Solly Zuckerman: the making of a primatological career in Britain, 1925-1945

Solly Zuckerman's work has been largely dismissed or marginalized by both historians of primatology and primatologists. This paper, using archival and published materials, re-examines both his life and his research into primate sexuality and sociology in the 1920s, endocrinology in the 1930s, and the effects of bomb blast in the 1940s. Despite the many flaws in his work, which is now largely outdated, his career reveals a great deal about the audiences for primatological knowledge in pre-war and wartime Britain; the interlocking circles of the scientific community that impinged on primatology; and competing ideas of what constituted a scientifically correct methodology for the observation of primate behaviour. Also noted is the gap between Zuckerman's self-presentation as the scourge of anthropomorphism and the anthropomorphism of his remarks in private notebooks. Although his work well illustrates familiar themes of patriarchy, military and colonialism in the history of primatology, it also suggests another, underexplored dimension of that science: primatology as an example of cross-species social interaction.     

Modelling the impact of geometric parameters on the redox potential of blue copper proteins

The synthesis and structure of a homologous series of cationic N(2)S(2) copper(I) Schiff base complexes constructed using o-tert-butylthiobenzaldehyde and a series of terminal diamines (ethane, propane, butane) are reported. The complexes differ only in the length of the methylene chain between the imine groups. This simple modification forces the copper centre to shift geometry from a planar (1,2-diaminoethane) to a more distorted tetrahedral motif (1,4-diaminobutane). The redox potentials of the three cations were measured using cyclic voltammetry in donor (acetonitrile) and non-donor solvents (dichloromethane). The S-Cu-N angles for each complex are correlated against the respective redox potential allowing an analysis of the geometric impact on the redox potential in soft copper centres. The redox potential is observed to increase as the metal centre moves from a planar towards a tetrahedral motif. Comparing this data with the reported structures of the blue copper proteins (rusticyanin and plastocyanin) allows an assessment of the contribution of the geometry of the metal binding site to the operating potential of these proteins to be made.     

The gastroenteroinsular response to glucose ingestion during postexercise recovery

This study examined gastrointestinal hormone and peptide responses when glucose was ingested after prolonged exercise. Six endurance-trained male athletes ran on a treadmill for 2 h at 60% VO2 max. Immediately after the run, the athletes consumed 75 g of glucose in 250 ml of water (ExGLU) or flavored water as a placebo control (ExPL). On a separate visit, the athletes rested for 2 h and then consumed glucose (ConGLU). During the first 60 min of recovery from exercise alone (ExPL), plasma vasoactive intestinal peptide (VIP), gastrin, and glucagon-like peptide-1 (GLP-1) all increased significantly, whereas glucose, insulin, and gastric inhibitory polypeptide (GIP) were unchanged from the immediate postexercise value. When glucose was ingested after exercise (ExGLU), glucose, insulin, VIP, gastrin, GLP-1, and GIP were all increased (P < 0.01). However, when glucose was ingested after resting for 2 h (ConGLU), VIP levels were unaffected, although glucose, insulin, gastrin, GLP-1, and GIP levels increased (P < 0.05). The plasma glucose response was greater (P < 0.03) and the plasma insulin response lower (P < 0.004) during ExGLU compared with ConGLU. There was a significantly higher (P < 0.01) VIP response during the initial period of recovery in ExGLU than there was with both ExPL and ConGLU. Plasma VIP showed a modest negative correlation with circulating glucose (r = -0.35, P < 0.03) and insulin (r = -0.37, P < 0.03) during the ExGLU recovery period. In summary, when glucose is ingested after prolonged exercise, there is mild insulin resistance and a corresponding rapid transitory increase in plasma VIP. These data suggest that VIP may play an important glucoregulatory role when glucose is ingested during the immediate postexercise recovery period.     

A flexible framework for multi-particle refinement in cryo-electron tomography

Cryo-electron tomography (cryo-ET) and subtomogram averaging (STA) are increasingly used for macromolecular structure determination in situ. Here, we introduce a set of computational tools and resources designed to enable flexible approaches to STA through increased automation and simplified metadata handling. We create a bidirectional interface between the Dynamo software package and the Warp-Relion-M pipeline, providing a framework for ab initio and geometrical approaches to multiparticle refinement in M. We illustrate the power of working within this framework by applying it to EMPIAR-10164, a publicly available dataset containing immature HIV-1 virus-like particles (VLPs), and a challenging in situ dataset containing chemosensory arrays in bacterial minicells. Additionally, we provide a comprehensive, step-by-step guide to obtaining a 3.4-Å reconstruction from EMPIAR-10164. The guide is hosted on https://teamtomo.org/, a collaborative online platform we establish for sharing knowledge about cryo-ET.

Employing optimal computational methodology in cryo-electron tomography is not always easy; this article provides a set of tools and a complete guide to obtaining high-resolution structures from cryo-ET data.     

Immediate and long-term effects of testosterone on song plasticity and learning in juvenile song sparrows

Steroid sex hormones play critical roles in the development of brain regions used for vocal learning. It has been suggested that puberty-induced increases in circulating testosterone (T) levels crystallize a bird's repertoire and inhibit future song learning. Previous studies show that early administration of T crystallizes song repertoires but have not addressed whether new songs can be learned after this premature crystallization. We brought 8 juvenile song sparrows (Melospiza melodia) into the laboratory in the late summer and implanted half of them with subcutaneous T pellets for a two week period in October. Birds treated with T tripled their singing rates and crystallized normal songs in 2 weeks. After T removal, subjects were tutored by 4 new adults. Birds previously treated with T tended toward learning fewer new songs post T, consistent with the hypothesis that T helps to close the song learning phase. However, one T-treated bird proceeded to learn several new songs in the spring, despite singing perfectly crystallized songs in the fall. His small crystallized fall repertoire and initial lag behind other subjects in song development suggest that this individual may have had limited early song learning experience. We conclude that an exposure to testosterone sufficient for crystallization of a normal song repertoire does not necessarily prevent future song learning and suggest that early social experiences might override the effects of hormones in closing song learning.     

