Aurantiochytrium strain BL10是破囊壺菌 (thraustochytrid) 中，少數會大量產生阿米巴細胞 (amoeboid cell) 的品系，其形成的原因與遷移機制目前尚未釐清。由過去實驗室長期的培養及觀察中，已知於液態培養條件下，阿米巴細胞容易出現在BL10的對數生長期，同時當營養基中有較高的葡萄糖、酵母萃出物及硫酸根離子濃度時，阿米巴細胞的比例也會隨之提高。由於在液態培養的條件下，培養基內溶氧量達到最低時，恰好也是阿米巴出現的比例達到最高峰的時候，因此溶氧量的降低可能是另一個會誘發阿米巴細胞形成的外生性因子。在固態培養條件下，阿米巴細胞則容易出現在遠離其他細胞群聚的位置，同時朝向遠離細胞群聚的方向移動。由此推測，細胞密度提高所導致周遭的營養濃度降低，或是自體分泌物質的增加，可能影響阿米巴細胞的形成，乃至於其遷徙方向。
　　為進一步探討BL10形成阿米巴細胞之原因，在液態培養部份，分析培養過程中阿米巴出現的時間點和比例與生長曲線、溶氧量、pH值以及培養基成分的相關性，發現阿米巴細胞的大量出現和溶氧量最低點時間一致 (10-12 hours) ，且若將培養基營養濃度提高，則會有更低的溶氧量與更高的阿米巴細胞比例，由此推測溶氧量應是誘發阿米巴細胞形成的重要原因之一。而在固態培養部分，發現BL10需在具充足營養的培養基上生長才足以產生阿米巴細胞。此外，當BL10群落可順利形成阿米巴細胞後，同時也會分泌物質影響阿米巴細胞的形成，此物質大小介於30kD至100kD，目前已利用凝膠過濾法完成初步的分離。
　　另一方面，在以固態培養基進行細胞遷移實驗後，已初步排除培養基內營養源和阿米巴細胞移動方向的關聯性，然而卻發現阿米巴細胞的趨性和細胞密度有關。阿米巴細胞明顯會朝向agar plate中，細胞密度較低的區域移動。推判在細胞密度高之區域，可能會累積高濃度的化學排斥因子，目前經測試發現該物質分子大小應介於30kD至100kD。此外，同時也發現有化學引誘因子的存在，其大小介於10kD至30kD之間。
　　後續研究中，則將進一步確認抑制阿米巴細胞形成的物質成分是否與影響阿米巴細胞遷移之物質相同，並且完成該物質之分離、純化與身分鑑定。BL10阿米巴細胞的形成需要充足的營養、適合的環境條件以及適當濃度的內生性因子，此外，溶氧量的降低也是影響其形成的重要條件。而在阿米巴生成之後，它的遷移則與營養無關，與其自身分泌的化學誘因分子與化學排斥因子關係密切。本研究開發出合適的活性測試平台，可用以研究阿米巴細胞的形成與遷移，將來冀望能釐清各外源性因子與內生性因子的作用，進一步了解其機制。

Aurantiochytrium sp. BL10 is one of the few thraustochytrid strains that exist as amoeboid cells at some point during their life cycle. Thus, we sought to identify the bio-functions of amoeboid cells and investigate the molecular mechanisms which underlie the transition between vegetative and amoeboid phases.
Previous observations related to the formation and migration of amoeboid cells led to hypotheses about these possible mechanisms. This current study found that amoeboid cells only exist when the culture is in the exponential stage of growth, such that extensive cell division significantly decreases oxygen levels, leading to a sudden expansion of the amoeboid cell population.
When BL10 was cultivated on agar plates, amoeboid cells always formed in the border region of a colony, moving away from areas of greater cell densities where the accumulation of various macromolecules acted as a chemorepellent.
Autocrine substances were extracted from the cultured agar using water and then separated using a molecular sieve or gel filtration column. Certain substances were observed to affect the formation of amoeboid cells, the molecular weight of which should be between 30 and 100 kDa. Other substances affected the migration of amoeboid cells. According to the results of a cell migration assay, the extract should have both chemorepellent and chemoattractant ,and their molecular size should be between 30-100kDa and 10-30kDa.
