Boxfish (Ostraciidae) have peculiar body shapes, with conspicuous keels formed by their bony carapaces. Previous studies have proposed various hydrodynamic roles for these keels, including reducing drag during swimming, contributing to passive stabilisation of the swimming course, or providing resistance against roll rotations. We tested these hypotheses using computational fluid dynamics simulations of five species of Ostraciidae with a range of carapace shapes. The hydrodynamic performance of the original carapace surface models, obtained from laser scanning of museum specimens, was compared with models where the keels had been digitally reduced. The original carapaces showed no reduced drag or increased passive stability against pitch and yaw compared to the reduced-keel carapaces. However, consistently for all studied species, a strong increase in roll drag and roll added mass was observed for the original carapaces compared to the reduced-keel carapaces, despite the relatively small differences in keel height. In particular, the damping of roll movement by resistive drag torques increased considerably by the presence of keels. Our results suggest that the shape of the boxfish carapace is important in enabling the observed roll-free forward swimming of boxfish and may facilitate the control of manoeuvres.

The hydrodynamic function of keels in boxfish

Basal metabolic rate (BMR) – the rate of energy use needed to perform basic, life-sustaining functions – is a universal measure of metabolic rate allowing for comparisons of energy expenditure between species. Many animals inhabit a vast array of challenging environments, an example being living in confined spaces where oxygen levels are likely to be low. Previously it has been shown that species can exhibit both geno- and phenotypic adaptations in metabolic rate to exploit such unique niches. Living for extended periods of time within an enclosed space – in a burrow, den or crevice – will likely require certain physiological and morphological adaptations, and thus influence the biology of the species that occupy them. In this study we are taking a global look at the mammalian kingdom to understand the relationship between BMR and burrow use (fossoriality) in mammals. In particular, we aimed to determine if there was a trait within BMR associated with fossoriality, versus species which live above ground. We used pre-existing data for mammalian BMR and body mass, and 24-life history traits. To account for variation in body size, residual BMR was used (RBMR), controlling for any phylogenetic trends through a phylogenetic least squares model (PGLS) and an MCMCglmm, to account for inter- and intra-specific variation. Overall, mammalian metabolic rate is dictated primarily by environmental temperature. Only aquatic mammals had a detectable trait in RBMR and there was no significant differences in RBMR of terrestrial, fossorial and subterranean mammals, suggesting that species occupying a subterranean niche do not pay any baseline metabolic costs on account of their burrowing lifestyle. This may possibly explain why certain species can live above ground whilst also occupying an underground shelter at night or during other periods of the day. Aquatic mammals, however, had a significantly higher RBMR to all other groups apart from flying mammals. This significantly high BMR may also be due to the energetically demanding thermoregulatory need to maintaining a constant body temperature in cold water, particularly the Arctic/Antarctic waters that the large aquatic mammals in the study will be visiting seasonally, if not occupying year-round. This study has shown that environmental temperature is an important factor when exploring differences in mammalian BMR. Temperature can be used to predict BMR and therefore strongly infers whether a mammal is physiologically suited to living in a particular place or habitat. Changes to the environmental temperatures that these species are experiencing are likely to have knock on effects and alter population spread and change, as well as persistence of populations in certain areas. This highlights the importance of climate change and the largescale effects that small changes in environmental temperature may have on the diversity and distribution of mammalian species on the planet.

No evidence for a signal in mammalian basal metabolic rate associated with a fossorial lifestyle.

Programmed cell death (PCD) is a genetically managed biological process that results in the targeted sacrifice of unwanted or diseased cells. Plants use PCD for various purposes such as development, defence against pathogens, response to abiotic stress caused by UV radiation or heat shock. Several proteinases are involved in the PCD process; among them, cathepsin B (CathB) which plays an important role in pathogen defence, plant development, germination, senescence, microspore embryogenesis and abiotic stress response. A greater understanding of the molecular mechanisms underlying the processes downstream of CathB is the next important step for new discoveries in cell biology and applications in biotechnology. To achieve this goal, it is important to discover and test substrates cleaved by plant CathB. Up to 13 substrates for CathB were identified in animal cells, and we found orthologous genes in Arabidopsis thaliana for eight of them. Among these, we are testing some candidate substrates for CathB. To experimentally validate the cleavage site, we used leaf agro-infiltration to co-expressed substrate GFP-fusion and CathB in tobacco cells and carried out cleavage assays. in vivo and in vitro results will be presented. 
















