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A compilation of selected references to the use of deuterium in biochemical, pharmacological, clinical and environmental applications for the period 1971-1976 is presented. As a further aid, author and subject indices have been compiled.
A compilation of selected references of the use of 15N in biochemical, pharmacological, clinical and environmental applications for the period 1971--1976 is presented. Author and subject indices have been compiled to enable the reader to make further use of this information.
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The first biennial updated compilation, for the period 1977-1978, of selected references to the use of 2H, 13C, 15N, 18 O and 34S in biochemical, pharmacological, clinical and environmental applications is presented. Author and subject indices for this information are compiled to enable the reader to make further use of these references.
1. We utilized the induction of tyrosine hydroxylase, a catecholamine-synthesizing enzyme, in sympathetic ganglia and adrenal medullae to explore the central and peripheral mechanisms through which choline, various environmental stresses, and drugs that alter blood pressure or central neurotransmission affect various portions of the sympathetic nervous system. Animals received each treatment chronically, and enzyme activity was measured in the superior cervical, stellate, and coeliac ganglia and in the adrenal medullae.2. Choline administration increased tyrosine hydroxylase activity in all four tissues, probably by increasing the release of acetylcholine from preganglionic sympathetic neurones that synapse on catecholamine-producing ganglion and chromaffin cells; carbachol and nicotine had similar effects.3. Insulin enhanced tyrosine hydroxylase activity primarily in the coeliac ganglion and the adrenal medullae, but not in the superior cervical ganglia.4. Reserpine and phenoxybenzamine increased the activity of the enzyme in all four tissues.5. Prolonged exposure to a cold environment increased enzyme activity in all four tissues, but especially in the stellate and coeliac ganglia; forced swimming affected tyrosine hydroxylase only in these two ganglia.6. Several drugs known to modify central neurotransmission were found to increase tyrosine hydroxylase activity in some portions of the sympathetic nervous system but not in others. 5,7-Dihydroxytryptamine, which destroys terminals of serotoninergic neurones, enhanced enzyme activity in all four tissues, but primarily in the coeliac ganglion and adrenal medullae. ET-495 (a dopaminergic agonist), D-amphetamine, and morphine induced tyrosine hydroxylase activity in the adrenal medullae and the coeliac ganglion, but not in the superior cervical ganglia. Oxotremorine, a centrally acting muscarinic agonist, increased tyrosine hydroxylase activity only in the adrenal medullae; its effect was not blocked by methylatropine, a peripheral muscarinic blocker.7. These data indicate that specific neurones in the central nervous system, which utilize specific neurotransmitters and which are differentially affected by drugs and environmental inputs, selectively influence the outflows through the various zones of the sympathetic nervous system.
BACKGROUND: Environmental niches represent important reservoirs of Escherichia coli with stress-adaptation traits that support persistence outside the host. Contaminated irrigation water and soils can facilitate transfer to fresh produce, where bacterial survival may reduce the effectiveness of downstream control measures. This study investigated the co-occurrence of biofilm formation, acid tolerance, and antibiotic resistance (AR) in environmental E. coli and their contribution to persistence along the farm-to-produce continuum. RESULTS: Eighteen E. coli isolates recovered from irrigation water, soil, and lettuce were characterized using phenotypic assays and genome-based analyses. Most isolates remained susceptible to the majority of tested antibiotics, with multidrug resistance observed in only 11.1% of isolates. In contrast, moderate-to-strong biofilm formation was widespread (83.3%), and several isolates exhibited reduced susceptibility to acetic acid at concentrations relevant to household washing practices. Genotypic screening revealed a broad distribution of adhesion, iron acquisition, biofilm-associated, and plasmid-borne resistance determinants, indicating substantial functional diversity. Significant positive associations were observed between acid tolerance, biofilm formation, and antibiotic resistance, suggesting co-occurrence of stress-adaptation phenotypes rather than definitive evolutionary convergence. While antibiotic resistance phenotypes showed strong concordance with corresponding resistance genes, biofilm formation and acid tolerance were not associated with specific genetic determinants, supporting a multifactorial basis of these traits. CONCLUSIONS: These findings demonstrate that environmental E. coli can combine multiple stress-adaptation mechanisms that enhance persistence across agricultural and food-associated environments, even in the absence of high-risk resistance profiles. The observed co-occurrence of phenotypic traits highlights the potential for co-selection under environmental pressures and underscores the limitations of relying solely on downstream decontamination strategies. Effective risk mitigation requires integrated, preventive approaches targeting pre-harvest contamination and environmental reservoirs.
