Characterization of Coelomocytes of the Ascidian Halocynthia roretzi Based on Phase-contrast, Time-lapse Video and Scanning Electron Microscopic Observations

Dan-Sohkawa, Marina; Morimoto, Masashi; Mishima, Hideki; Kaneko, Hiroyuki

doi:10.2108/zsj.12.289

Cited by 22 publications

(12 citation statements)

References 4 publications

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“…Other hemocytes, such as fusogenic phagocytes and vacuolated cells, displayed relatively weak signals. Some of stained hemocyte cell types have been reported to show phagocytic activity (33). No hemocytes were stained with the preimmune rabbit serum (Fig.…”

Section: Hemocyte Specific Expression Of ␣ Hr1mentioning

confidence: 95%

Cloning and Characterization of Integrin α Subunits from the Solitary Ascidian,Halocynthia roretzi

Miyazawa

Azumi

Nonaka

2001

The Journal of Immunology

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Recent molecular and biochemical analysis has revealed the presence of an opsonic complement system in the solitary ascidian, Halocynthia roretzi, composed of at least C3, two mannan binding protein-associated serine proteases, and factor B. To elucidate further the structure and function of this apparently primitive complement system in the urochordates, we looked for the ascidian complement receptor type 3 (CR3), or type 4 (CR4), which are members of the leukocyte integrin family in mammals. Using degenerate primers, we isolated two integrin α subunits (αHr1 and αHr2) from the hemocyte mRNA of H. roretzi, by RT-PCR, and the entire coding sequence of αHr1 was determined from cDNA clones. αHr1 contains an I domain, the inserted domain characteristic of a subset of mammalian α subunits, including the leukocyte integrin family. A phylogenetic tree constructed for the α subunits also supports the ancestral position of αHr1 in the monophyletic cluster of I domain-containing α integrins. The αHr1 gene shows hemocyte-specific expression on Northern blot analysis. Western blot analysis and immunocytochemical staining of the hemocytes of H. roretzi using anti-αHr1 Ab showed that αHr1 subunits exist on the surface of a subpopulation of phagocytic hemocytes. Furthermore, anti-αHr1 Ab inhibited C3-dependent phagocytosis, but not basic phagocytosis, of yeast cells by ascidian hemocytes. These observations strongly suggest that αHr1 constitutes an integrin molecule on the hemocytes of H. roretzi that functions as an ancestral form of CR3 and CR4 and mediates phagocytosis in the primitive complement system of the ascidian.

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Section: Hemocyte Specific Expression Of ␣ Hr1mentioning

confidence: 95%

Cloning and Characterization of Integrin α Subunits from the Solitary Ascidian,Halocynthia roretzi

Miyazawa

Azumi

Nonaka

2001

The Journal of Immunology

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“…Unlike the surface structure of a cyst-like cell of a similar size within the diseased tunic (Figure S3A), numerous and continuous cellulose fibers covered the cell and connected it to the intact homogeneous tunic matrix (arrow in Figure 2F and Figure S3B). 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: 80%

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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“…In the present study, the hemocytes that are exactly like 'paramyxean-infected cells' in light microscopy reported by Choi et al (2006) were also found in the internal organs of all ascidians observed, irrespective of the health condition of the animals. Therefore, these cells are most likely a type of normal hemocyte of the ascidian, possibly the vacuolated cell (Dan-Sohkawa et al 1995).…”

Section: Discussionmentioning

confidence: 99%

Mass mortality of cultured ascidians Halocynthia roretzi associated with softening of the tunic and flagellate-like cells

Kumagai¹,

Suto²,

Ito³

et al. 2010

Dis. Aquat. Org.

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Characterization of Coelomocytes of the Ascidian Halocynthia roretzi Based on Phase-contrast, Time-lapse Video and Scanning Electron Microscopic Observations

Cited by 22 publications

References 4 publications

Cloning and Characterization of Integrin α Subunits from the Solitary Ascidian,Halocynthia roretzi

Cloning and Characterization of Integrin α Subunits from the Solitary 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

Mass mortality of cultured ascidians Halocynthia roretzi associated with softening of the tunic and flagellate-like cells

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