Biology subjects

Derecka, K.

Publications and source records attributed to Derecka, K..

2 recordsLinked to original sources

bioRxiv2020

Feeding recombinant Royalactin: Measures of improved lifespan and mitochondrial function in Caenorhabditis elegans

Ageing, the decline of biological functions over time, is inherent to eukaryotes. Female honeybees attain a long-lived queen phenotype upon continuous consumption of royal jelly, whereas restricted supply of this nutritional substance promotes the development of worker bees, which are short-lived. An abundant protein found within royal jelly is major royal jelly protein 1 (MRJP1), also known as Royalactin. Health- and lifespan promoting effects have been attributed to Royalactin in species from diverse animal taxa, suggesting it acts on phylogenetically conserved physiological processes. Here, we explore the effects of feeding the nematode Caenorhabditis elegans with Escherichia coli that express a recombinant form of Royalactin (RArec). We confirm that consumption of RArec increases body size, improves locomotion and extends lifespan. We discover a link between Royalactin and mitochondria, organelles which play a key part in the ageing process: both spare respiratory capacity and morphology indicate improved mitochondrial function in RArec fed C. elegans. These results demonstrate the feasibility of using recombinant Royalactin to gain further insight into processes of healthy ageing in many species. RArec production allows insight into potential beneficial effects across species.

physiology↗

bioRxiv2019

Thiamethoxam exposure in honey bees deregulates short ORF gene expression in the brain and compromises the immune response

Maximizing crop yields relies on the use of agrochemicals to control insect pests. One of the most widely used classes of insecticides are neonicotinoids that interfere with signalling of the neurotransmitter acetylcholine, but these can also disrupt crop-pollination services provided by bees. Here, we analysed whether chronic low dose long-term exposure to the neonicotinoid thiamethoxam alters gene expression and alternative splicing in brains of Africanized honey bees, Apis mellifera, as adaptation to altered neuronal signalling. We find differentially regulated genes that show concentration-dependent responses to thiamethoxam, but no changes in alternative splicing. Most differentially expressed genes have no annotated function but encode short Open Reading Frames (sORFs), a characteristic feature of anti-microbial peptides. As this suggested that immune responses may be compromised by thiamethoxam exposure, we tested the impact of thiamethoxam on bee immunity by injecting bacteria. We show that intrinsically sub-lethal thiamethoxam exposure makes bees more vulnerable to normally non-pathogenic bacteria. Our findings imply a synergistic mechanism for the observed bee population declines that concern agriculturists, conservation ecologists and the public.

pharmacology and toxicology↗