[{"status":"public","publisher":"Institute of Science and Technology Austria","date_updated":"2026-07-29T10:01:24Z","article_processing_charge":"No","doi_confirm":"1","date_published":"2014-02-01T00:00:00Z","type":"dissertation","publication_status":"published","corr_author":"1","publist_id":"5814","abstract":[{"text":"In this thesis I studied various individual and social immune defences employed by the invasive garden ant Lasius neglectus mostly against entomopathogenic fungi.  The first two chapters of this thesis address the phenomenon of 'social immunisation'. Social immunisation, that is the immunological protection of group members due to social contact to a pathogen-exposed nestmate, has been described in various social insect species against different types of pathogens. However, in the case of entomopathogenic fungi it has, so far, only been demonstrated that social immunisation exists at all. Its underlying mechanisms r any other properties were, however, unknown. In the first chapter of this thesis I identified the mechanistic basis of social immunisation in L. neglectus against the entomopathogenous fungus Metarhizium. I could show that nestmates of a pathogen-exposed individual contract low-level infections due to social interactions. These low-level infections are, however, non-lethal and cause an active stimulation of the immune system, which protects the nestmates upon subsequent pathogen encounters. In the second chapter of this thesis I investigated the specificity and colony level effects of social immunisation. I demonstrated that the protection conferred by social immunisation is highly specific, protecting ants only against the same pathogen strain. In addition, depending on the respective context, social immunisation may even cause fitness costs. I further showed that social immunisation crucially affects sanitary behaviour and disease dynamics within ant groups. In the third chapter of this thesis I studied the effects of the ectosymbiotic fungus Laboulbenia formicarum on its host L. neglectus. Although Laboulbeniales are the largest order of insect-parasitic fungi, research concerning host fitness consequence is sparse. I showed that highly Laboulbenia-infected ants sustain fitness costs under resource limitation, however, gain fitness benefits when exposed to an entomopathogenus fungus. These effects are probably cause by a prophylactic upregulation of behavioural as well as physiological immune defences in highly infected ants.","lang":"eng"}],"day":"01","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","alternative_title":["ISTA Thesis"],"title":"Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus","publication_identifier":{"issn":["2663-337X"]},"OA_place":"publisher","degree_awarded":"PhD","year":"2014","citation":{"apa":"Konrad, M. (2014). <i>Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus</i>. Institute of Science and Technology Austria.","ama":"Konrad M. Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus. 2014.","chicago":"Konrad, Matthias. “Immune Defences in Ants: Effects of Social Immunisation and a Fungal Ectosymbiont in the Ant Lasius Neglectus.” Institute of Science and Technology Austria, 2014.","ieee":"M. Konrad, “Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus,” Institute of Science and Technology Austria, 2014.","ista":"Konrad M. 2014. Immune defences in ants: Effects of social immunisation and a fungal ectosymbiont in the ant Lasius neglectus. Institute of Science and Technology Austria.","mla":"Konrad, Matthias. <i>Immune Defences in Ants: Effects of Social Immunisation and a Fungal Ectosymbiont in the Ant Lasius Neglectus</i>. Institute of Science and Technology Austria, 2014.","short":"M. Konrad, Immune Defences in Ants: Effects of Social Immunisation and a Fungal Ectosymbiont in the Ant Lasius Neglectus, Institute of Science and Technology Austria, 2014."