It Takes Two to Make a Thing Go Right: Epistasis, Two-Component Response Systems, and Bacterial Adaptation.

Understanding the interplay between genotype and fitness is a core question in evolutionary biology. Here, we address this challenge in the context of microbial adaptation to environmental stressors. This study explores the role of epistasis in bacterial adaptation by examining genetic and phenotypic changes in silver-adapted populations, focusing on the role of beneficial mutations in two-component response systems (TCRS).

Genotype-by-environment interactions govern fitness changes associated with adaptive mutations in two-component response systems.

Two-component response systems (TCRS) are the main mechanism by which prokaryotes acclimate to changing environments. These systems are composed of a membrane bound histidine kinase (HK) that senses external signals and a response regulator (RR) that activates transcription of response genes. Despite their known role in acclimation, little is known about the role TCRS play in environmental adaptation.

High fat diet reveals sex-specific fecal and liver metabolic alterations in C57BL/6J obese mice.

Obesity is a major health concern that poses significant risks for many other diseases, including diabetes, cardiovascular disease, and cancer. Prevalence of these diseases varies by biological sex. This study utilizes a mouse (C57BL/6J) model of obesity to analyze liver and fecal metabolic profiles at various time points of dietary exposure: 5, 9, and 12 months in control or high fat diet (HFD)-exposed mice.

Favored Races in the Struggle for Life: Racism and the Speciation Concept.

Evolutionary speciation, whether it be cladistic or phyletic, has always been associated with race concepts. Biological races are conceived as definable stages of divergence from a common ancestor. However, the species concept in Western science began within a special creationist framework.

Embedded racism: Inequitable niche construction as a neglected evolutionary process affecting health.

Racial health disparities are a pervasive feature of modern experience and structural racism is increasingly recognized as a public health crisis. Yet evolutionary medicine has not adequately addressed the racialization of health and disease, particularly the systematic embedding of social biases in biological processes leading to disparate health outcomes delineated by socially defined race. In contrast to the sheer dominance of medical publications which still assume genetic 'race' and omit mention of its social construction, we present an alternative biological framework of racialized health.

Serving Two Masters: Effect of Dual Resistance on Antibiotic Susceptibility.

The prevalence of multidrug-resistant bacteria and their increased pathogenicity has led to a growing interest in metallic antimicrobial materials and bacteriophages as potential alternatives to conventional antibiotics. This study examines how resistance to excess iron (III) influences the evolution of bacteriophage resistance in the bacterium . We utilized experimental evolution in to test the effect of the evolution of phage T7 resistance on populations resistant to excess iron (III) and populations without excess iron resistance.

Reporting off-target effects of recombinant engineering using the pORTMAGE system.

pORTMAGE recombineering is a simple technique for incorporation of novel point mutations into bacterial genomes that eliminates off-target effects. Here we inserted point mutations into the cusS gene from Escherichia coli, then, using Illumina sequencing, report genetic variants in all mutant strains. Several off-site mutations were found at high frequency.

Experimental Evolution of Copper Resistance in Produces Evolutionary Trade-Offs in the Antibiotics Chloramphenicol, Bacitracin, and Sulfonamide.

The rise in antimicrobial resistant bacteria have prompted the need for antibiotic alternatives. To address this problem, significant attention has been given to the antimicrobial use and novel applications of copper. As novel applications of antimicrobial copper increase, it is important to investigate how bacteria may adapt to copper over time.

Adaptation to simulated microgravity in Streptococcus mutans.

Long-term space missions have shown an increased incidence of oral disease in astronauts' and as a result, are one of the top conditions predicted to impact future missions. Here we set out to evaluate the adaptive response of Streptococcus mutans (etiological agent of dental caries) to simulated microgravity. This organism has been well studied on earth and treatment strategies are more predictable.

Race in the Reading: A Study of Problematic Uses of Race and Ethnicity in a Prominent Pediatrics Textbook.

