Amoebidiidae is a family of single-celled eukaryotes, previously thought to be zygomycetefungi belonging to the class , but molecular phylogenetic analyses[1][2][3] place the family with the opisthokont group Mesomycetozoea[4] (= Ichthyosporea[5]). The family was originally called Amoebidiaceae,[6] and considered the sole family of the fungal order Amoebidiales that included two genera: Amoebidium and Paramoebidium. However, Amoebidiidae is now monogeneric as it was recently emended to include only Amoebidium (and Paramoebidium is now the sole genus of the family Paramoebidiidae).[7] Species of Amoebidium are considered obligate symbionts of freshwater-dwelling arthropod hosts such as midge larvae and water fleas (Daphnia).[8] However, because Amoebidium species attach to the exoskeleton (exterior) of the host and grow in axenic culture, at least some species may be facultative symbionts.[9]
The "amoeb-" prefix refers to the amoeba-like dispersal cells that are produced during the life cycle of Amoebidium.[10]
Descriptionedit
As the family is monogeneric, the description follows that of the genus, Amoebidium. Amoebidium species are single-celled, cigar-shaped or tubular in vegetative growth form (= thallus), and attach to the exoskeleton of various freshwater arthropod hosts (Crustaecea or Insecta) by means of a secreted, glue-like basal holdfast.[9] The thalli are coenocytic (i.e. lack divisions within the cell) and are unbranched.[9] Sexual reproduction is unknown. Asexual reproduction may proceed along two different routes: 1) the entire content of the cell divides into elongated, uninucleate spores (known as sporangiospores or endospores) with the cell wall breaking apart to release the spores or 2) the entire content of the cell divides to produce teardrop-shaped, motile amoeboid cells that disperse for a short time, then encyst and produce spores from the cyst (called cystospores).[10][11] Currently there are five described species in the family.[9]
Taxonomic and phylogenetic historyedit
The classification of Amoebidium and Paramoebidium with the fungal trichomycetes was early considered tenuous due to the production of amoeboid dispersal cells,[12][13] a feature not seen among Fungi. Later studies found no evidence of chitin in the cell wall of these species, further casting doubt on their relatedness to Fungi.[11][14] However, their overall morphology (i.e. hair-like growth form with a basal holdfast), production of spores, and residence in the digestive tract of arthropods were considered strong enough characters to include them with the fungal trichomycetes until additional evidence could resolve their placement.[15]
In 2000, two independent studies[1][2] used molecular phylogenetic evidence to show that Amoebidium parasiticum was more closely related to a small clade of animal-associated protist parasites (known as the DRIP clade[16] at the time) than the fungal trichomycetes. In 2005, Cafaro[3] obtained rDNA sequence data from an unidentified Paramoebidium species and it was placed as sister to Amoebidium in the phylogeny. Therefore, Amoebidiaceae was renamed Amoebidiidae[6] to reflect its classification outside of Fungi and with the protist clade that was renamed Mesomycetozoea.[4] The analyses of Cafaro[3] showed a monophyletic relationship between Amoebidium and Paramoebidium, although his dataset had limited taxon sampling with one representative sequence from each genus.
However, a recent molecular phylogenetic analysis of the Ichthyophonida that included broad taxon and gene sampling found evidence of polyphyly between Amoebidium and Paramoebidium.[7] Although topology tests conducted on the dataset (Approximately Unbiased[17] and Shimodaira-Hasegawa[18] tests) did not reject a sister-taxon relationship of the genera, the authors felt there was enough molecular, physiological, and ecological differences to separate the genera into different families.[7] For example, Amoebidium species attach to the exterior of the host whereas Paramoebidium species reside in the digestive tract[8] and ultrastructural analyses found variations in pore arrangement at the spore tips of Amoebidium parasiticum and Paramoebidium curvum.[19]
Referencesedit
^ abBenny, G. L., and O'Donnell, K. 2000. Amoebidium parasiticum is a protozoan, not a Trichomycete. Mycologia92: 1133-1137.
^ abUstinova, I, Krienitz, L., and Huss, V. A. R. 2000. Hyaloraphidium curvatum is not a green alga, but a lower fungus; Amoebidium parasiticum is not a fungus, but a member of the DRIPS. Protist151: 253-262.