},"author":[{"first_name":"Matthias","id":"46528076-F248-11E8-B48F-1D18A9856A87","full_name":"Konrad, Matthias","last_name":"Konrad"}],"language":[{"iso":"eng"}],"department":[{"_id":"SyCr"},{"_id":"GradSch"}],"date_created":"2018-12-11T11:51:46Z","page":"131","month":"02","supervisor":[{"orcid":"0000-0002-2193-3868","last_name":"Cremer","full_name":"Cremer, Sylvia M","id":"2F64EC8C-F248-11E8-B48F-1D18A9856A87","first_name":"Sylvia M"}],"_id":"1395","oa_version":"None"},{"author":[{"last_name":"Stock","full_name":"Stock, Miriam","id":"42462816-F248-11E8-B48F-1D18A9856A87","first_name":"Miriam"}],"citation":{"mla":"Stock, Miriam. <i>Evolution of a Fungal Pathogen towards Individual versus Social Immunity in Ants</i>. Institute of Science and Technology Austria, 2014.","short":"M. Stock, Evolution of a Fungal Pathogen towards Individual versus Social Immunity in Ants, Institute of Science and Technology Austria, 2014.","ieee":"M. Stock, “Evolution of a fungal pathogen towards individual versus social immunity in ants,” Institute of Science and Technology Austria, 2014.","chicago":"Stock, Miriam. “Evolution of a Fungal Pathogen towards Individual versus Social Immunity in Ants.” Institute of Science and Technology Austria, 2014.","ista":"Stock M. 2014. Evolution of a fungal pathogen towards individual versus social immunity in ants. Institute of Science and Technology Austria.","ama":"Stock M. Evolution of a fungal pathogen towards individual versus social immunity in ants. 2014.","apa":"Stock, M. (2014). <i>Evolution of a fungal pathogen towards individual versus social immunity in ants</i>. Institute of Science and Technology Austria."},"department":[{"_id":"SyCr"},{"_id":"GradSch"}],"date_created":"2018-12-11T11:51:49Z","language":[{"iso":"eng"}],"page":"101","month":"04","supervisor":[{"first_name":"Sylvia M","id":"2F64EC8C-F248-11E8-B48F-1D18A9856A87","full_name":"Cremer, Sylvia M","last_name":"Cremer","orcid":"0000-0002-2193-3868"}],"oa_version":"None","_id":"1404","alternative_title":["ISTA Thesis"],"title":"Evolution of a fungal pathogen towards individual versus social immunity in ants","publication_identifier":{"issn":["2663-337X"]},"OA_place":"publisher","degree_awarded":"PhD","year":"2014","type":"dissertation","publication_status":"published","corr_author":"1","publist_id":"5803","abstract":[{"lang":"eng","text":"The co-evolution of hosts and pathogens is characterized by continuous adaptations of both parties. Pathogens of social insects need to adapt towards disease defences at two levels: 1) individual immunity of each colony member consisting of behavioural defence strategies as well as humoral and cellular immune responses and 2) social immunity that is collectively performed by all group members comprising behavioural, physiological and organisational defence strategies.\r\n\r\nTo disentangle the selection pressure on pathogens by the collective versus individual level of disease defence in social insects, we performed an evolution experiment using the Argentine Ant, Linepithema humile, as a host and a mixture of the general insect pathogenic fungus Metarhizium spp. (6 strains) as a pathogen. We allowed pathogen evolution over 10 serial host passages to two different evolution host treatments: (1) only individual host immunity in a single host treatment, and (2) simultaneously acting individual and social immunity in a social host treatment, in which an exposed ant was accompanied by two untreated nestmates.\r\n\r\nBefore starting the pathogen evolution experiment, the 6 Metarhizium spp. strains were characterised concerning conidiospore size killing rates in singly and socially reared ants, their competitiveness under coinfecting conditions and their influence on ant behaviour. We analysed how the ancestral atrain mixture changed in conidiospere size, killing rate and strain composition dependent on host treatment (single or social hosts) during 10 passages and found that killing rate and conidiospere size of the pathogen increased under both evolution regimes, but different depending on host treatment.\r\n\r\nTesting the evolved strain mixtures that evolved under either the single or social host treatment under both single and social current rearing conditions in a full factorial design experiment revealed that the additional collective defences in insect societies add new selection pressure for their coevolving pathogens that compromise their ability to adapt to its host at the group level. To our knowledge, this is the first study directly measuring the influence of social immunity on pathogen evolution."