Student or educator? Sign up with your school email and get 6 months of Pro free.
CoChat
Sign Up
Cited by 782

The DOI matches its Crossref record; 3 of the 3 references it cites were found in a registry or an index.

Mechanisms of germ cell specification across the metazoans: epigenesis and preformation

Open access
Extavour, Cassandra G., Akam, Michael·2003·Development
DOI 10.1242/dev.00804
Open this paper in CoChat — free account

Abstract

Germ cells play a unique role in gamete production, heredity and evolution. Therefore, to understand the mechanisms that specify germ cells is a central challenge in developmental and evolutionary biology. Data from model organisms show that germ cells can be specified either by maternally inherited determinants (preformation) or by inductive signals (epigenesis). Here we review existing data on 28 metazoan phyla, which indicate that although preformation is seen in most model organisms, it is actually the less prevalent mode of germ cell specification, and that epigenetic germ cell specification may be ancestral to the Metazoa.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1242/dev.00804

Cites

3 of 3 references verified0 citation errors · 0 not checkable

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Show all 3 references

Research works printed but not linked: 100

  1. Anderson, D. T. (1973). Embryology and Phylogeny in Annelids and Arthropods. Oxford:Pergamon.
  2. Bateson, W. (1885). The later stages in the development of Balanoglossus kowalevskii, with a suggestion as to the affinities of the Enteropneusta. Quart. J. Microscop. Sci.25,81-122. · DOI
  3. Berg, G. J. and Gassner, G. (1978). Fine structure of the blastoderm embryo of the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: gelechiidae). Int. J. Insect Morphol. Embryol.1,81-105. · doi:10.1016/s0020-7322(78)80017-8
  4. Bolker, J. A. and Raff, R. A. (1996). Developmental genetics and traditional homology. BioEssays18,489-494. · DOI
  5. Bradley, J. T., Kloc, M., Wolfe, K. G., Estridge, B. H. and Bilinski, S. M. (2001). Balbiani bodies in cricket oocytes:development, ultrastructure, and presence of localized RNAs. Differentiation67,117-127. · doi:10.1046/j.1432-0436.2001.670404.x
  6. Buehr, M. and Blackler, A. W. (1970). Sterility and partial sterility in the South African clawed toad following the pricking of the egg. J. Embryol. Exp. Morphol.23,375-384. · doi:10.1242/dev.23.2.375
  7. Caldwell, W. H. (1887). The Embryology of Monotremata and Marsupialia. Part I. Philos. Trans. R. Soc. Lond. B. Biol. Sci.178,463-486.
  8. Carré, D., Djediat, C. and Sardet, C.(2002). Formation of a large Vasa-positive granule and its inheritance by germ cells in the enigmatic Chaetognaths. Development129,661-670. · DOI
  9. Chiquoine, A. D. (1954). The identification,origin, and migration of the primordial germ cells in the mouse embryo. Anat. Rec.2,135-146. · DOI · Paper page
  10. Dale, L., Howes, G., Price, B. M. and Smith, J. C.(1992). Bone morphogenetic protein 4: a ventralizing factor in early Xenopus development. Development115,573-585. · DOI · Paper page
  11. Deppe, U., Schierenberg, E., Cole, T., Krieg, C., Schmitt, D.,Yoder, B. and von Ehrenstein, G. (1978). Cell lineages of the embryo of the nematode Caenorhabditis elegans.Proc. Natl. Acad. Sci. USA75,376-380. · DOI · Paper page
  12. Dohmen, M. R. and Verdonk, N. H. (1974). The structure of a morphogenetic cytoplasm, present in the polar lobe of Bithynia tentaculata (Gastropoda, Prosobranchia). J. Embryol. Exp. Morphol.31,423-433. · doi:10.1242/dev.31.2.423