Our results confirm that the formation of BL10 amoeboid cells is affected by the amount of dissolved oxygen, such that lower levels of dissolved oxygen within the medium resulted in a higher proportion of amoeboid cells. The formation and migration of amoeboid cells was also affected by autocrine signaling. So far, an active-test platform and a method of separating substances have been established, and the identification of these autocrine substances has been initiated.

Alderman, D.J., Harrison, J.L., Bremer, G.B. & Jones, E.B.G. (1974) . Taxonomic revisions in the marine biflagellate fungi: The ultrastructural evidence. Marine Biology, 25: 345-357.
Aman, A. & Piotrowski, T. (2010) . Cell migration during morphogenesis. Developmental Biology, 341: 20-33.
Amon, J.P. & Perkins, F.O. (1968) . Structure of Labyrinthula sp. Zoospores*. J Eukaryot Microbiol, 15: 543-546.
Annesley, S. & Fisher, P. (2009) . Dictyostelium discoideum—a model for many reasons. Mol Cell Biochem, 329: 73-91.
Barth, C., Le, P. & Fisher, P.R. (2007) . Mitochondrial Biology and Disease in Dictyostelium. IN Kwang, W.J. (Ed.) International Review of Cytology. Academic Press.
Ben-Amotz, A. (1975) . Adaptation of the unicellular alga dunaliella parva to a saline environment1. Journal of Phycology, 11: 50-54.
Berrocal, A., Navarrete, J., Oviedo, C. & Nickerson, K.W. (2012) . Quorum sensing activity in Ophiostoma ulmi: effects of fusel oils and branched chain amino acids on yeast-mycelial dimorphism. Journal of Applied Microbiology, 113: 126-134.
Blokesch, M. (2012) . A quorum sensing-mediated switch contributes to natural transformation of Vibrio cholerae. Mobile Genetic Elements, 2: 224-227.
Bongiorni, L., Jain, R., Raghukumar, S. & Aggarwal, R.K. (2005a) . Thraustochytrium gaertnerium sp. nov.: a New Thraustochytrid Stramenopilan Protist from Mangroves of Goa, India. Protist, 156: 303-315.
Bongiorni, L., Pignataro, L. & Santangelo, G. (2004) . Thraustochytrids (fungoid protist) : an unexplored component of marine sediment microbiota. Scientia Marina, 68: 43-48.
Bongiorni, L., Pusceddu, A. & Danovaro, R. (2005b) . Enzymatic activities of epiphytic and benthic thraustochytrids involved in organic matter degradation. Aquatic microbial ecology, 41: 299-305.
Bremer, G.B. & Talbot, G. (1995) . Cellulolytic Enzyme Activity in the Marine Protist Schizochytrium aggregatum. Botanica Marina.
Brock, D.A. & Gomer, R.H. (2005) . A secreted factor represses cell proliferation in Dictyostelium. Development, 132: 4553-4562.
Chaung, K.-C., Chu, C.-Y., Su, Y.-M. & Chen, Y.-M. (2012) . Effect of culture conditions on growth, lipid content, and fatty acid composition of Aurantiochytrium mangrovei strain BL10. AMB Express, 2: 1-11.
Chi, Z., Liu, Y., Frear, C. & Chen, S. (2009) . Study of a two-stage growth of DHA-producing marine algae Schizochytrium limacinum SR21 with shifting dissolved oxygen level. Appl Microbiol Biotechnol, 81: 1141-1148.
Chin, H.J., Shen, T.F., Su, H.P. & Ding, S.T. (2006) . Schizochytrium limacinum SR-21 as a source of docosahexaenoic acid: optimal growth and use as a dietary supplement for laying hens. Australian Journal of Agricultural Research, 57: 13-20.
Coral, G., Huberman, A., De La Lanza, G. & Monroy-Ruiz, J. (1998) . Muscle Pigmentation of Rainbow Trout (Oncorhynchus mykiss) Fed on Oil-Extracted Pigment from Langostilla (Pleuroncodes planipes) Compared with Two Commercial Sources of Astaxanthin. Journal of Aquatic Food Product Technology, 7: 31-45.
Dewel, R.A., Connell, M.U. & Dewel, W.C. (2003) . Bridging Morphological Transitions to the Metazoa. Integrative and Comparative Biology, 43: 28-46.