}],"acknowledgement":"This work was funded by the DFG and the ERC.","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","day":"01","status":"public","publisher":"Institute of Science and Technology Austria","date_updated":"2026-07-29T10:05:33Z","article_processing_charge":"No","doi_confirm":"1","date_published":"2014-04-01T00:00:00Z"},{"type":"dissertation","corr_author":"1","publication_status":"published","abstract":[{"lang":"eng","text":"Phosphatidylinositol (Ptdlns) is a structural phospholipid that can be phosphorylated into various lipid signaling molecules, designated polyphosphoinositides (PPIs). The reversible phosphorylation of PPIs on the 3, 4, or 5 position of inositol is performed by a set of organelle-specific kinases and phosphatases, and the characteristic head groups make these molecules ideal for regulating biological processes in time and space. In yeast and mammals, Ptdlns3P and Ptdlns(3,5)P2 play crucial roles in trafficking toward the lytic compartments, whereas the role in plants is not yet fully understood. Here we identified the role of a land plant-specific subgroup of PPI phosphatases, the suppressor of actin 2 (SAC2) to SAC5, during vauolar trafficking and morphogenesis in Arabidopsis thaliana. SAC2-SAC5 localize to the tonoplast along with Ptdlns3P, the presumable product of their activity. in SAC gain- and loss-of-function mutants, the levels of Ptdlns monophosphates and bisphosphates were changed, with opposite effects on the morphology of storage and lytic vacuoles, and the trafficking toward the vacuoles was defective. Moreover, multiple sac knockout mutants had an increased number of smaller storage and lytic vacuoles, whereas extralarge vacuoles were observed in the overexpression lines, correlating with various growth and developmental defects. The fragmented vacuolar phenotype of sac mutants could be mimicked by treating wild-type seedlings with Ptdlns(3,5)P2, corroborating that this PPI is important for vacuole morphology. Taken together, these results provide evidence that PPIs, together with their metabolic enzymes SAC2-SAC5, are crucial for vacuolar trafficking and for vacuolar morphology and function in plants."}],"publist_id":"5805","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","day":"01","status":"public","date_updated":"2026-07-29T10:06:44Z","publisher":"Institute of Science and Technology Austria","doi_confirm":"1","date_published":"2014-12-01T00:00:00Z","article_processing_charge":"No","department":[{"_id":"JiFr"},{"_id":"GradSch"}],"language":[{"iso":"eng"}],"date_created":"2018-12-11T11:51:49Z","citation":{"apa":"Marhavá, P. (2014). <i>Molecular mechanisms of patterning and subcellular trafficking in Arabidopsis thaliana</i>. Institute of Science and Technology Austria.","ama":"Marhavá P. Molecular mechanisms of patterning and subcellular trafficking in Arabidopsis thaliana. 2014.","ista":"Marhavá P. 2014. Molecular mechanisms of patterning and subcellular trafficking in Arabidopsis thaliana. Institute of Science and Technology Austria.","chicago":"Marhavá, Petra. “Molecular Mechanisms of Patterning and Subcellular Trafficking in Arabidopsis Thaliana.” Institute of Science and Technology Austria, 2014.","ieee":"P. Marhavá, “Molecular mechanisms of patterning and subcellular trafficking in Arabidopsis thaliana,” Institute of Science and Technology Austria, 2014.","mla":"Marhavá, Petra. <i>Molecular Mechanisms of Patterning and Subcellular Trafficking in Arabidopsis Thaliana</i>. Institute of Science and Technology Austria, 2014.","short":"P. Marhavá, Molecular Mechanisms of Patterning and Subcellular Trafficking in Arabidopsis Thaliana, Institute of Science and Technology Austria, 2014."},"author":[{"id":"44E59624-F248-11E8-B48F-1D18A9856A87","first_name":"Petra","last_name":"Marhavá","full_name":"Marhavá, Petra"}],"page":"90","month":"12","supervisor":[{"last_name":"Friml","orcid":"0000-0002-8302-7596","full_name":"Friml, Jiří","id":"4159519E-F248-11E8-B48F-1D18A9856A87","first_name":"Jiří"}],"_id":"1402","oa_version":"None","title":"Molecular mechanisms of patterning and subcellular trafficking in Arabidopsis thaliana","publication_identifier":{"issn":["2663-337X"]},"alternative_title":["ISTA Thesis"],"OA_place":"publisher","year":"2014","degree_awarded":"PhD"},{"doi_confirm":"1","status":"public","has_accepted_license":"1","publisher":"Institute of Science and Technology Austria","publist_id":"5804","day":"01","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","publication_status":"published","acknowledged_ssus":[{"_id":"SSU"}],"degree_awarded":"PhD","title":"Forces driving epithelial spreading in zebrafish epiboly","OA_place":"publisher","file_date_updated":"2026-03-09T14:53:14Z","oa_version":"None","_id":"1403","related_material":{"record":[{"id":"2282","status":"public","relation":"part_of_dissertation"},{"status":"public","id":"2950","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"3373"}]},"citation":{"ama":"Behrndt M. Forces driving epithelial spreading in zebrafish epiboly. 