Unravelling the effects of the environment and host genotype on the gut microbiome

Nature Reviews Microbiology

Volumn 9, Issue 4, 2011, Pages 279-290

  Spor, Aymé ^a   Koren, Omry ^a   Ley, Ruth ^a  

^a Department of Obstetrics Gynecology   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

LEUKOCYTE ANTIGEN; TOLL LIKE RECEPTOR 2; TOLL LIKE RECEPTOR 4; TOLL LIKE RECEPTOR 5;

ADAPTIVE IMMUNITY; ARTICLE; DIET; GENETICS; GENOTYPE; HOST; HUMAN; INNATE IMMUNITY; INTESTINE FLORA; METABOLISM; MICROBIOME; NONHUMAN; PRIORITY JOURNAL; STOCHASTIC MODEL; TWINS;

ADAPTIVE IMMUNITY; ANIMALS; DIET; ENVIRONMENT; GASTROINTESTINAL TRACT; GENES; GENOTYPE; HUMANS; IMMUNITY, INNATE; METAGENOME; MICE; MICE, INBRED STRAINS; MICROBIAL CONSORTIA; TWINS;

EID: 79952748287     PISSN: 17401526     EISSN: None     Source Type: Journal    
DOI: 10.1038/nrmicro2540     Document Type: Article

References (121)

1. Koenig, J.E. et al. Microbes and Health Sackler Colloquium: succession of microbial consortia in the developing infant gut microbiome. Proc. Natl Acad. Sci. USA 28Jul 2010 (doi:10.1073/pnas.1000081107).
2. Palmer, C., Bik, E.M., DiGiulio, D.B., Relman, D.A. & Brown, P.O. Development of the human infant intestinal microbiota. PLoS Biol. 5, e177 (2007).
3. Dethlefsen, L., Huse, S., Sogin, M.L. & Relman, D.A. The pervasive effects of an antibiotic on the human gut microbiota, as revealed by deep 16S rRNA sequencing. PLoS Biol. 6, e280 (2008).
4. Eckburg, P.B. et al. Diversity of the human intestinal microbial flora. Science 308, 1635-1638 (2005). (Pubitemid 40807514)
5. Ley, R.E., Turnbaugh, P.J., Klein, S. & Gordon, J.I. Microbial ecology: human gut microbes associated with obesity. Nature 444, 1022-1023 (2006). (Pubitemid 46018512)
6. Qin, J. et al. A human gut microbial gene catalogue established by metagenomic sequencing. Nature 464, 59-65 (2010).
7. Turnbaugh, P.J. et al. A core gut microbiome in obese and lean twins. Nature 457, 480-484 (2009).
8. Moodley, Y. et al. The peopling of the Pacific from a bacterial perspective. Science 323, 527-530 (2009).
9. Schwarz, S. et al. Horizontal versus familial transmission of Helicobacter pylori. PLoS Pathog. 4, e1000180 (2008).
10. Vaishampayan, P.A. et al. Comparative metagenomics and population dynamics of the gut microbiota in mother and infant. Genome Biol. Evol. 6, 53-66 (2010).
11. Dethlefsen, L., Eckburg, P.B., Bik, E.M. & Relman, D.A. Assembly of the human intestinal microbiota. Trends. Ecol. Evol. 21, 517-523 (2006). (Pubitemid 44233957)
12. Ley, R.E., Peterson, D.A. & Gordon, J.I. Ecological and evolutionary forces shaping microbial diversity in the human intestine. Cell 124, 837-848 (2006). (Pubitemid 43261456)
13. Tims, S., Zoetendal, E.G., de Vos, W.M. & Kleerebezem, M. in: Metagenomics of the Human Body (ed. Nelson, K.E.) 15-41 (Springer, Berlin, 2011).
14. Frank, D.N. et al. Molecular-phylogenetic characterization of microbial community imbalances in human inflammatory bowel diseases. Proc. Natl Acad. Sci. USA 104, 13780-13785 (2007). (Pubitemid 350003397)
15. Sartor, R.B. Microbial influences in inflammatory bowel diseases. Gastroenterology 134, 577-594 (2008). (Pubitemid 351173057)
16. Larsen, N. et al. Gut microbiota in human adults with type2 diabetes differs from non-diabetic adults. PLoS ONE 5, e9085 (2010).