^ abcCafaro, M. 2005. Eccrinales (Trichomycetes) are not fungi, but a clade of protists at the early divergence of animals and fungi. Molecular Phylogenetics and Evolution 35: 21-34.
^ abMendoza L, Taylor JW, Ajello L (October 2002). "The class mesomycetozoea: a heterogeneous group of microorganisms at the animal-fungal boundary". Annu. Rev. Microbiol. 56: 315–44. doi:10.1146/annurev.micro.56.012302.160950
^Cavalier-Smith, T. 1998. Neomonada and the origin of animals and fungi. In: Coombs GH, Vickerman K, Sleigh MA, Warren A (ed.) Evolutionary relationships among protozoa. Kluwer, London, pp. 375-407.
^ abWill Karlisle Reeves (2003). "Emendation of the family name Amoebidiaceae (Choanozoa, Mesomycetozoa, Ichthyosporea)". Comparative Parasitology. 70 (1): 78–79. doi:10.1654/1525-2647(2003)070[0078:EOTFNA]2.0.CO;2.
^ abcReynolds, N.K., M.E. Smith, E.D. Tretter, J. Gause, D. Heeney, M.J. Cafaro, J.F. Smith, S.J. Novak, W.A. Bourland, M.M. White. 2017. Resolving relationships at the animal-fungal divergence: A molecular phylogenetic study of the protist trichomycetes (Ichthyosporea, Eccrinida). Molecular Phylogenetics and Evolution in press, available online 20Feb.2017. https://dx.doi.org/10.1016/j.ympev.2017.02.007
^ abLichtwardt, R.W. 2001. Trichomycetes: fungi in relationship with insects and other arthropods. In: Symbiosis. J. Seckbach, ed. Kluwer Academic Publishers, Netherlands, p. 515-588.
^ abLichtenstein, J. L. 1917a. Sur un Amoebidium a commensalisme interne du rectum des larves d'Anaximperator Leach: Amoebidiumfasciculatum n. sp. Archives de Zoologie Expérimentale et Générale56: 49-62.
^ abWhisler, H.C., 1963. Observations on some new and unusual enterophilous phycomycetes. Canadian Journal of Botany, 41(6), pp.887–900.
^Léger, L., and Duboscq, O. 1929. L'évolution des Paramoebidium, nouveau genre d'Eccrinides, parasite des larves aquatiques d'Insectes. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences Paris189: 75-77.
^Cienkowski, L. 1861. Ueber parasitische Schläuche auf Crustaceen und einigen Insektenlarven (Amoebidiumparasiticum m.). Botanische Zeitung19: 169-174.
^Trotter, M.J. & Whisler, H.C., 1965. Chemical composition of the cell wall of Amoebidium parasiticum. Canadian Journal of Botany, (43), pp.869–876.
^Moss, S.T., 1979. Commensalism of Trichomycetes. In L. R. Batra, ed. Insect-Fungus Symbiosis Nutrition, Mutualism, and Commensalism. Montclair: Allanheld, Osmun & Co. Publishers, Inc., pp. 175–227.
^Ragan MA, Goggin CL, Cawthorn RJ, et al. (October 1996). "A novel clade of protistan parasites near the animal-fungal divergence". Proc. Natl. Acad. Sci. U.S.A. 93 (21): 11907–12. doi:10.1073/pnas.93.21.11907
^Shimodaira, H., 2002. An approximately unbiased test of phylogenetic tree selection. Syst. Biol. 51, 492–508.
^Shimodaira, H., Hasegawa, M., 1999. Multiple Comparisons of Log-Likelihoods with Applications to Phylogenetic Inference. Mol. Biol. Evol. 16, 1114–1116.
^Dang, S.-N., Lichtwardt, R.W., 1979. Fine Structure of Paramoebidium (Trichomycetes) and a new species with virus-like particles. Am. J. Bot. 66, 1093-1104.