2014.","apa":"Behrndt, M. (2014). <i>Forces driving epithelial spreading in zebrafish epiboly</i>. Institute of Science and Technology Austria.","mla":"Behrndt, Martin. <i>Forces Driving Epithelial Spreading in Zebrafish Epiboly</i>. Institute of Science and Technology Austria, 2014.","short":"M. Behrndt, Forces Driving Epithelial Spreading in Zebrafish Epiboly, Institute of Science and Technology Austria, 2014.","chicago":"Behrndt, Martin. “Forces Driving Epithelial Spreading in Zebrafish Epiboly.” Institute of Science and Technology Austria, 2014.","ista":"Behrndt M. 2014. Forces driving epithelial spreading in zebrafish epiboly. Institute of Science and Technology Austria.","ieee":"M. Behrndt, “Forces driving epithelial spreading in zebrafish epiboly,” Institute of Science and Technology Austria, 2014."},"date_published":"2014-08-01T00:00:00Z","article_processing_charge":"No","date_updated":"2026-07-29T10:07:19Z","abstract":[{"text":"A variety of developmental and disease related processes depend on epithelial cell sheet spreading. In order to gain insight into the biophysical mechanism(s) underlying the tissue morphogenesis we studied the spreading of an epithelium during the early development of the zebrafish embryo. In zebrafish epiboly the enveloping cell layer (EVL), a simple squamous epithelium, spreads over the yolk cell to completely engulf it at the end of gastrulation. Previous studies have proposed that an actomyosin ring forming within the yolk syncytial layer (YSL) acts as purse string that through constriction along its circumference pulls on the margin of the EVL. Direct biophysical evidence for this hypothesis has however been missing. The aim of the thesis was to understand how the actomyosin ring may generate pulling forces onto the EVL and what cellular mechanism(s) may facilitate the spreading of the epithelium. Using laser ablation to measure cortical tension within the actomyosin ring we found an anisotropic tension distribution, which was highest along the circumference of the ring. However the low degree of anisotropy was incompatible with the actomyosin ring functioning as a purse string only. Additionally, we observed retrograde cortical flow from vegetal parts of the ring into the EVL margin. Interpreting the experimental data using a theoretical distribution that models  the tissues as active viscous gels led us to proposen that the actomyosin ring has a twofold contribution to EVL epiboly. It not only acts as a purse string through constriction along its circumference, but in addition constriction along the width of the ring generates pulling forces through friction-resisted cortical flow. Moreover, when rendering the purse string mechanism unproductive EVL epiboly proceeded normally indicating that the flow-friction mechanism is sufficient to drive the process. Aiming to understand what cellular mechanism(s) may facilitate the spreading of the epithelium we found that tension-oriented EVL cell divisions limit tissue anisotropy by releasing tension along the division axis and promote epithelial spreading. Notably, EVL cells undergo ectopic cell fusion in conditions in which oriented-cell division is impaired or the epithelium is mechanically challenged. Taken together our study of EVL epiboly suggests a novel mechanism of force generation for actomyosin rings through friction-resisted cortical flow and highlights the importance of tension-oriented cell divisions in epithelial morphogenesis.","lang":"eng"}],"type":"dissertation","corr_author":"1","ddc":["590"],"year":"2014","publication_identifier":{"issn":["2663-337X"]},"alternative_title":["ISTA Thesis"],"supervisor":[{"orcid":"0000-0002-0912-4566","last_name":"Heisenberg","full_name":"Heisenberg, Carl-Philipp