Pax6 geeni yhteistä kaikille eläimille, joka näyttää indusoivan silmän syntyä.
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A possible Precambrian origin for topographic maps in the visual system
James N. Ingram
Trends in Neurosciences, 2002, 25:5:232
The various solutions to the problem of photoreception in the animal
kingdom have been regarded as independent evolutionary inventions.
Indeed, it would be difficult to imagine visual systems more different
than those of flies and humans. However, the eyes of animals as diverse
as flatworms, arthropods, cephalopods and vertebrates appear to be
derived from a prototypical light-sensing organ that was present in the
common ancestor of all groups. This hypothetical creature lived >550
million years ago and swam in Precambrian oceans, and the genes required
to build its primitive visual system have been inherited by today's
animals. The gene known as Pax6, for example, appears to be the master
control gene for eye development in all animals, having been so
dramatically conserved through 550 million years of evolution that mouse
and squid versions of the gene can induce ectopic eyes when expressed in
fruit flies.
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-----
A possible Precambrian origin for topographic maps in the visual system
James N. Ingram
Trends in Neurosciences, 2002, 25:5:232
The various solutions to the problem of photoreception in the animal
kingdom have been regarded as independent evolutionary inventions.
Indeed, it would be difficult to imagine visual systems more different
than those of flies and humans. However, the eyes of animals as diverse
as flatworms, arthropods, cephalopods and vertebrates appear to be
derived from a prototypical light-sensing organ that was present in the
common ancestor of all groups. This hypothetical creature lived >550
million years ago and swam in Precambrian oceans, and the genes required
to build its primitive visual system have been inherited by today's
animals. The gene known as Pax6, for example, appears to be the master
control gene for eye development in all animals, having been so
dramatically conserved through 550 million years of evolution that mouse
and squid versions of the gene can induce ectopic eyes when expressed in
fruit flies.
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Vastaukset 2
Vanhimmat
Kyllä vaan on Taivaan Isä kaiken ihmeellisesti tehnyt. Hyvää jatkoa ja siunausta.
miten ja mistä se trilobiitin silmä(mikä vaan niistä muistaakseni kolmesta erilaisesta) kehittyikään?