Encystation of Giardia intestinalis鈥?/em>a Journey from the Duodenum to the Colon

详细信息    查看全文

• 作者：Elin Einarsson ; Staffan G. Sv盲rd
• 关键词：Protozoa ; Differentiation ; Encystation ; specific vesicle ; Cyst ; Cyst wall protein
• 刊名：Current Tropical Medicine Reports
• 出版年：2015
• 出版时间：September 2015
• 年：2015
• 卷：2
• 期：3
• 页码：101-109
• 全文大小：816KB
• 参考文献：Papers of particular interest, published recently, have been highlighted as: 鈥?Of importance 鈥⑩€?Of major importance1.Lane S, Lloyd D. Current trends in research into the waterborne parasite Giardia. Crit Rev Microbiol. 2002;28:123鈥?7. doi:10.鈥?080/鈥?040-840291046713 .PubMed CrossRef
  2.Halliez MCM, Buret AG. Extra-intestinal and long term consequences of Giardia duodenalis infections. World J Gastroenterol WJG. 2013;19:8974鈥?5. doi:10.鈥?748/鈥媤jg.鈥媣19.鈥媔47.鈥?974 .PubMed CrossRef
  3.Escobedo AA, Hanevik K, Almirall P, Cimerman S, Alfonso M. Management of chronic Giardia infection. Expert Rev Anti Infect Ther. 2014;12:1143鈥?7. doi:10.鈥?586/鈥?4787210.鈥?014.鈥?42283 .PubMed CrossRef
  4.Ankarklev J, Jerlstr枚m-Hultqvist J, Ringqvist E, Troell K, Sv盲rd SG. Behind the smile: cell biology and disease mechanisms of Giardia species. Nat Rev Microbiol. 2010;8:413鈥?2. doi:10.鈥?038/鈥媙rmicro2317 .PubMed
  5.Bernander R, Palm JE, Sv盲rd SG. Genome ploidy in different stages of the Giardia lamblia life cycle. Cell Microbiol. 2001;3:55鈥?2.PubMed CrossRef
  6.Erlandsen SL, Macechko PT, van Keulen H, Jarroll EL. Formation of the Giardia cyst wall: studies on extracellular assembly using immunogold labeling and high resolution field emission SEM. J Eukaryot Microbiol. 1996;43:416鈥?9.PubMed CrossRef
  7.Einarsson E, Sv盲rd SG, Troell K. UV irradiation responses in Giardia intestinalis. Exp Parasitol. 2015;154:25鈥?2. doi:10.鈥?016/鈥媕.鈥媏xppara.鈥?015.鈥?3.鈥?24 .PubMed CrossRef
  8.Boucher SE, Gillin FD. Excystation of in vitro-derived Giardia lamblia cysts. Infect Immun. 1990;58:3516鈥?2.PubMed Central PubMed
  9.Luj谩n HD, Mowatt MR, Byrd LG, Nash TE. Cholesterol starvation induces differentiation of the intestinal parasite Giardia lamblia. Proc Natl Acad Sci U S A. 1996;93:7628鈥?3.PubMed Central PubMed CrossRef
  10.Kane AV, Ward HD, Keusch GT, Pereira ME. In vitro encystation of Giardia lamblia: large-scale production of in vitro cysts and strain and clone differences in encystation efficiency. J Parasitol. 1991;77:974鈥?1.PubMed CrossRef
  11.鈥?/div>Morf L, Spycher C, Rehrauer H, Fournier CA, Morrison HG, Hehl AB. The transcriptional response to encystation stimuli in Giardia lamblia is restricted to a small set of genes. Eukaryot Cell. 2010;9:1566鈥?6. doi:10.鈥?128/鈥婨C.鈥?0100-10 . First microarray study of the transcriptional changes during the encystation process. identified a set of conserved early upregulated genes and the importance of the Myb transcription factor.PubMed Central PubMed CrossRef
  12.English J, Pearson G, Wilsbacher J, Swantek J, Karandikar M, Xu S, et al. New insights into the control of MAP kinase pathways. Exp Cell Res. 1999;253:255鈥?0. doi:10.鈥?006/鈥媏xcr.鈥?999.鈥?687 .PubMed CrossRef