Mastitis is an inflammatory reaction caused by bacterial infection of the teat, and a relationship between its onset and cattle major histocompatibility complex (BoLA) region has been reported. However, no comprehensive genetic analysis of mastitis caused by environmental streptococci has been reported. Here, we resequenced the BoLA region using a hybridisation capture target next-generation sequencing (NGS) method to identify disease susceptibility markers mapped to the BoLA region in environmental streptococcal mastitis. This study examined 75 cows with mastitis caused by environmental streptococci selected from 1641 cows with mastitis and 222 healthy cows without mastitis in Japan. Targeted sequences obtained from MiSeq NGS were aligned to the bovine reference genome (ARS-UCD1.2/bosTau9), and 2,920,355 variants were detected within the BoLA region of the 297 Holstein cattle. In an association study using 2264 variants after quality control, the top 20 variants with the lowest P values were selected and assigned to the 18 surrounding candidate genes, and a gene network analysis of these genes resulted in the narrowing down of five candidate genes POU5F1, IER3, GNL1, ABCF1, and PRR3. Multivariate effect analysis of all 6 SNPs associated with these 5 genes revealed that they were significantly correlated with mastitis, indicating that they were useful for classification of mastitis-resistant and mastitis-susceptible cattle. This is the first report to identify SNPs associated with environmental streptococcal mastitis with an NGS-based association study using targeted resequencing in the BoLA region, and understanding host factors may provide important clues for mastitis control.
Year-to-year climate variability poses a challenge for agriculture by increasing crop yield variability; therefore, there is a need to identify genotypes that can withstand these fluctuations. With the right selection criteria, genotypes with yield stability across variable environmental conditions can be selected. Methods such as Finlay-Wilkinson random regression (FWRR) may allow us to use sparse datasets-common in plant breeding pipelines-and incorporate genomic data to leverage phenotypic information from related genotypes to predict yield stability. Our objective was to examine how the number of environments and the variance among those environments affect stability predictions. We also integrate FWRR as a genomic prediction tool for characterizing yield stability, comparing it to the traditional genomic prediction models as a reference. We used three datasets: one highly unbalanced dataset for oats (Avena sativa L.) and two completely balanced datasets with different numbers of environments for barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.). We fit standard Finlay-Wilkinson (FW) and FWRR models to estimate grain yield and stability under various scenarios. We found that the estimated stability values obtained were similar using balanced datasets for FW or FWRR. FWRR also achieved moderate predictive ability for stability using unbalanced datasets under 10-fold cross-validation (CV1) with new genotypes. In terms of environmental representation, selecting the right set of environments for inclusion in the model was more important than adding more environments. Our results suggest the possibility of using FWRR to select stable genotypes earlier in line development, as well as to design resource-efficient stability-testing schemes.
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Nucella lapillus is an important player in rocky shore food chains and has been a focal organism of ecological and evolutionary studies for decades. Despite poor dispersal, they have a broad geographic range, which makes them an ideal species to examine isolation by distance and selection across environmental gradients. Here we present the fully annotated genome of N. lapillus generated with Oxford Nanopore Techonology sequencing at ∼37× coverage. The genome assembly is 2.32 Gbp and consists of 2,525 contigs, with an N50 length of 2 Mbp. Repeat annotation identified 2,491 families that cover 67.56% of the genome, which is similar to other gastropods. Despite its large size and high proportion of repeats, the genome is of high quality. Benchmarking Universal Single-Copy Ortholog (BUSCO) analysis revealed a score of 96.8%. Functional annotation of the genome produced 45,848 protein-coding genes with a 96.6% BUSCO score. Genomic resources for mollusks lag behind that of other phyla, perhaps because many of their innate characteristics complicate DNA extraction, sequencing, and assembly. This new N. lapillus genome will increase our genomic understanding of the second largest phylum (and the most diverse class within said phylum) and serve as a key resource to advance studies on the organismal biology and population genetics of this iconic species as well as the connection between genomic variation and community-level processes.
