Linalool acts as a fast and reversible anesthetic in Hydra

Autoři: Tapan Goel aff001;  Rui Wang aff002;  Sara Martin aff002;  Elizabeth Lanphear aff002;  Eva-Maria S. Collins aff001
Působiště autorů: Department of Physics, University of California San Diego, La Jolla, CA, United States of America aff001;  Department of Biology, Swarthmore College, Swarthmore, PA, United States of America aff002;  Department of Bioengineering, University of California San Diego, La Jolla, CA, United States of America aff003
Vyšlo v časopise: PLoS ONE 14(10)
Kategorie: Research Article
doi: 10.1371/journal.pone.0224221


The ability to make transgenic Hydra lines has allowed for quantitative in vivo studies of Hydra regeneration and physiology. These studies commonly include excision, grafting and transplantation experiments along with high-resolution imaging of live animals, which can be challenging due to the animal’s response to touch and light stimuli. While various anesthetics have been used in Hydra studies, they tend to be toxic over the course of a few hours or their long-term effects on animal health are unknown. Here, we show that the monoterpenoid alcohol linalool is a useful anesthetic for Hydra. Linalool is easy to use, non-toxic, fast acting, and reversible. It has no detectable long-term effects on cell viability or cell proliferation. We demonstrate that the same animal can be immobilized in linalool multiple times at intervals of several hours for repeated imaging over 2–3 days. This uniquely allows for in vivo imaging of dynamic processes such as head regeneration. We directly compare linalool to currently used anesthetics and show its superior performance. Linalool will be a useful tool for tissue manipulation and imaging in Hydra research in both research and teaching contexts.

Klíčová slova:

Anesthesia – Anesthetics – Fluorescence imaging – In vivo imaging – Neurons – Hydra – Urethanes – Head regeneration


1. Lenhoff SG, Lenhoff HM, Trembley A. Hydra and the Birth of Experimental Biology, 1744: Abraham Trembley’s Memoires concerning the polyps. Boxwood Press; 1986.

2. Bode HR. The interstitial cell lineage of hydra: a stem cell system that arose early in evolution. J Cell Sci. 1996;109: 1155–1164. 8799806

3. Campbell RD. Cell Movements in Hydra. Am Zool. Oxford University Press; 1974;14: 523–535. doi: 10.1093/icb/14.2.523

4. Gierer A, Berking S, Bode H, David CNN, Flick K, Hansmann G, et al. Regeneration of Hydra from Reaggregated Cells. Nat New Biol. Nature Publishing Group UK; 1972;239: 98–101. doi: 10.1038/newbio239098a0 4507522

5. Shimizu H, Sawada Y, Sugiyama T. Minimum Tissue Size Required for Hydra Regeneration. Dev Biol. Academic Press; 1993;155: 287–296. doi: 10.1006/dbio.1993.1028 8432387

6. Steele RE. Developmental Signaling in Hydra: What Does It Take to Build a “Simple” Animal? Dev Biol. Academic Press; 2002;248: 199–219. doi: 10.1006/dbio.2002.0744 12167399

7. David CN, Murphy S. Characterization of interstitial stem cells in hydra by cloning. Dev Biol. Academic Press; 1977;58: 372–383. doi: 10.1016/0012-1606(77)90098-7 328331

8. Bosch TCG. Hydra and the evolution of stem cells. BioEssays. John Wiley & Sons, Ltd; 2009;31: 478–486. doi: 10.1002/bies.200800183 19274660

9. Bosch TCG. Why polyps regenerate and we don’t: Towards a cellular and molecular framework for Hydra regeneration. Dev Biol. Academic Press; 2007;303: 421–433. doi: 10.1016/j.ydbio.2006.12.012 17234176

10. Galliot B, Buzgariu W, Schenkelaars Q, Wenger Y. Non-developmental dimensions of adult regeneration in Hydra. Int J Dev Biol. 2018;62: 373–381. doi: 10.1387/ijdb.180111bg 29938750

11. Cochet-Escartin O, Locke TT, Shi WH, Steele RE, Collins E-MS. Physical Mechanis ms Driving Cell Sorting in Hydra. Biophys J. Cell Press; 2017;113: 2827–2841. doi: 10.1016/j.bpj.2017.10.045 29262375

12. Petersen HO, Höger SK, Looso M, Lengfeld T, Kuhn A, Warnken U, et al. A comprehensive transcriptomic and proteomic analysis of hydra head regeneration. Mol Biol Evol. 2015;32. doi: 10.1093/molbev/msv079 25841488