  13.Ellis JG, Davila M, Chakrabarti R. Potential involvement of extracellular signal-regulated kinase 1 and 2 in encystation of a primitive eukaryote, Giardia lamblia. Stage-specific activation and intracellular localization. J Biol Chem. 2003;278:1936鈥?5. doi:10.鈥?074/鈥媕bc.鈥婱209274200 .PubMed CrossRef
  14.Gibson C, Schanen B, Chakrabarti D, Chakrabarti R. Functional characterisation of the regulatory subunit of cyclic AMP-dependent protein kinase a homologue of Giardia lamblia: differential expression of the regulatory and catalytic subunits during encystation. Int J Parasitol. 2006;36:791鈥?. doi:10.鈥?016/鈥媕.鈥媔jpara.鈥?005.鈥?1.鈥?08 .PubMed CrossRef
  15.Baz谩n-Tejeda ML, Arg眉ello-Garc铆a R, Berm煤dez-Cruz RM, Robles-Flores M, Ortega-Pierres G. Protein kinase C isoforms from Giardia duodenalis: identification and functional characterization of a beta-like molecule during encystment. Arch Microbiol. 2007;187:55鈥?6. doi:10.鈥?007/鈥媠00203-006-0174-9 .PubMed CrossRef
  16.Kim K-T, Mok MTS, Edwards MR. Protein kinase B from Giardia intestinalis. Biochem Biophys Res Commun. 2005;334:333鈥?1. doi:10.鈥?016/鈥媕.鈥媌brc.鈥?005.鈥?6.鈥?06 .PubMed CrossRef
  17.Lauwaet T, Davids BJ, Torres-Escobar A, Birkeland SR, Cipriano MJ, Preheim SP, et al. Protein phosphatase 2A plays a crucial role in Giardia lamblia differentiation. Mol Biochem Parasitol. 2007;152:80鈥?. doi:10.鈥?016/鈥媕.鈥媘olbiopara.鈥?006.鈥?2.鈥?01 .PubMed Central PubMed CrossRef
  18.Sulemana A, Paget TA, Jarroll EL. Commitment to cyst formation in Giardia. Microbiol Read Engl. 2014;160:330鈥?. doi:10.鈥?099/鈥媘ic.鈥?.鈥?72405-0 .CrossRef
  19.Hehl AB, Marti M, K枚hler P. Stage-specific expression and targeting of cyst wall protein-green fluorescent protein chimeras in Giardia. Mol Biol Cell. 2000;11:1789鈥?00.PubMed Central PubMed CrossRef
  20.鈥⑩€?/div>Faso C, Bischof S, Hehl AB. The proteome landscape of Giardia lamblia encystation. PLoS One. 2013;8:e83207. doi:10.鈥?371/鈥媕ournal.鈥媝one.鈥?083207 . First large-scale proteomic analysis of the encystation process. Identifies a large number of proteins with known and putative roles in encystation. This will be the start of a large number of follow-up studies of proteins with changed expression during encystation.PubMed Central PubMed CrossRef
  21.Campbell JD, Faubert GM. Comparative studies on Giardia lamblia encystation in vitro and in vivo. J Parasitol. 1994;80:36鈥?4.PubMed CrossRef
  22.Adam RD. Biology of Giardia lamblia. Clin Microbiol Rev. 2001;14:447鈥?5. doi:10.鈥?128/鈥婥MR.鈥?4.鈥?.鈥?47-475.鈥?001 .PubMed Central PubMed CrossRef
  23.Best AA, Morrison HG, McArthur AG, Sogin ML, Olsen GJ. Evolution of eukaryotic transcription: insights from the genome of Giardia lamblia. Genome Res. 2004;14:1537鈥?7. doi:10.鈥?101/鈥媑r.鈥?256604 .PubMed Central PubMed CrossRef
  24.Sun C-H, Palm D, McArthur AG, Sv盲rd SG, Gillin FD. A novel Myb-related protein involved in transcriptional activation of encystation genes in Giardia lamblia. Mol Microbiol. 2002;46:971鈥?4.PubMed CrossRef