Inducible Coexpression of Connexin37 or Connexin40 with Connexin43 Selectively Affects Intercellular Molecular Transfer

Many tissues express multiple gap junction proteins, or connexins (Cx); for example, Cx43, Cx40, and Cx37 are coexpressed in vascular cells. This study was undertaken to elucidate the consequences of coexpression of Cx40 or Cx37 with Cx43 at different ratios. EcR-293 cells (which endogenously produce Cx43) were transfected with ecdysone-inducible plasmids encoding Cx37 or Cx40. Immmunoblotting showed a ponasterone dose-dependent induction of Cx37 or Cx40 while constant levels of Cx43 were maintained. The coexpressed connexins colocalized at appositional membranes. Double whole-cell patch clamp recordings showed no significant change in total junctional conductances in cells treated with 0, 0.5, or 4?μM ponasterone; however, they did show a diversity of unitary channel sizes consistent with the induced connexin expression. In cells with induced expression of either Cx40 or Cx37, intercellular transfer of microinjected Lucifer yellow was reduced, but transfer of NBD-TMA (2-(4-nitro-2,1,3-benzoxadiol-7-yl)[aminoethyl]trimethylammonium) was not affected. In cocultures containing uninduced EcR cells together with cells induced to coexpress Cx37 or Cx40, Lucifer yellow transfer was observed only between the cells expressing Cx43 alone. These data show that induced expression of either Cx37 or Cx40 in Cx43-expressing cells can selectively alter the intercellular exchange of some molecules without affecting the transfer of others.     

Patch Use in Free‐Ranging Goats: Does a Large Mammalian Herbivore Forage like Other Central Place Foragers?

Classic central place foraging theory does not focus on the foraging of central place herbivores. This is especially true with regard to large mammalian herbivores. To understand the foraging dynamics of these neglected foragers, we measured giving‐up densities (GUDs) in artificial food patches. We did this at different distances away from the central point (i.e. corral) for a herd of free‐ranging domestic goats. To determine temporal changes, we conducted the study over a 3‐mo period during an extended dry season. Throughout our study, goats foraged across a gradient of food availability where forage was more available farther away from the central point. In contrast to the prediction that predation risk and/or increased travel costs were the main drivers of foraging decisions, we found that the goats increased their feeding effort (i.e. achieved lower GUDs) the farther away they moved from the central point. This suggests that either metabolic or missed opportunity costs were the main factors that influenced foraging decisions. In addition, we suggest that social foraging may have also played a role. With increases in foraging opportunities away from the central point, a herd will likely move slowly while foraging. As a result, individuals can feed intensively from patches but remain part of the group. Ironically, owing to the sustained close proximity of other group members, individuals may perceive patches farther from the central point as being safer. Temporally, the goats increased their feeding effort throughout the dry season. This suggests there was a decline in food quality and/or availability across the environment as the study progressed. Despite this increase in feeding effort, the negative relationship with distance did not change. Ultimately, our results provide key insight into how metabolic, missed opportunity and perceived predation costs influence the feeding decisions of large central place herbivores.     

Quantitative trait loci associated with chemical composition of the chicken carcass

Major objectives of the poultry industry are to increase meat production and to reduce carcass fatness, mainly abdominal fat. Information on growth performance and carcass composition are important for the selection of leaner meat chickens. To enhance our understanding of the genetic architecture underlying the chemical composition of chicken carcasses, an F₂ population developed from a broiler × layer cross was used to map quantitative trait loci (QTL) affecting protein, fat, water and ash contents in chicken carcasses. Two genetic models were applied in the QTL analysis: the line‐cross and the half‐sib models, both using the regression interval mapping method. Six significant and five suggestive QTL were mapped in the line‐cross analysis, and four significant and six suggestive QTL were mapped in the half‐sib analysis. A total of eleven QTL were mapped for fat (ether extract), five for protein, four for ash and one for water contents in the carcass using both analyses. No study to date has reported QTL for carcass chemical composition in chickens. Some QTL mapped here for carcass fat content match, as expected, QTL regions previously associated with abdominal fat in the same or in different populations, and novel QTL for protein, ash and water contents in the carcass are presented here. The results described here also reinforce the need for fine mapping and to perform multi‐trait analyses to better understand the genetic architecture of these traits.     

Synthesis and antimicrobial activities of structurally novel S,S'-bis(heterosubstituted) disulfides

The central focus of this study is on the antibacterial and antifungal properties of synthetically produced S,S'-bis(heterosubstituted) disulfides as a means to control the growth of various infection-causing pathogens. Staphylococcus aureus, Francisella tularensis and Candida albicans were each found to be highly susceptible to several of these compounds by agar or broth dilution and Kirby-Bauer diffusion assays. These structurally simple, low molecular weight disulfides have shown promising bioactivities and may serve as leads to the development of effective new antibacterials for pathogenic bacteria such as methicillin-resistant S. aureus and F. tularensis.