Do, M.-K.Q., Sato, Y., Shimizu, N., Suzuki, T., Shono, J.-I., Mizunoya, W., Nakamura, M., Ikeuchi, Y., Anderson, J.E. & Tatsumi, R. (2011) . Growth factor regulation of neural chemorepellent Sema3A expression in satellite cell cultures. American Journal of Physiology - Cell Physiology, 301: C1270-C1279.
Enderling, H., Hlatky, L. & Hahnfeldt, P. (2012) . The promoting role of a tumour-secreted chemorepellent in self-metastatic tumour progression. Mathematical Medicine and Biology, 29: 21-29.
Francis, J.T. & Hennessey, T.M. (1995) . Chemorepellents in Paramecium and Tetrahymena. J Eukaryot Microbiol, 42: 78-83.
Gaertner, A. (1977) . Revision of the Thraustochytriaceae (Lower Marine Fungi) I. Ulkenia nov. gen., with description of three new species. Vroff Inst Meeresf Bremerhaven Suppl, 16: 139-157.
Gaertner, A. (1981) . A new marine Phycomycetes, Schizochytrium minutum, sp. nov.(Thraustochytriaceae) from saline habitats. Verroff Inst Meeresfoasch Bremerh, 19: 61-69.
Gomer, R.H., Jang, W. & Brazill, D. (2011) . Cell density sensing and size determination. Development, Growth & Differentiation, 53: 482-494.
Guerin, M., Huntley, M.E. & Olaizola, M. (2003) . Haematococcus astaxanthin: applications for human health and nutrition. Trends in Biotechnology, 21: 210-216.
Hemmingsen, M., Vedel, S., Skafte-Pedersen, P., Sabourin, D., Collas, P., Bruus, H. & Dufva, M. (2013) . The Role of Paracrine and Autocrine Signaling in the Early Phase of Adipogenic Differentiation of Adipose-derived Stem Cells. PLoS ONE, 8: e63638.
Honda, D., Yokochi, T., Nakahara, T., Erata, M. & Higashihara, T. (1998) . Schizochytrium limacinum sp. nov., a new thraustochytrid from a mangrove area in the west Pacific Ocean. Mycological Research, 102: 439-448.
Imtiyaz, H. & Simon, M.C. (2010) . Hypoxia-Inducible Factors as Essential Regulators of Inflammation. IN Simon, M.C. (Ed.) Diverse Effects of Hypoxia on Tumor Progression. Springer Berlin Heidelberg.
Jain, R., Yuen, I.S., Taphouse, C.R. & Gomer, R.H. (1992) . A density-sensing factor controls development in Dictyostelium. Genes & development, 6: 390-400.
Jechlinger, M., Sommer, A., Moriggl, R., Seither, P., Kraut, N., Capodiecci, P., Donovan, M., Cordon-Cardo, C., Beug, H., Gr, Xfc & Nert, S. (2006) . Autocrine PDGFR signaling promotes mammary cancer metastasis. The Journal of Clinical Investigation, 116: 1561-1570.
Junger, W.G. (2011) . Immune cell regulation by autocrine purinergic signalling. Nat Rev Immunol, 11: 201-212.
Kazama, F.Y. (1974) . Ultrastructure of Thraustochytrium sp. Zoospores. IV. External Morphology with Notes on the Zoospores of Schizochytrium sp. Mycologia, 66: 272-280.
Kindle, K.L. (1990) . High-frequency nuclear transformation of Chlamydomonas reinhardtii. Proceedings of the National Academy of Sciences, 87: 1228-1232.
Kindt, T.J. & Kuby, J. (2007) . Kuby immunology: Macmillan.
Kjellerup, B.V., Gudmonsson, G., Sowers, K. & Nielsen, P.H. (2006) . Evaluation of analytical methods for determining the distribution of biofilm and active bacteria in a commercial heating system. Biofouling, 22: 133-139.
Koch, C., Brumme, B., Schmidt, M., Flieger, K., Schnetter, R. & Wilhelm, C. (2011) . The life cycle of the amoeboid alga Synchroma grande (Synchromophyceae, Heterokontophyta) – highly adapted yet equally equipped for rapid diversification in benthic habitats. Plant Biology, 13: 801-808.
Kole, T.P., Tseng, Y., Jiang, I., Katz, J.L. & Wirtz, D. (2005) . Intracellular Mechanics of Migrating Fibroblasts. Molecular Biology of the Cell, 16: 328-338.