J","id":"39427864-F248-11E8-B48F-1D18A9856A87","first_name":"Carl-Philipp J"}],"month":"08","date_created":"2018-12-11T11:51:49Z","department":[{"_id":"CaHe"},{"_id":"GradSch"}],"language":[{"iso":"eng"}],"author":[{"last_name":"Behrndt","full_name":"Behrndt, Martin","id":"3ECECA3A-F248-11E8-B48F-1D18A9856A87","first_name":"Martin"}],"file":[{"date_updated":"2026-03-09T14:53:14Z","file_id":"21421","access_level":"closed","file_name":"2014 Behrnd final.pdf","relation":"main_file","checksum":"67df5501b1b5b313c3bf9a360d713693","creator":"cchlebak","date_created":"2026-03-09T14:53:14Z","file_size":24842978,"content_type":"application/pdf"}],"page":"91"},{"main_file_link":[{"url":"http://dzufferey.github.io/files/2013_thesis.pdf"}],"month":"09","supervisor":[{"first_name":"Thomas A","id":"40876CD8-F248-11E8-B48F-1D18A9856A87","full_name":"Henzinger, Thomas A","last_name":"Henzinger","orcid":"0000−0002−2985−7724"}],"page":"134","file":[{"date_created":"2021-02-22T11:28:36Z","creator":"dernst","checksum":"ed2d7b52933d134e8dc69d569baa284e","file_size":1514906,"success":1,"content_type":"application/pdf","access_level":"open_access","file_id":"9176","date_updated":"2021-02-22T11:28:36Z","relation":"main_file","file_name":"2013_Zufferey_thesis_final.pdf"},{"date_created":"2021-11-16T14:42:52Z","checksum":"cecc4c4b14225bee973d32e3dba91a55","creator":"cchlebak","file_size":1378313,"content_type":"application/pdf","file_id":"10298","access_level":"closed","date_updated":"2021-11-17T13:47:58Z","file_name":"2013_Zufferey_thesis_final_pdfa.pdf","relation":"main_file"}],"author":[{"id":"4397AC76-F248-11E8-B48F-1D18A9856A87","first_name":"Damien","last_name":"Zufferey","orcid":"0000-0002-3197-8736","full_name":"Zufferey, Damien"}],"language":[{"iso":"eng"}],"date_created":"2018-12-11T11:51:50Z","department":[{"_id":"ToHe"},{"_id":"GradSch"}],"year":"2013","alternative_title":["ISTA Thesis"],"publication_identifier":{"issn":["2663-337X"]},"ec_funded":1,"abstract":[{"lang":"eng","text":"Motivated by the analysis of highly dynamic message-passing systems, i.e. unbounded thread creation, mobility, etc. we present a framework for the analysis of depth-bounded systems. Depth-bounded systems are one of the most expressive known fragment of the π-calculus for which interesting verification problems are still decidable. Even though they are infinite state systems depth-bounded systems are well-structured, thus can be analyzed algorithmically. We give an interpretation of depth-bounded systems as graph-rewriting systems. This gives more flexibility and ease of use to apply depth-bounded systems to other type of systems like shared memory concurrency.\r\n\r\nFirst, we develop an adequate domain of limits for depth-bounded systems, a prerequisite for the effective representation of downward-closed sets. Downward-closed sets are needed by forward saturation-based algorithms to represent potentially infinite sets of states. Then, we present an abstract interpretation framework to compute the covering set of well-structured transition systems. Because, in general, the covering set is not computable, our abstraction over-approximates the actual covering set. Our abstraction captures the essence of acceleration based-algorithms while giving up enough precision to ensure convergence. We have implemented the analysis in the PICASSO tool and show that it is accurate in practice. Finally, we build some further analyses like termination using the covering set as starting point."}],"ddc":["000"],"corr_author":"1","type":"dissertation","article_processing_charge":"No","date_published":"2013-09-05T00:00:00Z","oa":1,"date_updated":"2026-04-09T14:35:24Z","doi":"10.15479/at:ista:1405","oa_version":"Published Version","_id":"1405","project":[{"grant_number":"S 11407_N23","_id":"25832EC2-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","name":"Rigorous Systems Engineering"},{"grant_number":"267989","_id":"25EE3708-B435-11E9-9278-68D0E5697425","call_identifier":"FP7","name":"Quantitative Reactive Modeling"}],"citation":{"ama":"Zufferey D. Analysis of dynamic message passing programs. 