Development of a real-time PCR assay for tracking the spatiotemporal dynamics of a cyanophage and its Synechococcus host in waters of shrimp aquaculture ecosystems.

One of the most abundant and ubiquitous members of the phytoplankton in the marine ecosystem is the unicellular cyanobacteria of the genus Synechococcus, which contributes to a substantial fraction of the ocean's primary productivity. Nevertheless, like any other organism, Synechococcus is infected by a specific kind of virus: the cyanophages. These viruses, highly abundant and widely distributed throughout the world's oceans, shape the bacterial communities by regulating their abundance, diversity, and physiology. However, the information regarding the occurrence of Synechococcus-infecting phages in the Gulf of California and their impact on host populations in shrimp farming ecosystems is currently unavailable. This is relevant since it is of critical importance for the shrimp's health and growth, as well as for optimizing farm productivity. In this study, a highly specific and sensitive qPCR method to quantitatively estimate the abundance of Synechococcus sp., and the Synechococcus-infecting phages was developed. Moreover, the spatiotemporal abundance patterns of the phage and its host in a shrimp farm on the Gulf of California were estimated, and the ecological impact of this interaction is discussed. Our results contribute to a better comprehension of the virus-host interaction, which could ultimately affect the primary productivity surrounding shrimp farming facilities.