• Nuclear preservation in Caudipteryx

    From Pandora@21:1/5 to All on Sat Sep 25 16:57:16 2021
    Nuclear preservation in the cartilage of the Jehol dinosaur
    Caudipteryx

    Abstract

    Previous findings on dinosaur cartilage material from the Late
    Cretaceous of Montana suggested that cartilage is a vertebrate tissue
    with unique characteristics that favor nuclear preservation. Here, we
    analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
    Early Cretaceous Jehol biota of Northeast China. The cartilage
    fragment is highly diagenetically altered when observed in
    ground-sections but shows exquisite preservation after
    demineralization. It reveals transparent, alumino-silicified
    chondrocytes and brown, ironized chondrocytes. The histochemical stain Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
    cells) was applied to both the demineralized cartilage of Caudipteryx
    and that of a chicken. The two specimens reacted identically, and one
    dinosaur chondrocyte revealed a nucleus with fossilized threads of
    chromatin. This is the second example of fossilized chromatin threads
    in a vertebrate material. These data show that some of the original
    nuclear biochemistry is preserved in this dinosaur cartilage material
    and further support the hypothesis that cartilage is very prone to
    nuclear fossilization and a perfect candidate to further understand
    DNA preservation in deep time.

    https://www.nature.com/articles/s42003-021-02627-8

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  • From erik simpson@21:1/5 to Pandora on Sat Sep 25 08:30:35 2021
    On Saturday, September 25, 2021 at 7:57:18 AM UTC-7, Pandora wrote:
    Nuclear preservation in the cartilage of the Jehol dinosaur
    Caudipteryx

    Abstract

    Previous findings on dinosaur cartilage material from the Late
    Cretaceous of Montana suggested that cartilage is a vertebrate tissue
    with unique characteristics that favor nuclear preservation. Here, we
    analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
    Early Cretaceous Jehol biota of Northeast China. The cartilage
    fragment is highly diagenetically altered when observed in
    ground-sections but shows exquisite preservation after
    demineralization. It reveals transparent, alumino-silicified
    chondrocytes and brown, ironized chondrocytes. The histochemical stain Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
    cells) was applied to both the demineralized cartilage of Caudipteryx
    and that of a chicken. The two specimens reacted identically, and one dinosaur chondrocyte revealed a nucleus with fossilized threads of
    chromatin. This is the second example of fossilized chromatin threads
    in a vertebrate material. These data show that some of the original
    nuclear biochemistry is preserved in this dinosaur cartilage material
    and further support the hypothesis that cartilage is very prone to
    nuclear fossilization and a perfect candidate to further understand
    DNA preservation in deep time.

    https://www.nature.com/articles/s42003-021-02627-8

    Very interesting result. The identical response to histochemical stains seen in Caudipteryx and
    chicken is pretty amazing. Not Jurassic Park yet (just early Cretaceous), but getting closer. Have
    to acknowedge Glenn's stupid but precient comment on another thread:

    https://groups.google.com/g/sci.bio.paleontology/c/b83QxKc5qgY/m/j4QNkOOcAgAJ

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  • From John Harshman@21:1/5 to Pandora on Sat Sep 25 09:45:32 2021
    On 9/25/21 7:57 AM, Pandora wrote:
    Nuclear preservation in the cartilage of the Jehol dinosaur
    Caudipteryx

    Abstract

    Previous findings on dinosaur cartilage material from the Late
    Cretaceous of Montana suggested that cartilage is a vertebrate tissue
    with unique characteristics that favor nuclear preservation. Here, we
    analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
    Early Cretaceous Jehol biota of Northeast China. The cartilage
    fragment is highly diagenetically altered when observed in
    ground-sections but shows exquisite preservation after
    demineralization. It reveals transparent, alumino-silicified
    chondrocytes and brown, ironized chondrocytes. The histochemical stain Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
    cells) was applied to both the demineralized cartilage of Caudipteryx
    and that of a chicken. The two specimens reacted identically, and one dinosaur chondrocyte revealed a nucleus with fossilized threads of
    chromatin. This is the second example of fossilized chromatin threads
    in a vertebrate material. These data show that some of the original
    nuclear biochemistry is preserved in this dinosaur cartilage material
    and further support the hypothesis that cartilage is very prone to
    nuclear fossilization and a perfect candidate to further understand
    DNA preservation in deep time.

    https://www.nature.com/articles/s42003-021-02627-8

    I'm not optimistic that anything will come of this, but wouldn't it be
    cool if it did?

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  • From Oxyaena@21:1/5 to John Harshman on Mon Sep 27 15:43:25 2021
    On 9/25/2021 12:45 PM, John Harshman wrote:
    On 9/25/21 7:57 AM, Pandora wrote:
    Nuclear preservation in the cartilage of the Jehol dinosaur
    Caudipteryx

    Abstract

    Previous findings on dinosaur cartilage material from the Late
    Cretaceous of Montana suggested that cartilage is a vertebrate tissue
    with unique characteristics that favor nuclear preservation. Here, we
    analyze additional dinosaur cartilage in Caudipteryx (STM4-3) from the
    Early Cretaceous Jehol biota of Northeast China. The cartilage
    fragment is highly diagenetically altered when observed in
    ground-sections but shows exquisite preservation after
    demineralization. It reveals transparent, alumino-silicified
    chondrocytes and brown, ironized chondrocytes. The histochemical stain
    Hematoxylin and Eosin (that stains the nucleus and cytoplasm in extant
    cells) was applied to both the demineralized cartilage of Caudipteryx
    and that of a chicken. The two specimens reacted identically, and one
    dinosaur chondrocyte revealed a nucleus with fossilized threads of
    chromatin. This is the second example of fossilized chromatin threads
    in a vertebrate material. These data show that some of the original
    nuclear biochemistry is preserved in this dinosaur cartilage material
    and further support the hypothesis that cartilage is very prone to
    nuclear fossilization and a perfect candidate to further understand
    DNA preservation in deep time.

    https://www.nature.com/articles/s42003-021-02627-8

    I'm not optimistic that anything will come of this, but wouldn't it be
    cool if it did?

    That reminds me of the time they claimed to get viable DNA from some 40
    million year old bug fossils found preserved in Amber. It's now thought
    those results were due to carelessness, contamination, and several other factors. In other words, they were inauthentic.

    https://en.wikipedia.org/wiki/Ancient_DNA#1990s

    The half-life of DNA is thought to be around 500 years old, so the
    absolute upper limit for DNA recovery is around six million years or so.
    Far too young to get anything meaningful from anything found in the
    fossil of a non-avian dinosaur, that's for sure. Useful for the study of
    human evolution, however.

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