Cytocentrifugation as an additional method to study echinoderm coelomocytes: a comparative approach combining living cells, stained preparations, and energy-dispersive x-ray spectroscopy

Author(s)

Queiroz, Vinicius ; Arizza, Vincenzo ; Vazzana, Mirella ; Rozas, Enrique E. ; Custodio, Marcio R.

• Document type: Journal article
• Source: Revista de Biología Tropical; v. 69, p. 14-pg., 2021-03-01.

Abstract

Introduction: Echinoderm coelomocytes have traditionally been investigated through a morphological approach using light microscopy, which relies on the idea of constant cell shape as a stable character. However, this can be affected by biotic or abiotic conditions. Objective: To analyze if the consistency in cell morphology offered by the cytocentrifugation method, might be used as a convenient tool to study echinoderm coelomocytes. Methods: Cells of Echinaster (Othilia) brasiliensis (Asteroidea), Holothuria (Holothuria) tubulosa (Holothuroidea), Eucidaris tribuloides, Arbacia lixula, Lytechinus variegatus, and Echinometra lucunter (Echinoidea) were spread on microscope slides by cytocentrifugation, stained, and analyzed through light microscopy. Additionally, fluorescence microscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy were applied to cytospin preparations, to complement the analysis of granular and colorless spherulocytes of Eucidaris tribuloides. Results: Altogether, 11 cell types, including phagocytes, spherulocytes, vibratile cells, and progenitor cells were identified in the samples analyzed. The granular spherulocyte, a newly-described cell type, was observed in all Echinoidea and was very similar to the acidophilic spherulocytes of Holothuria (Holothuria) tubulosa. Conclusions: Cytocentrifugation proved to be versatile, either as the main method of investigation in stained preparations, or as a framework on which other procedures may be performed. Its ability to maintain a constant morphology allowed accurate correspondence between live and fixed/stained cells, differentiation among similar spherulocytes as well as comparisons between similar cells of Holothuroidea and Echinoidea. (AU)

• FAPESP's process: 15/21460-5 - Physiological function, chemical composition and ontogeny of Echinoid spherulocytes (Echinodermata).
• Grantee: Vinicius Queiroz Araújo
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/14497-8 - Physiological function and origin of the spherulocytes in the sea urchin Paracentrotus lividus (Echinodermata: Echinoidea)
• Grantee: Vinicius Queiroz Araújo
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/50218-2 - CEPEMA - Cooperative Center of Environmental Engineering
• Grantee: Claudio Augusto Oller do Nascimento
• Support Opportunities: Research Projects - Thematic Grants