4 ms·

> The scientists think the sea slugs are using the energy from the photosynthesis occurring in cells that they’ve gained from algae they’ve eaten. So they have

by scribu 6y ago

> The scientists think the sea slugs are using the energy from the photosynthesis occurring in cells that they’ve gained from algae they’ve eaten. So they have enough active algae cells in their head to power the growth of a whole new body. Incredible!

_Microft 6y ago
The summary of the paper mentions this process, it is called Kleptoplasty and - unsurprisingly - it has an article on Wikipedia including some cool photos! https://en.wikipedia.org/wiki/Kleptoplasty https://en.wikipedia.org/wiki/Kleptoplasty I am not the biggest fan of slugs but this one is amazing: https://en.wikipedia.org/wiki/Kleptoplasty#/media/File:Costasiella_Kuroshimae_(19080120525)_(2).jpg https://en.wikipedia.org/wiki/Kleptoplasty#/media/File:Costa...
- TeMPOraL 6y ago
  Also related: https://en.wikipedia.org/wiki/Kleptoprotein https://en.wikipedia.org/wiki/Kleptoprotein I sort of assumed this happens as a part of normal digestion, but existence of this term would imply that reusing digested proteins wholesale is in fact not common. (EDIT: also I wish I could clone myself and keep my clone doing my software job, while I'd go full-time into learning biology and biotech; life is so fascinating.)
  - _Microft 6y ago
    This is really surprising. How do these proteins evade digestion - or do e.g. fish not denaturalize proteins during digestion at all? I would assume that they do to protect themselves from pathogens contained in their food?
    - TeMPOraL 6y ago
      The paper that introduced the term "kleptoprotein" seems to be from 2020, so this is very fresh research. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6949039/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6949039/ From what little I understand from it, it doesn't seem they have the mechanism explained yet, though they hint that it's possible the immune system may have been co-opted for this. Relevant paragraph from "Discussion" section below: Kleptoprotein in bioluminescent fish was unexpected because ingested proteins are usually decomposed in digestive systems, including pyloric caeca in fishes, into amino acids or oligopeptides and absorbed through the gut wall as nutrients. This means that the original structure and enzymatic activity of ingested proteins are typically not maintained during their passage through digestive tracts. However, the phenomenon of protein uptake without full digestion has been reported in some vertebrate immune systems. For example, M cells in mammalian intestinal epithelia play an important role for the immune system by taking macromolecules or even microbes into the cell as antigens via pinocytosis (24). Similar antigen-sampling functions were reported in the intestinal epithelium of cyprinid fishes, and the presence of M cell–like cells was reported in the intestine of a salmonid fish (25–27). While this mechanism for protein uptake is not selective and the protein is not used for its original function, these immune systems may have been co-opted to serve a kleptoprotein role in Parapriacanthus bioluminescence during evolution. We expect that the reason why ostracod luciferase was exploited for kleptoprotein bioluminescence of Parapriacanthus is due partly to its high proteolytic resistance and highly stable nature (fig. S9). Kleptoprotein bioluminescence using the ostracod luciferase might have also evolved in parallel in some other teleost lineages, e.g., the apogonid fishes Jaydia ellioti and Rhabdamia cypselura, which use vargulin for their luminescence and whose light organs are connected to the digestive tract (16, 17), as in Parapriacanthus.
- whoisburbansky 6y ago
  Funny that the wiki page calls out that the energy benefit from having all that chloroplast around is actually marginal at best, and actually seems to hurt sometimes because of higher levels of reactive oxygen species created as a byproduct of photosynthesis, causing them to die sooner.
- agumonkey 6y ago
  This is above anything I could imagine being imagined by a random artist. Very surprising.
whoisburbansky 6y ago
I'm being ridiculously pedantic, but they're technically using the saved up chloroplast (not the whole algae cell) to power moving the head around enough to eat more algae, which is what powers the body-growing.

by scribu 6y ago

_Microft 6y ago

The summary of the paper mentions this process, it is called Kleptoplasty and - unsurprisingly - it has an article on Wikipedia including some cool photos! https://en.wikipedia.org/wiki/Kleptoplasty https://en.wikipedia.org/wiki/Kleptoplasty I am not the biggest fan of slugs but this one is amazing: https://en.wikipedia.org/wiki/Kleptoplasty#/media/File:Costasiella_Kuroshimae_(19080120525)_(2).jpg https://en.wikipedia.org/wiki/Kleptoplasty#/media/File:Costa...

TeMPOraL 6y ago
Also related: https://en.wikipedia.org/wiki/Kleptoprotein https://en.wikipedia.org/wiki/Kleptoprotein I sort of assumed this happens as a part of normal digestion, but existence of this term would imply that reusing digested proteins wholesale is in fact not common. (EDIT: also I wish I could clone myself and keep my clone doing my software job, while I'd go full-time into learning biology and biotech; life is so fascinating.)
- _Microft 6y ago
  This is really surprising. How do these proteins evade digestion - or do e.g. fish not denaturalize proteins during digestion at all? I would assume that they do to protect themselves from pathogens contained in their food?
  - TeMPOraL 6y ago
    The paper that introduced the term "kleptoprotein" seems to be from 2020, so this is very fresh research. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6949039/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6949039/ From what little I understand from it, it doesn't seem they have the mechanism explained yet, though they hint that it's possible the immune system may have been co-opted for this. Relevant paragraph from "Discussion" section below: Kleptoprotein in bioluminescent fish was unexpected because ingested proteins are usually decomposed in digestive systems, including pyloric caeca in fishes, into amino acids or oligopeptides and absorbed through the gut wall as nutrients. This means that the original structure and enzymatic activity of ingested proteins are typically not maintained during their passage through digestive tracts. However, the phenomenon of protein uptake without full digestion has been reported in some vertebrate immune systems. For example, M cells in mammalian intestinal epithelia play an important role for the immune system by taking macromolecules or even microbes into the cell as antigens via pinocytosis (24). Similar antigen-sampling functions were reported in the intestinal epithelium of cyprinid fishes, and the presence of M cell–like cells was reported in the intestine of a salmonid fish (25–27). While this mechanism for protein uptake is not selective and the protein is not used for its original function, these immune systems may have been co-opted to serve a kleptoprotein role in Parapriacanthus bioluminescence during evolution. We expect that the reason why ostracod luciferase was exploited for kleptoprotein bioluminescence of Parapriacanthus is due partly to its high proteolytic resistance and highly stable nature (fig. S9). Kleptoprotein bioluminescence using the ostracod luciferase might have also evolved in parallel in some other teleost lineages, e.g., the apogonid fishes Jaydia ellioti and Rhabdamia cypselura, which use vargulin for their luminescence and whose light organs are connected to the digestive tract (16, 17), as in Parapriacanthus.
whoisburbansky 6y ago
Funny that the wiki page calls out that the energy benefit from having all that chloroplast around is actually marginal at best, and actually seems to hurt sometimes because of higher levels of reactive oxygen species created as a byproduct of photosynthesis, causing them to die sooner.
agumonkey 6y ago
This is above anything I could imagine being imagined by a random artist. Very surprising.

whoisburbansky 6y ago

I'm being ridiculously pedantic, but they're technically using the saved up chloroplast (not the whole algae cell) to power moving the head around enough to eat more algae, which is what powers the body-growing.