Spatial familial networks to infer demographic structure of wild populations

1. In social species, reproductive success and rates of dispersal vary among individuals resulting in spatially structured populations. Network analyses of familial relationships may provide insights on how these parameters influence population‐level demographic patterns. These methods, however, have rarely been applied to genetically derived pedigree data from wild populations.
2. Here, we use parent–offspring relationships to construct familial networks from polygamous boreal woodland caribou (Rangifer tarandus caribou) in Saskatchewan, Canada, to inform recovery efforts. We collected samples from 933 individuals at 15 variable microsatellite loci along with caribou‐specific primers for sex identification. Using network measures, we assess the contribution of individual caribou to the population with several centrality measures and then determine which measures are best suited to inform on the population demographic structure. We investigate the centrality of individuals from eighteen different local areas, along with the entire population.
3. We found substantial differences in centrality of individuals in different local areas, that in turn contributed differently to the full network, highlighting the importance of analyzing networks at different scales. The full network revealed that boreal caribou in Saskatchewan form a complex, interconnected familial network, as the removal of edges with high betweenness did not result in distinct subgroups. Alpha, betweenness, and eccentricity centrality were the most informative measures to characterize the population demographic structure and for spatially identifying areas of highest fitness levels and family cohesion across the range. We found varied levels of dispersal, fitness, and cohesion in family groups.
4. Synthesis and applications: Our results demonstrate the value of different network measures in assessing genetically derived familial networks. The spatial application of the familial networks identified individuals presenting different fitness levels, short‐ and long‐distance dispersing ability across the range in support of population monitoring and recovery efforts.

     

Lymphoid cells from senescent animals contain specific inhibitors of immune response

Extracts prepared from old cow lymphoid cells (OCE) inhibit the primary and secondary in vitro responses to SRBC of mouse spleen cells. The active factor in OCE is a protein of 10,000–15,000 MW, and it does affects neither lymphocyte stimulation by Con A and LPS, nor cell viability. Various experiments suggest that OCE and its active factor interfere with mechanisms of differentiation of lymphocytes into antibody-producing cells. In the present state of purification the amount of product corresponding to 50% inhibition of the immune response is about 0.3 μg/ml.     

Composition en bases de l'ADN et position taxonomique de bactéries marines fermentant le glucose,du genre Vibrio et des genres voisins

Résumé L'analyse du GC% des souches marines appartenant au genre Vibrio confirme leur classement préalable, obtenu selon la méthode adansonnienne. La comparaison, tant par la valeur de leur GC% que par leur similitude phénotypique, des genres Photobacterium et Beneckea avec le genre Vibrio montre que la différenciation de ces trois genres n'est pas très nette.Le genre Vibrio se subdivise en quatre groupes de souches. Un premier groupe comprend les souches marines libres. Le second groupe rassemble les souches marines parasites des animaux poïkilothermes. Le troisième groupe est composé de souches, capables de parasiter les animaux poïkilothermes comme les animaux homéothermes. Enfin, le dernier groupe est constitué, contrairement aux trois premiers, par des souches ne nécessitant pas de NaCl pour croître.On constate que ces quatre groupes ont une localisation écologique différente.

---

Deoxyribonucleic acid base composition and taxonomic relationships among marine usual characters and related bacteria

Summary DNA base composition of marine strains of genus Vibrio corroborate the results obtained by the adansonian method of classification.Comparisons of phenotypic and GC% values of genera Photobacterium and Beneckea with the genus Vibrio show that differentiation between these three genera is not clear.Genus Vibrio can be separated in four groups. The first contains free-living marine strains. The second group includes the marine strains pathogenic to poïkilothermic animals. The third group is composed of strains pathogenic to poïkilothermic and homeothermic animals. The last group is made up of strains which, contrary to the other groups, have shown no specific requirement of sodium for growth. We ascertain that each group has a typical ecologic localization.

     

Sequence of a gene encoding a (poly ManA) alginate lyase active on Pseudomonas aeruginosa alginate

Abstract To overcome problems associated with Western blotting of denatured proteins, we have used quantitative immunoelectrophoretic techniques to perform functional analysis of the Neisseria gonorrhoeae common antigen. Using these techniques, we show (a) that Neisseria gonorrhoeae expresses an antigen that is cross-reactive with the common antigen of Pseudomonas aeruginosa and Legionella micdadei and with the GroEl-like protein of Chlamydia , and (b) that this N. gonorrhoeae common antigen has lectin-like activity and can be precipitated with three different sugars immobilized on agarose beads: α- d -glucosamine, maltose and fucose.