13. Burnett AL, Diehl NA. The nervous system of hydra. I. Types, distribution and origin of nerve elements. J Exp Zool. John Wiley & Sons, Ltd; 1964;157: 217–226. doi: 10.1002/jez.1401570205 14225241

14. Bode H, Berking S, David CN, Gierer A, Schaller H, Trenkner E. Quantitative analysis of cell types during growth and morphogenesis in Hydra. Wilhelm Roux Arch für Entwicklungsmechanik der Org. Springer-Verlag; 1973;171: 269–285. doi: 10.1007/BF00577725 28304608

15. David CN. A quantitative method for maceration of hydra tissue. Wilhelm Roux Arch für Entwicklungsmechanik der Org. Springer-Verlag; 1973;171: 259–268. doi: 10.1007/BF00577724 28304607

16. Dupre C, Yuste R. Non-overlapping Neural Networks in Hydra vulgaris. Curr Biol. Cell Press; 2017;27: 1085–1097. doi: 10.1016/j.cub.2017.02.049 28366745

17. Noro Y, Yum S, Nishimiya-Fujisawa C, Busse C, Shimizu H, Mineta K, et al. Regionalized nervous system in Hydra and the mechanism of its development. Gene Expr Patterns. Elsevier; 2019;31: 42–59. doi: 10.1016/j.gep.2019.01.003 30677493

18. Koizumi O. Developmental neurobiology of hydra, a model animal of cnidarians. Can J Zool. NRC Research Press Ottawa, Canada; 2002;80: 1678–1689. doi: 10.1139/z02-134

19. Han S, Taralova E, Dupre C, Yuste R. Comprehensive machine learning analysis of Hydra behavior reveals a stable basal behavioral repertoire. Elife. 2018;7. doi: 10.7554/eLife.32605 29589829

20. Ando H, Sawada Y, Shimizu H, Sugiyama T. Pattern formation in hydra tissue without developmental gradients. Dev Biol. Academic Press; 1989;133: 405–414. doi: 10.1016/0012-1606(89)90044-4 2731636

21. Browne EN. The production of new hydranths in Hydra by the insertion of small grafts. J Exp Zool. John Wiley & Sons, Ltd; 1909;7: 1–23. doi: 10.1002/jez.1400070102

22. Yao T. Studies on the organizer problem in Pelmatohydra oligactis. I. The induction potency of the implants and the nature of the induced hydranth. J Exp Biol. 1945;21: 147–150. Available:

23. Bode HR. The head organizer in Hydra. Int J Dev Biol. UPV/EHU Press; 2012;56: 473–478. doi: 10.1387/ijdb.113448hb 22689359

24. MacWillia ms HK. Hydra transplantation phenomena and the mechanism of Hydra head regeneration: II. Properties of the head activation. Dev Biol. Academic Press; 1983;96: 239–257. doi: 10.1016/0012-1606(83)90325-1 6825956

25. Technau U, Cramer von Laue C, Rentzsch F, Luft S, Hobmayer B, Bode HR, et al. Parameters of self-organization in Hydra aggregates. Proc Natl Acad Sci U S A. National Academy of Sciences; 2000;97: 12127–31. doi: 10.1073/pnas.97.22.12127 11050241

26. Gierer A, Meinhardt H. A Theory of Biological Pattern Formation. Kybernetik. 1972;12: 30–39. 4663624

27. Chapman JA, Kirkness EF, Simakov O, Hampson SE, Mitros T, Weinmaier T, et al. The dynamic genome of Hydra. Nature. 2010;464: 592–596. doi: 10.1038/nature08830 20228792

28. Siebert S, Farrell JA, Cazet JF, Abeykoon Y, Primack AS, Schnitzler CE, et al. Stem cell differentiation trajectories in Hydra resolved at single-cell resolution. bioRxiv. Cold Spring Harbor Laboratory; 2018; 460154. doi: 10.1101/460154

29. Juliano CE, Lin H, Steele RE. Generation of Transgenic Hydra by Embryo Microinjection. J Vis Exp. 2014;91: e51888. doi: 10.3791/51888 25285460

30. Glauber KM, Dana CE, Park SS, Colby DA, Noro Y, Fujisawa T, et al. A small molecule screen identifies a novel compound that induces a homeotic transformation in Hydra. Development. 2015;142: 2081–2081. doi: 10.1242/dev.126235 26015540

