Correlative Fine Structural, Behavioral, and Histochemical Analysis of Ascidian Blood Cells

Fuke, Masako T.; Fukumoto, Manabu

doi:10.1111/j.1463-6395.1993.tb01221.x

Cited by 26 publications

(20 citation statements)

References 26 publications

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“…Although we have yet to determine the location and form of the enzyme in the resting hemocytes, our supposition for the momentis that the enzymeis present in so-called vacuolated cells (13). When hemocytes are harshly managed, the rate of oxygen consumption increased (data not shown).…”

Section: Discussionmentioning

confidence: 95%

Hemocytes Release Phenoloxidase upon Contact Reaction, an Allogeneic Interaction, in the Ascidian Halocynthia roretzi.

Akita

Hoshi

1995

Cell Struct. Funct.

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Keywords: allogeneic recognition/ascidian hemocyte/phenoloxidase/respiratory burst/exocytotic burst/superoxide anion ABSTRACT. Contact reaction is the morphological expression of allogeneic recognition by hemocytes in the ascidian, Halocynthia roretzi', namely they undergo an exocytotic burst upon contact with non-self (allogeneic) hemocytes in vitro. Wehave found that contact reaction is accompanied by a burst of cyanide-insensitive oxygen consumption that, unlike exocytotic events of mammalianphagocytes, is Ca2+-dependentand does not culminate in the production of superoxide anions or H2O2. Instead, the burst is due to the release of phenoloxidase from hemocytes as known for the self-defense systems in insects and crustaceans. The activity of phenoloxidase released from hemocytes corresponds well to the degree of contact reaction observed under the microscope. Therefore, it is possible to quantify the contact reaction simply by measuring the activity of phenoloxidase released from hemocytes into the medium.

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Section: Discussionmentioning

confidence: 95%

Hemocytes Release Phenoloxidase upon Contact Reaction, an Allogeneic Interaction, in the Ascidian Halocynthia roretzi.

Akita

Hoshi

1995

Cell Struct. Funct.

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“…This structure is not likely to be formed by rod-shaped projections and/or pseudopodia, which are generally known to protrude from tunic cells [48]. Furthermore, we were able to distinguish a small rounded cell (∼ 3.3 µm in diameter) from a large (9–10 µm) viriform cell involved in tunic formation [49] (Figure 2F). …”

Section: Resultsmentioning

confidence: 81%

RNA-Seq-Based Metatranscriptomic and Microscopic Investigation Reveals Novel Metalloproteases of Neobodo sp. as Potential Virulence Factors for Soft Tunic Syndrome in Halocynthia roretzi

et al. 2012

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Bodonids and trypanosomatids are derived from a common ancestor with the bodonids being a more primitive lineage. The Neobodonida, one of the three clades of bodonids, can be free-living, commensal or parasitic. Despite the ecological and evolutionary significance of these organisms, however, many of their biological and pathological features are currently unknown. Here, we employed metatranscriptomics using RNA-seq technology combined with field-emission microscopy to reveal the virulence factors of a recently described genus of Neobodonida that is considered to be responsible for ascidian soft tunic syndrome (AsSTS), but whose pathogenesis is unclear. Our microscopic observation of infected tunic tissues suggested putative virulence factors, enabling us to extract novel candidate transcripts; these included cysteine proteases of the families C1 and C2, serine proteases of S51 and S9 families, and metalloproteases grouped into families M1, M3, M8, M14, M16, M17, M24, M41, and M49. Protease activity/inhibition assays and the estimation of expression levels within gene clusters allowed us to identify metalloprotease-like enzymes as potential virulence attributes for AsSTS. Furthermore, a multimarker-based phylogenetic analysis using 1,184 concatenated amino acid sequences clarified the order Neobodo sp. In sum, we herein used metatranscriptomics to elucidate the in situ expression profiles of uncharacterized putative transcripts of Neobodo sp., combined these results with microscopic observation to select candidate genes relevant to pathogenesis, and used empirical screening to define important virulence factors.

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“…The reaction triggered by direct contact between reactive cells, results in mutual cell devacuolation and prolonged incapacitation of the cells in contact. The allogeneic reaction seems to be triggered by an absence of common self-markers (Fuke and Nakamura, 1983;Fuke, 1990), as reported for natural killer cells of mammals (Ljunggren and Karre, 1990). A high level of polymorphism in H. roretzi, of similar magnitude to that in the mouse MHC class I, has been revealed.…”

Section: Introductionmentioning

confidence: 73%

Cell Types Involved in Allogeneic Contact Reactions of the Solitary Ascidian, Halocynthia roretzi

Fuke

2001

Zoological Science

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ABSTRACT-The blood cells of a solitary ascidian, Halocynthia roretzi exhibit the allogeneic cellular reaction in vitro denoted as the "contact reaction" (Fuke, 1980). Nine cell types have been recognized in the blood and body fluid of H. roretzi (Fuke and Fukumoto, 1993). In the present study, the precise role of each cell type in allogeneic reactions is investigated in vitro. The vacuolated cells show devacuolation after contact with almost all other cell types from different reactive animals. These cells include hyaline amoebocytes, granular amoebocytes, macrogranular cells, small amoebocytes and giant cells (large basophilic cells), as well as vacuolated cells. The hyaline amoebocytes and small amoebocytes, which belong to the phagocyte series exhibit contact reactions with the cells of phagocyte series from other specimens of H. roretzi. They also show a contact reaction when in contact with granular amoebocytes. Therefore, almost all cell types have the materials responsible for individuality on their cell surface and can directly show the allogeneic cellular reactivity when they contact each other. To determine whether the contact reaction is involved in cell death, the loss of plasma membrane integrity was examined using fluorescent dyes. The number of cells showing uptake of ethidium bromide increased immediately after mixing of allogeneic cells. Almost the same cell types as those showing allogeneic behavior by light microscopy, as described above, exhibited loss of cell membrane integrity.These results are discussed in the context of immune systems in invertebrates and vertebrates.

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Correlative Fine Structural, Behavioral, and Histochemical Analysis of Ascidian Blood Cells

Cited by 26 publications

References 26 publications

Hemocytes Release Phenoloxidase upon Contact Reaction, an Allogeneic Interaction, in the Ascidian Halocynthia roretzi.

Hemocytes Release Phenoloxidase upon Contact Reaction, an Allogeneic Interaction, in the Ascidian Halocynthia roretzi.

RNA-Seq-Based Metatranscriptomic and Microscopic Investigation Reveals Novel Metalloproteases of Neobodo sp. as Potential Virulence Factors for Soft Tunic Syndrome in Halocynthia roretzi

Cell Types Involved in Allogeneic Contact Reactions of the Solitary Ascidian, Halocynthia roretzi

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