Range-Wide and Regional Patterns of Population Structure and Genetic Diversity in the Gopher Tortoise

The gopher tortoise (Gopherus polyphemus) has experienced dramatic population declines throughout its distribution in the southeastern United States and is federally listed as threatened in the area west of the Tombigbee and Mobile rivers. While there is molecular support for recognizing the listed portion of the range as genetically distinct, other research has suggested that additional population structure exists at both range-wide and regional scales. In this study, we sought to comprehensively define genetic population structure at both spatial scales by doubling the data available in terms of the number of sampling sites, individuals, and microsatellite loci compared to previously published work. We also compared patterns of genetic diversity, gene flow, and demographic history across the range. We collected 933 individuals from 47 sampling sites across the range and genotyped them for 20 microsatellite loci. Our range-wide analyses supported the recognition of five genetic groups (or regions) delineated by the Tombigbee and Mobile rivers, Apalachicola and Chattahoochee rivers, and the transitional areas between several physiographic province sections of the Coastal Plains (i.e., Eastern Gulf, Sea Island, and Floridian). We found genetic admixture at sampling sites along the boundaries of these genetically defined groups. We detected some degree of additional genetic structure within each of the five regions. Notably, within the range listed as threatened under the Endangered Species Act, we found some support for two additional genetic groups loosely delineated by the Pascagoula and Chickasawhay rivers, and we detected four more genetic groups within the Florida region that seemed to reflect the influence of the local physiography. Additionally, our range-wide analysis found the periphery of the range had lower levels of genetic diversity relative to the core. We suggest that the five main genetic groups delineated in our study warrant recognition as management units in terms of conservation planning. Intraregional population structure also points to the potential importance of other barriers to gene flow at finer spatial scales, although additional work is needed to better delineate these genetic groups

Evaluation of the safety of palivizumab in the second season of exposure in young children at risk for severe respiratory syncytial virus infection

Background: Palivizumab reduces respiratory syncytial virus (RSV) hospitalisations in high-risk infants. Those with severe bronchopulmonary dysplasia may require two seasons of prophylaxis. There is concern that this humanised antibody might cause an adverse immune response in a second season of use. Objective: To evaluate and compare the occurrence of anti-palivizumab antibodies and clinical adverse events in subjects receiving monthly palivizumab injections for a first and second season, and to assess frequency and severity of RSV disease in the two groups. Design and Patients: Subjects aged ≤2 years at severe risk for RSV disease were designated as first season (no previous palivizumab exposure) or second season subjects (received palivizumab in previous RSV season). Palivizumab injections (15 mg/kg) were administered monthly for up to 5 months. Anti-palivizumab antibody titres and serum palivizumab concentrations were measured; adverse events were recorded. Results: No first (n = 71) or second (n = 63) season subjects experienced a significant anti-palivizumab antibody response (titre ≥1:80). Serum palivizumab concentrations were similar for the two groups. Nine (12.7%) first season and 8 (12.7%) second season subjects experienced one or more serious adverse events; most were respiratory and all were considered to be not or probably not related to palivizumab. No deaths occurred during the study. Conclusions: Monthly palivizumab injections were not associated with adverse immune responses or adverse events in young children receiving palivizumab for one or two seasons. Children receiving palivizumab for a second season did not experience more severe adverse events than those receiving it for the first time.SCOPUS: ar.jinfo:eu-repo/semantics/publishe