February 15, 2024
amoebidiidae, family, single, celled, eukaryotes, previously, thought, zygomycete, fungi, belonging, class, trichomycetes, molecular, phylogenetic, analyses, place, family, with, opisthokont, group, mesomycetozoea, ichthyosporea, family, originally, called, am. Amoebidiidae is a family of single celled eukaryotes previously thought to be zygomycete fungi belonging to the class Trichomycetes but molecular phylogenetic analyses 1 2 3 place the family with the opisthokont group Mesomycetozoea 4 Ichthyosporea 5 The family was originally called Amoebidiaceae 6 and considered the sole family of the fungal order Amoebidiales that included two genera Amoebidium and Paramoebidium However Amoebidiidae is now monogeneric as it was recently emended to include only Amoebidium and Paramoebidium is now the sole genus of the family Paramoebidiidae 7 Species of Amoebidium are considered obligate symbionts of freshwater dwelling arthropod hosts such as midge larvae and water fleas Daphnia 8 However because Amoebidium species attach to the exoskeleton exterior of the host and grow in axenic culture at least some species may be facultative symbionts 9 AmoebidiidaeAmoebidium parasiticumScientific classificationDomain Eukaryota unranked Opisthokonta unranked HolozoaClass IchthyosporeaOrder IchthyophonidaFamily AmoebidiidaeLichtenstein 1917 ex Kirk Canon amp David 2001GeneraAmoebidium Contents 1 Etymology 2 Description 3 Taxonomic and phylogenetic history 4 ReferencesEtymology editThe amoeb prefix refers to the amoeba like dispersal cells that are produced during the life cycle of Amoebidium 10 Description editAs the family is monogeneric the description follows that of the genus Amoebidium Amoebidium species are single celled cigar shaped or tubular in vegetative growth form thallus and attach to the exoskeleton of various freshwater arthropod hosts Crustaecea or Insecta by means of a secreted glue like basal holdfast 9 The thalli are coenocytic i e lack divisions within the cell and are unbranched 9 Sexual reproduction is unknown Asexual reproduction may proceed along two different routes 1 the entire content of the cell divides into elongated uninucleate spores known as sporangiospores or endospores with the cell wall breaking apart to release the spores or 2 the entire content of the cell divides to produce teardrop shaped motile amoeboid cells that disperse for a short time then encyst and produce spores from the cyst called cystospores 10 11 Currently there are five described species in the family 9 Taxonomic and phylogenetic history editThe classification of Amoebidium and Paramoebidium with the fungal trichomycetes was early considered tenuous due to the production of amoeboid dispersal cells 12 13 a feature not seen among Fungi Later studies found no evidence of chitin in the cell wall of these species further casting doubt on their relatedness to Fungi 11 14 However their overall morphology i e hair like growth form with a basal holdfast production of spores and residence in the digestive tract of arthropods were considered strong enough characters to include them with the fungal trichomycetes until additional evidence could resolve their placement 15 In 2000 two independent studies 1 2 used molecular phylogenetic evidence to show that Amoebidium parasiticum was more closely related to a small clade of animal associated protist parasites known as the DRIP clade 16 at the time than the fungal trichomycetes In 2005 Cafaro 3 obtained rDNA sequence data from an unidentified Paramoebidium species and it was placed as sister to Amoebidium in the phylogeny Therefore Amoebidiaceae was renamed Amoebidiidae 6 to reflect its classification outside of Fungi and with the protist clade that was renamed Mesomycetozoea 4 The analyses of Cafaro 3 showed a monophyletic relationship between Amoebidium and Paramoebidium although his dataset had limited taxon sampling with one representative sequence from each genus However a recent molecular phylogenetic analysis of the Ichthyophonida that included broad taxon and gene sampling found evidence of polyphyly between Amoebidium and Paramoebidium 