from the threaded-granules dept.
A piece of high school genetics, relied on for many sorts of genetic testing, has been found to have exceptions. Although mitochondrial DNA (mtDNA) is normally received from the mother, three families have been identified where people received some of their mtDNA, three-quarters in the most extreme case, from their father. The finding may change the way we treat mitochondrial diseases and brings genetic testing for maternal ancestry into question.
MtDNA exists separately from the rest of our DNA, inside the thousands of mitochondria within each cell, rather than the cell nucleus. It is so widely accepted as being from the mother's side it is sometimes known as the Eve Gene, the idea being that it can be traced back to some primeval mother of all living humans. Testing of mtDNA is used to identify maternal ancestry.
However, all that will have to change after Dr Shiyu Luo of the Cincinnati Children's Hospital Medical Center published a paper in the Proceedings of the National Academy of Sciences.
Luo's first exception is a boy who at four was hospitalized with symptoms suggestive of mitochondrial disease. Sequencing of the boy's mitochondria revealed no disease-causing genes, but some oddities in the mtDNA that led Luo and colleagues to sequence other family members for comparison. Around 40 percent of the boy's mitochondria matched that from his mother's father, and only 60 percent came from his grandmother.
After testing of other members of the same family, and other families with mitochondrial diseases, Luo found that, while paternal inheritance is very rare, it has occurred at least 17 times in three tested families.
(Score: 2) by MichaelDavidCrawford on Wednesday November 28 2018, @07:56AM
She was an African woman sixty thousand years ago.
That's a long enough time that somebody's male MtDNA could be in _all_ of us.
Or rather, just _some_ of us.
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(Score: 0) by Anonymous Coward on Wednesday November 28 2018, @12:25PM (6 children)
i hope nobody failed or had to "repeat-year" highschool because they got this question "wrong" in biology class.
which makes one wonder what other new research wonders will over turn the present schooll text books?
which kinda leads to the suggestion that going to school (not uni) is more about learning to submit and memorize then acctually learning something useful (besides reading, writing and basic calculations).
maybe if someone would have mentioned above to me during school time i would have approached the whole thing differently, less serious and more like a game of useless obstecles...
(Score: 4, Insightful) by Anonymous Coward on Wednesday November 28 2018, @01:54PM
If you get one question "wrong" and that causes you to fail the class, I don't think this one question is the central piece of the problem.
(Score: 5, Interesting) by ikanreed on Wednesday November 28 2018, @04:13PM (3 children)
You know that passing science class tests always means "Giving the answer that was generally thought to be correct when the textbook was published", right? And that's when they don't purposefully simplify because they deem kids too dumb to understand the difference between a probability cloud and a single particle floating around a nucleus.
I wouldn't expect anything below a university undergraduate with some kind of focus in biology to need this level of nuance for classes.
What I personally wonder about though, is all the assumptions that have gone into conclusions about "y chromosome adam" and "mitochondrial eve" and whether all the analyses of those concepts are now bunk.
(Score: 2) by nitehawk214 on Wednesday November 28 2018, @05:02PM (2 children)
"Giving the answer that was generally thought to be correct when the textbook was published" Also means "Even if it is generally thought to be wrong, now."
I went to primary school pre-internet, so it was much easier to declare "the textbook is the bible, it shall not be questioned." I wonder how teachers handle this now in the age of standardized tests.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 3, Insightful) by ikanreed on Wednesday November 28 2018, @05:13PM
They standardize the tests by making them match the textbooks they require all the schools to have. Some states even test students on known to be wrong answers for political reasons. *cough*Texas*hack*
That's not the joke answer. That's what they do.
(Score: 3, Insightful) by DeathMonkey on Wednesday November 28 2018, @06:49PM
Good. They should get used to the fact that science changes all the time as it improves itself.
Learning something, and then later learning why it's actually wrong is how science should be taught.
(Score: 1, Interesting) by Anonymous Coward on Wednesday November 28 2018, @07:17PM
Not overturned, refined.
(Score: 3, Interesting) by opinionated_science on Wednesday November 28 2018, @01:48PM
this has been known for many years (I read it in a book ,so that's how old....!!!).
All things in biology are "fuzzy", although that's not so easy to parameterize...;-)
(Score: 2) by bob_super on Wednesday November 28 2018, @06:04PM
> is very rare, it has occurred at least 17 times in three tested families.
Did someone go to buy a lottery ticket shortly after, or did they just redefine "rare" when I wasn't looking ?
Even with 15 kids per generation and 5 generations, finding something 17 times in 3 tested families would definitely make me think it's about as rare as Chinese steak.