Messy eaters: Swabbing prey DNA from the exterior of inconspicuous predators when foraging cannot be observed

Complex coevolutionary relationships among competitors, predators, and prey have shaped taxa diversity, life history strategies, and even the avian migratory patterns we see today. Consequently, accurate documentation of prey selection is often critical for understanding these ecological and evolutionary processes. Conventional diet study methods lack the ability to document the diet of inconspicuous or difficult‐to‐study predators, such as those with large home ranges and those that move vast distances over short amounts of time, leaving gaps in our knowledge of trophic interactions in many systems. Migratory raptors represent one such group of predators where detailed diet studies have been logistically challenging. To address knowledge gaps in the foraging ecology of migrant raptors and provide a broadly applicable tool for the study of enigmatic predators, we developed a minimally invasive method to collect dietary information by swabbing beaks and talons of raptors to collect trace prey DNA. Using previously published COI primers, we were able to isolate and reference gene sequences in an open‐access barcode database to identify prey to species. This method creates a novel avenue to use trace molecular evidence to study prey selection of migrating raptors and will ultimately lead to a better understanding of raptor migration ecology. In addition, this technique has broad applicability and can be used with any wildlife species where even trace amounts of prey debris remain on the exterior of the predator after feeding.     

Lactoferrin activates plasma membrane oxidase and Na+/H+ antiport activity.

Lactoferrin is a growth stimulant. The basis for this effect is not clear since it is not thought to be involved in iron uptake through endocytosis. Ferric lactoferrin supports external ferrous chelate formation by K562 and HeLa cells, and ferric lactoferrin stimulates the reduction of external ferric iron by cells. Ferric lactoferrin also stimulates NADH oxidase activity in isolated rat liver plasma membranes and stimulates amiloride sensitive proton release from K562 cells. The evidence that ferric lactoferrin can participate in oxidoreduction reactions at the plasma membrane leading to activation of Na+/H+ exchange provides an alternative explanation for the proliferative effect.     

Export chaperone SecB uses one surface of interaction for diverse unfolded polypeptide ligands

SecB, a remarkable chaperone involved in protein export, binds diverse ligands rapidly with high affinity and low specificity. Site‐directed spin labeling and electron paramagnetic resonance spectroscopy were used to investigate the surface of interaction on the export chaperone SecB. We examined SecB in complex with the unfolded precursor form of outer membrane protein OmpA as well as with a truncated version of OmpA that includes the transmembrane domain and lacks both the signal peptide and the periplasmic domain. In addition, we studied the binding of SecB to the unfolded mature form of galactose‐binding protein, a soluble periplasmic protein. We have previously used the same strategy to map the binding surface for the precursor of galactose‐binding protein. We show that for all ligands tested the patterns of contact are the same.     

A solid-phase radioimmunoassay for fibrinogen.

A solid-phase radioimmunoassay for fibrinogen has been developed utilizing [¹⁴C]-methylated fibrinogen as standard antigen and fibrinogen-specific antibodies covalently linked to Sepharose. Fibrinogen was [¹⁴C]-methylated by reductive alkylation using [¹⁴C] formaldehyde and sodium borohydride. The methylated fibrinogen was unaltered in clotting ability and antigenicity.The assay, an isotope dilution assay, is quantitative for picomole amounts of fibrinogen. It is specific for fibrinogen in homologous plasma and in the presence of a variety of other proteins.