31. Wittlieb J, Anton-Erxleben F, Bosch TCG, Lohmann JU, Khalturin K. Transgenic Hydra allow in vivo tracking of individual stem cells during morphogenesis. Proc Natl Acad Sci. 2006;103: 6208–6211. doi: 10.1073/pnas.0510163103 16556723

32. Carter JA, Hyland C, Steele RE, Collins E-MS. Dynamics of Mouth Opening in Hydra. Biophys J. 2016;110: 1191–1201. doi: 10.1016/j.bpj.2016.01.008 26958895

33. Rushforth NB, Burnett AL, Maynard R. Behavior in hydra: Contraction responses of hydra pirardi to mechanical and light stimuli. Science (80-). American Association for the Advancement of Science; 1963;139: 760–761. doi: 10.1126/SCIENCE.139.3556.760

34. Macklin M. The effect of urethan on hydra. Biol Bull. Marine Biological Laboratory; 1976;150: 442–52. doi: 10.2307/1540684 953073

35. Benos DJ, Kirk RG, Barba WP, Goldner MM. Hyposmotic fluid formation in Hydra. Tissue Cell. Churchill Livingstone; 1977;9: 11–22. doi: 10.1016/0040-8166(77)90045-3 898170

36. Münder S, Tischer S, Grundhuber M, Büchels N, Bruckmeier N, Eckert S, et al. Notch-signalling is required for head regeneration and tentacle patterning in Hydra. Dev Biol. Academic Press; 2013;383: 146–157. doi: 10.1016/j.ydbio.2013.08.022 24012879

37. Takahashi T, Hamaue N. Molecular characterization of Hydra acetylcholinesterase and its catalytic activity. FEBS Lett. No longer published by Elsevier; 2010;584: 511–516. doi: 10.1016/j.febslet.2009.11.081 19951706

38. Buzgariu W, Wenger Y, Tcaciuc N, Catunda-Lemos A-P, Galliot B. Impact of cycling cells and cell cycle regulation on Hydra regeneration. Dev Biol. Academic Press; 2018;433: 240–253. doi: 10.1016/j.ydbio.2017.11.003 29291976

39. Smith KM, Gee L, Bode HR. HyAlx, an aristaless-related gene, is involved in tentacle formation in hydra. Development. 2000;127.

40. Rentzsch F, Hobmayer B, Holstein TW. Glycogen synthase kinase 3 has a proapoptotic function in Hydra gametogenesis. Dev Biol. Academic Press; 2005;278: 1–12. doi: 10.1016/j.ydbio.2004.10.007 15649456

41. Badhiwala KN, Gonzales DL, Vercosa DG, Avants BW, Robinson JT. Microfluidics for electrophysiology, imaging, and behavioral analysis of Hydra †. 2018;18: 2523. doi: 10.1039/c8lc00475g 29987278

42. Lommel M, Tursch A, Rustarazo-Calvo L, Trageser B, Holstein TW. Genetic knockdown and knockout approaches in Hydra. bioRxiv. Cold Spring Harbor Laboratory; 2017; 230300. doi: 10.1101/230300

43. Loomis WF. Glutathione Control Of The Specific Feeding Reactions Of Hydra. Ann N Y Acad Sci. John Wiley & Sons, Ltd (10.1111); 1955;62: 211–227. doi: 10.1111/j.1749-6632.1955.tb35372.x

44. Kepner WA, Hopkins DLL. Reactions of Hydra to Chloretone. J Exp Zool. Wiley-Blackwell; 1938;38: 951–959. doi: 10.1002/jez.1400380403

45. Takaku Y, Hwang JS, Wolf A, Böttger A, Shimizu H, David CN, et al. Innexin gap junctions in nerve cells coordinate spontaneous contractile behavior in Hydra polyps. Sci Rep. Nature Publishing Group; 2015;4: 3573. doi: 10.1038/srep03573 24394722

46. Aprotosoaie AC, Hǎncianu M, Costache II, Miron A. Linalool: A review on a key odorant molecule with valuable biological properties. Flavour Fragr J. 2014;29: 193–219. doi: 10.1002/ffj.3197

47. Linck V de M, da Silva AL, Figueiró M, Luis Piato Â, Paula Herrmann A, Dupont Birck F, et al. Inhaled linalool-induced sedation in mice. Phytomedicine. Urban & Fischer; 2009;16: 303–307. doi: 10.1016/j.phymed.2008.08.001 18824339

