Sanders et al., 2013 - Verification of Intraovum Transmission of a Microsporidium of Vertebrates: Pseudoloma neurophilia Infecting the Zebrafish, Danio rerio. PLoS One   8(9):e76064 Full text @ PLoS One

Fig. 1

Spores of Pseudoloma neurophilia in Luna-stained histological sections of progeny of infected zebrafish, Danio rerio.

A.Spores (red) in the epidermis of a 7 d post-fertilization (pf) larval zebrafish. B. Spores in the resorbing yolk-sac of the same 7 dpf larval zebrafish. C. Spore aggregate beneath the intestinal epithelium of an 8 wk pf juvenile fish. D. Spores in the ovigerous stroma adjacent to developing follicles in an 8 wk pf fish. Bar = 10 μm.

Fig. 2

Spores of Pseudoloma neurophilia in developing embryo of zebrafish, Danio rerio.

A. Aggregated spores (arrow) in a 4 hpf embryo. Bar = 0.5 mm. B. Two foci of spores (arrows) visible in the same embryo at 24 hpf. C. Spores (arrows) in the same embryo at 48 hpf. D. Differential interference contrast micrograph of spores from an embryo. Bar = 10 μm.

Fig. 3

Modes of transmission of Pseudoloma neurophilia in the zebrafish, Danio rerio.

A. Luna-stained histological section showing P. neurophilia spores (red) within a secondary oocyte. Sexually mature female fish have been shown to harbor the parasite in both ovigerous stromal tissue and within various developmental stages of oocytes. B. Luna-stained histological section of kidney from an adult male zebrafish with spores present (red) within the epithelium of a renal tubule. The presence of spores in these structures is proposed to be one method by which spores can be released into the environment by live fish. C. P. neurophilia spores (arrow) present within a developing embryo. D. The presence of high numbers of P. neurophilia spores in spawn water and the high susceptibility of larval fish can result in infected progeny. E. Intraovum transmission of P. neurophilia is proposed to result in either the death of the developing embryo or larvae with the subsequent release of spores into the water infecting tank mates or F. live, infected animals that then go on to transmit the parasite horizontally and, later, vertically.

Acknowledgments:
ZFIN wishes to thank the journal PLoS One for permission to reproduce figures from this article. Please note that this material may be protected by copyright. Full text @ PLoS One