Purpose: Aspects of medical education and clinical practice continue to reflect the antiquated notion that race is a biologically valid distinction among individuals rather than a social construct. The authors analyzed the use of race and ethnicity in a popular pediatrics textbook to determine if these concepts were being used consistently and correctly.

Method: In May 2021, using the search function on the American Academy of Pediatrics (AAP) eBooks platform, the authors searched for 29 race- or ethnicity-related terms (e.

Inequality in science and the case for a new agenda.

The history of the scientific enterprise demonstrates that it has supported gender, identity, and racial inequity. Further, its institutions have allowed discrimination, harassment, and personal harm of racialized persons and women. This has resulted in a suboptimal and demographically narrow research and innovation system, a concomitant limited lens on research agendas, and less effective knowledge translation between science and society.

Human biological variation and the "normal".

Anatomically modern human being is a relatively young species (~300 000 years old) with small amounts of genetic variation contained within them. The vast majority of its existence was spent in Eastern Africa, migration out of the region began around 100 000 YBP. Sub-Saharan African populations have the greatest amount of human genetic variation.

Experimental Evolution of Magnetite Nanoparticle Resistance in .

Both ionic and nanoparticle iron have been proposed as materials to control multidrug-resistant (MDR) bacteria. However, the potential bacteria to evolve resistance to nanoparticle bacteria remains unexplored. To this end, experimental evolution was utilized to produce five magnetite nanoparticle-resistant (FeNP) populations of .

Too much of a good thing: Adaption to iron (II) intoxication in .

Background: There has been an increased usage of metallic antimicrobial materials to control pathogenic and multi-drug resistant bacteria. Yet, there is a corresponding need to know if this usage leads to genetic adaptations that could produce more harmful strains.

Methodology: Experimental evolution was used to adapt K-12 MG1655 to excess iron (II) with subsequent genomic analysis.

High-Fat Diet-Induced Weight Gain, Behavioral Deficits, and Dopamine Changes in Young C57BL/6J Mice.

Chronic exposure to a high-fat diet (HFD) may predispose individuals to neuropathologies and behavioral deficits. The objective of this study was to determine the temporal effects of a HFD on weight gain, behavioral deficits, and dopamine changes in young mice. One-month old C57BL/6J male and female mice were fed either a control diet (containing 10% calories from fat) or a HFD (containing 45% of calories from fat) for 5 months.

Genomic evolution of antibiotic resistance is contingent on genetic background following a long-term experiment with .

Antibiotic resistance is a growing health concern. Efforts to control resistance would benefit from an improved ability to forecast when and how it will evolve. Epistatic interactions between mutations can promote divergent evolutionary trajectories, which complicates our ability to predict evolution.

Pancreatic Trauma: Imaging Review and Management Update.

Traumatic injuries of the pancreas are uncommon and often difficult to diagnose owing to subtle imaging findings, confounding multiorgan injuries, and nonspecific clinical signs. Nonetheless, early diagnosis and treatment are critical, as delays increase morbidity and mortality. Imaging has a vital role in diagnosis and management.

Microbial community dynamics during anaerobic co-digestion of corn stover and swine manure at different solid content, carbon to nitrogen ratio and effluent volumetric percentages.

The methane production and the microbial community dynamics of thermophilic anaerobic co-digestion (AD) of corn stover, swine manure and effluent were conducted at total solid (TS) content of 5%, 10% and 15%, the carbon to nitrogen ratio (C/N) of 20, 30 and 40 and the effluent volumetric percentage (EVP) of 20%, 40% and 60%. For batches with 5% TS, the highest methane yield of 238.5-283.

Experimental evolution of gallium resistance in .

Background And Objectives: Metallic antimicrobial materials are of growing interest due to their potential to control pathogenic and multidrug-resistant bacteria. Yet we do not know if utilizing these materials can lead to genetic adaptations that produce even more dangerous bacterial varieties.

Methodology: Here we utilize experimental evolution to produce strains of K-12 MG1655 resistant to, the iron analog, gallium nitrate (Ga(NO)).