Autor(es): Dunn, A. M.; Hogg, J. C.; Hatcher, M. J.

Resumo: Microsporidia are unusual amongst eukaryotic parasites in that they utilize both vertical and horizontal transmission and vertically transmitted species can cause sex ratio distortion in their host. Here we study vertical transmission in two species of feminising microsporidia, Nosema granulosis and Dictyocoela duebenum, infecting a single population of the crustacean host Gammarus duebeni and measure the effect of temperature on parasite transmission and replication. N. granulosis was vertically transmitted to 82% of the host embryos and D. duebenum was transmitted to 72% of host embryos. For both parasites, we report relatively low parasite burdens in developing host embryos. However, the parasites differ in their pattern of replication and burden within developing embryos. Whilst N. granulosis undergoes replication during host development, the burden of D. duebenum declines, leading us to propose that parasite dosage and feminisation efficiency underlie the different parasite frequencies in the field. We also examine the effect of temperature on parasite transmission and replication. Temperature does not affect the percentage of young that inherit the infection. However, low temperatures inhibit parasite replication relative to host cell division, resulting in a reduction in parasite burden in infected embryos. The reduced parasite burden at low temperatures may underpin reduced feminization at low temperatures and so limit the spread of sex ratio distorters through the host population. (c) 2005 Australian Society for Parasitology Inc Published by Elsevier Ltd. All rights reserved.

Palavras-Chave: Vertical transmission; Ferminisation; Sex ratio distortion; Gammarus duebeni; Nosema granulosis; Dictyocoela duebenum; Wolbachia

Imprenta: International Journal for Parasitology, v. 36, n. 4, p. 409-414, 2006

Identificador do objeto digital: 10.1016/j.ijpara.2005.11.005

Descritores: Aedes aegypti - Cell

Data de publicação: 2006

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