Category: Uncategorized

OBLIGATORY SYMBIOSIS. "Virtually all terrestrial arthropod species harbor vertically transmitted microbial endosymbionts that play critical roles in the biology of their hosts. Many well-studied examples involve obligate bacterial endosymbionts (i.e., they are absolutely required for survival and reproduction) that supply their host with essential nutrients that are missing from its diet." https://lnkd.in/dn7-uaE View in LinkedIn

VERTICAL SYMBIONTS. "The vertical transmission of symbiotic microorganisms is omnipresent in insects, while the evolutionary process remains totally unclear. In many cases, host insects and symbiotic microbes have phylogenetic congruence, strongly suggesting that these symbiotic associations have been maintained by strict vertical transmission." https://lnkd.in/dvW6NMZ View in LinkedIn

EXAMPLE OF NICHE EXPANSION. "Aphids and other sap-feeding insects rely on phloem sap or xylem sap as their only food, and these diets are extremely limited in essential amino acids and some vitamins. Use of these unbalanced diets is possible because symbionts supply missing nutrients." https://lnkd.in/dcBwzRs View in LinkedIn

NICHE EXPANSION VIA SYMBIONTS. "On macroevolutionary time scales, symbiont acquisition has often enabled evolutionary diversification and ecological expansion. By acquiring maternally transmitted bacterial symbionts, many insect lineages have succeeded in unlocking new ecological niches, particularly ones that present nutritionally unbalanced diets." https://lnkd.in/dcBwzRs View in LinkedIn

ESSENTIAL SYMBIONTS. "To ensure that offspring acquire these microbial partners, insects have evolved diverse mechanisms for vertical transmission of the symbionts, including ovarial transmission in aphids, egg smearing in anobiid beetles, coprophagy in termites, milk gland transmission in tsetse flies, and capsular transmission in plataspid stinkbugs." https://lnkd.in/dvW6NMZ View in LinkedIn

METABOLIC SYMBIOSIS. "Insects that feed exclusively on nutritionally limited or persistent food sources, such as plant phloem sap, vertebrate blood, or woody materials, commonly possess symbiotic microorganisms in their guts. Symbiotic microbes are essential for host survival and reproduction and play pivotal roles in host metabolism, such as providing essential nutrients and digesting food materials." https://lnkd.in/dvW6NMZ View in LinkedIn

SEXUAL SELECTION. "Male and female reproductive traits display some of the most rapid evolution observed in nature, suggesting that sexual selection as well as sexual conflict are major forms of selection. However, natural selection plays an important part as well, as environmental variation might also drive divergence in reproductive traits." https://lnkd.in/dChz5SR View in LinkedIn

VIRAL ECOSYSTEM. "Similar to gut bacteria, interpersonal variation in the virome is high. Changing the focus from individual agents that are implicated in disease toward a community view has already precipitated paradigm shifts in the view of the virome and disease, and the same will likely be true for eukaryotic microbes." https://lnkd.in/dRUEtkS View in LinkedIn

DODGING THE RABBIT HOLE. "Highly reduced genomes of insect symbionts contain mostly genes involved with cell replication, transcription, and translation: Mutations in these genes will impact fitness of individual symbiont cells, where selfishness can originate. Thus, eukaryotic organelles may have escaped the symbiosis rabbit hole primarily because genes controlling symbiont replication are transferred to the host genome." https://lnkd.in/dcBwzRs View in LinkedIn

SO ENDS this contemplation of hereditable endosymbionts, a half-way stop in the spectrum to engulfment of algae to make a permanent organelle such as a chloroplast and mitochondrion. Clearly, there are many examples in nature where critically important symbiotic organisms are inherited, mostly maternally, by a variety of mechanisms, ensuring that the offspring have immediate inoculations of these outsourced metabolic factories. View in LinkedIn