Krauss, G. (2006) . Biochemistry of signal transduction and regulation: Wiley. com.
Kroen, W.K. & Rayburn, W.R. (1984) . Influence of growth status and nutrients on extracellular polysaccharide synthesis by the soil alga chlamydomonas mexicana (chlorophyceae) 1. Journal of Phycology, 20: 253-257.
Kumar, S.R. (1979) . Observations of the Life Cycle and Movement of the Thraustochytrid Ulkenia amoeboidea (Bahnweg & Sparrow) from the North Sea*. J Eukaryot Microbiol, 26: 564-566.
Kumar, S.R. (1982a) . Fine structure of the thraustochytrid Ulkenia amoeboidea. I. Vegetative thallus and formation of the amoeboid stage. Canadian Journal of Botany, 60: 1092-1102.
Kumar, S.R. (1982b) . Fine structure of the thraustochytrid Ulkenia amoeboidea. II. The amoeboid stage and formation of zoospores. Canadian Journal of Botany, 60: 1103-1114.
Kwak, M., Mu, L., Lu, Y., Chen, J.J., Wu, Y., Brower, K. & Fan, R. (2013) . Single-cell protein secretomic signatures as potential correlates to tumor cell lineage evolution and cell-cell interaction. Frontiers in Oncology, 3.
Laevsky, G. & Knecht, D.A. (2001) . Under-agarose folate chemotaxis of Dictyostelium discoideum amoebae in permissive and mechanically inhibited conditions. BioTechniques, 31: 1140-2, 1144, 1146-9.
Lah, G.J. & Key, B. (2012) . Dual roles of the chemorepellent axon guidance molecule RGMa in establishing pioneering axon tracts and neural fate decisions in embryonic vertebrate forebrain. Developmental Neurobiology, 72: 1458-1470.
Lamalice, L., Le Boeuf, F. & Huot, J. (2007) . Endothelial Cell Migration During Angiogenesis. Circulation Research, 100: 782-794.
Lefebvre, J.L., Kostadinov, D., Chen, W.S.V., Maniatis, T. & Sanes, J.R. (2012) . Protocadherins mediate dendritic self-avoidance in the mammalian nervous system. Nature, 488: 517-+.
Lewis, T.E., Nichols, P.D. & Mcmeekin, T.A. (1999) . The Biotechnological Potential of Thraustochytrids. Mar Biotechnol, 1: 580-587.
Lorenz, R.T. & Cysewski, G.R. (2000) . Commercial potential for Haematococcus microalgae as a natural source of astaxanthin. Trends in Biotechnology, 18: 160-167.
Manohar, M., Hirsh, M.I., Chen, Y., Woehrle, T., Karande, A.A. & Junger, W.G. (2012) . ATP release and autocrine signaling through P2X4 receptors regulate γδ T cell activation. Journal of Leukocyte Biology, 92: 787-794.
Mcbeath, R., Pirone, D.M., Nelson, C.M., Bhadriraju, K. & Chen, C.S. (2004) . Cell Shape, Cytoskeletal Tension, and RhoA Regulate Stem Cell Lineage Commitment. Developmental Cell, 6: 483-495.
Mcelwain, M.A., Ko, D.C., Gordon, M.D., Fyrst, H., Saba, J.D. & Nusse, R. (2011) . A Suppressor/Enhancer Screen in Drosophila Reveals a Role for Wnt-Mediated Lipid Metabolism in Primordial Germ Cell Migration. PLoS ONE, 6: e26993.
Messersmith, E.K., Leonardo, E.D., Shatz, C.J., Tessier-Lavigne, M., Goodman, C.S. & Kolodkin, A.L. (1995) . Sernaphorin III can function as a selective chemorepellent to pattern sensory projections in the spinal cord. Neuron, 14: 949-959.
Min, Y., Ghose, S., Boelte, K., Li, J., Yang, L. & Lin, P.C. (2011) . C/EBP-delta regulates VEGF-C autocrine signaling in lymphangiogenesis and metastasis of lung cancer through HIF-1 alpha. Oncogene, 30: 4901-4909.
Morita, E., Kumon, Y., Nakahara, T., Kagiwada, S. & Noguchi, T. (2006) . Docosahexaenoic Acid Production and Lipid-Body Formation in Schizochytrium limacinum SR21. Mar Biotechnol, 8: 319-327.
