Two New Species of Flagellates Cultivated from Insects of the Genus <i>Gerris</i>*

Wallace, F. G.; Clark, T. B.; Dyer, M. I.; Collins, Thomas M.

doi:10.1111/j.1550-7408.1960.tb05986.x

Cited by 21 publications

(12 citation statements)

References 7 publications

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“…Both isolates of Wallaceina maintained the set of morphotypes typical for this genus (Podlipaev, Frolov, and Kolesnikov 1990): promastigotes and endomastigotes, the morphotype characterized by the flagellum not extending beyond the deep flagellar pocket (Frolov 1994; Janovy, Lee, and Brumbaugh 1974), were found in culture, as well as in insect. There were epimastigotes in the culture of B. triatoma and mostly promastigotes, with the rare occurrence of choanomastigote‐like types, in Leptomonas collosoma and Leptomonas seymouri (not shown), in agreement with their taxonomic names and original descriptions (Cerisola et al 1971; Wallace 1977; Wallace et al 1960). …”

Section: Resultssupporting

confidence: 81%

Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia

Merzlyak

Yurchenko

Kolesnikov

et al. 2001

J Eukaryotic Microbiology

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With the aim of further investigating phylogenetic relationships in insect trypanosomatids, we have determined the sequences of small subunit rRNA genes from ten isolates, which were originally classified as Leptomonas, Blastocrithidia, and Wallaceina based on their morphology in the hosts. The inferred maximum likelihood, parsimony, and distance trees indicate that the Leptomonas and Blastocrithidia are polyphyletic, and confirm the polyphyly of Herpetomonas and Crithidia. Blastocrithidia triatoma and Leptomonas collosoma were among the earliest branching lineages among the insect trypanosomatids, while most other isolates were found within a closely related terminal clade, which also included Crithidia fasciculata. This analysis has clearly demonstrated that the morphological classification system of insect trypanosomatids does not always reflect their genetic affinities warranting its revision in the future.

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Section: Resultssupporting

confidence: 81%

Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia

Merzlyak

Yurchenko

Kolesnikov

et al. 2001

J Eukaryotic Microbiology

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“…This result complements the findings of Arnqvist and Maki (1990), who reported negative correlations of trypanosomatid load scores with survival time under starvation and with a measure of locomotor endurance in adult water striders. Unlike most of the gerrid populations studied previously (Laird 1959, Wallace et al 1960, Tieszen and Molyneux 1989, Arnqvist and Maki 1990but see Becker 1923), prevalences of trypanosomatids observed in our study were so low throughout the season that these gut parasites at most can have a Gregarine load marginal influence on the dynamics of the host population.…”

Section: Discussioncontrasting

confidence: 48%

“…These genera are distinguishable morphologically (Wallace et al 1960, 1965, Wallace 1966. Usually, Blastocrithidiu occurred in the midgut, and Leptomonas in the hindgut.…”

Section: Trypanosomatidsmentioning

confidence: 99%

Influence of gut parasites on growth performance in the water strider Gerris buenoi (Hemiptera: Gerridae)

et al. 1997

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Water striders harbor a diverse assemblage of symbionts in their digestive tract. We used a field experiment, in which water striders were reared in enclosures in their natural pond habitat, to assess the effects of gut symbionts on growth. Trypanosomatid flagellates had significant adverse effects on both development time and adult size, and therefore are clearly parasitic. Yet because of their low prevalences (2% or less), trypanosomatids cannot be a major factor in the dynamics of our study population. Gregarines occurred in 36% of the water striders, often in high numbers, and filling the entire midgut of some bugs. Nevertheless, infected and uninfected gerrids did not differ in their growth, and gregarine loads were uncorrelated with development time and adult size attained. We also did not find effects of gregarines in a second experiment with different rearing conditions, including a treatment with food stress. We used a quantitative genetic approach to test if resistance against gregarines has a heritable component. There was no evidence for any genetic variation, suggesting that variability in gregarine loads is the result of environmental heterogeneity. Comparison with published reports from water striders shows that there is a great variability in the diversity and prevalence of symbionts among different populations and species of gerrids.

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“…Frequently, these fusion events are dependent on extracellular calcium (7). We have used cultured Leptomonas cells, originally from water strider hindgut (29), to extend the studies of the trypanosomatid fluid secretion apparatus. The basic ultrastructure and plasma membrane specializations of this flagellate have been presented in a previous publication (14) .…”

mentioning

confidence: 99%

A novel model for fluid secretion by the trypanosomatid contractile vacuole apparatus.

Linder¹,

Staehelin²

1979

The Journal of Cell Biology

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We have studied fluid secretion by the contractile vacuole apparatus of the trypanosomatid flagellate Leptomonas collosoma with thin sections and freezefracture replicas of cells stabilized by ultrarapid freezing without prior fixation or cryoprotection . The ultrarapid freezing has revealed membrane specializations related to fluid segregation and transport as well as membrane rearrangements which may accompany water expulsion at systole . This osmoregulatory apparatus consists of the spongiome, the contractile vacuole, and the fluid discharge site. The coated tubules of the spongiome converge on the contractile vacuole from all directions . These 60-to 70-nm tubules contain characteristic double rows of I Inm intramembrane particles in a helical configuration which fracture predominantly with the E face . Short double rows of similar particles are also frequently found on both faces of the contractile vacuole itself, in addition to many smaller particles on the P face . The spongiome tubules fuse with the vacuole during the filling stage of each cycle and then detach before secretion . The contractile vacuole membrane is permanently attached to the plasma membrane of the flagellar pocket by a dense adhesion plaque. In some ultrarapidly frozen cells, 20-to 40-nm perforations can be visualized within the plaque and the adjacent membranes during the presumptive time of discharge . The formation of the plaque perforations and the membrane channels occurs without fusion of the vacuole and the plasma membrane and does not require extracellular calcium . On the basis of our results, we have developed a model for water secretion which suggests that the adhesion plaque may induce pore formation in the adjoining lipid bilayers, thereby allowing bulk expulsion of the fluid .KEY WORDS secretion " contractile vacuole freeze-fracture -membrane fusion trypanosomatidThe study of the membrane events during secretion is significant for our understanding of broad physiological problems as well as for molecular models of membrane behavior. Fluid secretion in

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Two New Species of Flagellates Cultivated from Insects of the Genus *Gerris**

Cited by 21 publications

References 7 publications

Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia

Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia

Influence of gut parasites on growth performance in the water strider Gerris buenoi (Hemiptera: Gerridae)

A novel model for fluid secretion by the trypanosomatid contractile vacuole apparatus.

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Two New Species of Flagellates Cultivated from Insects of the Genus Gerris*

Cited by 21 publications

References 7 publications

Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia

Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia

Influence of gut parasites on growth performance in the water strider Gerris buenoi (Hemiptera: Gerridae)

A novel model for fluid secretion by the trypanosomatid contractile vacuole apparatus.

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Two New Species of Flagellates Cultivated from Insects of the Genus *Gerris**