  13. Ephrussi, A. and Lehmann, R. (1992). Induction of germ cell formation by oskar.Nature358,387-392. · DOI · Paper page
  14. Everett, N. B. (1945). The present status of the germ-cell problem in vertebrates. Biol. Rev.20, 45-55. · doi:10.1111/j.1469-185x.1945.tb00313.x
  15. Extavour, C. and García-Bellido, A.(2001). Germ cell selection in genetic mosaics in Drosophila melanogaster.Proc. Natl. Acad. Sci. USA98,11341-11346. · doi:10.1073/pnas.201409198
  16. Eyal-Giladi, H., Ginsburg, M. and Farbarov, A.(1981). Avian primordial germ cells are of epiblastic origin. J. Embryol. Exp. Morphol.65,139-147. · doi:10.1242/dev.65.1.139
  17. Fujimura, M. and Takamura, K. (2000). Characterization of an ascidian DEAD-box gene, Ci-DEAD1: specific expression in the germ cells and its mRNA localization in the posterior-most blastomeres in early embryos. Dev. Genes Evol.210, 64-72. · doi:10.1007/s004270050012
  18. Fujiwara, Y., Komiya, T., Kawabata, H., Sato, M., Fujimoto, H.,Furusawa, M. and Noce, T. (1994). Isolation of a DEAD-family protein gene that encodes a murine homolog of Drosophila vasa and its specific expression in germ cell lineage. Proc. Natl. Acad. Sci. USA91,12258-12262. · DOI · Paper page
  19. Ginsburg, M., Snow, M. H. L. and McLaren, A.(1990). Primordial germ cells in the mouse embryo during gastrulation. Development110,521-528. · DOI · Paper page
  20. Gomperts, M., García-Castro, M., Wylie, C. and Heasman,J. (1994). Interactions between primordial germ cells play a role in their migration in mouse embryos. Development120,135-141. · DOI
  21. Gustafsson, M. K. S. (1976). Studies on cytodifferentiation in neck region of Diphyllobothrium dendriticumNitzch, 1824. Z. Parasitenk50,323-329. · doi:10.1007/bf02462976
  22. Heasman, J., Quarmby, J. and Wylie, C. C.(1984). The mitochondrial cloud of Xenopus oocytes: the source of germinal granule material. Dev. Biol.105,458-469. · doi:10.1016/0012-1606(84)90303-8
  23. Heys, F. (1931). The problem of the origin of germ cells. Q. Rev. Biol.6, 1-45. · doi:10.1086/394368
  24. Hird, S. N., Paulsen, J. E. and Strome, S.(1996). Segregation of germ granules in living Caenorhabditis elegans embryos: cell-type-specific mechanisms for cytoplasmic localisation. Development122,1303-1312. · DOI
  25. Hogan, B. L. (1996). Bone morphogenetic proteins: multifunctional regulators of vertebrate development. Genes Dev.10,1580-1594. · DOI · Paper page
  26. Holland, L. Z. and Holland, N. D. (1992). Early development in the lancelet (=Amphioxus) Branchiostoma floridae from sperm entry through pronuclear fusion: presence of vegetal pole plasm and lack of conspicuous ooplasmic segregation. Biol. Bull.182, 77-96. · doi:10.2307/1542182
  27. Houston, D. W. and King, M. L. (2000a). A critical role for Xdazl, a germ plasm-localized RNA, in the differentiation of primordial germ cells in Xenopus.Development127,447-456. · doi:10.1242/dev.127.3.447
  28. Houston, D. W. and King, M. L. (2000b). Germ plasm and molecular determinants of germ cell fate. Curr. Top. Dev. Biol.50,155-181. · DOI
  29. Huettner, A. F. (1923). The origin of the germ cells in Drosophila melanogaster.J. Morphol.2, 385-422. · doi:10.1002/jmor.1050370204
  30. Hughes, R. L. and Hall, L. S. (1998). Early development and embryology of the platypus. Philos. Trans. R. Soc. Lond. B. Biol. Sci.353,1101-1114. · DOI