Morohoshi, T., Tokita, K., Ito, S., Saito, Y., Maeda, S., Kato, N. & Ikeda, T. (2013) . Inhibition of quorum sensing in gram-negative bacteria by alkylamine-modified cyclodextrins. Journal of Bioscience and Bioengineering, 116: 175-179.
Pacini, E. & Juniper, B.E. (1983) . The ultrastructure of the formation and development of the amoeboid tapetum in Arum italicum miller. Protoplasma, 117: 116-129.
Pals, S.T., De Gorter, D.J.J. & Spaargaren, M. (2007) . Lymphoma dissemination: the other face of lymphocyte homing. Blood, 110: 3102-3111.
Perkins, F.O. (1973) . Observations of thraustochytriaceous (Phycomycetes) and labyrinthulid (Rhizopodea) ectoplasmic nets on natural and artificial substrates—an electron microscope study. Canadian Journal of Botany, 51: 485-491.
Phillips, J.E. & Gomer, R.H. (2012) . A secreted protein is an endogenous chemorepellant in Dictyostelium discoideum. Proceedings of the National Academy of Sciences, 109: 10990-10995.
Porter, D. (1990) . Phylum Labyrinthulomycota. Handbook of Protoctista: 388-398.
Raghukumar, S. (1992) . Bacterivory: a novel dual role for thraustochytrids in the sea. Marine Biology, 113: 165-169.
Raghukumar, S. (2002) . Ecology of the marine protists, the Labyrinthulomycetes (Thraustochytrids and Labyrinthulids) . European Journal of Protistology, 38: 127-145.
Raghukumar, S., Sharma, S., Raghukumar, C., Sathe-Pathak, V. & Chandramohan, D. (1994) . Thraustochytrid and fungal component of marine detritus. IV. Laboratory studies on decomposition of leaves of the mangrove Rhizophora apiculata Blume. Journal of Experimental Marine Biology and Ecology, 183: 113-131.
Ramsdell, A.F. (1996) . The Role of Autocrine Signaling in Epithelial-mesenchymal Transformation: Induction of Endocardial Cushion Tissue is a Progressive, Homogenetic Event: Medical University of South Carolina.
Ryan, R.P. & Dow, J.M. (2008) . Diffusible signals and interspecies communication in bacteria. Microbiology, 154: 1845-1858.
Schauder, S. & Bassler, B.L. (2001) . The languages of bacteria. Genes & development, 15: 1468-80.
Siegenthaler, P.A., Belsky, M.M., Goldstein, S. & Menna, M. (1967) . Phosphate Uptake in an Obligately Marine Fungus II. Role of Culture Conditions, Energy Sources, and Inhibitors. Journal of Bacteriology, 93: 1281-1288.
Souissi, S., Michalec, F.-G., Dur, G., Mahjoub, M.-S., Schmitt, F.G. & Hwang, J.-S. (2010) . How does salinity influence the swimming speed of the estuarine calanoid copepod Eurytemora affinis?: Reply. Journal of Plankton Research, 32: 1227-1229.
Sparrow, F.K., Jr. (1936) . Biological Observations on the Marine Fungi of Woods Hole Waters. Biological Bulletin, 70: 236-263.
Steinert, M. & Heuner, K. (2005) . Dictyostelium as host model for pathogenesis. Cellular Microbiology, 7: 307-314.
Sugarman, B. & Mummaw, N. (1988) . The Effect of Hormones on Trichomonas vaginalis. Journal of General Microbiology, 134: 1623-1628.
Urushihara, H. (2009) . The cellular slime mold: eukaryotic model microorganism. Experimental animals / Japanese Association for Laboratory Animal Science, 58: 97-104.
Volz, P.A., Hsu, Y.-C. & Liu, C.-H. (1976) . The Thraustochytriaceae and Other Intertidal Fungi of Taiwan. TAIWANIA, 21: 1-5.
Waterbury, J.B. & Stanier, R.Y. (1978) . Patterns of growth and development in pleurocapsalean cyanobacteria. Microbiological Reviews, 42: 2-44.
Werbowetski, T., Bjerkvig, R. & Del Maestro, R.F. (2004) . Evidence for a secreted chemorepellent that directs glioma cell invasion. Journal of Neurobiology, 60: 71-88.
