Czechia

Gut microbiomes are integral to animal eco-physiology and are hypothesized to shape the adaptive evolution of animal life. However, directly estimating the extent to which gut microbiomes are under selection within free-living animal populations is challenging. The inheritance mechanisms that allow for the intergenerational transmission of microbiome variation within animal populations are also unclear. However, joint characterization of the inheritance and fitness consequences of microbiome variation are critical for understanding the role of microbiota in animal adaptation. To address these knowledge gaps in parallel, I quantified relationships between gut microbiomes and host survival in the wild, by using shallow shotgun metagenomic sequencing to characterize microbiota communities in archived fecal samples collected across seven years of a long-term individual-based study of Sable Island feral horses (2820 samples from 905 individuals). Using quantitative genetic animal models, I then estimated the narrow-sense heritability and social transmissibility of survival-associated microbiota. Analysis of these data indicate that horse survival may be strongly connected to methane production in the hindgut. Furthermore, quantitative genetic analyses suggest the involvement of both host genetics and social effects in structuring the microbiome, and that these effects may be strongest for the microbiota most closely connected to horse survival. By dovetailing estimates of natural selection and inheritance, these results provide a fuller understanding of how host-microbiome relationships evolve in nature.

SEB Conference Prague 2024

Straight from the horse&#39;s mouth: lessons of gut microbiome selection and inheritance from Sable Island

natural selection

evolution

microbiome

Straight from the horse's mouth: lessons of gut microbiome selection and inheritance from Sable Island

technical paper

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The equid locomotor transition is one of the most iconic morphofunctional shifts in terrestrial mammals. Throughout their evolution, equids reduced their side-digits, with different phylogenetic clades exhibiting greater or lesser degrees of digit reduction. One hypothesised driver behind the reduction (and loss in equinin equids) of side-digits is their potential lack of functionality during locomotion. However, hipparionin equids retain side-digits until their extinction during the middle-Pleistocene, despite coexisting with monodactyl equids for over 7 Ma. In this study, we aim to shed light on the functionality of the side-digits of extinct equids using an extant morphological bracket, comparing toe-ground interception across ecologically diverse ungulates which exhibit side-digits. Modern and extinct ungulate proximal phalanges were measured and compared across a broad range of taxa using a toe-reduction index (a morphometric measure of central-to-side-toe length). Using high-resolution 3D scans, joint range-of-motion was estimated from osteological material; we then built and analysed a series of ungulate distal limb skeletons, rotating the third proximal phalange parasagittally at biologically realistic, regularly spaced intervals. Toe-to-ground interception for the side-digits was scored for the varying degrees of central digit extension, and under hypothetically increasing substrate compliances (mimicking different underfoot conditions, e.g. mud). Our results from toe-reduction indices align with 3D virtual ROM experiments, which themselves demonstrate widespread functionality in the side digits of transitional and hipparionin equids (e.g. Nannippus). This preliminary study refutes the notion of functional redundancy in equid side-digits, paving the way for more advanced investigations in the future.

Using modern ungulate analogues to explore equid side-toe function through an iconic evolutionary transition

Equids can be distinguished from every other extant mammal by their monodactyl feet. Classically, equid evolution is portrayed as a linear, gradual evolution from tetradactyly to monodactyly, culminating in the modern monodactyl genus Equus (including the domestic horse). Although the linearity of this locomotor transition has now been reassessed in favour of a more complex evolutionary history, the musculoskeletal and physiological similarity of modern equid limbs remains unexplored. Are domestic horse limbs representative for wild equids (e.g., zebras, onagers, etc.), or are there substantial differences in their muscle architecture or myological arrangement which might affect efforts to biomechanically model the musculoskeletal system of extinct species? Here, we explore this question by quantitatively describing the forelimb muscle architecture of all extant Equus species. Gross dissections were performed to record origin and insertions sites, and quantitative metrics recorded (muscle-tendon unit (MTU) length, MTU mass, muscle mass, pennation angle, and fascicle length). Muscle physiological cross-sectional area (PCSA) and ligament (and tendon) anatomical cross-sectional area (ACSA) were then calculated. Results confirm attachment sites of all muscles are homologous across all species, with little individual variation. When normalised for size, the forelimb muscles of caballines, zebras, and wild asses exhibit comparable muscular architecture and force-generating capacities. Although limited by sample size, these results indicate that scaled data for modern equids (domestic and wild) are very comparable, which will facilitate much smoother translation of experimental data from domestic horses into digital simulation of (at least the later stages of) the equid locomotor transition.