2013. doi:<a href=\"https://doi.org/10.15479/at:ista:1405\">10.15479/at:ista:1405</a>","apa":"Zufferey, D. (2013). <i>Analysis of dynamic message passing programs</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:1405\">https://doi.org/10.15479/at:ista:1405</a>","short":"D. Zufferey, Analysis of Dynamic Message Passing Programs, Institute of Science and Technology Austria, 2013.","mla":"Zufferey, Damien. <i>Analysis of Dynamic Message Passing Programs</i>. Institute of Science and Technology Austria, 2013, doi:<a href=\"https://doi.org/10.15479/at:ista:1405\">10.15479/at:ista:1405</a>.","chicago":"Zufferey, Damien. “Analysis of Dynamic Message Passing Programs.” Institute of Science and Technology Austria, 2013. <a href=\"https://doi.org/10.15479/at:ista:1405\">https://doi.org/10.15479/at:ista:1405</a>.","ieee":"D. Zufferey, “Analysis of dynamic message passing programs,” Institute of Science and Technology Austria, 2013.","ista":"Zufferey D. 2013. Analysis of dynamic message passing programs. Institute of Science and Technology Austria."},"related_material":{"record":[{"status":"public","id":"4361","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"3251"},{"relation":"part_of_dissertation","id":"2847","status":"public"}]},"degree_awarded":"PhD","file_date_updated":"2021-11-17T13:47:58Z","OA_place":"publisher","title":"Analysis of dynamic message passing programs","acknowledgement":"This work was supported in part by the Austrian Science Fund NFN RiSE (Rigorous Systems Engineering) and by the ERC Advanced Grant QUAREM (Quantitative Reactve Modeling).\r\nChapter 2, 3, and 4 are joint work with Thomas A. Henzinger and Thomas Wies. Chapter 2 was published in FoSSaCS 2010 as “Forward Analysis of Depth-Bounded Processes” [112]. Chapter 3 was published in VMCAI 2012 as “Ideal Abstractions for Well-Structured Transition Systems” [114]. Chap- ter 5.1 is joint work with Kshitij Bansal, Eric Koskinen, and Thomas Wies. It was published in TACAS 2013 as “Structural Counter Abstraction” [13]. The author’s contribution in this part is mostly related to the implementation. The theory required to understand the method and its implementation is quickly recalled to make the thesis self-contained, but should not be considered as a contribution. For the details of the methods, we refer the reader to the orig- inal publication [13] and the corresponding technical report [14]. Chapter 5.2 is ongoing work with Shahram Esmaeilsabzali, Rupak Majumdar, and Thomas Wies. I also would like to thank the people who supported over the past 4 years. My advisor Thomas A. Henzinger who gave me a lot of freedom to work on projects I was interested in. My collaborators, especially Thomas Wies with whom I worked since the beginning. The members of my thesis committee, Viktor Kun- cak and Rupak Majumdar, who also agreed to advise me. Simon Aeschbacher, Pavol Cerny, Cezara Dragoi, Arjun Radhakrishna, my family, friends and col- leagues who created an enjoyable environment. ","day":"05","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","publist_id":"5802","publication_status":"published","publisher":"Institute of Science and Technology Austria","status":"public","has_accepted_license":"1"},{"publication_identifier":{"issn":["2663-337X"]},"title":"Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading","alternative_title":["ISTA Thesis"],"OA_place":"publisher","acknowledged_ssus":[{"_id":"Bio"},{"_id":"PreCl"}],"year":"2013","degree_awarded":"PhD","language":[{"iso":"eng"}],"department":[{"_id":"CaHe"},{"_id":"GradSch"}],"date_created":"2018-12-11T11:51:50Z","author":[{"id":"3AFBBC42-F248-11E8-B48F-1D18A9856A87","first_name":"Pedro","last_name":"Campinho","orcid":"0000-0002-8526-5416","full_name":"Campinho, Pedro"}],"citation":{"ama":"Campinho P. Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading. 2013.","apa":"Campinho, P. (2013). <i>Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading</i>. Institute of Science and Technology Austria.","short":"P. Campinho, Mechanics of Zebrafish Epiboly: Tension-Oriented Cell Divisions Limit Anisotropic Tissue Tension in Epithelial Spreading, Institute of Science and Technology Austria, 2013.","mla":"Campinho, Pedro. <i>Mechanics of Zebrafish Epiboly: Tension-Oriented Cell Divisions Limit Anisotropic Tissue Tension in Epithelial Spreading</i>. Institute of Science and Technology Austria, 2013.","ieee":"P. Campinho, “Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading,” Institute of Science and Technology Austria, 2013.","ista":"Campinho P. 2013. Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading. Institute of Science and Technology Austria.","chicago":"Campinho, Pedro. “Mechanics of Zebrafish Epiboly: Tension-Oriented Cell Divisions Limit Anisotropic Tissue Tension in Epithelial Spreading.” Institute of Science and Technology Austria, 2013."},"page":"123","month":"10","supervisor":[{"first_name":"Carl-Philipp J","id":"39427864-F248-11E8-B48F-1D18A9856A87","full_name":"Heisenberg, Carl-Philipp J","orcid":"0000-0002-0912-4566","last_name":"Heisenberg"}],"_id":"1406","oa_version":"None","status":"public","date_updated":"2026-07-29T10:00:09Z","publisher":"Institute of Science and Technology Austria","date_published":"2013-10-01T00:00:00Z","doi_confirm":"1","article_processing_charge":"No","type":"dissertation","corr_author":"1","publication_status":"published","publist_id":"5801","abstract":[{"lang":"eng","text":"Epithelial spreading is a critical part of various developmental and wound repair processes. Here we use zebrafish epiboly as a model system to study the cellular and molecular mechanisms underlying the spreading of epithelial sheets. During zebrafish epiboly the enveloping cell layer (EVL), a simple squamous epithelium, spreads over the embryo to eventually cover the entire yolk cell by the end of gastrulation. The EVL leading edge is anchored through tight junctions to the yolk syncytial layer (YSL), where directly adjacent to the EVL margin a contractile actomyosin ring is formed that is thought to drive EVL epiboly. The prevalent view in the field was that the contractile ring exerts a pulling force on the EVL margin, which pulls the EVL towards the vegetal pole. However, how this force is generated and how it affects EVL morphology still remains elusive. Moreover, the cellular mechanisms mediating the increase in EVL surface area, while maintaining tissue integrity and function are still unclear. Here we show that the YSL actomyosin ring pulls on the EVL margin by two distinct force-generating mechanisms. One mechanism is based on contraction of the ring around its circumference, as previously proposed. The second mechanism is based on actomyosin retrogade flows, generating force through resistance against the substrate. The latter can function at any epiboly stage even in situations where the contraction-based mechanism is unproductive. Additionally, we demonstrate that during epiboly the EVL is subjected to anisotropic tension, which guides the orientation of EVL cell division along the main axis (animal-vegetal) of tension. The influence of tension in cell division orientation involves cell elongation and requires myosin-2 activity for proper spindle alignment. Strikingly, we reveal that tension-oriented cell divisions release anisotropic tension within the EVL and that in the absence of such divisions, EVL cells undergo ectopic fusions. We conclude that forces applied to the EVL by the action of the YSL actomyosin ring generate a tension anisotropy in the EVL that orients cell divisions, which in turn limit tissue tension increase thereby facilitating tissue spreading."}],"user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","day":"01"},{"_id":"2964","oa_version":"None","month":"06","supervisor":[{"first_name":"Peter M","id":"353C1B58-F248-11E8-B48F-1D18A9856A87","full_name":"Jonas, Peter M","last_name":"Jonas","orcid":"0000-0001-5001-4804"}],"page":"65","date_created":"2018-12-11T12:00:35Z","language":[{"iso":"eng"}],"related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"3258"}]},"department":[{"_id":"PeJo"},{"_id":"GradSch"}],"author":[{"id":"394AB1C8-F248-11E8-B48F-1D18A9856A87","first_name":"Sooyun","last_name":"Kim","full_name":"Kim, Sooyun"}],"citation":{"ama":"Kim S. Active properties of hippocampal CA3 pyramidal neuron dendrites. 2012.","apa":"Kim, S. (2012). <i>Active properties of hippocampal CA3 pyramidal neuron dendrites</i>. Institute of Science and Technology Austria.","short":"S. Kim, Active Properties of Hippocampal CA3 Pyramidal Neuron Dendrites, Institute of Science and Technology Austria, 2012.","mla":"Kim, Sooyun. <i>Active Properties of Hippocampal CA3 Pyramidal Neuron Dendrites</i>. Institute of Science and Technology Austria, 2012.","chicago":"Kim, Sooyun. “Active Properties of Hippocampal CA3 Pyramidal Neuron Dendrites.” Institute of Science and Technology Austria, 2012.","ieee":"S. Kim, “Active properties of hippocampal CA3 pyramidal neuron dendrites,” Institute of Science and Technology Austria, 2012.","ista":"Kim S. 2012. Active properties of hippocampal CA3 pyramidal neuron dendrites. Institute of Science and Technology Austria."