Biology subjects

Ingram, T. L.

Publications and source records attributed to Ingram, T. L..

3 recordsLinked to original sources

bioRxiv2021

The elephant retina examined across a range of ages

The effect of aging in the human retina has been well documented, as have the signs of age-related retinal disease. Comparative studies in animals allow us to further investigate how the retina ages in different species. The African bush elephant (Loxodonta africana) has a retina comparable to other mammalian species, but with some reported distinctive differences in retinal ganglion cell (RGC) distribution and type. This is a first survey of the retina of Loxodonta africana from individuals aged 2 months to 32 years old. Gross examination, H&E staining and cell counts were used to compare calves (0-5 years), juveniles (6-10 years), sub-adults (11-20 years) and adults (>20 years). Dorsal-ventral eye diameter was shown to be significantly greater with age, whilst no significant changes in photoreceptor number were found. Changes in retinal thickness differed from past findings in elephants and humans, with thickness decreasing, then increasing in adults. Various morphological differences were evident in the samples including the presence of nuclei in the outer plexiform layer (OPL), degeneration of the inner plexiform layer (IPL), interruptions in nuclei columns of the outer nuclear layer (ONL), and larger unidentified cells within the inner nuclear layer (INL). These are initial observations provide some baseline information for a species where this range of samples has not been described previously.

zoology↗

bioRxiv2020

The effect of E-liquid exposure on Caenorhabditis elegans.

E-cigarettes are being promoted as a less harmful alternative to smoking tobacco. However, vaping is a new phenomenon and safety profiles have not been fully established. Model organisms can be used to examine the cellular processes that may be changed by exposure to the E-liquids used for vaping. Mitochondria are essential in eukaryotic cells for production of ATP, protein biogenesis, metabolic pathways, cellular signalling, stress responses and apoptosis. Mitochondrial health can be used as a proxy for many aspects of healthy cellular physiology. Mutations in the PINK1 gene can lead to mitochondria-specific autophagy deficiency. We exposed two strains of Caenorhabditis elegans, CB5600 control and CC46 pink1, with 10% concentrations of nine different flavoured E liquids. We measured lifespan, movement, body size, brood size, and we examined their mitochondrial networks to investigate the effect of the E-liquids. We show that the CC46 (pink1) strain is affected by the E-liquids, even the flavours without nicotine, and that they have reduced lifespan, movement ability and mitochondrial organisation. We found that some E-liquids can dramatically shorten lifespan in this strain. Our data emphasise a need to carefully ascertain the potential harm that may be caused by the use of E-liquids.

cell biology↗

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↗