  25.Huang Y-C, Su L-H, Lee GA, Chiu P-W, Cho C-C, Wu J-Y, et al. Regulation of cyst wall protein promoters by Myb2 in Giardia lamblia. J Biol Chem. 2008;283:31021鈥?. doi:10.鈥?074/鈥媕bc.鈥婱805023200 .PubMed Central PubMed CrossRef
  26.Davis-Hayman SR, Hayman JR, Nash TE. Encystation-specific regulation of the cyst wall protein 2 gene in Giardia lamblia by multiple cis-acting elements. Int J Parasitol. 2003;33:1005鈥?2.PubMed CrossRef
  27.Wang C-H, Su L-H, Sun C-H. A novel ARID/Bright-like protein involved in transcriptional activation of cyst wall protein 1 gene in Giardia lamblia. J Biol Chem. 2007;282:8905鈥?4. doi:10.鈥?074/鈥媕bc.鈥婱611170200 .PubMed CrossRef
  28.Sun C-H, Su L-H, Gillin FD. Novel plant-GARP-like transcription factors in Giardia lamblia. Mol Biochem Parasitol. 2006;146:45鈥?7. doi:10.鈥?016/鈥媕.鈥媘olbiopara.鈥?005.鈥?0.鈥?17 .PubMed CrossRef
  29.Su L-H, Pan Y-J, Huang Y-C, Cho C-C, Chen C-W, Huang S-W, et al. A novel E2F-like protein involved in transcriptional activation of cyst wall protein genes in Giardia lamblia. J Biol Chem. 2011;286:34101鈥?0. doi:10.鈥?074/鈥媕bc.鈥婱111.鈥?80206 .PubMed Central PubMed CrossRef
  30.Chuang S-F, Su L-H, Cho C-C, Pan Y-J, Sun C-H. Functional redundancy of two Pax-like proteins in transcriptional activation of cyst wall protein genes in Giardia lamblia. PLoS One. 2012;7:e30614. doi:10.鈥?371/鈥媕ournal.鈥媝one.鈥?030614 .PubMed Central PubMed CrossRef
  31.Lin B-C, Su L-H, Weng S-C, Pan Y-J, Chan N-L, Li T-K, et al. DNA topoisomerase II is involved in regulation of cyst wall protein genes and differentiation in Giardia lamblia. PLoS Negl Trop Dis. 2013;7:e2218. doi:10.鈥?371/鈥媕ournal.鈥媝ntd.鈥?002218 .PubMed Central PubMed CrossRef
  32.Pan Y-J, Cho C-C, Kao Y-Y, Sun C-H. A novel WRKY-like protein involved in transcriptional activation of cyst wall protein genes in Giardia lamblia. J Biol Chem. 2009;284:17975鈥?8. doi:10.鈥?074/鈥媕bc.鈥婱109.鈥?12047 .PubMed Central PubMed CrossRef
  33.Worgall TS, Davis-Hayman SR, Magana MM, Oelkers PM, Zapata F, Juliano RA, et al. Sterol and fatty acid regulatory pathways in a Giardia lamblia-derived promoter: evidence for SREBP as an ancient transcription factor. J Lipid Res. 2004;45:981鈥?. doi:10.鈥?194/鈥媕lr.鈥婱400024-JLR200 .PubMed CrossRef
  34.鈥?/div>Birkeland SR, Preheim SP, Davids BJ, Cipriano MJ, Palm D, Reiner DS, et al. Transcriptome analyses of the Giardia lamblia life cycle. Mol Biochem Parasitol. 2010;174:62鈥?. doi:10.鈥?016/鈥媕.鈥媘olbiopara.鈥?010.鈥?5.鈥?10 . First study of transcriptional changes during the whole Giardia life cycle. Shows that the parasite prepares for excystation in the end of encystation.PubMed Central PubMed CrossRef
  35.Stefanic S, Morf L, Kulangara C, Reg枚s A, Sonda S, Schraner E, et al. Neogenesis and maturation of transient Golgi-like cisternae in a simple eukaryote. J Cell Sci. 2009;122:2846鈥?6. doi:10.鈥?242/鈥媕cs.鈥?49411 .PubMed CrossRef
  36.Jerlstr枚m-Hultqvist J, Stadelmann B, Birkestedt S, Hellman U, Sv盲rd SG. Plasmid vectors for proteomic analyses in Giardia: purification of virulence factors and analysis of the proteasome. Eukaryot Cell. 2012;11:864鈥?3. doi:10.鈥?128/鈥婨C.鈥?0092-12 .PubMed Central PubMed CrossRef