48. Heldwein CG, Silva L de L, Gai EZ, Roman C, Parodi TV parfau., Bürger ME, et al. S-(+)-Linalool from Lippia alba: Sedative and anesthetic for silver catfish (Rhamdia quelen). Vet Anaesth Analg. 2014;41: 621–629. doi: 10.1111/vaa.12146 24628858

49. Boothe T, Hilbert L, Heide M, Berninger L, Huttner WB, Zaburdaev V, et al. A tunable refractive index matching medium for live imaging cells, tissues and model organis ms. eLife—Tools Resour. 2017; doi: 10.1111/jam.13772

50. Höferl M, Krist S, Buchbauer G. Chirality Influences the Effects of Linalool on Physiological Parameters of Stress. Planta Med. Georg Thieme Verlag KG Stuttgart · New York; 2006;72: 1188–1192. doi: 10.1055/s-2006-947202 16983600

51. Rodenak-Kladniew B, Castro A, Stärkel P, De Saeger C, García de Bravo M, Crespo R. Linalool induces cell cycle arrest and apoptosis in HepG2 cells through oxidative stress generation and modulation of Ras/MAPK and Akt/mTOR pathways. Life Sci. Elsevier; 2018;199: 48–59. doi: 10.1016/j.lfs.2018.03.006 29510199

52. Kanaya HJ, Kobayakawa Y, Itoh TQ. Hydra vulgaris exhibits day-night variation in behavior and gene expression levels. Zool Lett. Zoological Letters; 2019;5: 1–12. doi: 10.1186/s40851-019-0127-1 30891311

53. Hagstrom D, Cochet-Escartin O, Zhang S, Khuu C, Collins E-MS. Freshwater Planarians as an Alternative Animal Model for Neurotoxicology. Toxicol Sci. Oxford University Press; 2015;147: 270–285. doi: 10.1093/toxsci/kfv129 26116028

54. McLaughlin S. Evidence that polycystins are involved in Hydra cnidocyte discharge. Invertebr Neurosci. 2017;17: 1. doi: 10.1007/s10158-016-0194-3 28078622

55. Livshits A, Shani-Zerbib L, Maroudas-Sacks Y, Braun E, Keren K. Structural Inheritance of the Actin Cytoskeletal Organization Determines the Body Axis in Regenerating Hydra. Cell Rep. ElsevierCompany.; 2017;18: 1410–1421. doi: 10.1016/j.celrep.2017.01.036 28178519

56. Shimizu H, Sawada Y. Transplantation phenomena in hydra: Cooperation of position-dependent and structure-dependent factors determines the transplantation result. Dev Biol. Academic Press; 1987;122: 113–119. doi: 10.1016/0012-1606(87)90337-X

57. Rand HW, Bovard JF, Minnich DE. Localization of Formative Agencies in Hydra. Proc Natl Acad Sci U S A. National Academy of Sciences; 1926;12: 565–70. Available: doi: 10.1073/pnas.12.9.565 16577013

58. Szymanski JR, Yuste R. Mapping the Whole-Body Muscle Activity of Hydra vulgaris. Curr Biol. Elsevier Ltd.; 2019;29: 1807–1817.e3. doi: 10.1016/j.cub.2019.05.012 31130460

59. Engel U. Nowa, a novel protein with minicollagen Cys-rich domains, is involved in nematocyst formation in Hydra. J Cell Sci. 2002;115: 3923–3934. doi: 10.1242/jcs.00084 12244130

60. Campbell RD, David CN. Cell Cycle Kinetics and Development of Hydra attenuata. II. Interstitial cells. J Cell Sci. 1974;16: 349–358. 4448825

61. David CN, Campbell RD. Cell cycle kinetics and development of Hydra attenuata. I. Epithelial cells. J Cell Sci. 1972;11: 557–68. 5076361

62. Miljkovic-Licina M, Chera S, Ghila L, Galliot B. Head regeneration in wild-type hydra requires de novo neurogenesis. Development. The Company of Biologists Ltd; 2007;134: 1191–201. doi: 10.1242/dev.02804 17301084

63. Hausman RE, Burnett AL. The mesoglea of Hydra. IV. A qualitative radioautographic study of the protein component. J Exp Zool. John Wiley & Sons, Ltd; 1971;177: 435–446. doi: 10.1002/jez.1401770405

64. Shimizu H, Zhang X, Zhang J, Leontovich A, Fei K, Yan L, et al. Epithelial morphogenesis in hydra requires de novo expression of extracellular matrix components and matrix metalloproteinases. Development. 2002;129: 1521 LP– 1532.