},"year":"2012","degree_awarded":"PhD","OA_place":"publisher","title":"Active properties of hippocampal CA3 pyramidal neuron dendrites","publication_identifier":{"issn":["2663-337X"]},"alternative_title":["ISTA Thesis"],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","day":"01","abstract":[{"text":"CA3 pyramidal neurons are important for memory formation and pattern completion in the hippocampal network. These neurons receive multiple excitatory inputs from numerous sources. Therefore, the rules of spatiotemporal integration of multiple synaptic inputs and propagation of action potentials are important to understand how CA3 neurons contribute to higher brain functions at cellular level. By using confocally targeted patch-clamp recording techniques, we investigated the biophysical properties of rat CA3 pyramidal neuron dendrites. We found two distinct dendritic domains critical for action potential initiation and propagation: In the proximal domain, action potentials initiated in the axon backpropagate actively with large amplitude and fast time course. In the distal domain, Na+-channel mediated dendritic spikes are efficiently evoked by local dendritic depolarization or waveforms mimicking synaptic events. These findings can be explained by a high Na+-to-K+ conductance density ratio of CA3 pyramidal neuron dendrites. The results challenge the prevailing view that proximal mossy fiber inputs activate CA3 pyramidal neurons more efficiently than distal perforant inputs by showing that the distal synapses trigger a different form of activity represented by dendritic spikes. The high probability of dendritic spike initiation in the distal area may enhance the computational power of CA3 pyramidal neurons in the hippocampal network.  ","lang":"eng"}],"publist_id":"3755","corr_author":"1","publication_status":"published","type":"dissertation","date_published":"2012-06-01T00:00:00Z","article_processing_charge":"No","date_updated":"2026-06-18T18:41:53Z","publisher":"Institute of Science and Technology Austria","status":"public"},{"alternative_title":["ISTA Thesis"],"title":"Dendritic cell migration across basement membranes in the skin","publication_identifier":{"issn":["2663-337X"]},"OA_place":"publisher","degree_awarded":"PhD","year":"2010","citation":{"ama":"Pflicke H.   Dendritic cell migration across basement membranes in the skin. 2010.","apa":"Pflicke, H. (2010). <i>  Dendritic cell migration across basement membranes in the skin</i>. Institute of Science and Technology Austria.","mla":"Pflicke, Holger. <i>  Dendritic Cell Migration across Basement Membranes in the Skin</i>. Institute of Science and Technology Austria, 2010.","short":"H. Pflicke,   Dendritic Cell Migration across Basement Membranes in the Skin, Institute of Science and Technology Austria, 2010.","ieee":"H. Pflicke, “  Dendritic cell migration across basement membranes in the skin,” Institute of Science and Technology Austria, 2010.","chicago":"Pflicke, Holger. “  Dendritic Cell Migration across Basement Membranes in the Skin.” Institute of Science and Technology Austria, 2010.","ista":"Pflicke H. 2010.   Dendritic cell migration across basement membranes in the skin. Institute of Science and Technology Austria."},"author":[{"id":"CAA57A9A-5B61-11E9-B130-E0C1E1F2C83D","first_name":"Holger","last_name":"Pflicke","full_name":"Pflicke, Holger"}],"department":[{"_id":"CaHe"},{"_id":"GradSch"}],"language":[{"iso":"eng"}],"date_created":"2018-12-11T12:06:08Z","supervisor":[{"full_name":"Heisenberg, Carl-Philipp J","last_name":"Heisenberg","orcid":"0000-0002-0912-4566","first_name":"Carl-Philipp J","id":"39427864-F248-11E8-B48F-1D18A9856A87"}],"month":"07","_id":"3962","oa_version":"None","status":"public","publisher":"Institute of Science and Technology Austria","date_updated":"2026-04-09T14:37:07Z","article_processing_charge":"No","date_published":"2010-07-01T00:00:00Z","type":"dissertation","publication_status":"published","corr_author":"1","publist_id":"2165","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","day":"01"}]