Characterising the proteolytic network of plant cathepsin B

Early-life conditions are important in shaping variation in individual quality and rates of ageing. Our understanding of this relationship between early-life conditions and late-life outcomes is particularly lacking in the context of age-related functional declines, which are often overlooked in favour of age-specific mortality and reproduction. Flight is a metabolically costly trait in insects and is closely associated with fitness in wild burying beetle populations, including Nicrophorus vespilloides. Therefore, flight represents an interesting avenue along which to examine ageing in an expensive functional trait that is closely related to fitness. We manipulated early-life environments through adjusting food availability to explore the role early-life-environments play in shaping lifespan and ageing in flight. Preliminary results find that individuals from higher quality early-life environments (abundance of food) exhibited superior peak flight-speed that was maintained across all assayed ages (10-99 days old). Peak flight speed was seen to decline only in the oldest-aged beetles (90+ days old), an age-range which exceeds that of most studies of ageing performed on this species . However, poorer-quality early-life environments (dearth of food) was associated with increased survival in later life. Beetles displayed a decreased propensity to fly at increasing ages, but no accompanying decrease in time spent in flight was detected . We show that high-quality early-life environments can contribute to improved measures of peak flight performance but have a less pronounced role in shaping patterns of age-related declines in flight. Furthermore, these early-life benefits may also be associated with reduced adult lifespan.

Effects of early-life conditions on age-related flight performance in Nicrophorus vespilloides 

Testing how evolutionary cold adaptation affects metabolism and performance of fish we compared the acute responses to warming of the stenothermal Antarctic eelpout Pachycara brachycephalum and of the eurythermal common eelpout Zoarces viviparus from the North Sea. We investigated whole animal oxygen consumption rate and ammonia excretion. As excretion of ammonia via the gills reflects whole animal metabolic patterns, especially nitrogen and amino acid metabolism, we also investigated the temperature dependent protein synthesis rate of gills in vivo and connected it to respiration and ammonia excretion. 
Both species were exposed to temperature changes within their species-specific thermal window:  P. brachycephalum -acclimated to 0°C- at a rate of 2°C day-1 until 10°C, and Z. viviparus - acclimated to 4°C - at a rate of 3°C day-1 until 22°C. Once temperature stabilized (within 12 hours), oxygen consumption rates were measured repeatedly and water samples were taken to determine the ammonia excretion of each fish individually. In a parallel experiment, we investigated the temperature dependent protein synthesis rate (Ks) of gills after intraperitoneal injections of 13C-labeled phenylalanine. The gill tissue was sampled 1.5 and 3 hours after the injection.
All measured parameters followed an exponential increase with warming for both species, however, with different Q10 values (e.g. Q10 protein synthesis rate P. brachycephalum 4.2 vs. 2.8 Z. viviparus). Protein synthesis rates at the same temperatures were similar in both species (P. brachycephalum vs. Z. viviparus: 4°C Ks= 2.5 vs. 2.6 % day-1; 10°C Ks= 4.5 vs. 4.3% day-1) indicating no cold compensation regarding protein synthesis in gills of the Antarctic eelpout. It will be discussed how these results are related to oxygen uptake and ammonia excretion.

The impact of acute warming on the respiratory system of fish – a comparison of eelpouts from Antarctica and temperate zones

While group-living can increase foraging efficiency and feeding consistency, individual variation in behaviour can cause disparity in food intake among groupmates. For example, bolder individuals may secure more food if they are more exploratory or are willing to take risks to obtain food items. Temperature variation may further modulate phenotypic variation among groupmates and alter levels of feeding disparity within groups. 
We examined the effects of ambient temperature on group foraging in a social catfish, the bronze corydoras (Corydoras aeneus). Groups of 30 fish were placed within large mesocosms and were observed for feeding behaviour at both of 24°C or 28°C, with at least two weeks acclimation to each temperature. Feeding behaviour among individuals within groups was highly repeatably, with the same individuals being consistently first to feed when presented with food items, even when the same groups were tested across temperatures (R = 0.467). Temperature increased group activity and feeding rate, with groups finding food quicker at the warmer temperature, even though groups were more cohesive (individuals closer together) at the cooler temperature. Together, these data highlight individual variation within a group foraging context, whereby specific individuals are more successful at securing food than their groupmates. This will have implications for the relative costs and benefits of group membership for individuals.

