Discovery Of Genetically Distinct Sympatric Lineages in the Freshwater Mussel Cyprogenia Aberti (Bivalvia: Unionidae)

The western fanshell, Cyprogenia aberti, occurs in the CentralHighlands region of North America and is the only congener ofthe federally endangered fanshell, C. stegaria. Due to a reductionin range size and local extirpations, extant populations ofC. aberti have become increasingly isolated. Consequently, C.aberti has been the focus of numerous conservation efforts,yet no work has examined the degree of genetic variation amongthe species' disjunct populations. Phylogenetic analyses ofnucleotide sequences from two mitochondrial gene portions (CO1and ND1) revealed results important to the conservation managementof C. aberti. First, phylogenetic analyses do not support amonophyletic C. aberti. Second, C. aberti is comprised of asmany as five independent lineages, one of which includes thefederally endangered C. stegaria. Third, analysis recoveredtwo genetically distinct sympatric lineages of C. aberti inthe Ouachita River Drainage. These phylogenetic results suggestthat the five distinct evolutionary lineages of C. aberti shouldbe managed as separate conservation units. This study illustrateswhy it is critical to evaluate genetic variability in endangeredand threatened ‘species’ prior to implementing arecovery program. These data also reveal the value of assessingbiological diversity of nonimperiled taxa before populationsare extirpated and valuable genetic data necessary for reconstructionof evolutionary relationships is lost. (Received 24 October 2005; accepted 8 June 2006)     

Hunting the Gatherers: Ethnographic Collectors, Agents, and Agency in Melanesia, 1870s–1930s

Hunting the Gatherers: Ethnographic Collectors, Agents, and Agency in Melanesia, 1870s–1930s. Michael O'Hanlon and Robert L. Welsch. eds. Salem: Peabody Essex Museum,2001 .268 pp.     

Regional management units for marine turtles: a novel framework for prioritizing conservation and research across multiple scales

Background

Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques — including site-based monitoring, genetic analyses, mark-recapture studies and telemetry — can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges.

Methodology/Principal Findings

To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine- to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally.

Conclusions/Significance

The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework — including maps and supporting metadata — will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis.     

Processing of VSVG protein is not a rate-limiting step for its efflux from the Golgi complex

The secretory membrane system is comprised of membrane-bound organelles defined by specific sets of proteins that function in sequential modification of cargo proteins and lipids. This processing of cargo proteins and lipids is coupled to their secretory transport. Here, we investigated the effect of inhibiting N-glycan processing by swainsonine, an inhibitor of Golgi alpha1,2-mannosidase-II, on secretory transport of the thermo-reversible tsO45 mutant of vesicular stomatitis virus glycoprotein tagged with green fluorescent protein (VSVG-FP). Quantitative analysis using kinetic modeling combined with live cell imaging was used to derive the rate coefficients that delineate secretory transport of VSVG-FP. We found that neither inhibition of N-glycan processing nor elimination by mutagenesis of the first of the two asparagine-linked glycans had any significant effect on the rate of VSVG-FP transport through the Golgi. These data suggest that at least for VSVG, the multi-enzymatic process of N-glycan modification does not comprise a rate-limiting step for its Golgi efflux.     

Lifetime weight patterns in male physicians: the effects of cohort and selective survival

Objective: The natural history of lifetime weight change is not well understood because of conflicting evidence from cross‐sectional and longitudinal studies. Cross‐sectional analyses find that adult weight is highest at ～60 years of age and lower thereafter. Longitudinal analyses have not found this pattern. Our objective was to test whether cohort effects and selective survival may explain the differences observed between cross‐sectional and longitudinal studies. Research Methods and Procedures: We analyzed data on white men from the Johns Hopkins Precursors Study (n = 1197). Weight and height were measured at enrollment during medical school. The Precursors Study collected subsequent weight measurements by self‐report and follows all participants for mortality. Results: In preliminary analyses that ignored cohort and survival effects, average weight increased 0.16 kg/yr to age 65 (p < 0.001) and declined 0.10 kg/yr thereafter (p = 0.002). When controlling for differing rates of weight change by cohort and survival group, the apparent decline after 65 years of age was mostly explained. Discussion: These data suggest that, in white men, weight increases steadily until age 65 and then plateaus. These findings emphasize the necessity of longitudinal rather than cross‐sectional data to describe lifetime weight patterns.     

Genetic effects on mating success and partner choice in a social mammal

Mating behavior has profound consequences for two phenomena--individual reproductive success and the maintenance of species boundaries--that contribute to evolutionary processes. Studies of mating behavior in relation to individual reproductive success are common in many species, but studies of mating behavior in relation to genetic variation and species boundaries are less commonly conducted in socially complex species. Here we leveraged extensive observations of a wild yellow baboon (Papio cynocephalus) population that has experienced recent gene flow from a close sister taxon, the anubis baboon (Papio anubis), to examine how admixture-related genetic background affects mating behavior. We identified novel effects of genetic background on mating patterns, including an advantage accruing to anubis-like males and assortative mating among both yellow-like and anubis-like pairs. These genetic effects acted alongside social dominance rank, inbreeding avoidance, and age to produce highly nonrandom mating patterns. Our results suggest that this population may be undergoing admixture-related evolutionary change, driven in part by nonrandom mating. However, the strength of the genetic effect is mediated by behavioral plasticity and social interactions, emphasizing the strong influence of social context on mating behavior in socially complex species.     

Using rigidity analysis to probe mutation-induced structural changes in proteins

Predicting the effect of a single amino acid substitution on the stability of a protein structure is a fundamental task in macromolecular modeling. It has relevance to drug design and understanding of disease-causing protein variants. We present KINARI-Mutagen, a web server for performing in silico mutation experiments on protein structures from the Protein Data Bank. Our rigidity-theoretical approach permits fast evaluation of the effects of mutations that may not be easy to perform in vitro, because it is not always possible to express a protein with a specific amino acid substitution. We use KINARI-Mutagen to identify critical residues, and we show that our predictions correlate with destabilizing mutations to glycine. In two in-depth case studies we show that the mutated residues identified by KINARI-Mutagen as critical correlate with experimental data, and would not have been identified by other methods such as Solvent Accessible Surface Area measurements or residue ranking by contributions to stabilizing interactions. We also generate 48 mutants for 14 proteins, and compare our rigidity-based results against experimental mutation stability data. KINARI-Mutagen is available at http://kinari.cs.umass.edu.