Simple Nutrition of <i>Crithidia deanei</i>, a Reduviid Trypanosomatid with an Endosymbiont*

Mundim, Maria Hermelinda; Roitman, Isaac; Hermans, Maria A.; Kitajima, Elliot Watanabe

doi:10.1111/j.1550-7408.1974.tb03691.x

Cited by 62 publications

(65 citation statements)

References 13 publications

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“…This organelle carries sufficient information to code for a complex set of proteins, and it is capable of independent protein synthesis (33). Moreover, it relieves the host cell from dependence on exogenous heme (9), ornithine metabolism enzymes (7), purines, and various amino acids (32). Therefore, it seems plausible that the endosymbiont could compensate the host with some enzymatic functions that would allow the loss of all but a rudimentary PFR.…”

Section: Evolutionary Distribution Of the Pfrmentioning

confidence: 99%

Cryptic Paraflagellar Rod in Endosymbiont-Containing Kinetoplastid Protozoa

et al. 2005

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Cilia and flagella are central to many biological processes in a diverse range of organisms. The kinetoplastid protozoa are very appealing models for the study of flagellar function, particularly in the light of the availability of extensive trypanosomatid genome information. In addition to the highly conserved 9 ؉ 2 axoneme, the kinetoplastid flagellum contains a characteristic paraflagellar rod structure (PFR). The PFR is necessary for full motility and provides support for metabolic regulators that may influence flagellar beating. However, there is an intriguing puzzle: one clade of endosymbiont-containing kinetoplastids apparently lack a PFR yet are as motile as species that possess a PFR and are able to attach to the invertebrate host epithelia. We investigated how these organisms are able to locomote despite the apparent lack of PFR. Here we have identified a PFR1 gene in the endosymbiont-bearing trypanosome Crithidia deanei. This gene is expressed in C. deanei and is able to partially complement a pfr1 null mutation in Leishmania mexicana cells, demonstrating that the encoded protein is functional. Careful reexamination of C. deanei flagellar ultrastructure revealed a greatly reduced PFR missed by many previous analyses. This affirms the PFR as a canonical organelle of kinetoplastids. Moreover, although PFR proteins have been conserved in evolution, primary sequence differences contribute to particular PFR morphotypes characteristic of different kinetoplastid species.Cilia and flagella are central to many biological processes in a diverse range of organisms. In the order Kinetoplastida-the group of flagellates that include trypanosomatid parasites and bodonids-the flagellum is the classical organelle of motility (42). In parasitic species, the kinetoplastid flagellum has also evolved to be an organelle of attachment to the invertebrate vector, playing a critical role in parasite transmission to the vertebrate host (42). Moreover, recent work shows that the kinetoplastid flagellum is also involved in cell division; positioning of the new flagellum, one of the earliest event in cell duplication, defines the axis of polarity in the dividing cell and the position of the internal organelles (31). Finally, flagellar wave reversal in a Ca 2ϩ -dependent manner as an avoidance response has been studied in trypanosomatids (39), suggesting that the flagellum in these species may also be a specialized sensory organelle.The main component of both cilia and flagella is the axoneme. This microtubule-based organelle was most probably present in the ancestor of all modern eukaryotes and is highly conserved in several deeply diverged lines. In many organisms, the axoneme is augmented by extra-axonemal structures-for example, the fibrous sheath in mammalian spermatozoa and the R-fiber of dinoflagellates. In the Kinetoplastida, a characteristic structure known as the paraflagellar rod (PFR) runs alongside the axoneme to form the flagellum. This PFR is an elegant and stable lattice-like arrangement of protein filaments which ...