Investigation into the effect of temperature on social foraging in Corydoras aeneus

Mitochondria are most known for their role in energy production, but they are also implicated in many other cellular functions (apoptosis, ROS production, cell proliferation, aging). In humans, the mitochondrial DNA was believed to encode only 37 genes involved in energy production and mitochondrial translation. However, recent studies have shown that within these genes could hide several small alternative genes (genes with translation initiation or termination sequences distinct from the reference gene sequences in which they are found) coding for micropeptides with a broad spectrum of functions that can be newly added to the large list of functions in which mitochondria are involved.

Following the discovery of the mitochondrial alternative gene mtaltnd4, we try to elucidate the functions of the gene and its peptide (MTALTND4) by studying: (1) the expression pattern of the peptide in different human tissues and blood plasma, (2) the involvement of the gene in the major mitochondrial functions by exposing cells to various treatments, (3) the interaction partners of MTALTND4 by mass spectrometry and (4) the impact of the peptide on cell transcriptome. 

We have found that mtaltnd4 may potentially produce a signaling protein in response to stress that would regulate certain cell metabolic processes and there is surely more to discover.











The alternative gene mtaltnd4: uncovering the mitochondria’s hidden functions

Improving the performance of the CO2-fixing enzyme Rubisco is among targets for increasing crop yields. Here, Earth system models (ESM) of canopy C3 and C4 photosynthesis were combined with species-specific Rubisco parameters to quantify the consequences of bioengineering foreign Rubiscos into C3 and C4 crops under field conditions. The sunlit/shaded model for canopy photosynthesis was used together with species-specific Rubisco kinetics parameters including maximum rate (Kcat), Michaelis-Menten constant for CO2 (Kc21%O2), specificity for CO2 to O2 (Sc/o), and associated heat activation (Ha) values. Canopy scale consequences of replacing native Rubiscos in wheat, maize and sugar beet with foreign enzymes from 27 species were modelled using data from Ameriflux and Fluxnet databases. Variation among the included Rubisco kinetics differentially affected modelled carbon uptake rates, and Rubiscos from several species of C4 grasses showed the greatest potential of over 50% carbon uptake improvement in wheat, and over 25% improvement in sugar beet and maize. 

Rubisco substitutions predicted to enhance crop performance through carbon uptake modelling

The enlarged brains of homeotherms bring behavioural advantages, but also incur high energy expenditures. The ‘expensive brain’ (EB) hypothesis posits that the energetic costs of the enlarged brain and the resulting increased cognitive abilities (CA) were met by either increased energy turnover or reduced allocation to other expensive organs, such as the gut. We tested the EB hypothesis by analysing correlated responses to selection in an experimental evolution model system, which comprises line types of laboratory mice selected for high or low basal metabolic rate (BMR), maximum (VO2max) metabolic rates and random-bred (unselected) lines. The traits are implicated in the evolution of homeothermy, having been pre-requisites for the encephalization and exceptional CA of mammals, including humans. High-BMR mice had bigger guts, but not brains, than mice of other line types. Yet, they were superior in the cognitive tasks carried out in both reward and avoidance learning contexts and had higher neuronal plasticity (indexed as the long-term potentiation) than their counterparts. Our data indicate that the evolutionary increase of CA in mammals was initially associated with increased BMR and brain plasticity. It was also fuelled by an enlarged gut, which was not traded off for brain size.