7 Although topology tests conducted on the dataset Approximately Unbiased 17 and Shimodaira Hasegawa 18 tests did not reject a sister taxon relationship of the genera the authors felt there was enough molecular physiological and ecological differences to separate the genera into different families 7 For example Amoebidium species attach to the exterior of the host whereas Paramoebidium species reside in the digestive tract 8 and ultrastructural analyses found variations in pore arrangement at the spore tips of Amoebidium parasiticum and Paramoebidium curvum 19 References edit a b Benny G L and O Donnell K 2000 Amoebidium parasiticum is a protozoan not a Trichomycete Mycologia 92 1133 1137 a b Ustinova I Krienitz L and Huss V A R 2000 Hyaloraphidium curvatum is not a green alga but a lower fungus Amoebidium parasiticum is not a fungus but a member of the DRIPS Protist 151 253 262 a b c Cafaro M 2005 Eccrinales Trichomycetes are not fungi but a clade of protists at the early divergence of animals and fungi Molecular Phylogenetics and Evolution 35 21 34 a b Mendoza L Taylor JW Ajello L October 2002 The class mesomycetozoea a heterogeneous group of microorganisms at the animal fungal boundary Annu Rev Microbiol 56 315 44 doi 10 1146 annurev micro 56 012302 160950 Cavalier Smith T 1998 Neomonada and the origin of animals and fungi In Coombs GH Vickerman K Sleigh MA Warren A ed Evolutionary relationships among protozoa Kluwer London pp 375 407 a b Will Karlisle Reeves 2003 Emendation of the family name Amoebidiaceae Choanozoa Mesomycetozoa Ichthyosporea Comparative Parasitology 70 1 78 79 doi 10 1654 1525 2647 2003 070 0078 EOTFNA 2 0 CO 2 a b c Reynolds N K M E Smith E D Tretter J Gause D Heeney M J Cafaro J F Smith S J Novak W A Bourland M M White 2017 Resolving relationships at the animal fungal divergence A molecular phylogenetic study of the protist trichomycetes Ichthyosporea Eccrinida Molecular Phylogenetics and Evolution in press available online 20Feb 2017 https dx doi org 10 1016 j ympev 2017 02 007 a b Lichtwardt R W 2001 Trichomycetes fungi in relationship with insects and other arthropods In Symbiosis J Seckbach ed Kluwer Academic Publishers Netherlands p 515 588 a b c d Lichtwardt R W M J Cafaro M M White 2001 The Trichomycetes Fungal Associates of Arthropods Revised Edition Published online http www nhm ku edu 7Efungi Monograph Text Mono htm Archived 2017 04 26 at the Wayback Machine a b Lichtenstein J L 1917a Sur un Amoebidium a commensalisme interne du rectum des larves d Anax imperator Leach Amoebidium fasciculatum n sp Archives de Zoologie Experimentale et Generale 56 49 62 a b Whisler H C 1963 Observations on some new and unusual enterophilous phycomycetes Canadian Journal of Botany 41 6 pp 887 900 Leger L and Duboscq O 1929 L evolution des Paramoebidium nouveau genre d Eccrinides parasite des larves aquatiques d Insectes Comptes Rendus Hebdomadaires des Seances de l Academie des Sciences Paris 189 75 77 Cienkowski L 1861 Ueber parasitische Schlauche auf Crustaceen und einigen Insektenlarven Amoebidium parasiticum m Botanische Zeitung 19 169 174 Trotter M J amp Whisler H C 1965 Chemical composition of the cell wall of Amoebidium parasiticum Canadian Journal of Botany 43 pp 869 876 Moss S T 1979 Commensalism of Trichomycetes In L R Batra ed Insect Fungus Symbiosis Nutrition Mutualism and Commensalism Montclair Allanheld Osmun amp Co Publishers Inc pp 175 227 Ragan MA Goggin CL Cawthorn RJ et al October 1996 A novel clade of protistan parasites near the animal fungal divergence Proc Natl Acad Sci U S A 93 21 11907 12 doi 10 1073 pnas 93 21 11907 Shimodaira H 2002 An approximately unbiased test of phylogenetic tree selection Syst Biol 51 492 508 Shimodaira H Hasegawa M 1999 Multiple Comparisons of Log Likelihoods with Applications to Phylogenetic Inference Mol Biol Evol 16 1114 1116 Dang S N Lichtwardt R W 1979 Fine Structure of Paramoebidium Trichomycetes and a new species with virus like particles Am J Bot 66 1093 1104 Retrieved from https en wikipedia org w index php title Amoebidiidae amp oldid 1197958051, 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