Pierce S K, Maugel T K, Rumpho M E, Hanten J J, Mondy W L
Biol Bull. 1999 Aug;197(1):1-6. doi: 10.2307/1542990.
In a few well-known cases, animal population dynamics are regulated by cyclical infections of protists, bacteria, or viruses. In most of these cases, the pathogen persists in the environment, where it continues to infect some percentage of successive generations of the host organism. This persistent re-infection causes a long-lived decline, in either population size or cycle, to a level that depends upon pathogen density and infection level (1-4). We have discovered, on the basis of 9 years of observation, an annual viral expression in Elysia chlorotica, an ascoglossan sea slug, that coincides with the yearly, synchronized death of all the adults in the population. This coincidence of viral expression and mass death is ubiquitous, and it occurs in the laboratory as well as in the field. Our evidence also suggests that the viruses do not re-infect subsequent generations from an external pathogen pool, but are endogenous to the slug. We are led, finally, to the hypothesis that the viruses may be involved in the maintenance of symbiotic chloroplasts within the molluscan cells.
在一些著名的案例中，动物种群动态受原生生物、细菌或病毒的周期性感染调节。在大多数此类案例中，病原体在环境中持续存在，在那里它继续感染宿主生物连续几代中的一定比例。这种持续的再感染会导致种群数量或周期出现长期下降，降至取决于病原体密度和感染水平的某个水平（1 - 4）。基于9年的观察，我们发现绿叶海天牛（一种裸鳃亚目海蛞蝓）中存在年度病毒表达，这与种群中所有成年个体每年同步死亡相吻合。病毒表达与大量死亡的这种巧合普遍存在，在实验室和野外都有发生。我们的证据还表明，这些病毒并非从外部病原体库再感染后代，而是海蛞蝓内源性的。最后，我们得出这样的假设：这些病毒可能参与了软体动物细胞内共生叶绿体的维持。
