Blastocrithidia is a genus of parasitic flagellate protist belonging to the family Trypanosomatidae.[1] It is a monoxenous parasite of heteropteran insects,[3] mainly inhabiting their hindgut and glands.[4]

Blastocrithidia
A species of Blastocrithidia, B. papi (vertical scale bar = 10 μm).[2]
Scientific classification Edit this classification
Domain: Eukaryota
Phylum: Euglenozoa
Class: Kinetoplastea
Order: Trypanosomatida
Family: Trypanosomatidae
Genus: Blastocrithidia
Laird 1959 [1]
Type species
Blastocrithidia gerridis
(Patton 1908) Laird 1959
Species

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Characteristics

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In addition to Blastocrithidia, one-host trypanosomatids from hemipteran and dipteran insects have been traditionally placed in genera Crithidia, Leptomonas, Herpetomonas, Rhynchoidomonas, and Wallaceina.[5][6] Blastocrithidia is characterized by epimastigote morphological forms, whereas opisthomastigotes and endomastigotes are exclusive features of the genera Herpetomonas and Wallaceina, respectively.[6] Blastocrithidia is also able to produce resistant cysts.[7]

Systematics

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The etymology of the genus name Blastocrithidia derives from the two Ancient Greek words βλαστός (blastós), meaning "sprout, scion, child or descendant", and κριθίδιον (krithídion), meaning "small grain of barley".[8][9]

The genus includes the following species.

Genomics

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Genetic code

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Blastocrithidia uses in its nuclear genome an alternative genetic code characterized by all three canonical stop codons reassigned to sense codons.[10]

Table of alternative codons in Blastocrithidia and comparison with the standard genetic code
Genetic code Translation
table
DNA codon RNA codon Conditional
translation
Standard translation
Blastocrithidia nuclear 31 TAA UAA Ter (*) or Glu (E) Ter (*)
TAG UAG Ter (*) or Glu (E) Ter (*)
TGA UGA Trp (W) Ter (*)
Amino acids biochemical properties nonpolar polar basic acidic Termination: stop codon

References

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  1. ^ a b Laird, Marshall (1959-10-01). "Blastocrithidia n.g. (Mastigophora: Protomonadina) for Crithidia (in part), with a subarctic record for B. gerridis (Patton)". Canadian Journal of Zoology. 37 (5): 749–752. doi:10.1139/z59-075. ISSN 0008-4301.
  2. ^ Frolov, Alexander O.; Malysheva, Marina N.; Ganyukova, Anna I.; Yurchenko, Vyacheslav; Kostygov, Alexei Y. (2018-09-27). "Obligate development of Blastocrithidia papi (Trypanosomatidae) in the Malpighian tubules of Pyrrhocoris apterus (Hemiptera) and coordination of host-parasite life cycles". PLOS ONE. 13 (9): e0204467. Bibcode:2018PLoSO..1304467F. doi:10.1371/journal.pone.0204467. ISSN 1932-6203. PMC 6160041. PMID 30261003.
  3. ^ Týč, Jiří; Votýpka, Jan; Klepetková, Helena; Šuláková, Hana; Jirků, Milan; Lukeš, Julius (2013-10-01). "Growing diversity of trypanosomatid parasites of flies (Diptera: Brachycera): Frequent cosmopolitism and moderate host specificity". Molecular Phylogenetics and Evolution. 69 (1): 255–264. doi:10.1016/j.ympev.2013.05.024. ISSN 1055-7903. PMID 23747522.
  4. ^ Tanada, Yoshinori; Kaya, Harry K. (2012-12-02). Insect Pathology. Academic Press. p. 397. ISBN 978-0-08-092625-4.
  5. ^ Merzlyak, Ekaterina; Yurchenko, Vyacheslav; Kolesnikov, Alexander A.; Alexandrov, Kirill; Podlipaev, Sergei A.; Maslov, Dmitri A. (2001-03-01). "Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia". The Journal of Eukaryotic Microbiology. 48 (2): 161–169. doi:10.1111/j.1550-7408.2001.tb00298.x. ISSN 1066-5234. PMID 12095103. S2CID 13880469.
  6. ^ a b Yurchenko, Vyacheslav Y.; Lukeš, Julius; Tesařová, Martina; Jirků, Milan; Maslov, Dmitri A. (2008-01-01). "Morphological Discordance of the New Trypanosomatid Species Phylogenetically Associated with the Genus Crithidia". Protist. 159 (1): 99–114. doi:10.1016/j.protis.2007.07.003. PMID 17931968.
  7. ^ Tieszen, K.; Molyneux, D. H.; Abdel-Hafez, S. K. (1985-03-01). "Ultrastructure of cyst formation in Blastocrithidia familiaris in Lygaeus pandurus (Hemiptera: Lygaeidae)". Zeitschrift für Parasitenkunde. 71 (2): 179–188. doi:10.1007/BF00926268. ISSN 1432-1955. S2CID 30176747.
  8. ^ Bailly, Anatole (1981-01-01). Abrégé du dictionnaire grec français. Paris: Hachette. ISBN 978-2010035289. OCLC 461974285.
  9. ^ Bailly, Anatole. "Greek-french dictionary online". www.tabularium.be. Retrieved April 14, 2020.
  10. ^ Záhonová, Kristína; Kostygov, Alexei Y.; Ševčíková, Tereza; Yurchenko, Vyacheslav; Eliáš, Marek (2016). "An Unprecedented Non-canonical Nuclear Genetic Code with All Three Termination Codons Reassigned as Sense Codons". Current Biology. 26 (17): 2364–2369. doi:10.1016/j.cub.2016.06.064. PMID 27593378.