‘The first time it happened, it gave rise to all complex life,’ scientists say

For the first time in at least a billion years, two lifeforms have merged into a single organism.

The process, called primary endosymbiosis, has only happened twice in the history of the Earth, with the first time giving rise to all complex life as we know it through mitochondria. The second time that it happened saw the emergence of plants.

Now, an international team of scientists have observed the evolutionary event happening between a species of algae commonly found in the ocean and a bacterium.

  • @I_am_10_squirrels@beehaw.org
    6•22 days ago

    From the Science paper, https://www.science.org/doi/10.1126/science.adk1075

    Editor’s summary

    Many partnerships have been formed between nitrogen-fixing microbes and carbon-fixing eukaryotes that need nitrogen to grow. The possibility of a eukaryote with a nitrogen-fixing organelle derived from endosymbiosis, which is called a nitroplast, has been speculated. Studying a marine alga with a cyanobacterial endosymbiont, Coale et al. used soft x-ray tomography to visualize cell morphology and division of the alga, revealing a coordinated cell cycle in which the endosymbiont divides and is split evenly, similar to the situation for plastids and mitochondria in these cells (see the Perspective by Massana). Proteomics revealed that a sizable fraction of the proteins in this structure are encoded by and imported from the alga, including many that are essential for biosynthesis, cell growth, and division. These results offer a fascinating view into the transition from an endosymbiont into a bona fide organelle. —Michael A. Funk

  • AutoTL;DRBEnglish
    3•23 days ago

    This is the best summary I could come up with:

    The process, called primary endosymbiosis, has only happened twice in the history of the Earth, with the first time giving rise to all complex life as we know it through mitochondria.

    Now, an international team of scientists have observed the evolutionary event happening between a species of algae commonly found in the ocean and a bacterium.

    The process involves the algae engulfing the bacterium and providing it with nutrients, energy and protection in return for functions that it could not previously perform – in this instance, the ability to “fix” nitrogen from the air.

    The algae then incorporates the bacterium as an internal organ called an organelle, which becomes vital to the host’s ability to function.

    The researchers from the US and Japan who made the discovery said it will offer new insights into the process of evolution, while also holding the potential to fundamentally change agriculture.

    “This system is a new perspective on nitrogen fixation, and it might provide clues into how such an organelle could be engineered into crop plants,” said Dr Coale.

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