Electrodes have been developed for the assay of glucose, urea, amino acids, uric acid, phosphate, nitrate and perchlorate. The electrodes for the organic compounds are enzyme electrodes which are prepared by chemically immobilizing an enzyme over the outside of a conventional ion-selective electrode. These electrodes will be discussed in depth. The progress and the development of the electrodes that show sensitivity and selectivity for phosphate, nitrate and perchlorate will be outlined. The basis of these sensors is a complex of a transition metal of either an analog of thiourea or an organic chelator, such as 1,10-phenanthraline. Such electrodes respond linearly to phosphate, nitrate or perchlorate, and show selectivity over sulphate, halides and acetate. The linear range of all these electrodes is approx. 10(-1)-10(-5) M with a near Nernstian slope and a reproducibility of 1%. The electrodes are stable and can be used continuously.
On account, notably, of a competition between different component functions for individual sites in polypeptide chains, each protein molecule represents a functional compromise, with some functions optimized, but the overall state of the molecule "suboptimal". The proposal is made that the selection coefficient relating to a protein molecule under given conditions can in principle be broken down into partial selection coefficients relevant to the different functions that the molecule carries out. At general-function sites, each fixation improves some function, while others deteriorate, at first nonsignificantly, and the overall adaptive state of the molecule fluctuates around its maximum. A selective mechanism is described whereby kaleidoscopic changes in primary structure at variable sites are indefinitely promoted, independently of any environmental changes and with the molecule remaining close to a state of maximal overall adaptation. The paradoxical aspect of this proposal is analyzed. The implication of specific functions in substitutions at general-function sites is noted. Further, it is shown that a certain category of changes in the internal environment of the organism can be integrated into the constant-environmental model for selection. Genetic sufficiency is considered a notion more adequate than genetic optimality for describing biological fitness and for providing a basis for the present model. On this basis selection occurs without genetic load. Multipolymorphism is one of the consequences. Several lines of evidence, in particular observations on polymorphism in deep sea organisms, seem to support the model. It is pointed out that it provides a theoretical foundation for a molecular evolutionary clock. The theoretical constancy of the clock depends on the constancy of functional density. The question of the evolution of functional density is examined. Comparisons of observed substitution frequencies with values expected on a random basis are rejected as a measure of the contribution to evolution of nondetermination. They are considered to reflect a hierarchy in the resistance of the molecules to different amino acid residues as substituents. A limited component of "true" randomness, again accompanied by selection, is on the other hand provided by the model. Most amino acid substitutions are considered evolutionary noise, even though noise compatible with selection. It is proposed that evolutionary significant substitutions may be identified by monitoring changes in functional density and weighted functional density.
Although local adaptation influences species distributions, its role in driving evolutionary resilience under climate change remains unclear. Current predictive models focus on genetic adaptation to present climates, providing limited insight into future adaptive capacity. We hypothesise that historical responses to climatic shifts can reveal candidate loci for local adaptation in the future. Combining ecological niche modelling and genomic analyses, we investigate spatiotemporal patterns and mechanisms of local adaptation of the Western Palearctic barn owl (Tyto alba). Ecological modelling reveals that barn owls now occupy a broader climatic niche than during the Last Glacial Maximum. Genomic analyses indicate ongoing adaptation, with regions under selection linked to environmental factors across all populations. We find that local adaptation drives evolutionary changes across populations, enabling colonisation of new habitats and shaping responses to climate change in resident populations. We show that standing genetic diversity plays a crucial role in adaptation to past, present, and future environmental shifts.
Grain yield is a central target in wheat breeding, yet accurately predicting it remains challenging because it depends on many genes and responds strongly to environmental variation. Genomic selection (GS) has improved breeding efficiency by enabling genome-based prediction of genetic merit, but predictability (PA) for grain yield is often limited under stress environments. At the same time, advances in high-throughput phenotyping (HTP) using unmanned aerial vehicles (UAVs) provide phenomic data that capture environment-responsive plant performance and may complement genomic information. In this study, we evaluated genomic and phenomic models for predicting grain yield in elite bread wheat lines across irrigated, drought, and heat-stress environments. Using a sparse phenotyping framework, we compared parametric and non-parametric models. PA was evaluated within environments and under cross-environment sparse phenotyping scenarios. Genomic models provided a stable baseline and enabled effective information sharing across environments when phenotypic data were incomplete. Phenomics-only models captured environment-specific plant responses but were more sensitive to environmental context. Multiomics models that integrated genomic and phenomic information consistently achieved the highest PA, with the largest gains observed under stress conditions. Overall, our results demonstrate that integrating genomics and UAV-based phenomics within sparse phenotyping designs offers a practical and scalable approach to improve grain yield prediction in wheat.