65. Hufnagel LA, Myhal ML. Observations on a Spirochaete Symbiotic in Hydra. Trans Am Microsc Soc. 1977;96: 406. doi: 10.2307/3225874

66. Hufnagel LA, Kass-Simon G, Lyon MK. Functional organization of battery cell complexes in tentacles ofHydra attenuata. J Morphol. John Wiley & Sons, Ltd; 1985;184: 323–341. doi: 10.1002/jmor.1051840307 29976015

67. Shimizu H, Koizumi O, Fujisawa T. Three digestive movements in Hydra regulated by the diffuse nerve net in the body column. J Comp Physiol A. Springer-Verlag; 2004;190: 623–630. doi: 10.1007/s00359-004-0518-3 15168068

68. Dexter JP, Tamme MB, Lind CH, Collins E-MS. On-chip immobilization of planarians for in vivo imaging. Sci Rep. Nature Publishing Group; 2015;4: 6388. doi: 10.1038/srep06388 25227263

69. Letizia C., Cocchiara J, Lalko J, Api A. Fragrance material review on linalool. Food Chem Toxicol. Pergamon; 2003;41: 943–964. doi: 10.1016/s0278-6915(03)00015-2 12804650

70. Nordt SP. Chlorobutanol toxicity. Ann Pharmacother. 1996;30: 1179–80. Available: 8893127

71. Tuveson DA, Jacks T. Modeling human lung cancer in mice: Similarities and shortcomings [Internet]. Oncogene. Nature Publishing Group; 1999. pp. 5318–5324. doi: 10.1038/sj.onc.1203107 10498884

72. Salaman MH, Roe FJ. Incomplete carcinogens: ethyl carbamate (urethane) as an initiator of skin tumour formation in the mouse. Br J Cancer. Nature Publishing Group; 1953;7: 472–81. doi: 10.1038/bjc.1953.49 13126391

73. Sakano K, Oikawa S, Hiraku Y, Kawanishi S. Metabolism of carcinogenic urethane to nitric oxide is involved in oxidative DNA damage. Free Radic Biol Med. Pergamon; 2002;33: 703–714. doi: 10.1016/s0891-5849(02)00969-3 12208357

74. Bernardini G, Vismara C, Boracchi P, Camatini M. Lethality, teratogenicity and growth inhibition of heptanol in Xenopus assayed by a modified frog embryo teratogenesis assay-Xenopus (FETAX) procedure. Sci Total Environ. Elsevier; 1994;151: 1–8. doi: 10.1016/0048-9697(94)90480-4 8079149

75. Slooff W, Canton JH, Hermens JLM. Comparison of the susceptibility of 22 freshwater species to 15 chemical compounds. I. (Sub)acute toxicity tests. Aquat Toxicol. Elsevier; 1983;4: 113–128. doi: 10.1016/0166-445X(83)90049-8

76. Nogi T, Levin M. Characterization of innexin gene expression and functional roles of gap-junctional communication in planarian regeneration. Dev Biol. Academic Press; 2005;287: 314–335. doi: 10.1016/j.ydbio.2005.09.002 16243308

77. Marcum BA, Campbell RD. Development of Hydra lacking nerve and interstitial cells. J Cell Sci. 1978;29.

78. Elisabetsky E, Marschner J, Onofre Souza D. Effects of linalool on glutamatergic system in the rat cerebral cortex. Neurochem Res. 1995;20: 461–465. doi: 10.1007/bf00973103 7651584

79. Re L, Barocci S, Sonnino S, Mencarelli A, Vivani C, Paolucci G, et al. Linalool modifies the nicotinic receptor-ion channel kinetics at the mouse neuromuscular junction. Pharmacol Res. 2000;42: 177–181. doi: 10.1006/phrs.2000.0671 10887049

80. Pierobon P, Concas A, Santoro G, Marino G, Minei R, Pannaccione A, et al. Biochemical and functional identification of GABA receptors in Hydra vulgaris. Life Sci. Pergamon; 1995;56: 1485–1497. doi: 10.1016/0024-3205(95)00111-i 7752813

81. Bellis SL, Grosvenor W, Kass-Simon G, Rhoads DE. Chemoreception in Hydra vulgaris (attenuata): initial characterization of two distinct binding sites for l-glutamic acid. Biochim Biophys Acta—Biomembr. Elsevier; 1991;1061: 89–94. doi: 10.1016/0005-2736(91)90272-A