  31. Humphrey, R. R. (1925). The primordial germ cells of Hemidactylium and other Amphibia. J. Morphol. Physiol.41,1-43. · doi:10.1002/jmor.1050410103
  32. Humphrey, R. R. (1929). The early position of the primordial germ cells in Urodeles: evidence from experimental studies. Anat. Rec.42,301-314. · doi:10.1002/ar.1090420306
  33. Ikenishi, K. and Nieuwkoop, P. D. (1978). Location and ultrastructure of primordial germ cells (PGCs) in Ambystoma mexicanum.Dev. Growth Diff.20, 1-9. · doi:10.1111/j.1440-169x.1978.00001.x
  34. Ikenishi, K., Kotani, M. and Tanabe, K. (1974). Ultrastructural changes associated with UV irradiation in the `germinal plasm'of Xenopus laevis.Dev. Biol.36,155-168. · doi:10.1016/0012-1606(74)90198-5
  35. Ikenishi, K., Nakazato, S. and Okuda, T.(1986). Direct evidence for the presence of germ cell determinant in vegetal pole cytoplasm of Xenopus laevis and in a subcellular fraction of it. Dev. Growth Diff.28,563-568. · doi:10.1111/j.1440-169x.1986.00563.x
  36. Illmensee, K. and Mahowald, A. P. (1974). Transplantation of posterior polar plasm in Drosophila. Induction of germ cells at the anterior pole of the egg. Proc. Natl. Acad. Sci. USA4,1016-1020.
  37. Illmensee, K. and Mahowald, A. P. (1976). The autonomous function of germ plasm in a somatic region of the Drosophila egg. Exp. Cell Res.97,127-140. · DOI
  38. Illmensee, K., Mahowald, A. P. and Loomis, M. R.(1976). The ontogeny of germ plasm during oogenesis in Drosophila.Dev. Biol.49, 40-65. · doi:10.1016/0012-1606(76)90257-8
  39. Iseto, T. and Nishida, H. (1999). Ultrastructural studies on the centrosome-attracting body: electron-dense matrix and its role in unequal cleavages in ascidian embryos. Dev. Growth Diff.41,601-609. · doi:10.1046/j.1440-169x.1999.00457.x
  40. Johnson, A. D., Bachvarova, R. F., Drum, M. and Masi, T.(2001). Expression of axolotl DAZL RNA, a marker of germ plasm: widespread maternal RNA and onset of expression in germ cells approaching the gonad. Dev. Biol.234,402-415. · DOI
  41. Johnson, A. D., Drum, M., Bachvarova, R. F., Masi, T., White, M. E. and Crother, B. I. (2003). Evolution of predetermined germ cells in vertebrate embryos: implications for macroevolution. Evol. Dev.5,414-431. · DOI
  42. Jones, C. M., Lyons, K. M., Lapan, P. M., Wright, C. V. and Hogan, B. L. (1992). DVR-4 (bone morphogenetic protein-4) as a posterior-ventralizing factor in Xenopus mesoderm induction. Development115,639-647. · DOI · Paper page
  43. Karagenc, L., Cinnamon, Y., Ginsburg, M. and Petitte, J. N.(1996). Origin of primordial germ cells in the prestreak chick embryo. Dev. Genet.19,290-301. · doi:10.1002/(sici)1520-6408(1996)19:4<290::aid-dvg2>3.0.co;2-4
  44. Kloc, M., Bilinski, S., Chan, A. P. and Etkin, L. D.(2001). Mitochondrial ribosomal RNA in the germinal granules in Xenopus embryos revisited. Differentiation67, 80-83. · doi:10.1046/j.1432-0436.2001.067003080.x
  45. Kloc, M., Dougherty, M. T., Bilinski, S., Chan, A. P., Brey, E.,King, M. L., Patrick, C. W., Jr and Etkin, L. D. (2002). Three-dimensional ultrastructural analysis of RNA distribution within germinal granules of Xenopus.Dev. Biol.241, 79-93. · doi:10.1006/dbio.2001.0488
  46. Ladurner, P., Rieger, R. and Baguñà, J.(2000). Spatial distribution and differentiation potential of stem cells in hatchlings and adults in the marine platyhelminth Macrostomum sp.: a bromodeoxyuridine analysis. Dev. Biol.226,231-241. · DOI