17. Peterson, D.A., Frank, D.N., Pace, N.R. & Gordon, J.I. Metagenomic approaches for defining the pathogenesis of inflammatory bowel diseases. Cell Host Microbe 3, 417-427 (2008). (Pubitemid 351773097)
18. Wang, Y. et al. 16S rRNA gene-based analysis of fecal microbiota from preterm infants with and without necrotizing enterocolitis. ISME J. 3, 944-954 (2009).
19. Turnbaugh, P.J., Backhed, F., Fulton, L. & Gordon, J.I. Diet-induced obesity is linked to marked but reversible alterations in the mouse distal gut microbiome. Cell Host Microbe 3, 213-223 (2008). (Pubitemid 351494716)
20. Vijay-Kumar, M. et al. Metabolic syndrome and altered gut microbiota in mice lacking Toll-like receptor 5. Science 328, 228-231 (2010).
21. Garrett, W.S. et al. Communicable ulcerative colitis induced by T-bet deficiency in the innate immune system. Cell 131, 33-45 (2007). (Pubitemid 47505255)
22. Wen, L. et al. Innate immunity and intestinal microbiota in the development of Type1 diabetes. Nature 455, 1109-1113 (2008).
23. Borody, T.J. et al. Bacteriotherapy using fecal flora: toying with human motions. J.Clin. Gastroenterol. 38, 475-483 (2004). (Pubitemid 38808419)
24. You, D.M., Franzos, M.A. & Holman, R.P. Successful treatment of fulminant Clostridium difficile infection with fecal bacteriotherapy. Ann. Intern. Med. 148, 632-633 (2008). (Pubitemid 351669152)
25. Grehan, M.J. et al. Durable alteration of the colonic microbiota by the administration of donor fecal flora. J.Clin. Gastroenterol. 44, 551-561 (2010).
26. Benson, A.K. et al. Individuality in gut microbiota composition is a complex, polygenic trait shaped by multiple environmental and host genetic factors. Proc. Natl Acad. Sci. USA 107, 18933-18938 (2010).
27. Ley, R.E. et al. Obesity alters gut microbial ecology. Proc. Natl Acad. Sci. USA 102, 11070-11075 (2005). (Pubitemid 41105994)
28. Whittaker, R.H. Evolution and measurement of species diversity. Taxon 21, 213-251 (1972).
29. Orcutt, R.P., Gianni, F.J. & Judge, R.J. Development of an "Altered Schaedler Flora" for NCI gnotobiotic rodents. Microecol. Ther. 17, 59 (1987).
30. Deloris Alexander, A. et al. Quantitative PCR assays for mouse enteric flora reveal strain-dependent differences in composition that are influenced by the microenvironment. Mamm. Genome 17, 1093-1104 (2006). (Pubitemid 44764287)
31. Dethlefsen, L., McFall-Ngai, M. & Relman, D.A. An ecological and evolutionary perspective on human-microbe mutualism and disease. Nature 449, 811-818 (2007). (Pubitemid 47598621)
32. Louis, P., Scott, K.P., Duncan, S.H. & Flint, H.J. Understanding the effects of diet on bacterial metabolism in the large intestine. J.Appl. Microbiol. 102, 1197-1208 (2007). (Pubitemid 46633434)
33. Tilg, H. Obesity, metabolic syndrome, and microbiota: multiple interactions. J.Clin. Gastroenterol. 44, S16-S18 (2010).
34. Turnbaugh, P.J. et al. The effect of diet on the human gut microbiome: a metagenomic analysis in humanized gnotobiotic mice. Sci. Transl. Med. 1, 6ra14 (2009).
35. Zhang, C. et al. Interactions between gut microbiota, host genetics and diet relevant to development of metabolic syndromes in mice. ISME J. 4, 232-241 (2010).
36. Duncan, S.H. et al. Reduced dietary intake of carbohydrates by obese subjects results in decreased concentrations of butyrate and butyrate-producing bacteria in feces. Appl. Environ. Microbiol. 73, 1073-1078 (2007).
37. Sonnenburg, E.D. et al. Specificity of polysaccharide use in intestinal bacteroides species determines diet-induced microbiota alterations. Cell 141, 1241-1252 (2010).