  37.Sinha A, Datta SP, Ray A, Sarkar S. A reduced VWA domain-containing proteasomal ubiquitin receptor of Giardia lamblia localizes to the flagellar pore regions in microtubule-dependent manner. Parasit Vectors. 2015;8:120. doi:10.鈥?186/鈥媠13071-015-0737-1 .PubMed Central PubMed CrossRef
  38.Ni帽o CA, Prucca CG, Chaparro J, Luj谩n HD, Wasserman M. The ubiquitin-activating enzyme (E1) of the early
  anching eukaryote Giardia intestinalis shows unusual proteolytic modifications and play important roles during encystation. Acta Trop. 2012;123:39鈥?6. doi:10.鈥?016/鈥媕.鈥媋ctatropica.鈥?012.鈥?3.鈥?12 .PubMed CrossRef
  39.Vranych CV, Rivero MR, Merino MC, Mayol GF, Zamponi N, Maletto BA, et al. SUMOylation and deimination of proteins: two epigenetic modifications involved in Giardia encystation. Biochim Biophys Acta. 1843;2014:1805鈥?7. doi:10.鈥?016/鈥媕.鈥媌bamcr.鈥?014.鈥?4.鈥?14 .
  40.Merino MC, Zamponi N, Vranych CV, Touz MC, R贸polo AS. Identification of Giardia lamblia DHHC proteins and the role of protein S-palmitoylation in the encystation process. PLoS Negl Trop Dis. 2014;8:e2997. doi:10.鈥?371/鈥媕ournal.鈥媝ntd.鈥?002997 .PubMed Central PubMed CrossRef
  41.Lujan HD. Mechanisms of adaptation in the intestinal parasite Giardia lamblia. Essays Biochem. 2011;51:177鈥?1. doi:10.鈥?042/鈥媌se0510177 .PubMed
  42.Faso C, Hehl AB. Membrane trafficking and organelle biogenesis in Giardia lamblia: use it or lose it. Int J Parasitol. 2011;41:471鈥?0. doi:10.鈥?016/鈥媕.鈥媔jpara.鈥?010.鈥?2.鈥?14 .PubMed CrossRef
  43.Gillin FD, Reiner DS, Gault MJ, Douglas H, Das S, Wunderlich A, et al. Encystation and expression of cyst antigens by Giardia lamblia in vitro. Science. 1987;235:1040鈥?.PubMed CrossRef
  44.Gerwig GJ, van Kuik JA, Leeflang BR, Kamerling JP, Vliegenthart JFG, Karr CD, et al. The Giardia intestinalis filamentous cyst wall contains a novel beta(1鈥?)-N-acetyl-D-galactosamine polymer: a structural and conformational study. Glycobiology. 2002;12:499鈥?05.PubMed CrossRef
  45.Luj谩n HD, Mowatt MR, Conrad JT, Bowers B, Nash TE. Identification of a novel Giardia lamblia cyst wall protein with leucine-rich repeats. Implications for secretory granule formation and protein assembly into the cyst wall. J Biol Chem. 1995;270:29307鈥?3.PubMed CrossRef
  46.Sun C-H, McCaffery JM, Reiner DS, Gillin FD. Mining the Giardia lamblia genome for new cyst wall proteins. J Biol Chem. 2003;278:21701鈥?. doi:10.鈥?074/鈥媕bc.鈥婱302023200 .PubMed CrossRef
  47.鈥⑩€?/div>Faso C, Konrad C, Schraner EM, Hehl AB. Export of cyst wall material and Golgi organelle neogenesis in Giardia lamblia depend on endoplasmic reticulum exit sites. Cell Microbiol. 2013;15:537鈥?3. doi:10.鈥?111/鈥媍mi.鈥?2054 . Paper showing the importance of ER exit sites in the formation of encystation-specific vesicles (ESVs).PubMed CrossRef
  48.Reiner DS, McCaffery JM, Gillin FD. Reversible interruption of Giardia lamblia cyst wall protein transport in a novel regulated secretory pathway. Cell Microbiol. 2001;3:459鈥?2.PubMed CrossRef