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Section: Evolutionary Distribution Of the Pfrmentioning

confidence: 99%

Cryptic Paraflagellar Rod in Endosymbiont-Containing Kinetoplastid Protozoa

et al. 2005

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“…After the production of aposymbiotic strains, it became clear that only endosymbiont-containing cells could be cultivated in a medium with no hemin. In the case of C. deanei, Mundim et al [25] reported that it could be grown in a chemically de¢ned medium containing two amino acids, methionine and tyrosine, four vitamins (folic acid, thiamine, biotin and nicotinamide), and no source of hemin and purine. Indeed, the ability to grow in a chemically de¢ned medium is now being routinely used for the detection of new trypanosomatid isolates containing endosymbiont.…”

Section: W De Souza MCM Motta / Fems Microbiology Letters 173 (1mentioning

confidence: 99%

Endosymbiosis in protozoa of the Trypanosomatidae family

Souza¹

1999

FEMS Microbiology Letters

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A small number of trypanosomatids present bacterium endosymbionts in the cytoplasm, which divide synchronously with the host cell. Crithidia oncopleti, Crithidia deanei, Crithidia desouzai, Blastocrithidia culicis and Herpetomonas roitmani are the best characterized species. The endosymbiont is surrounded by two membranes separated from each other by an electronlucent space. The presence of the endosymbiont led to the appearance of morphological changes which include the lack of the paraflagellar rod associated to the axoneme, the morphology of the kinetoplast and the association of the sub-pellicular microtubules with portions of the protozoan plasma membrane. Aposymbiotic strains could be obtained by antibiotic treatment, opening the possibility to make comparative analysis of endosymbiont-containing an endosymbiont-free populations of the same species. It is clear that metabolic cycles are established between the prokaryiont and the host cell. The results obtained show that endosymbiont-containing species of trypanosomatids constitute an excellent model to study basic processes on the endosymbiont^host cell relationship and the origin of new organelles. z

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“…Bacterial endosymbionts have been observed in some insect trypanosomatids (7,8)-e.g., Crithidia oncopelti (9), Crithidia deanei (10), Crithidia desouzai (11), Blastocrithidia culicis (12), and Herpetomonas roitmani (13). The symbionts defy cultivation outside their hosts and are limited usually to one per protozoan.…”

mentioning

confidence: 99%

Monophyletic origin of beta-division proteobacterial endosymbionts and their coevolution with insect trypanosomatid protozoa Blastocrithidia culicis and Crithidia spp.

Maslov²,

Chang³

1994

Proc. Natl. Acad. Sci. U.S.A.

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Some trypanosomatid protozoa (order Kinetoplastida) are well known to harbor bacterial endosymbionts.Their phylogenetic positions and evolutionary relationships with the hosts were deduced by comparing the rRNA gene sequences. Earlier, we observed that these symbionts from three Crithidia spp. are identical and are closely related to BordeteUa bronchiseptica. We have now sequenced the genes of another endosymbiont and the host protozoan Blastocrithidia culicis. The 16S rRNA genes of the Blastocrithidia and Crithidia symbionts share =-97% identity and form a distinct group, branching off the B. bronchiseptica lineage in the 3-division of Proteobacteria. Comparison of their secondary structures in the stem regions suggests compensatory mutations of the symbiont sequences, contributing to their biased base transitions from G to A and C to T. Two putative genes encoding tRNAne and tRNAh are highly conserved in the otherwise variable internal transcribed spacer region. Comparisons of the host rRNA gene sequences suggest that the symbiontcontaining Crithidia and Blastocrithidia are more akin to each other than to other trypanosomatids. The evidence suggests that Blastocrithdia and COthidia symbionts descend from a common ancestor, which had presumably entered an ancestral host and thence coevolved with it into different species. We therefore propose naming the symbionts Kinetoplastbactetoum blastocrithid and Kinetoplastbateoium crhi.

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Simple Nutrition of Crithidia deanei, a Reduviid Trypanosomatid with an Endosymbiont*

Cited by 62 publications

References 13 publications

Cryptic Paraflagellar Rod in Endosymbiont-Containing Kinetoplastid Protozoa

Cryptic Paraflagellar Rod in Endosymbiont-Containing Kinetoplastid Protozoa

Endosymbiosis in protozoa of the Trypanosomatidae family

Monophyletic origin of beta-division proteobacterial endosymbionts and their coevolution with insect trypanosomatid protozoa Blastocrithidia culicis and Crithidia spp.

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