38. Stewart, J.A., Chadwick, V.S. & Murray, A. Investigations into the influence of host genetics on the predominant eubacteria in the faecal microflora of children. J.Med. Microbiol. 54, 1239-1242 (2005). (Pubitemid 41783834)
39. Zoetendal, E.G., Akkermans, A.D., Akkermans-van Vliet, W.M., de Visser, J.A. & de Vos, W.M. The host genotype affects the bacterial community in the human gastronintestinal tract. Microb. Ecol. Health Dis. 13, 129-134 (2001). (Pubitemid 32905860)
40. Turnbaugh, P. et al. Organismal, genetic, and transcriptional variation in the deeply sequenced gut microbiomes of identical twins. Proc. Natl Acad. Sci. USA 107, 7503-7508 (2010).
41. Teucher, B. et al. Dietary patterns and heritability of food choice in a UK female twin cohort. Twin Res. Hum. Genet. 10, 734-748 (2007). (Pubitemid 47608008)
42. Vinkhuyzen, A.A., van der Sluis, S., de Geus, E.J., Boomsma, D.I. & Posthuma, D. Genetic influences on 'environmental' factors. Genes Brain Behav. 9, 276-287 (2010).
43. Matsumoto, M. et al. Voluntary running exercise alters microbiota composition and increases n-butyrate concentration in the rat cecum. Biosci. Biotechnol. Biochem. 72, 572-576 (2008). (Pubitemid 351353675)
44. Santacruz, A. et al. Interplay between weight loss and gut microbiota composition in overweight adolescents. Obesity 17, 1906-1915 (2009).
45. Friswell, M.K. et al. Site and strain-specific variation in gut microbiota profiles and metabolism in experimental mice. PLoS ONE 5, e8584 (2010).
46. Loh, G., Brodziak, F. & Blaut, M. The Toll-like receptors TLR2 and TLR4 do not affect the intestinal microbiota composition in mice. Environ. Microbiol. 10, 709-715 (2008). (Pubitemid 351160911)
47. Kovacs, A. et al. Genotype is a stronger determinant than sex of the mouse gut microbiota. Microb. Ecol. 6, 423-428 (2011).
48. Darvasi, A. & Soller, M. Advanced intercross lines, an experimental population for fine genetic mapping. Genetics 141, 1199-1207 (1995).
49. Wang, X. et al. Using advanced intercross lines for high-resolution mapping of HDL cholesterol quantitative trait loci. Genome Res. 13, 1654-1664 (2003). (Pubitemid 36874483)
50. Kelly, S.A. et al. Genetic architecture of voluntary exercise in an advanced intercross line of mice. Physiol. Genomics 42, 190-200 (2010).
51. Mohamadzadeh, M. et al. Lactobacilli activate human dendritic cells that skew Tcells toward T helper 1 polarization. Proc. Natl Acad. Sci. USA 102, 2880-2885 (2005). (Pubitemid 40299885)
52. Presley, L.L., Wei, B., Braun, J. & Borneman, J. Bacteria associated with immunoregulatory cells in mice. Appl. Environ. Microbiol. 76, 936-941 (2010).
53. Devlin, B., Daniels, M. & Roeder, K. The heritability of IQ. Genetics 137, 597-606 (1994).
54. Visscher, P.M. et al. Assumption-free estimation of heritability from genome-wide identity-by-descent sharing between full siblings. PLoS Genet. 2, e41 (2006).
55. Khachatryan, Z.A. et al. Predominant role of host genetics in controlling the composition of gut microbiota. PLoS ONE 3, e3064 (2008).
56. Ting, J.P., Kastner, D.L. & Hoffman, H.M. CATERPILLERs, pyrin and hereditary immunological disorders. Nature Rev. Immunol. 6, 183-195 (2006). (Pubitemid 43290988)
57. Kelesidis, T., Kelesidis, I., Chou, S. & Mantzoros, C.S. Narrative review: the role of leptin in human physiology: emerging clinical applications. Ann. Intern. Med. 152, 93-100 (2010).
58. Fernandez-Riejos, P. et al. Role of leptin in the activation of immune cells. Mediators Inflamm. 2010, 568343 (2010).
59. Jeon, J.P. et al. Copy number variation at leptin receptor gene locus associated with metabolic traits and the risk of type2 diabetes mellitus. BMC Genomics 11, 426 (2010).