  49.Slavin I, Saura A, Carranza PG, Touz MC, Nores MJ, Luj谩n HD. Dephosphorylation of cyst wall proteins by a secreted lysosomal acid phosphatase is essential for excystation of Giardia lamblia. Mol Biochem Parasitol. 2002;122:95鈥?.PubMed CrossRef
  50.Davids BJ, Mehta K, Fesus L, McCaffery JM, Gillin FD. Dependence of Giardia lamblia encystation on novel transglutaminase activity. Mol Biochem Parasitol. 2004;136:173鈥?0.PubMed CrossRef
  51.鈥⑩€?/div>Konrad C, Spycher C, Hehl AB. Selective condensation drives partitioning and sequential secretion of cyst wall proteins in differentiating Giardia lamblia. PLoS Pathog. 2010;6:e1000835. doi:10.鈥?371/鈥媕ournal.鈥媝pat.鈥?000835 . Paper showing that the ESV cargo is processed and separated into different phases during the transport to the plasma membrane. Shows the complex, induced protein transport during encystation.PubMed Central PubMed CrossRef
  52.Davids BJ, Reiner DS, Birkeland SR, Preheim SP, Cipriano MJ, McArthur AG, et al. A new family of giardial cysteine-rich non-VSP protein genes and a novel cyst protein. PLoS One. 2006;1:e44. doi:10.鈥?371/鈥媕ournal.鈥媝one.鈥?000044 .PubMed Central PubMed CrossRef
  53.Chiu P-W, Huang Y-C, Pan Y-J, Wang C-H, Sun C-H. A novel family of cyst proteins with epidermal growth factor repeats in Giardia lamblia. PLoS Negl Trop Dis. 2010;4:e677. doi:10.鈥?371/鈥媕ournal.鈥媝ntd.鈥?000677 .PubMed Central PubMed CrossRef
  54.鈥⑩€?/div>Wampfler PB, Tosevski V, Nanni P, Spycher C, Hehl AB. Proteomics of secretory and endocytic organelles in Giardia lamblia. PLoS One. 2014;9:e94089. doi:10.鈥?371/鈥媕ournal.鈥媝one.鈥?094089 . First proteomic analysis of ESVs. Several new putative ESV cargo proteins identified.PubMed Central PubMed CrossRef
  55.Lopez AB, Sener K, Jarroll EL, van Keulen H. Transcription regulation is demonstrated for five key enzymes in Giardia intestinalis cyst wall polysaccharide biosynthesis. Mol Biochem Parasitol. 2003;128:51鈥?.PubMed CrossRef
  56.Morrison HG, McArthur AG, Gillin FD, Aley SB, Adam RD, Olsen GJ, et al. Genomic minimalism in the early diverging intestinal parasite Giardia lamblia. Science. 2007;317:1921鈥?. doi:10.鈥?126/鈥媠cience.鈥?143837 .PubMed CrossRef
  57.Karr CD, Jarroll EL. Cyst wall synthase: N-acetylgalactosaminyltransferase activity is induced to form the novel N-acetylgalactosamine polysaccharide in the Giardia cyst wall. Microbiol Read Engl. 2004;150:1237鈥?3.CrossRef
  58.Chatterjee A, Carpentieri A, Ratner DM, Bullitt E, Costello CE, Robbins PW, et al. Giardia cyst wall protein 1 is a lectin that binds to curled fibrils of the GalNAc homopolymer. PLoS Pathog. 2010;6:e1001059. doi:10.鈥?371/鈥媕ournal.鈥媝pat.鈥?001059 .PubMed Central PubMed CrossRef
  59.Midlej V, Meinig I, de Souza W, Benchimol M. A new set of carbohydrate-positive vesicles in encysting Giardia lamblia. Protist. 2013;164:261鈥?1. doi:10.鈥?016/鈥媕.鈥媝rotis.鈥?012.鈥?1.鈥?01 .PubMed CrossRef
  60.Mohareb EW, Rogers EJ, Weiner EJ, Bruce JI. Giardia lamblia: phospholipid analysis of human isolates. Ann Trop Med Parasitol. 1991;85:591鈥?.PubMed
