LSI Blog - Friday, July 16, 2010
Pseudogenes: No Longer Considered Vestigial
They have been found to help protect their protein-
producing twin genes.
Summary: Some genes are able to distract interfering molecules by using
pseudogenes as decoys, according to a new study. The pseudogenes,
"defective" copies of protein-encoding genes, can often make RNA copies
of the instructions within their DNA but are unable to actually make
proteins.
Because the pseudogenes can't make proteins, most biologists have
considered them as being vestigial, which means degenerate or defective
copies of functioning genes. However, the new study, published in the
June 24 edition of Nature, reports that these "doppelganger" genes are
not only still alive, but actually may be important regulators of their protein-
making twins.
The discovery that pseudogenes have a function could transform biology,
according to Pier Paolo Pandolfi, a geneticist and biologist from Boston
who led the study. It has already changed the perspective of people in his
lab, he says. “Now we are unable to think the same. It changes the way
we do biology on a daily basis.”
Pandolfi's group found that RNA from a pseudogene called PTENP1 acts
as a decoy by attracting tiny regulatory molecules called microRNAs away
from the pseudogene's counterpart, a powerful anticancer gene called
PTEN. MicroRNAs are small pieces of RNA that can interfere with the
cell's ability to make protein. Pandolfi thinks that the microRNAs are
unable to tell PTENP1 apart from PTEN. The researchers showed that
removing the protective PTENP1 from cells did indeed squelch protein
production.
The scientists also found that tumors from colon cancer patients were
sometimes missing PTENP1, a hint that the pseudogene could have
helped protect against the tumor had it been present. However, it is too
early to tell if all the thousands of pseudogenes in humans are able to
regulate their protein-coding siblings in a similar way. Frank Furnari, a
cancer biologist at the U. of California in San Diego, did say, “For sure we
know the importance of microRNAs, and now to have this mechanism by
which microRNAs are regulated by what we thought was junk DNA is
somewhat surprising and exciting.”
To read the entire article, click on SCIENCE NEWS.
Comment: The idea that there might be vestigial organs or features has
often been used to support the notion of evolution. It stands to reason
that if creatures have evolved into new kinds of creatures, they will likely
have retained body parts that have lost a function or ability and become
degenerate. These organs or body parts that once had a purpose but
which no longer function properly have been called vestigial. Note: a
newer definition of "vestigial" simply means a body part that has become
smaller and has a reduced function, but I am here using the traditional
meaning.
Are there any organs that truly are vestigial? An Australian creationist
organization says there once were around 180 organs such as the
appendix, tonsils, pineal gland, and thymus that had been considered
useless and vestigial because they were no longer needed. Today that
list has shrunk dramatically as important functions for these organs have
been discovered. It appears something similar has happened with the
pseudogenes. Could it be these pseudogenes were created as they
currently are for the purpose of protecting their twins and were never
intended to produce proteins?
When God had finished creating the world, He said it was very good
(Genesis 1:31). Therefore it doesn't seem reasonable to suggest He
created any "junk DNA" or any body parts in humans or in any other
species that did not have important functions. Of course, sin destroyed
this perfect world and some things have degenerated. In fact, our genes
themselves seem to be degenerating due to the effects of harmful
mutations. However, blame this situation on sin, not on evolution.
Happily, the time is coming when all our organs and other body parts will
work perfectly, with no evidence of disease or degeneration. We will have
glorified bodies (Philippians 3:21) and pure souls in heaven, and our free
ticket there is made possible by the suffering and death of Jesus Christ.
Pseudogenes: No Longer Considered Vestigial
They have been found to help protect their protein-
producing twin genes.
Summary: Some genes are able to distract interfering molecules by using
pseudogenes as decoys, according to a new study. The pseudogenes,
"defective" copies of protein-encoding genes, can often make RNA copies
of the instructions within their DNA but are unable to actually make
proteins.
Because the pseudogenes can't make proteins, most biologists have
considered them as being vestigial, which means degenerate or defective
copies of functioning genes. However, the new study, published in the
June 24 edition of Nature, reports that these "doppelganger" genes are
not only still alive, but actually may be important regulators of their protein-
making twins.
The discovery that pseudogenes have a function could transform biology,
according to Pier Paolo Pandolfi, a geneticist and biologist from Boston
who led the study. It has already changed the perspective of people in his
lab, he says. “Now we are unable to think the same. It changes the way
we do biology on a daily basis.”
Pandolfi's group found that RNA from a pseudogene called PTENP1 acts
as a decoy by attracting tiny regulatory molecules called microRNAs away
from the pseudogene's counterpart, a powerful anticancer gene called
PTEN. MicroRNAs are small pieces of RNA that can interfere with the
cell's ability to make protein. Pandolfi thinks that the microRNAs are
unable to tell PTENP1 apart from PTEN. The researchers showed that
removing the protective PTENP1 from cells did indeed squelch protein
production.
The scientists also found that tumors from colon cancer patients were
sometimes missing PTENP1, a hint that the pseudogene could have
helped protect against the tumor had it been present. However, it is too
early to tell if all the thousands of pseudogenes in humans are able to
regulate their protein-coding siblings in a similar way. Frank Furnari, a
cancer biologist at the U. of California in San Diego, did say, “For sure we
know the importance of microRNAs, and now to have this mechanism by
which microRNAs are regulated by what we thought was junk DNA is
somewhat surprising and exciting.”
To read the entire article, click on SCIENCE NEWS.
Comment: The idea that there might be vestigial organs or features has
often been used to support the notion of evolution. It stands to reason
that if creatures have evolved into new kinds of creatures, they will likely
have retained body parts that have lost a function or ability and become
degenerate. These organs or body parts that once had a purpose but
which no longer function properly have been called vestigial. Note: a
newer definition of "vestigial" simply means a body part that has become
smaller and has a reduced function, but I am here using the traditional
meaning.
Are there any organs that truly are vestigial? An Australian creationist
organization says there once were around 180 organs such as the
appendix, tonsils, pineal gland, and thymus that had been considered
useless and vestigial because they were no longer needed. Today that
list has shrunk dramatically as important functions for these organs have
been discovered. It appears something similar has happened with the
pseudogenes. Could it be these pseudogenes were created as they
currently are for the purpose of protecting their twins and were never
intended to produce proteins?
When God had finished creating the world, He said it was very good
(Genesis 1:31). Therefore it doesn't seem reasonable to suggest He
created any "junk DNA" or any body parts in humans or in any other
species that did not have important functions. Of course, sin destroyed
this perfect world and some things have degenerated. In fact, our genes
themselves seem to be degenerating due to the effects of harmful
mutations. However, blame this situation on sin, not on evolution.
Happily, the time is coming when all our organs and other body parts will
work perfectly, with no evidence of disease or degeneration. We will have
glorified bodies (Philippians 3:21) and pure souls in heaven, and our free
ticket there is made possible by the suffering and death of Jesus Christ.