60. Park, K.S. et al. Polymorphisms in the leptin receptor (LEPR)-putative association with obesity and T2DM.J.Hum. Genet. 51, 85-91 (2006).
61. Sun, Q. et al. Genome-wide association study identifies polymorphisms in LEPR as determinants of plasma soluble leptin receptor levels. Hum. Mol. Genet. 19, 1846-1855 (2010).
62. Waldram, A. et al. Top-down systems biology modeling of host metabotype-microbiome associations in obese rodents. J.Proteome Res. 8, 2361-2375 (2009).
63. Turnbaugh, P.J. et al. An obesity-associated gut microbiome with increased capacity for energy harvest. Nature 444, 1027-1031 (2006). (Pubitemid 46018515)
64. El Homsi, M. et al. Leptin modulates the expression of secreted and membrane-associated mucins in colonic epithelial cells by targeting PKC, PI3K, and MAPK pathways. Am. J.Physiol. Gastrointest. Liver Physiol. 293, G365-G373 (2007). (Pubitemid 47105166)
65. Plaisancie, P. et al. Luminal leptin activates mucin-secreting goblet cells in the large bowel. Am. J. Physiol. Gastrointest. Liver Physiol. 290, G805-G812 (2006).
66. Crawford, P.A. et al. Regulation of myocardial ketone body metabolism by the gut microbiota during nutrient deprivation. Proc. Natl Acad. Sci. USA 106, 11276-11281 (2009).
67. Barbosa, T. & Rescigno, M. Host-bacteria interactions in the intestine: homeostasis to chronic inflammation. Wiley Interdiscip. Rev. Syst. Biol. Med. 2, 80-97 (2010).
68. Barrett, J.C. et al. Genome-wide association defines more than 30 distinct susceptibility loci for Crohn's disease. Nature Genet. 40, 955-962 (2008).
69. Imielinski, M. et al. Common variants at five new loci associated with early-onset inflammatory bowel disease. Nature Genet. 41, 1335-1340 (2009).
70. Potter, C. et al. Association between anti-tumour necrosis factor treatment response and genetic variants within the TLR and NFκB signalling pathways. Ann. Rheum. Dis. 69, 1315-1320 (2010).
71. Teran-Ventura, E. et al. Characterization of housing-related spontaneous variations of gut microbiota and expression of toll-like receptors 2 and 4 in rats. Microb. Ecol. 60, 691-702 (2010).
72. Albert, E.J., Sommerfeld, K., Gophna, S., Marshall, J.S. & Gophna, U. The gut microbiota of toll-like receptor 2-deficient mice exhibits lineage-specific modifications. Environ. Microbiol. Rep. 1, 65-70 (2009).
73. Thompson, C.L., Hofer, M.J., Campbell, I.L. & Holmes, A.J. Community dynamics in the mouse gut microbiota: a possible role for IRF9-regulated genes in community homeostasis. PLoS ONE 5, e10335 (2010).
74. Gonsky, R. et al. Distinct IFNG methylation in a subset of ulcerative colitis patients based on reactivity to microbial antigens. Inflamm. Bowel Dis. 17, 171-178 (2011).
75. Gootenberg, D.B. & Turnbaugh, P.J. Humanized animal models of the microbiome. J.Anim. Sci. 10Sep 2010 (doi:10.2527/jas.2010-3371).
76. Waterston, R.H. et al. Initial sequencing and comparative analysis of the mouse genome. Nature 420, 520-562 (2002). (Pubitemid 35477048)
77. Ley, R.E. et al. Evolution of mammals and their gut microbes. Science 320, 1647-1651 (2008). (Pubitemid 351931256)
78. Dominguez-Bello M.G. et al. Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns. Proc. Natl Acad. Sci. USA 107, 11971-11975 (2010).
79. Matsumiya, Y., Kato, N., Watanabe, K. & Kato, H. Molecular epidemiological study of vertical transmission of vaginal Lactobacillus species from mothers to newborn infants in Japanese, by arbitrarily primed polymerase chain reaction. J.Infect. Chemother. 8, 43-49 (2002). (Pubitemid 34456579)
80. Tannock, G., Fuller, R., Smith, S. & Hall, M. Plasmid profiling of members of the family Enterobacteriaceae, lactobacilli, and bifidobacteria to study the transmission of bacteria from mother to infant. J.Clin. Microbiol. 28, 1225-1228 (1990). (Pubitemid 20194408)
81. Ley, R.E., Lozupone, C.A., Hamady, M., Knight, R. & Gordon, J.I. Worlds within worlds: evolution of the vertebrate gut microbiota. Nature Rev. Microbiol. 6, 776-788 (2008).