Could 'wild horses' drag you away? Comparing muscular architecture in the forelimbs of extant equids (Perissodactyla: Equidae).

To cope with environmental challenges due to global change, organisms must modulate their physiology to survive. Various environmental stressors like heat and pollution have been suggested to cause increased oxidative stress in animals. However, in many organisms with multiple life-stages, like the Calanoid copepods, how different life-stages respond to environmental stressors remains unclear. The planktonic marine copepod Calanus finmarchicus is a low trophic species, an important food source to several commercially important fish, and a keystone species in the ocean. Therefore, it is important to understand how they respond to stress. To investigate the physiological and life-history effects of critical life-stages of C. finmarchicus to heat stress and oxidative stress, we exposed fertilised eggs and adult males and females to graded doses of paraquat, an oxidative stress inducer, at different temperatures. We measured the eggs’ hatching rate, defined the 96 hours LC50 of paraquat, and examined antioxidant mechanisms by measuring the transcription level of biomarkers genes involved in oxidative damage such as superoxide dismutase in both eggs and adults in response to both heat stress and paraquat treatments. Preliminary results showed no additive nor synergistic effects of heat and oxidative stress on the metabolic response of adult females. We hypothesised that early life stages and adult males are more sensitive to oxidative stress and temperature change than adult females. A better understanding of how copepods respond to environmental changes and the physiological mechanisms underpinning these responses will help us predict marine ecosystem dynamics in relation to global change.

Effects of environmental challenges on physiological and life-history performance of a small marine copepod, Calanus finmarchicus.

Many water systems suffer from reduced or completely disrupted connectivity due to human activities, causing negative effects for species and ecosystems. Artificial transport past migration barriers, so called trap-and-transport, can be used as a management tool to mitigate fish population declines. The efficiency of trap-and-transport is, however, rarely evaluated, in particular for downstream transport of catadromous species such as the European eel. In this study we analysed seven years of trap and transport data (2016-2022), encompassing more than 65 000 transported eels, to evaluate stress and mortality during all steps of the trap and transport process. We found that average mortality rate was generally low but could be as high as 10%. Mortality during all steps of the trap and transport procedure was affected by temperature, with higher temperatures leading to higher mortality. We also found that when mortality in the fishing gear had been high, mortality during holding was also high. Mortality during transport was additionally affected by transport time, with longer transport time causing higher mortality. In addition to mortality rates, we also evaluated stress during trap and transport by surgically implanting biologgers measuring heart rate, which was used as a proxy for stress. Similar to mortality, stress was affected by temperature, with higher temperatures causing higher stress levels, in particular during transport. We conclude that although trap-and-transport, fishways, and other alternatives aiming at reducing negative impacts can reduce mortality, such measures require maintenance and human interference, wherefore removal of migration barriers should be the long-term goal.

Evaluating stress and mortality during trap and transport in the European eel

The project aimed to investigate the influence of geography,
evolutionary history, and host genetics on the skin microbiome diversity
of the moor frog (Rana arvalis), a widespread amphibian species. By
examining 12 populations from two geographical clusters, we explored
the association between bacterial diversity and composition and the
major histocompatibility complex class II exon 2 diversity. Results
revealed significant variations in MHC alleles/supertypes and genetic
diversity based on geography and evolutionary history. While bacterial
alpha diversity remained consistent across clusters, it correlated
positively with expected MHC heterozygosity and negatively with
MHC nucleotide diversity. Moreover, bacterial community composition
exhibited significant differences between clusters and specific MHC
alleles/supertypes. These findings underscore the impact of historical
demographic events on hologenomic variation and provide insights
into how immunogenetic host variability and microbial diversity may
collectively influence host fitness and disease susceptibility, ultimately
affecting population persistence.

Association between the skin microbiome and MHC class II diversity in an amphibian

Differences in growth rate and metabolism between individuals can determine competitive social dynamics as well as survival during vulnerable life stages. While this inter-individual variability has received growing attention, variability within individuals can also be substantial but has rarely been studied. Here, we used the ecologically and culturally important estuarine fish Galaxias maculatus to understand inter- and intra-individual variability in metabolism and determine their relative contributions to growth.