  47. Lawson, K. A., Dunn, N. R., Roelen, B. A., Zeinstra, L. M.,Davis, A. M., Wright, C. V., Korving, J. P. and Hogan, B. L.(1999). Bmp4 is required for the generation of primordial germ cells in the mouse embryo. Genes Dev.13,424-436. · DOI · Paper page
  48. Lin, S., Long, W., Chen, J. and Hopkins, N.(1992). Production of germ-line chimeras in zebrafish by cell transplants from genetically pigmented to albino embryos. Proc. Natl. Acad. Sci. USA89,4519-4523. · DOI
  49. Mahowald, A. P. (2001). Assembly of the Drosophila germ plasm. Int. Rev. Cytol.203,187-213. · DOI · Paper page
  50. Manton, S. M. (1928). On the embryology of a mysid crustacean, Hemimysis lamornae.Phil. Trans. R. Soc. Lond. Ser. B. Biol. Sci.216,363-463.
  51. Matova, N. and Cooley, L. (2001). Comparative aspects of animal oogenesis. Dev. Biol.231,291-320. · DOI · Paper page
  52. McLaren, A. (2003). Primordial germ cells in the mouse. Dev. Biol. (in press). · DOI · Paper page
  53. Morgan, T. H. (1894). The development of Balanoglossus.J. Morphol.9, 1-86. · DOI
  54. Naito, M., Sano, A., Matsubara, Y., Harumi, T., Tagami, T.,Sakurai, M. and Kuwana, T. (2001). Localization of primordial germ cells or their precursors in stage X blastoderm of chickens and their ability to differentiate into functional gametes in opposite-sex recipient gonads. Reproduction121,547-552. · doi:10.1530/rep.0.1210547
  55. Nakamura, Y., Makabe, K. W. and Nishida, H.(2003). Localization and expression pattern of type I postplasmic mRNAs in embryos of the ascidian Halocynthia roretzi.Gene Expr. Patterns3,71-75. · doi:10.1016/s1567-133x(02)00069-8
  56. Nardi, F., Spinsanti, G., Boore, J. L., Carapelli, A., Dallai,R. and Frati, F. (2003). Hexapod origins: monophyletic or paraphyletic? Science299,1887-1889. · DOI · Paper page
  57. Nelsen, O. E. (1934). The segregation of the germ cells in the grasshopper, Melanoplus differentialis (Acrididae;Orthoptera). J. Morphol.545-575. · doi:10.1002/jmor.1050550306
  58. Nielsen, C. (2001). Animal Evolution: Interrelationships of the Living Phyla. Oxford: Oxford University Press.
  59. Nieuwkoop, P. D. and Sutasurya, L. A. (1979). Primordial Germ Cells in the Chordates. Cambridge:Cambridge University Press.
  60. Nieuwkoop, P. D. and Sutasurya, L. A. (1981). Primordial Germ Cells in the Invertebrates: from epigenesis to preformation. Cambridge: Cambridge University Press.
  61. Nishida, H. (1987). Cell lineage analysis in ascidian embryos by intracellular injection of a tracer enzyme. III. Up to the tissue restricted stage. Dev. Biol.121,526-541. · DOI · Paper page
  62. Nishida, H. and Satoh, N. (1983). Cell lineage analysis in ascidian embryos by intracellular injection of a tracer enzyme. I. Up to the eight-cell stage. Dev. Biol.99,382-394. · DOI · Paper page
  63. Nishida, H. and Satoh, N. (1985). Cell lineage analysis in ascidian embryos by intracellular injection of a tracer enzyme. II. The 16- and 32-cell stages. Dev. Biol.110,440-454. · DOI
  64. Nishikata, T., Hibino, T. and Nishida, H.(1999). The centrosome-attracting body, microtubule system, and posterior egg cytoplasm are involved in positioning of cleavage planes in the ascidian embryo. Dev. Biol.209, 72-85. · DOI
  65. Noce, T., Okamoto-Ito, S. and Tsunekawa, N.(2001). Vasa homolog genes in mammalian germ cell development. Cell Struct. Funct.26,131-136. · DOI
  66. Ogawa, M., Amikura, R., Akasaka, K., Kinoshita, T., Kobayashi,S. and Shimada, H. (1999). Asymmetrical distribution of mitochondrial rRNA into small micromeres of sea urchin embryos. Zool. Sci.16,445-451. · DOI