82. Jones, B.V., Begley, M., Hill, C., Gahan, C.G. & Marchesi, J.R. Functional and comparative metagenomic analysis of bile salt hydrolase activity in the human gut microbiome. Proc. Natl Acad. Sci. USA 105, 13580-13585 (2008).
83. Lozupone, C.A. et al. The convergence of carbohydrate active gene repertoires in human gut microbes. Proc. Natl Acad. Sci. USA 105, 15076-15081 (2008).
84. Samuel, B.S. et al. Genomic and metabolic adaptations of Methanobrevibacter smithii to the human gut. Proc. Natl Acad. Sci. USA 104, 10643-10648 (2007). (Pubitemid 47185718)
85. Clarke, T.B. et al. Recognition of peptidoglycan from the microbiota by Nod1 enhances systemic innate immunity. Nature Med. 16, 228-231 (2010).
86. Hooper, L.V. Do symbiotic bacteria subvert host immunity. Nature Rev. Microbiol. 7, 367-374 (2009).
87. Comstock, L.E. & Kasper, D.L. Bacterial glycans: key mediators of diverse host immune responses. Cell 126, 847-850 (2006). (Pubitemid 44310786)
88. Peterson, D.A., McNulty, N.P., Guruge, J.L. & Gordon, J.I. IgA response to symbiotic bacteria as a mediator of gut homeostasis. Cell Host Microbe 2, 328-339 (2007). (Pubitemid 350056397)
89. Walter, J., Britton, R.A. & Roos, S. Microbes and Health Sackler Colloquium: Host-microbial symbiosis in the vertebrate gastrointestinal tract and the Lactobacillus reuteri paradigm. Proc. Natl Acad. Sci. USA 25Jun 2010 (doi: 10.1073/pnas.1000099107).
90. Crowell-Davis, S. & Caudle, A. Coprophagy by foals: recognition of maternal feces. Appl. Anim. Behav. Sci. 24, 267-272 (1989).
91. Osawa, R., Blanshard, W.H. & Ocallaghan, P.G. Microbiological studies of the intestinal microflora of the koala, Phascolarctos cinereus. II. Pap, a special maternal feces consumed by juvenile koalas. Aust. J.Zool. 41, 611-620 (1993). (Pubitemid 2032990)
92. Lombardo, M. Access to mutualistic endosymbiotic microbes: an underappreciated benefit of group living. Behav. Ecol. Sociobiol. 62, 479-497 (2008).
93. Bik, E.M. et al. Bacterial diversity in the oral cavity of 10 healthy individuals. ISME J. 4, 962-974 (2010).
94. Costello, E.K. et al. Bacterial community variation in human body habitats across space and time. Science 326, 1694-1697 (2009).
95. Kim, T.K. et al. Heterogeneity of vaginal microbial communities within individuals. J.Clin. Microbiol. 47, 1181-1189 (2009).
96. Pei, Z. et al. Bacterial biota in the human distal esophagus. Proc. Natl Acad. Sci. USA 101, 4250-4255 (2004). (Pubitemid 38405915)
97. Price, L.B. et al. The effects of circumcision on the penis microbiome. PLoS ONE 5, e8422 (2010).
98. Chen, E.S. et al. APOA1/A5 variants and haplotypes as a risk factor for obesity and better lipid profiles in a Brazilian elderly cohort. Lipids 45, 511-517 (2010).
99. Liu, Z.K., Hu, M., Baum, L., Thomas, G.N. & Tomlinson, B. Associations of polymorphisms in the apolipoprotein A1/C3/A4/A5 gene cluster with familial combined hyperlipidaemia in Hong Kong Chinese. Atherosclerosis 208, 427-432 (2010).
100. Asquith, M.J., Boulard, O., Powrie, F. & Maloy, K.J. Pathogenic and protective roles of MyD88 in leukocytes and epithelial cells in mouse models of inflammatory bowel disease. Gastroenterology 139, 519-529.e2 (2010).