Brain size, gut size and cognitive abilities: the energy trade-offs tested in artificial selection experiment

So called ‘drop-in’ Biofuels produced from plants are becoming increasingly important for the aviation and shipping industries, which urgently need to move away from fossil fuels in order to limit their impact on the climate. Algae farms provide a number of benefits over traditional biofuel crops, such as sugar cane, by alleviating competition for arable land. When exposed to high light, the green alga Chlamydomonas reinhardtii produces triacylglycerols (TAGs) which can be converted to drop-in biodiesel. Excess light results in the over-reduction of the photosynthetic electron transport chain, and it has been suggested that the production of TAGs is in response to this redox imbalance. A deeper understanding, therefore, of how Chlamydomonas cells address redox imbalance will help to inform future work aiming to maximise TAG production in these conditions. Our work has highlighted a potential role for the phenomenon known as light enhanced respiration (LER) in responding to redox stress induced by high light. We show that presence of acetate in the growth media may allow cells to better acclimate to high light by increasing the capacity of the cells for LER. Autotrophic cells (cells grown without acetate) appear to be more susceptible to photodamage than mixotrophic (grown with acetate) when grown in high light. Our results display the complexity of the high light response and provide preliminary evidence for the potential of the mitochondria as a tool for addressing redox imbalance. 

A role for mitochondria during high light stress in Chlamydomonas reinhardtii

Microsphere super-resolution microscopy has recently received a lot of attention due to its simplicity and its capability to resolve features beyond the diffraction limit for living systems, in real time, without being invasive. Current systems which are able to image small biological structures are destructive, invasive (they use fluorescent dyes) or they provide reconstructed images (i.e. not a real time imaging of living organisms). The authors designed and built a bio-microscope tailored around the SMAL® (Super-Resolution Microsphere Amplifying Lens) objective lens which overcomes these drawbacks. The novelty of the setup is the ability to study cell’s structures and viruses which previously were not possible to be imaged using conventional white light microscopy. In this work, along various plant cells, label-free tobacco mosaic virus was employed for imaging in this work due to its stability, reliability, and its dimensions beyond the diffraction limit. The results were compared with images obtained using an X100/1.40 NA oil immersion objective lens fitted onto a white light microscope, in the same location. Microsphere assisted microscopy is a novel type of optical microscopy with great potential for high resolution imaging of in vivo biological structures and pathogens.

Optical super-resolution imaging of tissues and tobacco mosaic virus (TMV) using microsphere technology

Polyploids are of common occurrence among the plants. Several studies have been conducted to understand the impact of polyploidy on the evolution of plant genome. Natural polyploids do occur in the wild, but it is difficult to decipher which changes are due to polyploidy as the plants accumulate variation over the history of their existence. It is important to study the impact of polyploidy away from natural variation. Therefore, we generated synthetic neoautopolyploids in two species of Vigna L. using colchicine-based cotton swab method. The polyploids were screened via flowcytometry and confirmed polyploids were taken to the field to study biological parameters. The two species were found to be behaving differently based on various parameters like photosynthetic efficiency, cell density, stomatal count, cell size and nucleus size. We will be studying inheritance pattern of these traits in subsequent generations. Our study provides a proof that polyploidy does not always have a positive scaling effect on plants at various biological parameters and the changes are species specific. We will be studying genomic changes in future and will correlate them with morphological changes observed.  

Keywords: Polyploids, WGD, Autopolyploid, Flowcytometry, morphometery

Underline digital video library

The hydrodynamic function of keels in boxfish

No evidence for a signal in mammalian basal metabolic rate associated with a fossorial lifestyle.

Characterising the proteolytic network of plant cathepsin B

Effects of early-life conditions on age-related flight performance in Nicrophorus vespilloides

The impact of acute warming on the respiratory system of fish – a comparison of eelpouts from Antarctica and temperate zones

Investigation into the effect of temperature on social foraging in Corydoras aeneus

The alternative gene mtaltnd4: uncovering the mitochondria’s hidden functions

Rubisco substitutions predicted to enhance crop performance through carbon uptake modelling

Brain size, gut size and cognitive abilities: the energy trade-offs tested in artificial selection experiment

A role for mitochondria during high light stress in Chlamydomonas reinhardtii

Optical super-resolution imaging of tissues and tobacco mosaic virus (TMV) using microsphere technology

Whole Genome Duplication Show Species-Specific Morphological Changes In Neoautopolyploids

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