82. Kass-Simon G, Pannaccione A, Pierobon P. GABA and glutamate receptors are involved in modulating pacemaker activity in hydra. Comp Biochem Physiol—A Mol Integr Physiol. 2003;136: 329–342. doi: 10.1016/S1095-6433(03)00168-5 14511752

83. Kass-Simon G, Scappaticci AA. Glutamatergic and GABAnergic control in the tentacle effector syste ms of Hydra vulgaris. Hydrobiologia. Kluwer Academic Publishers; 2004;530–531: 67–71. doi: 10.1007/s10750-004-2647-7

84. Eržen I, Brzin M. Cholinergic mechanis ms in hydra. Comp Biochem Physiol Part C Comp Pharmacol. Pergamon; 1978;59: 39–43. doi: 10.1016/0306-4492(78)90009-6

85. Kass-Simon G, Passano LM. A neuropharmacological analysis of the pacemakers and conducting tissues ofHydra attenuata. J Comp Physiol? A. Springer-Verlag; 1978;128: 71–79. doi: 10.1007/BF00668375

86. Martin VJ, Littlefield CL, Archer WE, Bode HR. Embryogenesis in hydra. Biol Bull. Marine Biological Laboratory; 1997;192: 345–63. doi: 10.2307/1542745 9212444

87. Technau U, Miller MA, Bridge D, Steele RE. Arrested apoptosis of nurse cells during Hydra oogenesis and embryogenesis. Dev Biol. Academic Press; 2003;260: 191–206. doi: 10.1016/s0012-1606(03)00241-0 12885564

88. Hobmayer B, Rentzsch F, Kuhn K, Happel CM, von Laue CC, Snyder P, et al. WNT signalling molecules act in axis formation in the diploblastic metazoan Hydra. Nature. Nature Publishing Group; 2000;407: 186–189. doi: 10.1038/35025063 11001056

89. Glauber KM, Dana CE, Park SS, Colby DA, Noro Y, Fujisawa T, et al. A small molecule screen identifies a novel compound that induces a homeotic transformation in Hydra. Development. Oxford University Press for The Company of Biologists Limited; 2013;140: 4788–96. doi: 10.1242/dev.094490 24255098

90. Shimizu H, Koizumi O, Fujisawa T. Three digestive movements in Hydra regulated by the diffuse nerve net in the body column. J Comp Physiol A. Springer-Verlag; 2004;190: 623–630. doi: 10.1007/s00359-004-0518-3 15168068

91. Lenhoff HM, Brown RD. Mass culture of hydra: an improved method and its application to other aquatic invertebrates. Lab Anim. 1970;4: 139–154. doi: 10.1258/002367770781036463 5527814

92. Sugiyama T, Fujisawa T. Genetic analysis of developmental mechanis ms in Hydra. II. Isolation and characterization of an interstitial cell-deficient strain. J Cell Sci. 1978;29: 35–52. Available: 627611

93. Fujisawa T. Hydra regeneration and epitheliopeptides. Dev Dyn. John Wiley & Sons, Ltd; 2003;226: 182–189. doi: 10.1002/dvdy.10221 12557197

94. Tran CM, Fu S, Rowe T, Collins E-MS. Generation and long-term maintenance of nerve-free Hydra. J Vis Exp. 2017;125: e56115. doi: 10.3791/56115 28715393

95. Schindelin J, Arganda-Carreras I, Frise E, Kaynig V, Longair M, Pietzsch T, et al. Fiji: an open-source platform for biological-image analysis. Nat Methods. Nature Publishing Group; 2012;9: 676–682. doi: 10.1038/nmeth.2019 22743772

96. Thévenaz P, Ruttimann UE, Unser M. A Pyramid Approach to Subpixel Registration Based on Intensity. IEEE Trans Image Process. 1998;7: 27–41. Available: doi: 10.1109/83.650848 18267377

97. Otto JJ, Campbell RD. Budding inHydra attenuata: Bud stages and fate map. J Exp Zool. John Wiley & Sons, Ltd; 1977;200: 417–428. doi: 10.1002/jez.1402000311 874446

98. Cikala M, Wilm B, Hobmayer E, Böttger A, David CN. Identification of caspases and apoptosis in the simple metazoan Hydra. Curr Biol. Cell Press; 1999;9: 959–S2. doi: 10.1016/s0960-9822(99)80423-0 10508589

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