  61.Hernandez Y, Castillo C, Roychowdhury S, Hehl A, Aley SB, Das S. Clathrin-dependent pathways and the cytoskeleton network are involved in ceramide endocytosis by a parasitic protozoan, Giardia lamblia. Int J Parasitol. 2007;37:21鈥?2. doi:10.鈥?016/鈥媕.鈥媔jpara.鈥?006.鈥?9.鈥?08 .PubMed Central PubMed CrossRef
  62.Hernandez Y, Shpak M, Duarte TT, Mendez TL, Maldonado RA, Roychowdhury S, et al. Novel role of sphingolipid synthesis genes in regulating giardial encystation. Infect Immun. 2008;76:2939鈥?9. doi:10.鈥?128/鈥婭AI.鈥?0116-08 .PubMed Central PubMed CrossRef
  63.Sonda S, Stefanic S, Hehl AB. A sphingolipid inhibitor induces a cytokinesis arrest and blocks stage differentiation in Giardia lamblia. Antimicrob Agents Chemother. 2008;52:563鈥?. doi:10.鈥?128/鈥婣AC.鈥?1105-07 .PubMed Central PubMed CrossRef
  64.Mendez TL, De Chatterjee A, Duarte TT, Gazos-Lopes F, Robles-Martinez L, Roy D, et al. Glucosylceramide transferase activity is critical for encystation and viable cyst production by an intestinal protozoan, Giardia lamblia. J Biol Chem. 2013;288:16747鈥?0. doi:10.鈥?074/鈥媕bc.鈥婱112.鈥?38416 .PubMed Central PubMed CrossRef
  65.鈥?/div>De Chatterjee A, Mendez TL, Roychowdhury S, Das S. The assembly of GM1 glycolipid- and cholesterol-enriched raft-like membrane microdomains is important for giardial encystation. Infect Immun. 2015;83:2030鈥?2. doi:10.鈥?128/鈥婭AI.鈥?3118-14 . First study showing the presence and importance of raft-like microdomains in the Giardia plasma membrane. Drugs that interfere with formation of microdomains block formation of ESVs.PubMed CrossRef
  66.Head BP, Patel HH, Insel PA. Interaction of membrane/lipid rafts with the cytoskeleton: impact on signaling and function: membrane/lipid rafts, mediators of cytoskeletal arrangement and cell signaling. Biochim Biophys Acta. 1838;2014:532鈥?5. doi:10.鈥?016/鈥媕.鈥媌bamem.鈥?013.鈥?7.鈥?18 .
  67.Reiner DS, Ankarklev J, Troell K, Palm D, Bernander R, Gillin FD, et al. Synchronisation of Giardia lamblia: identification of cell cycle stage-specific genes and a differentiation restriction point. Int J Parasitol. 2008;38:935鈥?4. doi:10.鈥?016/鈥媕.鈥媔jpara.鈥?007.鈥?2.鈥?05 .PubMed CrossRef
  68.Jerlstr枚m-Hultqvist J, Franz茅n O, Ankarklev J, Xu F, Noh媒nkov谩 E, Andersson JO, et al. Genome analysis and comparative genomics of a Giardia intestinalis assemblage E isolate. BMC Genomics. 2010;11:543. doi:10.鈥?186/鈥?471-2164-11-543 .PubMed Central PubMed CrossRef
  69.Poxleitner MK, Carpenter ML, Mancuso JJ, Wang C-JR, Dawson SC, Cande WZ. Evidence for karyogamy and exchange of genetic material in the binucleate intestinal parasite Giardia intestinalis. Science. 2008;319:1530鈥?. doi:10.鈥?126/鈥媠cience.鈥?153752 .PubMed CrossRef
  70.Carpenter ML, Assaf ZJ, Gourguechon S, Cande WZ. Nuclear inheritance and genetic exchange without meiosis in the binucleate parasite Giardia intestinalis. J Cell Sci. 2012;125:2523鈥?2. doi:10.鈥?242/鈥媕cs.鈥?03879 .PubMed Central PubMed CrossRef
  71.Jir谩kov谩 K, Kulda J, Noh媒nkov谩 E. How nuclei of Giardia pass through cell differentiation: semi-open mitosis followed by nuclear interconnection. Protist. 2012;163:465鈥?9. doi:10.鈥?016/鈥媕.鈥媝rotis.鈥?011.鈥?1.鈥?08 .PubMed CrossRef