Specifically, we collected repeated measurements of metabolic and growth performance across 6 months to gauge inter- and intra-individual variability in both metrics for a wild-caught population of 160 G. maculatus. Groups of fish were fed to satiation and housed in tanks where each fish had a unique colored subcutaneous elastomer tag. Fish were initially measured for active, routine, and standard metabolic rates at 18℃ before being randomly assigned to an acclimation group at either 18℃ (benign summer temperature) or 23℃ (challenging summer temperature). We tracked each individual’s growth and collected a further five metabolic measurements per fish (~1 per month). 

Our results showed negligible correlation between specific growth rate and both standard and routine metabolic rates. Inter- and intra-individual variability were similar for both standard and routine metabolic rates (mass-standardized), including between temperature treatments. These findings provide some of the strongest evidence that the metabolic phenotype of an individual can change across time, matching the extent of the variability within a population. 


Intra- and inter-individual variability in metabolism drives growth performance of a temperate estuarine fish

Assessment IS learning. The power of assessment to do more than just test knowledge and understanding is substantial. Making our assessments meaningful to our students’ future lives, and authentic to the skills they will need is a major priority in the evolving Higher Education sector. Ensuring that our assessments are also student-centred, and develop their skills both as bioscientists and as independent, self-regulated learners, is also an important necessity. This talk will focus on ways in which we can enhance our assessments to ensure they are focused on supporting student learning and preparing them for their future employment needs, and will highlight the challenges associated with this.

Meaningful and student-centred assessment in Biosciences education

AI provides a fast and efficient way to generate textual outputs, produce images, analyse core learning, and evaluate biological data. This is driving a transformation in education, with consideration needed around current assessment practices as tools such as ChatGPT become more prevalent. In this talk, we will explore some of the pedagogic approaches and assessment strategies that have been successfully developed that allow for the incorporation of AI into the assessment. When used correctly, and ethically, AI can be a valuable learning aid for students and an effective facilitative tool for educators.

Generative AI: the power and the peril in Biosciences education

Characterization of differences in N assimilation and deficiency responses in C3 and C4 Cleome species
The evolution of C4 photosynthesis led to increased carbon assimilation rates and plant growth. In contrast to C3 plants, which use Rubisco for primary CO2 fixation in all photosynthetic cell types, in C4 plants carbon is initially fixed in mesophyll cells (MCs) by PEP carboxylase (PEPC). Subsequent decarboxylation of the resulting C4 acid takes place in the bundle sheath cells (BSCs). This increases the local CO2 concentration around Rubisco, which minimizes its oxygenation reaction reducing photorespiration and thereby improving photosynthetic efficiency. Similarly, in most C4 plants the reduction of nitrate and nitrite is restricted to MCs, while the further assimilation of reduced nitrogen into the amino acids glutamate and glutamine mainly takes place in the BSCs. Changes in the expression pattern of glycine decarboxylase (GDC) lead to the restriction of photorespiration and therefore serine production to BSCs. Balancing of metabolic routes is therefore necessary to maintain homeostasis of not only carbon but also nitrogen (N) metabolism. These differences in N requirements of the two photosynthetic mechanisms pose the question of how N assimilation pathways differ between C3 and C4 species and whether these changes are a consequence or prerequisite of C4 evolution. Characterization of mineral nutrition traits revealed clear differences in the N metabolism of C3 and C4 Cleome species under N deficiency conditions, indicating a higher N deficiency tolerance in the C4 species. The addition of NH4+ was shown to offset the reduction of biomass and photosynthetic efficiency in the C3 but not the C4 Cleome species.


Characterization of differences in N assimilation and deficiency responses in C3 and C4Cleome species

Warmer temperatures can cause various physiological and phenotypic changes in plants, many of which with detrimental consequences, and theses processes are regulated by a diverse set of molecular mechanisms. Temperature is also a major parameter for RNA structure formation and stability, and the plant cell’s environment, with its constant shifts in temperature, might have created ideal conditions for RNA structures to be selected and genetically transmitted as an adaptive mechanism to warmer temperatures. In this talk, I will present our work on post-transcriptional regulation in plant perception and acclimation to warmer temperatures, with a focus on the role of RNA structures.

Straight from the horse's mouth: lessons of gut microbiome selection and inheritance from Sable Island

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Straight from the horse's mouth: lessons of gut microbiome selection and inheritance from Sable Island

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Next from SEB Conference Prague 2024

Using modern ungulate analogues to explore equid side-toe function through an iconic evolutionary transition

Stay up to date with the latest Underline news!

PRESENTATIONS

CONFERENCES

COMPANY

RESOURCES

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