Nontraditional systems in aging research: an update

Abstract

Research on the evolutionary and mechanistic aspects of aging and longevity has a reductionist nature, as the majority of knowledge originates from experiments on a relatively small number of systems and species. Good examples are the studies on the cellular, molecular, and genetic attributes of aging (senescence) that are primarily based on a narrow group of somatic cells, especially fibroblasts. Research on aging and/or longevity at the organismal level is dominated, in turn, by experiments on Drosophila melanogaster, worms (Caenorhabditis elegans), yeast (Saccharomyces cerevisiae), and higher organisms such as mice and humans. Other systems of aging, though numerous, constitute the minority. In this review, we collected and discussed a plethora of up-to-date findings about studies of aging, longevity, and sometimes even immortality in several valuable but less frequently used systems, including bacteria (Caulobacter crescentus, Escherichia coli), invertebrates (Turritopsis dohrnii, Hydra sp., Arctica islandica), fishes (Nothobranchius sp., Greenland shark), reptiles (giant tortoise), mammals (blind mole rats, naked mole rats, bats, elephants, killer whale), and even 3D organoids, to prove that they offer biogerontologists as much as the more conventional tools. At the same time, the diversified knowledge gained owing to research on those species may help to reconsider aging from a broader perspective, which should translate into a better understanding of this tremendously complex and clearly system-specific phenomenon.

Transcriptomes of testis and pituitary from male Nile tilapia (O. niloticus L.) in the context of social status

“…The most striking difference between those families was the age of the fish (nine and twelve months vs. 34 months). Ageing and senescence are not very well understood processes yet, neither in mammals and even less in fish [ 76 , 77 ]. Early development from egg to embryo to larva are well-defined stages of the fish lifecycle.…”

Mutation or not, what directly establishes a neoplastic state, namely cellular immortality and autonomy, still remains unknown and should be prioritized in our research

“…In other words, the genomes of animals (including the human being) encode these cellular properties and thus do not need mutations for their occurrence [62,287,288]: First, a normal human body consists of not only somatic cells, which are mortal and may undergo symmetric division, but also germline cells that are immortal and undergo asymmetric division [289,290]. Actually, there are some plants and animals that are immortal as well [290,291]. Therefore, immortality has been evolutionarily built within, or encoded by, our genomes although normally the program is derelict in somatic cells.…”

Footprints in the Sand: Deep Taxonomic Comparisons in Vertebrate Genomics to Unveil the Genetic Programs of Human Longevity

“…Because of these selective constraints on the aging and lifespan processes across the tree of life, the diversity of longevities between organisms can be leveraged to decipher the core machinery facilitating it – potentially independent from the mechanisms involved in expression of aging-like pathologies. There is already a rich field investigating unconventional organisms with exceptionally long and short lifespans ( Mikuła-Pietrasik et al, 2021 ), but much of this research is done in relative taxonomic isolation – that is within one or few related lineages. Careful and extensive characterization of these unconventional lineages necessitates this limited sampling, but there will be genetic signatures arising from these analyses that are particular to the group, unrelated to their longevity.…”