Lack of compensatory body growth in a high performance moose Alces alces population

Considerable work has been done on disentangling important factors determining early development in body size, yet our knowledge of the extent to which animals living under varying conditions can achieve catch-up growth for a bad start in life is limited. Here, we investigated how body mass at the age of 8 months influenced adult body mass in a moose Alces alces population living under excellent environmental conditions on the island of Vega in northern Norway. We also investigated if mother age and birth date effects on calf body mass persisted until adulthood. We show that neither males nor females were able to show compensatory growth before they reached adulthood, and that part of the variation in adult body mass may have been due to variation in mother age and date of birth. The pattern observed in males can be related to their growth strategy in relation to reproduction, while such results were not expected in females where size-dependent start of reproduction is likely to interact with body growth. We suggest that the good environmental conditions experienced on Vega led to females having small somatic costs of an early start of reproduction or that larger females were able to acquire more resources for growth than their smaller conspecifics. In both cases, females that postpone their first reproduction may not be able to achieve catch-up growth for their lower early body mass compared to females that start reproduction at an early age. Our results concur with previous studies indicating that compensatory growth is weak in moose, increasing the likelihood that variation in life history characters are also transferred between generations.     

Multi-site substrate binding and interplay in barley alpha-amylase 1

Certain starch hydrolases possess secondary carbohydrate binding sites outside of the active site, suggesting that multi-site substrate interactions are functionally significant. In barley alpha-amylase both Tyr380, situated on a remote non-catalytic domain, and Tyr105 in subsite -6 of the active site cleft are principal carbohydrate binding residues. The dual active site/secondary site mutants Y105A/Y380A and Y105A/Y380M show that each of Tyr380 and Tyr105 is important, albeit not essential for binding, degradation, and multiple attack on polysaccharides, while Tyr105 predominates in oligosaccharide hydrolysis. Additional delicate structure/function relationships of the secondary site are uncovered using Y380A/H395A, Y380A, and H395A AMY1 mutants.     

Behavioral plasticity in rainbow trout (Oncorhynchus mykiss) with divergent coping styles: when doves become hawks

Consistent and heritable individual differences in reaction to challenges, often referred to as stress coping styles, have been extensively documented in vertebrates. In fish, selection for divergent post-stress plasma cortisol levels in rainbow trout (Oncorhynchus mykiss) has yielded a low (LR) and a high responsive (HR) strain. A suite of behavioural traits is associated with this physiological difference, with LR (proactive) fish feeding more rapidly after transfer to a new environment and being socially dominant over HR (reactive) fish. Following transport from the UK to Norway, a switch in behavioural profile occurred in trout from the 3rd generation; HR fish regained feeding sooner than LR fish in a novel environment and became dominant in size-matched HR–LR pairs. One year after transport, HR fish still fed sooner, but no difference in social dominance was found. Among offspring of transported fish, no differences in feeding were observed, but as in pre-transported 3rd generation fish, HR fish lost fights for social dominance against size-matched LR opponents. Transported fish and their offspring retained their distinctive physiological profile throughout the study; HR fish showed consistently higher post-stress cortisol levels at all sampling points. Altered risk-taking and social dominance immediately after transport may be explained by the fact that HR fish lost more body mass during transport than did LR fish. These data demonstrate that some behavioural components of stress coping styles can be modified by experience, whereas behavioural plasticity is limited by genetic effects determining social position early in life story.     

