Viral antibody dynamics in a chiropteran host

1. Bats host many viruses that are significant for human and domestic animal health, but the dynamics of these infections in their natural reservoir hosts remain poorly elucidated.<p></p> 2. In these, and other, systems, there is evidence that seasonal life-cycle events drive infection dynamics, directly impacting the risk of exposure to spillover hosts. Understanding these dynamics improves our ability to predict zoonotic spillover from the reservoir hosts.<p></p> 3. To this end, we followed henipavirus antibody levels of >100 individual E. helvum in a closed, captive, breeding population over a 30-month period, using a powerful novel antibody quantitation method.<p></p> 4. We demonstrate the presence of maternal antibodies in this system and accurately determine their longevity. We also present evidence of population-level persistence of viral infection and demonstrate periods of increased horizontal virus transmission associated with the pregnancy/lactation period.<p></p> 5.The novel findings of infection persistence and the effect of pregnancy on viral transmission, as well as an accurate quantitation of chiropteran maternal antiviral antibody half-life, provide fundamental baseline data for the continued study of viral infections in these important reservoir hosts

Incompatibility Systems in Switchgrass

Switchgrass (Panicum virgatum L.), a cross-pollinated perennial, produces very little or no seed when self-pollinated, indicating the presence of self-incompatibility mechanisms. Knowledge of self-incompatibility mechanisms is required to use germplasm effectively in a breeding program. The objective of this study was to characterize features of the incompatibility systems in switchgrass. Seed set and seed characteristics of reciprocal matings of tetraploid, octaploid, and tetraploid x octaploid plants were used as measures of incompatibility. Both bagged mutual pollination and manual emasculation and pollination methods were used to make crosses. The percentages of self-compatibility in the tetraploid and octaploid parent plants were 0.35 and 1.39%, respectively. Prefertilization incompatibility in switchgrass is apparently under gametophytic control, since there were significant differences in percentage of compatible pollen as measured by percentage of total seed set between reciprocal matings within ploidy levels. Results indicated that the prefertilization incompatibility system in switchgrass is similar to the S-Z incompatibility system found in other members of the Poaceae. A postfertilization incompatibility system also exists that inhibits intermatings among octaploid and tetraploid plants. In these interploidy crosses, two very distinctive types of abnormal seed were found. When the female parent was the tetraploid plant, the resulting seed was small and shriveled, while when the female parent was the octaploid, small seed with floury endosperm was obtained. These results are similar to those obtained for endosperm incompatibility due to the endosperm balance number system found in other species