Wolf, K., Mazo, I., Leung, H., Engelke, K., Von Andrian, U.H., Deryugina, E.I., Strongin, A.Y., Brocker, E.B. & Friedl, P. (2003) . Compensation mechanism in tumor cell migration: mesenchymal-amoeboid transition after blocking of pericellular proteolysis. J Cell Biol, 160: 267-277.
Wu, S.-T., Yu, S.-T. & Lin, L.-P. (2005) . Effect of culture conditions on docosahexaenoic acid production by Schizochytrium sp. S31. Process Biochemistry, 40: 3103-3108.
Yaguchi, T., Tanaka, S., Yokochi, T., Nakahara, T. & Higashihara, T. (1997) . Production of high yields of docosahexaenoic acid by Schizochytrium sp. strain SR21. J Amer Oil Chem Soc, 74: 1431-1434.
Yang, H.-L., Lu, C.-K., Chen, S.-F., Chen, Y.-M. & Chen, Y.-M. (2010) . Isolation and Characterization of Taiwanese Heterotrophic Microalgae: Screening of Strains for Docosahexaenoic Acid (DHA) Production. Mar Biotechnol, 12: 173-185.
Yin, Z., Sadok, A., Sailem, H., Mccarthy, A., Xia, X., Li, F., Garcia, M.A., Evans, L., Barr, A.R., Perrimon, N., Marshall, C.J., Wong, S.T. & Bakal, C. (2013) . A screen for morphological complexity identifies regulators of switch-like transitions between discrete cell shapes. Nat Cell Biol.
Yokoyama, R. & Honda, D. (2007) . Taxonomic rearrangement of the genus Schizochytrium sensu lato based on morphology, chemotaxonomic characteristics, and 18S rRNA gene phylogeny (Thraustochytriaceae, Labyrinthulomycetes) : emendation for Schizochytrium and erection of Aurantiochytrium and Oblongichytrium gen. nov. Mycoscience, 48: 199-211.
Yokoyama, R., Salleh, B. & Honda, D. (2007) . Taxonomic rearrangement of the genus Ulkenia sensu lato based on morphology, chemotaxonomical characteristics, and 18S rRNA gene phylogeny (Thraustochytriaceae, Labyrinthulomycetes) : emendation for Ulkenia and erection of Botryochytrium, Parietichytrium, and Sicyoidochytrium gen. nov. Mycoscience, 48: 329-341.
Yumura, S. & Fukui, Y. (1985) . Reversible Cyclic Amp-Dependent Change in Distribution of Myosin Thick Filaments in Dictyostelium. Nature, 314: 194-196.
Zaki, M., Andrew, N. & Insall, R.H. (2006) . Entamoeba histolytica cell movement: A central role for self-generated chemokines and chemorepellents. Proceedings of the National Academy of Sciences, 103: 18751-18756.
Zhang, K., Wong, P., Zhang, L., Jacobs, B., Borden, E.C., Aster, J.C. & Bedogni, B. (2012a) . A Notch1-neuregulin1 autocrine signaling loop contributes to melanoma growth. Oncogene, 31: 4609-4618.
Zhang, S., Luo, X., Wan, F. & Lei, T. (2012b) . The Roles of Hypoxia-Inducible Factors in Regulating Neural Stem Cells Migration to Glioma Stem Cells and Determinating Their Fates. Neurochem Res, 37: 2659-2666.
吳淑姿 (2002) . 海洋單細胞真菌-Schizochytrium sp. S31生產多元不飽和脂肪酸-DHA. 國立臺灣大學.
張榮權 (2008) . 以Thraustochytrium sp.發酵生產二十二碳六烯酸. 大葉大學.
陳淑芬 (2005) . 台南沿海地區海生鞭毛真菌多樣性. 嘉南學報 (科技類) : 80-87.
蔡喬筑 (1999) . 台灣北部沿海地區破囊壺菌科形態、分類學之研究. 國立臺灣師範大學.
盧怡萍 (2004) . 臺灣淡水紅樹林地區破囊壺菌科形態及分類學之研究. 國立臺灣師範大學.
蘇昱銘 (2012) . 來自北台灣之海洋異營性微藻分離株:Aurantiochytrium sp. strain BL10之生物特性研究. 國立成功大學.