Tissue tropism and viral levels of Acheta domesticus densovirus throughout the house cricket production

TL;DR

This study tracks the spread and levels of a virus in house crickets, showing it increases during development and is transmitted both ways.

Contribution

The study reveals AdDV tissue tropism and transmission routes in house crickets using quantitative PCR.

Findings

AdDV levels increase as crickets develop from nymphs to adults.

Mated crickets have higher AdDV levels than unmated ones.

AdDV is present in all tested tissues, especially the gut and ovaries.

Abstract

•Levels of the Acheta domesticus densovirus (AdDV) increase during house cricket development.•Mated adult crickets have higher levels of AdDV than unmated ones.•AdDV is present in the gut as well as the reproductive tissues of adult crickets.•AdDV is most likely transmitted horizontally as well as vertically among house crickets.

Levels of the Acheta domesticus densovirus (AdDV) increase during house cricket development.

Mated adult crickets have higher levels of AdDV than unmated ones.

AdDV is present in the gut as well as the reproductive tissues of adult crickets.

AdDV is most likely transmitted horizontally as well as vertically among house crickets.

The house cricket, Acheta domesticus, is commonly reared for food and feed purposes and is often infected with the Acheta domesticus densovirus (AdDV). This single-stranded DNA virus can cause high mortality in crickets resulting in colony collapse. AdDV disease outbreaks in cricket mass-rearing can be prevented by either obtaining virus-free crickets or by reducing virus spread. Therefore, insight into viral levels in cricket developmental stages and into viral transmission routes is needed. Viral levels were monitored using quantitative PCR on samples collected 1) simultaneously from different life stages present in the rearing room and 2) weekly from a single rearing container during the successive developmental stages. To study viral tissue tropism and to infer the route of virus transmission, viral levels were measured in cricket tissues and in mated and non-mated adult crickets. Results showed that viral levels increased when developing from nymphs into adults and that unmated individuals had significantly lower viral levels than mated individuals. Furthermore, AdDV was present in every tested tissue and the gut and ovaries of females showed the highest viral levels. Our results suggest that AdDV is both horizontally and vertically transmitted among house crickets and provide relevant information to establish virus-free cricket lines.

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