The effect of parental longevity on the length of survival of offspring has been examined according to selected demographic and environmental characteristics. The present study is based on 7,103 progeny, 20 years old or older. They were the sons and daughters of 1,766 men or women, 90 or more years old, who were alive in 1922-1930 at the time of ascertainment. The age at death of the other parent of the offspring is the basis of classification used in this analysis. A positive relationship was found between age at death of the non-proband parent and the age at death of the offspring. This relationship existed regardless of similarities or differences in the characteristics analyzed.
Two sets of evolutionary phenomena find no explanation through current theory. For the static phenomena (such as homology, homonomy, systematic weight, and "Type") there is no causal base, although these principles are responsible for all phenomena of predictable order in the living world. The dynamic phenomena (such as homodynamy, coadaptation, parallel evolution, orthogenesis, Cartesian transformation, typostrophy, hetermorphosis, systemic mutation, and spontaneous atavism) have no causal explanation, although they are responsible for all directed phenomena in macroevolution. These phenomena share one unifying principle which can be explained by a system theory of evolution based on, but extending, the current synthetic theory. This system theory envisages feedback conditions between genotype and phenotype by which the chances of successful adaptation increase if the genetic units, by insertion of superimposed genes, copy the functional dependencies of those phene structures for which they code. This positive feedback of the adaptive speed (or probability) within a single adaptive direction is compensated by negative feedback in most of the alternative directions. The negative feedback operates as selection not be environmental but by systemic conditions developed by the organization of the organism. The consequences are an imitatively organized system of gene interractions, the rehabilitation of classical systematics, the reality of the "natural system," and, in general, the resolution of the contradiction between neodarwinists and their critics, between reductionists and holists, between "a priori" and "a posteriori" views, between idealism and materialism, and between the notions of freedom and of purpose in evolution.
As organisms adapt to environmental changes, natural selection modifies the frequency of nonneutral alleles. For beneficial mutations, the outcome of this process may be a selective sweep, in which an allele rapidly increases in frequency and perhaps reaches fixation within a population. Selective sweeps have well-studied effects on patterns of local genetic variation in panmictic populations, but much less is known about the dynamics of sweeps in continuous space. In particular, because limited movement across a landscape leads to unique patterns of population structure, spatial dynamics may influence the trajectory of selected mutations. Here, we use forward-in-time, individual-based simulations in continuous space to study the impact of space on beneficial mutations as they sweep through a population. In particular, we show that selection changes the joint distribution of allele frequency and geographic range occupied by a focal allele and demonstrate that this signal can be used to identify selective sweeps. We then leverage this signal to identify in-progress selective sweeps within the malaria vector Anopheles gambiae, a species under strong selection pressure from vector control measures. By considering space, we identify multiple previously undescribed variants with potential phenotypic consequences, including mutations impacting known IR-associated genes and altering protein structure and properties. Our results demonstrate a novel signal for detecting selection in spatial population genetic data that may have implications for genomic surveillance and understanding geographic patterns of genetic variation.
The domestication of wild canids led to dogs no longer living in the wild but instead residing alongside humans. Extreme changes in behavior and diet associated with domestication may have led to the relaxation of the selective pressure on traits that may be less important in the domesticated context. Thus, here we hypothesize that strongly deleterious mutations may have become less deleterious in domesticated populations. We test this hypothesis by estimating the distribution of fitness effects (DFE) for new amino acid changing mutations using whole-genome sequence data from 24 gray wolves and 61 breed dogs. We find that the DFE is strikingly similar across canids, with 26-28% of new amino acid changing mutations being neutral/nearly neutral (|s| < 1e-5), and 41-48% under strong purifying selection (|s| > 1e-2). Our results are robust to different model assumptions suggesting that the DFE is stable across short evolutionary timescales, even in the face of putative drastic changes in the selective pressure caused by artificial selection during domestication and breed formation. On par with previous works describing DFE evolution, our data indicate that the DFE of amino acid changing mutations depends more strongly on genome structure and organismal characteristics, and less so on shifting selective pressures or environmental factors. Given the constant DFE and previous data showing that genetic variants that differentiate wolf and dog populations are enriched in regulatory elements, we speculate that domestication may have had a larger impact on regulatory variation than on amino acid changing mutations.