisome proliferator-activated receptor) pathways, UCP (uncoupling protein) activations and the changes in carbohydrates metabolism under environmental stress were studied.
We are focusing on cellular moderate metabolism shift for adequate energy supply and further antioxidant mechanism by studying intact organisms (medaka and cephalopods embryos) in face of ambient cold stress and CO₂ elevation.

著作目錄

1. Weaver, R., Hill, G. E., Kuan, P. L., Tseng, Y. C. Copper exposure reduces production of red carotenoids in a marine copepod. Ecol Indic, 70, 393-400, 2016. (Environmental science; Ranking: 52/225=23 %; IF: 3.190)

 

2. Hu, M. Y., Michael, K., Kreiss, C. M., Stumpp, M., Dupont, S, Tseng, Y. C.#, Lucassen, M.. Temperature modulates the effects of ocean acidification on intestinal ion transport in Atlantic cod, Gadus morhua. Front Physiol, 7, 198, 2016. (Physiology; Ranking: 20/83=24 %; IF: 4.031) (Corresponding author)

 

3. Hu, M. Y., Guh, Y. J., Shao, Y. T., Kuan, P. L., Chen, G. L., Lee, J. R., Jeng, M. S., Tseng, Y. C.#. Strong ion regulatory abilities enable the crab Xenograpsus testudinatus to inhabit highly acidified marine vent systems. Front Physiol 7, 14, 2016. (Physiology; Ranking: 20/83=24 %; IF:; 4.031) (Corresponding author)

 

4. Wang, Y. F., Yan, J. J., Tseng, Y. C. , Chen, R. D., Hwang, P. P. Molecular physiology of an extra-renal Cl- uptake mechanism for body fluid Cl- homeostasis. Int J Biol Sci 11(10), 1190-1203, 2015. (Biochemistry & Molecular Biology; Ranking: 63/289=22 %; IF: 3.982)

 

5. Hu, M. Y., Hwang, P. P., Tseng, Y. C.# Recent advances in understanding trans-epithelial acid-base regulation and excretion mechanisms in cephalopods. Tissue Barriers 3(4), e1064196. (Invited review article)

 

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