  67. Olsen, L. C., Aasland, R. and Fjose, A. (1997). A vasa-like gene in zebrafish identifies putative primordial germ cells. Mech. Dev.66,95-105. · DOI
  68. Pehrson, J. R. and Cohen, L. H. (1986). The fate of the small micromeres in sea urchin development. Dev. Biol.113,522-526. · DOI
  69. Ransick, A., Cameron, R. A. and Davidson, E. H.(1996). Postembryonic segregation of the germ line in sea urchins in relation to indirect development. Proc. Natl. Acad. Sci. USA93,6759-6763. · DOI
  70. Risley, P. L. (1933). Contributions on the development of the reproductive system in Sternotherus odoratus(Latreille). I. The embryonic origin and migration of the primordial germ cells. Zeit. Zellforsch. mikrosk. Anat.18,459-492. · doi:10.1007/bf00572100
  71. Ruiz-Trillo, I., Paps, J., Loukota, M., Ribera, C., Jondelius,U., Baguñà, J. and Riutort, M. (2002). A phylogenetic analysis of myosin heavy chain type II sequences corroborates that Acoela and Nemertodermatida are basal bilaterians. Proc. Natl. Acad. Sci. USA99,11246-11251. · DOI
  72. Saffman, E. E. and Lasko, P. (1999). Germline development in vertebrates and invertebrates. Cell. Mol. Life Sci.55,1141-1163. · DOI · Paper page
  73. Saitou, M., Barton, S. C. and Surani, M. A.(2002). A molecular programme for the specification of germ cell fate in mice. Nature418,293-300. · DOI · Paper page
  74. Selwood, L. (1968). Interrelationships between developing oocytes and ovarian tissues in the chiton Sypharochiton septentriones (Ashby) (Mollusca, Polyplacophora). J. Morphol.125,71-103. · doi:10.1002/jmor.1051250105
  75. Smith, L. D. (1966). The role of a `germinal plasm' in the formation of primordial germ cells in Rana pipiens.Dev. Biol.14,330-347. · doi:10.1016/0012-1606(66)90019-4
  76. Stoner, D. S. and Weissman, I. L. (1996). Somatic and germ cell parasitism in a colonial ascidian: possible role for a highly polymorphic allorecognition system. Proc. Natl. Acad. Sci. USA93,15254-15259. · DOI
  77. Strome, S. and Wood, W. B. (1982). Immunofluorescence visualization of germ-line-specific cytoplasmic granules in embryos, larvae, and adults of Caenorhabditis elegans.Proc. Natl. Acad. Sci. USA79,1558-1562. · DOI · Paper page
  78. Sutasurya, L. A. and Nieuwkoop, P. D. (1974). The induction of the primordial germ cells in the urodeles. Wilhelm Roux' Archiv. Entwick. Org.175,199-220. · doi:10.1007/bf00582092
  79. Swift, C. H. (1914). Origin and early history of the primordial germ-cells of the chick. Am. J. Anat.483-516. · DOI · Paper page
  80. Takamura, K., Fujimura, M. and Yamaguchi, Y.(2002). Primordial germ cells originate from the endodermal strand cells in the ascidian Ciona intestinalis.Dev. Genes Evol.212,11-18. · DOI
  81. Tam, P. P. and Zhou, S. X. (1996). The allocation of epiblast cells to ectodermal and germ-line lineages is influenced by the position of the cells in the gastrulating mouse embryo. Dev. Biol.178,124-132. · DOI · Paper page
  82. Tamarelle, M. (1979). Recherches ultrastructurales sur la ségregation et le développement de la lignée germinale chez les embryons de quatre collemboles (Insecta:Apterygota). Int. J. Insect Morphol. Embryol.8, 95-111. · doi:10.1016/0020-7322(79)90009-6
  83. Tanabe, K. and Kotani, M. (1974). Relationship between the amount of the “germinal plasm” and the number of primordial germ cells in Xenopus laevis.J. Embryol. Exp. Morphol.31,89-98. · doi:10.1242/dev.31.1.89