101. Hampe, J. et al. Association of NOD2 (CARD 15) genotype with clinical course of Crohn's disease: a cohort study. Lancet 359, 1661-1665 (2002). (Pubitemid 34518526)
102. Frank, D.N. et al. Disease phenotype and genotype are associated with shifts in intestinal-associated microbiota in inflammatory bowel diseases. Inflamm. Bowel Dis. 17, 179-184 (2011).
103. Petnicki-Ocwieja T. et al. Nod2 is required for the regulation of commensal microbiota in the intestine. Proc. Natl Acad. Sci. USA 106, 15813-15818 (2009).
104. Fellermann, K. et al. A chromosome 8 gene-cluster polymorphism with low human beta-defensin 2 gene copy number predisposes to Crohn disease of the colon. Am. J.Hum. Genet. 79, 439-448 (2006). (Pubitemid 44384253)
105. Wehkamp, J. et al. Reduced Paneth cell α-defensins in ileal Crohn's disease. Proc. Natl Acad. Sci. USA 102, 18129-18134 (2005). (Pubitemid 41798513)
106. Wehkamp, J. et al. The Paneth cell α-defensin deficiency of ileal Crohn's disease is linked to Wnt/Tcf-4. J.Immunol. 179, 3109-3118 (2007).
107. Baker, P.I., Love, D.R. & Ferguson, L.R. Role of gut microbiota in Crohn's disease. Expert Rev. Gastroenterol. Hepatol. 3, 535-546 (2009).
108. Salzman, N.H. et al. Enteric defensins are essential regulators of intestinal microbial ecology. Nature Immunol. 11, 76-83 (2010).
109. Ivanov, I. I. et al. Specific microbiota direct the differentiation of IL-17-producing T-helper cells in the mucosa of the small intestine. Cell Host Microbe 4, 337-349 (2008).
110. Ivanov, I. I & Littman, D.R. Segmented filamentous bacteria take the stage. Mucosal Immunol. 3, 209-212 (2010).
111. Artis, D. et al. RELMβ/FIZZ2 is a goblet cell-specific immune-effector molecule in the gastrointestinal tract. Proc. Natl Acad. Sci. USA 101, 13596-13600 (2004). (Pubitemid 39238448)
112. Hogan, S.P. et al. Resistin-like molecule β regulates innate colonic function: barrier integrity and inflammation susceptibility. J.Allergy Clin. Immunol. 118, 257-268 (2006). (Pubitemid 43946483)
113. Cash, H.L., Whitham, C.V., Behrendt, C.L. & Hooper, L.V. Symbiotic bacteria direct expression of an intestinal bactericidal lectin. Science 313, 1126-1130 (2006). (Pubitemid 44300239)
114. Hildebrandt, M.A. et al. High-fat diet determines the composition of the murine gut microbiome independently of obesity. Gastroenterology 137, 1716-1724.e2 (2009).
115. Yel, L. Selective IgA deficiency. J.Clin. Immunol. 30, 10-16 (2010).
116. Suzuki, K. et al. Aberrant expansion of segmented filamentous bacteria in IgA-deficient gut. Proc. Natl Acad. Sci. USA 101, 1981-1986 (2004). (Pubitemid 38229001)
117. Wijburg, O.L. et al. Innate secretory antibodies protect against natural Salmonella typhimurium infection. J.Exp. Med. 203, 21-26 (2006). (Pubitemid 43139640)
118. Nadal, I. et al. Shifts in clostridia, bacteroides and immunoglobulin-coating fecal bacteria associated with weight loss in obese adolescents. Int. J.Obes. 33, 758-767 (2009).
119. Toivanen, P., Vaahtovuo, J. & Eerola, E. Influence of major histocompatibility complex on bacterial composition of fecal flora. Infect. Immun. 69, 2372-2377 (2001). (Pubitemid 32239705)
120. Vaahtovuo, J., Toivanen, P. & Eerola, E. Bacterial composition of murine fecal microflora is indigenous and genetically guided. FEMS Microbiol. Ecol. 44, 131-136 (2003). (Pubitemid 37034607)
121. De Palma G. et al. Interplay between human leukocyte antigen genes and the microbial colonization process of the newborn intestine. Curr. Issues Mol. Biol. 12, 1-10 (2010).