Background
All complex life on Earth is eukaryotic. All eukaryotic cells share a common ancestor that arose just once in four billion years of evolution. Prokaryotes show no tendency to evolve greater morphological complexity, despite their metabolic virtuosity. Here I argue that the eukaryotic cell originated in a unique prokaryotic endosymbiosis, a singular event that transformed the selection pressures acting on both host and endosymbiont.

background

/pdf/energetics-and-genetics-across-the-prokaryote-eukaryote-48v6ix9e5a.pdf

Origins of death

Energetics and genetics across the prokaryote- eukaryote divide

Chemicals produced by aquatic organisms, and especially micro-organisms, have received increasing attention in the last decade for their role in shaping interactions and communities. Several cases emphasize the fact that chemical signals or defence may modulate interspecific interactions. Notably, it has been shown that diatoms, unicellular algae and key primary producers in aquatic ecosystems produce a wide range of bioactive metabolites. Among these compounds, polyunsaturated short-chain aldehydes in vitro strongly impair the reproduction of various potential grazers. In the field, the relationship between aldehyde production and reproductive failure in copepods remains unclear. Recent studies have suggested that these putative defence compounds may also be involved in intercellular communication and in interactions with competitors. Potential effects of the aldehyde precursors on various organisms have also been described. This review presents an overview of various results obtained in the last decade that could help us to understand the role of polyunsaturated aldehydes and their precursors in the ecology of diatoms. It is focused on the dichotomy between freshwater and marine environments. Indeed, most of the results on anti-proliferative aldehydes concern marine planktonic diatoms, whereas they are also known to be produced by benthic and freshwater species.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.2009.03033.x

Chemical interactions in diatoms: role of polyunsaturated aldehydes and precursors.

How we search for anti-aging interventions depends on what we think aging is. Surprisingly, the origin and significance of aging are unresolved questions of evolutionary theory, because experiments have diverged starkly from theoretical expectations. If we think that aging is a process of stochastic degradation, then we seek interventions that will repair the damage. If we think aging is a side-effect of fertility, we may look at ways that fertility hormones can be manipulated. But if we think that aging is an independent genetic program, with no other purpose than to assure our demise, then the most effective approach will be to discover what clocks trigger the self-destruction, and to seek interventions that reset the body’s primary clocks.

Evolutionary Origins of Aging

Tree barks, as a type of forestry residues, are a rich and renewable bioresource that can produce high value-added products Paulownia tomentosa var tomentosa (PTT) has been extensively used in traditional Chinese medicine to cure various diseases However, the antioxidative activity of the chemical constituents of the tree has not yet been investigated In this study, the bark of PTT were extracted and fractioned Then the resulting ethyl acetate (EtOAc) soluble fraction, which exhibited the strongest antioxidative effect, was subjected to repeated open column chromatography for purification The screening process was carried out under the guidance antioxidative activity via diphenylpicrylhydrazyl (DPPH) radical scavenging assay Eight phenolic compounds, glucodistylin (I), luteolin (II), ellagic acid (III), cistanoside F (IV), campneoside II (V), isocampneoside II (VI), verbascoside (VII), and isoverbascoside (VIII), were isolated and their structures were elucidated by various spectroscopic analyses Among the phenolics, II~VIII showed significant antioxidative activity

https://ojs.cnr.ncsu.edu/index.php/BioRes/article/download/BioRes_08_1_Si_628_Activity_Guided_Screening_Antioxidants/1908

Activity-Guided Screening of the Antioxidants from Paulownia tomentosa var. tomentosa Bark

Discriminating infected from healthy cells is the first step to understanding the mechanisms and ecological implications of viral infection. We have developed a method for detecting, sorting, and performing molecular analysis of individual, infected cells of the important microalga Emiliania huxleyi, based on known physiological responses to viral infection. Of three fluorescent dyes tested, FM 1-43 (for detecting membrane blebbing) gave the most unequivocal and earliest separation of cells. Furthermore, we were able to amplify the genomes of single infected cells using Multiple Displacement Amplification. This novel method to reliably discriminate infected from healthy cells in cultures will allow researchers to answer numerous questions regarding the mechanisms and implications of viral infection of E. huxleyi. The method may be transferable to other virus-host systems.

/pdf/targeted-sorting-of-single-virus-infected-cells-of-the-4maqdkjdm8.pdf

Origins of death

Citations

Energetics and genetics across the prokaryote- eukaryote divide

Chemical interactions in diatoms: role of polyunsaturated aldehydes and precursors.

Evolutionary Origins of Aging

Activity-Guided Screening of the Antioxidants from Paulownia tomentosa var. tomentosa Bark

Targeted sorting of single virus-infected cells of the coccolithophore Emiliania huxleyi.

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