M. circinelloides R7B is highly pathogenic for zebrafish. Zebrafish were i.p. injected with 2.5 × 10⁵ or 10⁷ (high dose: HD) live or UV-killed sporangiospores of the R7B or NRRL strains. (A) The survival rates of infected zebrafish are shown. Each experimental group contained 20 zebrafish, and each experiment was performed in duplicate. ^*P < 0.05; ^**P < 0.01; ^***P < 0.001. (B) Gross morphological examinations of adult zebrafish infected with M. circinelloides R7B and NRRL were imaged at 16 hpi. (C) Histological analysis of M circinelloides-infected zebrafish. Transverse sections were obtained from zebrafish injected with 2.5 × 10⁵ R7B spores/fish or 10⁷ NRRL spores/fish at 16 hpi. Note that the mycelium (black arrows) can invade several organs and promotes a strong leukocyte infiltration (red arrows). L, liver; G, gut; M, muscle; O, ovary; T, testis. Scale bars 10 µm

ZFIN is incorporating published figure images and captions as part of an ongoing project. Figures from some publications have not yet been curated, or are not available for display because of copyright restrictions.

ZFIN is incorporating published figure images and captions as part of an ongoing project. Figures from some publications have not yet been curated, or are not available for display because of copyright restrictions.

M. circinelloides promotes neutrophils and macrophages depletion in the head kidney. (A) Representative sections of zebrafish head kidneys infected with 2.5 × 10⁵ R7B spores/fish at 16 hpi and immunostained with anti-Lcp1 (pan-leukocyte marker) and anti-Mpx (neutrophil marker) antibodies. Note the robust depletion of myeloid cells. Scale bars 20 µm. (B) Quantification of Lcp1⁺ and Mpx⁺ cells is shown as the mean ± SEM of the immunostained area/total area of 4 randomly distributed optical areas from 4 fish at ×200 magnification. ^*P<0.05; ^**P<0.01; ^***P<0.001.

ZFIN is incorporating published figure images and captions as part of an ongoing project. Figures from some publications have not yet been curated, or are not available for display because of copyright restrictions.

M. circinelloides promotes the recruitment and apoptosis of macrophages in the infection site. (A) Representative serial sections of zebrafish head kidneys challenged with PBS, 2.5×10⁵ R7B spores/fish and 10⁷ (high dose, HD) NRRL spores/fish at 16 hpi and immunostained with anti-Lcp1, anti-Mpx, and anti-active Casp3 antibodies. Infiltrated leukocytes (black arrows) at 16 hpi were PAS⁺, Lcp1⁺ and most of them Casp3⁺ in the fish infected with the virulent strain (R7B) and the HD of the avirulent NRRL strain. Scale bars 20 µm. (B) Quantification of Lcp1⁺, Mpx^+, and Casp3⁺ cells is shown as the mean ± SEM of the immunostained area/total area of 4 randomly distributed optical regions from 4 fish at ×200 magnification. ^*P<0.05.