RRV Nonstructural 3 (aa 1333-1875) [His, GST]

Mature organisms often have to trade reproductive opportunities against the need to survive, especially in species with exaggerated, sexually selected traits. Life history theory predicts that old males with low residual reproductive value (RRV) would accept greater risk for current reproduction than their younger counterparts. Accordingly, we tested the prediction that, under predation risk, old males of the rock shrimp Rhynchocinetes typus pair with females faster and for a longer time than young males do. We exposed young and old dominant males (in the final ontogenetic stage, called "robustus") to a female in the absence and presence of a predator. As predicted, older robustus males modified their mating behavior when exposed to a predator. However, in contrast to the prediction, they delayed female seizure under predation risk, possibly to carefully assess the actual threat before initiating female guarding. Once they had established the mate-guarding position, old robustus males did not interrupt it until the end of female spawning and, in the presence of predators, even guarded the female significantly longer than in predator-free treatments. In contrast, younger robustus males did not delay female seizure but abandoned the female repeatedly when a predator was present, suggesting that they perceived and responded to the predation risk. Our results suggest that older robustus males have the experience to assess threats before engaging in risky behaviors that bolster their reproductive success. Although consistent with the theory that low RRV individuals should accept greater reproductive risk, we suggest that old individuals do not recklessly engage in risky behaviors but rather cautiously evaluate the threats before investing in a potentially terminal reproductive event.

During lytic replication of Kaposi's sarcoma-associated herpesvirus (KSHV), a nuclear viral long noncoding RNA known as PAN RNA becomes the most abundant polyadenylated transcript in the cell. Knockout or knockdown of KSHV PAN RNA results in loss of late lytic viral gene expression and, consequently, reduction of progeny virion release from the cell. Here, we demonstrate that knockdown of PAN RNA from the related Rhesus macaque rhadinovirus (RRV) phenocopies that of KSHV PAN RNA. These two PAN RNA homologs, although lacking significant nucleotide sequence conservation, can functionally substitute for each other to rescue phenotypes associated with the absence of PAN RNA expression. Because PAN RNA is exclusively nuclear, previous studies suggested that it directly interacts with host and viral chromatin to modulate gene expression. We studied KSHV and RRV PAN RNA homologs using capture hybridization analysis of RNA targets (CHART) and observed their association with host chromatin, but the loci differ between PAN RNA homologs. Accordingly, we find that KSHV PAN RNA is undetectable in chromatin following cell fractionation. Thus, modulation of gene expression at specific chromatin loci appears not to be the primary, nor the pertinent function of this viral long noncoding RNA. PAN RNA represents a cautionary tale for the investigation of RNA association with chromatin whereby cross-linking of DNA spatially adjacent to an abundant nuclear RNA gives the appearance of specific interactions. Similarly, PAN RNA expression does not affect viral transcription factor complex expression or activity, which is required for generation of the late lytic viral mRNAs. Rather, we provide evidence for an alternative model of PAN RNA function whereby knockdown of KSHV or RRV PAN RNA results in compromised nuclear mRNA export thereby reducing the cytoplasmic levels of viral mRNAs available for production of late lytic viral proteins.