Crystal structure of a prolactin receptor antagonist bound to the extracellular domain of the prolactin receptor

The crystal structure of the complex between an N-terminally truncated G129R human prolactin (PRL) variant and the extracellular domain of the human prolactin receptor (PRLR) was determined at 2.5A resolution by x-ray crystallography. This structure represents the first experimental structure reported for a PRL variant bound to its cognate receptor. The binding of PRL variants to the PRLR extracellular domain was furthermore characterized by the solution state techniques, hydrogen exchange mass spectrometry, and NMR spectroscopy. Compared with the binding interface derived from mutagenesis studies, the structural data imply that the definition of PRL binding site 1 should be extended to include residues situated in the N-terminal part of loop 1 and in the C terminus. Comparison of the structure of the receptor-bound PRL variant with the structure reported for the unbound form of a similar analogue ( Jomain, J. B., Tallet, E., Broutin, I., Hoos, S., van Agthoven, J., Ducruix, A., Kelly, P. A., Kragelund, B. B., England, P., and Goffin, V. (2007) J. Biol. Chem. 282, 33118-33131 ) demonstrates that receptor-induced changes in the backbone of the four-helix bundle are subtle, whereas large scale rearrangements and structuring occur in the flexible N-terminal part of loop 1. Hydrogen exchange mass spectrometry data imply that the dynamics of the four-helix bundle in solution generally become stabilized upon receptor interaction at binding site 1.     

BactMAP: An R package for integrating,analyzing and visualizing bacterial microscopy data

High-throughput analyses of single-cell microscopy data are a critical tool within the field of bacterial cell biology. Several programs have been developed to specifically segment bacterial cells from phase-contrast images. Together with spot and object detection algorithms, these programs offer powerful approaches to quantify observations from microscopy data, ranging from cell-to-cell genealogy to localization and movement of proteins. Most segmentation programs contain specific post-processing and plotting options, but these options vary between programs and possibilities to optimize or alter the outputs are often limited. Therefore, we developed BactMAP (Bacterial toolbox for Microscopy Analysis & Plotting), a command-line based R package that allows researchers to transform cell segmentation and spot detection data generated by different programs into various plots. Furthermore, BactMAP makes it possible to perform custom analyses and change the layout of the output. Because BactMAP works independently of segmentation and detection programs, inputs from different sources can be compared within the same analysis pipeline. BactMAP complies with standard practice in R which enables the use of advanced statistical analysis tools, and its graphic output is compatible with ggplot2, enabling adjustable plot graphics in every operating system. User feedback will be used to create a fully automated Graphical User Interface version of BactMAP in the future. Using BactMAP, we visualize key cell cycle parameters in Bacillus subtilis and Staphylococcus aureus, and demonstrate that the DNA replication forks in Streptococcus pneumoniae dissociate and associate before splitting of the cell, after the Z-ring is formed at the new quarter positions. BactMAP is available from https://veeninglab.com/bactmap .     

Primary Adsorption Site of Phage PBS1: the Flagellum of Bacillus subtilis

The adsorption of Bacillus subtilis phage PBS1 was studied, and it was demonstrated that the primary adsorption site for this phage is the flagellum of B. subtilis. The capacity of flagella to function for motility may be lost without the loss of their capacity to adsorb the phage and permit infection. Deoxyribonucleic acid injection by the phage is inhibited by cyanide, suggesting the requirement for cellular energy in the infection process.     

Physico-chemical environment,phytoplankton biomass and production in oligotrophic,softwater lake kalgaard,Denmark

Water chemistry of Lake Kalgaard in 1976–77 was characterized by low concentrations of total-CO₂ and inorganic nutrients. The ionic composition resembled that of precipitation (Na>Ca>Mg >K and Cl>SO₄>HCO₃). The seasonal pattern of total-CO₂ and PO₄ was regulated by internal processes and maximum concentrations as a result of decomposition processes occurred during summer stagnation. NO₃ concentrations showed the opposite pattern and were relatively high from late autumn through spring and were extremely low during summer. Total-P and PO₄ increased during summer due to release from the sediment. The phytoplankton biomass of surface water was low. The water chemistry suggested a shift from N-limitation of phytoplankton during summer to P-limitation at other seasons. Maximum algal concentrations occurred at 6 m during summer, probably due to a supply of nutrients (especially NH₄) from deeper layers. Phytoplankton productivity was often bimodal, with an upper maximum at depths of 0 or 2 m and a second maximum at 6 m.