2020, Article / Letter to editor (vol. 68, iss. May 2020, (2020))Montmorency Tart Cherries, MTC, (Prunus cerasus L.) possess a high anthocyanin content as well as one of the highest oxygen radical absorbance capacities of fruits at common habitual portion sizes. MTC have been shown to contribute to reducing plasma lipids, plasma glucose and fat mass in rats and strikingly, similar effects are observed in humans. However, there is a paucity of research examining the molecular mechanisms by which such MTC effects are induced. Here, we show that when exposed to MTC, Caenorhabditis elegans display an extension of lifespan, with a corresponding increase in fat content and increase in neuromuscular function. Using RNA interference, we have confirmed that MTC is likely to function via the Peroxisome Proliferator-Activated Receptor (PPAR) signalling pathway. Further, consumption of MTC alters the pharyngeal pumping rate of worms which provides encouraging evidence that MTC may be operating as a calorie restriction mimetic via metabolic pathways.
2019, Article / Letter to editor (J Exp Zool A Ecol Integr Physiol, vol. 331, iss. 3, (2019), pp. 201-212)Canalization, an intrinsic robustness of development to external (environmental) or internal (genetic) perturbations, was first proposed over half a century ago. However, whether the robustness to environmental stress (environmental canalization [EC]) and to genetic variation (genetic canalization) are underpinned by the same molecular basis remains elusive. The recent discovery of the involvement of two endoplasmic reticulum (ER)-associated DnaJ genes in developmental buffering, orthologues of which are conserved across Metazoa, indicates that the role of ER-associated DnaJ genes might be conserved across the animal kingdom. To test this, we surveyed the ER-associated DnaJ chaperones in the nematode Caenorhabditis elegans. We then quantified the phenotype, in the form of variance and mean of seam cell counts, from RNA interference knockdown of DnaJs under three different temperatures. We find that seven out of eight ER-associated DnaJs are involved in either EC or microenvironmental canalization. Moreover, we also found two DnaJ genes not specifically associated with ER (DNAJC2/dnj-11 and DNAJA2/dnj-19) were involved in canalization. Protein expression pattern showed that these DnaJs are upregulated by heat stress, yet not all of them are expressed in the seam cells. Moreover, we found that most of the buffering DnaJs also control lifespan. We therefore concluded that a number of DnaJ chaperones, not limited to those associated with the ER, are involved in canalization as a part of the complex system that underlies development.
2019, Article / Letter to editor (vol. 67, iss. 1, (2019), pp. 33-39)Caenorhabditis elegans is an invertebrate model organism used in many areas of biology including developmental biology and the identification of molecular mechanisms and pathways. However, several experimental approaches require large quantities of worms, which is limiting and time-consuming. We present a protocol that uses modern fermentation methodology to effectively produce large numbers of C. elegans using a 7-l bioreactor in a fed-batch cultivation procedure. The production is modular and flexible as well as being a self-controlled system, thus not much labor is required until harvesting C. elegans. The high-yield worm cultivation is flexible and simple to amend, and now allows for the extended application of C. elegans as a model organism and expression system, including large-scale protein production.
2019, Article / Letter to editor (vol. 41, iss. 10, (2019))From single-cell organisms to complex neural networks, all evolved to provide control solutions to generate context- and goal-specific actions. Neural circuits performing sensorimotor computation to drive navigation employ inhibitory control as a gating mechanism as they hierarchically transform (multi)sensory information into motor actions. Here, the focus is on this literature to critically discuss the proposition that prominent inhibitory projections form sensorimotor circuits. After reviewing the neural circuits of navigation across various invertebrate species, it is argued that with increased neural circuit complexity and the emergence of parallel computations, inhibitory circuits acquire new functions. The contribution of inhibitory neurotransmission for navigation goes beyond shaping the communication that drives motor neurons, and instead includes encoding of emergent sensorimotor representations. A mechanistic understanding of the neural circuits performing sensorimotor computations in invertebrates will unravel the minimum circuit requirements driving adaptive navigation.