  72.Sonda S, Morf L, Bottova I, Baetschmann H, Rehrauer H, Caflisch A, et al. Epigenetic mechanisms regulate stage differentiation in the minimized protozoan Giardia lamblia. Mol Microbiol. 2010;76:48鈥?7. doi:10.鈥?111/鈥媕.鈥?365-2958.鈥?010.鈥?7062.鈥媥 .PubMed CrossRef
  73.Gargantini PR, Serradell MC, Torri A, Lujan HD. Putative SF2 helicases of the early
  anching eukaryote Giardia lamblia are involved in antigenic variation and parasite differentiation into cysts. BMC Microbiol. 2012;12:284. doi:10.鈥?186/鈥?471-2180-12-284 .PubMed Central PubMed CrossRef
  74.Fuller-Pace FV. DExD/H box RNA helicases: multifunctional proteins with important roles in transcriptional regulation. Nucleic Acids Res. 2006;34:4206鈥?5. doi:10.鈥?093/鈥媙ar/鈥媑kl460 .PubMed Central PubMed CrossRef
  75.Prucca CG, Slavin I, Quiroga R, El铆as EV, Rivero FD, Saura A, et al. Antigenic variation in Giardia lamblia is regulated by RNA interference. Nature. 2008;456:750鈥?. doi:10.鈥?038/鈥媙ature07585 .PubMed CrossRef
  76.Saraiya AA, Li W, Wang CC. A microRNA derived from an apparent canonical biogenesis pathway regulates variant surface protein gene expression in Giardia lamblia. RNA N Y N. 2011;17:2152鈥?4. doi:10.鈥?261/鈥媟na.鈥?28118.鈥?11 .CrossRef
  77.鈥?/div>Liao J-Y, Guo Y-H, Zheng L-L, Li Y, Xu W-L, Zhang Y-C, et al. Both endo-siRNAs and tRNA-derived small RNAs are involved in the differentiation of primitive eukaryote Giardia lamblia. Proc Natl Acad Sci U S A. 2014;111:14159鈥?4. doi:10.鈥?073/鈥媝nas.鈥?414394111 . First study of changes in the level of siRNAs during encystation. tRNA fragments accumulate during the encystation process.PubMed Central PubMed CrossRef
  
• 作者单位：Elin Einarsson (1)
  Staffan G. Sv盲rd (1)
  
  1. Department of Cell and Molecular Biology, Uppsala University, BMC, Box 596, 751 24, Uppsala, Sweden
  
• 刊物类别：Tropical Medicine; Parasitology; Behavioral Sciences; Infectious Diseases;
• 刊物主题：Tropical Medicine; Parasitology; Behavioral Sciences; Infectious Diseases;
• 出版者：Springer International Publishing
• ISSN：2196-3045

文摘

The intestinal protozoan parasite Giardia intestinalis has a simple life cycle consisting of disease-causing trophozoites and infectious cysts. The parasite differentiates into the cyst stage (encystation) when duodenal trophozoites are swept further down in the small intestine. The encystation process can be divided into an early and a late phase. Expressions of cyst wall sugars and proteins are induced early during encystation, and Giardia has developed special transport systems for cyst wall material. This is combined with disassembly of the flagella and adhesive disc. In the later phase of encystation, nuclei are divided, DNA is replicated, and the parasites prepare for the next step in differentiation (excystation) via large changes in gene expression. Even if many aspects of the encystation process have been studied and much information has been gained during the last years, much still remains to be explored regarding this highly complex process. Keywords Protozoa Differentiation Encystation-specific vesicle Cyst Cyst wall protein