  84. Telford, M. J., Lockyer, A. E., Cartwright-Finch, C. and Littlewood, D. T. J. (2003). Combined large and small subunit ribosomal RNA phylogenies support a basal position of the acoelomorph flatworms. Proc. Roy. Soc. Lond. B.270,1077-1083. · DOI
  85. Tomioka, M., Miya, T. and Nishida, H. (2002). Repression of zygotic gene expression in the putative germline cells in ascidian embryos. Zool. Sci.19, 49-55. · doi:10.2108/zsj.19.49
  86. Toyooka, Y., Tsunekawa, N., Takahashi, Y., Matsui, Y., Satoh, M. and Noce, T. (2000). Expression and intracellular localization of mouse Vasa-homologue protein during germ cell development. Mech. Dev.93,139-149. · DOI · Paper page
  87. Tsunekawa, N., Naito, M., Sakai, Y., Nishida, T. and Noce,T. (2000). Isolation of chicken vasa homolog gene and tracing the origin of primordial germ cells. Development127,2741-2750. · DOI · Paper page
  88. Ullmann, S. L., Shaw, G., Alcorn, G. T. and Renfree, M. B.(1997). Migration of primordial germ cells to the developing gonadal ridges in the tammar wallaby Macropus eugenii.J. Reprod. Fertil.110,135-143. · doi:10.1530/jrf.0.1100135
  89. Walker, C. and Streisinger, G. (1983). Induction of Mutations by Gamma Rays in Pre-gonial Germ Cells of Zebrafish Embryos. Genetics103,125-136. · DOI
  90. Walvig, F. (1963). The Gonads and the Formation of the Sexual Cells. In The Biology of Myxine (ed. A. Brodal and R. Fange), pp. 530-580. Oslo:Universitetsforlaget.
  91. Whitington, P. M. and Dixon, K. E. (1975). Quantitative studies of germ plasm and germ cells during early embryogenesis of Xenopus laevis.J. Embryol. Exp. Morphol.33, 57-74. · doi:10.1242/dev.33.1.57
  92. Williamson, A. and Lehmann, R. (1996). Germ Cell Development in Drosophila.Ann. Rev. Cell Dev. Biol.12,365-391. · DOI
  93. Wolpert, L. (1998). Principles of development. London/Oxford: Current Biology/Oxford University Press.
  94. Woods, F. H. (1931). History of the germ cells in Sphaerium striatinum (Lam.). J. Morphol. Physiol.51,545-595. · doi:10.1002/jmor.1050510208
  95. Woods, F. H. (1932). Keimbahn determinants and continuity of the germ cells in Sphaerium striatinum (Lam.). J. Morphol.53,345-365. · doi:10.1002/jmor.1050530207
  96. Wylie, C. (2000). Germ cells. Curr. Opin. Genet. Dev.10,410-413. · DOI
  97. Ying, Y. and Zhao, G. Q. (2001). Cooperation of endoderm-derived BMP2 and extraembryonic ectoderm-derived BMP4 in primordial germ cell generation in the mouse. Dev. Biol.232,484-492. · DOI · Paper page
  98. Ying, Y., Liu, X. M., Marble, A., Lawson, K. A. and Zhao, G. Q. (2000). Requirement of Bmp8b for the generation of primordial germ cells in the mouse. Mol. Endocrinol.14,1053-1063. · doi:10.1210/mend.14.7.0479 · Paper page
  99. Yoon, C., Kawakami, K. and Hopkins, N. (1997). Zebrafish vasa homologue RNA is localized to the cleavage planes of 2- and 4-cell-stage embryos and is expressed in the primordial germ cells. Development124,3157-3166. · DOI · Paper page
  100. Zhou, Y. and King, M. L. (1996). Localization of Xcat-2 RNA, a putative germ plasm component, to the mitochondrial cloud in Xenopus stage I oocytes. Development122,2947-2953. · doi:10.1242/dev.122.9.2947

Cited by

Metadata

Authors
Extavour, C. G., & Akam, M.
Venue
Development
Publisher
The Company of Biologists
Published
2003-12-15
Volume
130
Issue
24
Pages
5869-5884
ISSN
  • 0950-1991 (ISSN-L)
  • 1477-9129
DOI
10.1242/dev.00804
OpenAlex
W2138292740
Cited by
782
References
3
FWCI
5.68
Type
journal article
Language
en
Open access
green

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.