Another accidental use for “junk DNA”

_{Denyse O'Leary

October 7, 2016

'Junk DNA', Intelligent Design, News}

Share: Facebook; Twitter; LinkedIn; Flipboard; Print; Email

mouse embryo showing enhancer activity (blue stain) in heart/Berkeley Labs

Researchers have shown that when parts of a genome known as enhancers are missing, the heart works abnormally, a finding that bolsters the importance of DNA segments once considered “junk” because they do not code for specific proteins.

…

“The cardiac changes that we observed in knockout mice lacking these enhancers highlight the role of noncoding sequences in processes that are important in human disease,” said study co-senior author Axel Visel, senior staff scientist and one of three lead researchers at the Mammalian Functional Genomics Laboratory, part of Berkeley Lab’s Environmental Genomics and Systems Biology (EGSB) Division. “Identifying and interpreting sequence changes affecting noncoding sequences is increasingly a challenge in human genetics. The genome-wide catalog of heart enhancers provided through this study will facilitate the interpretation of human genetic data sets.” Paper. (public access) – Diane E. Dickel, et al., Genome-wide compendium and functional assessment of in vivo heart enhancers. Nature Communications, 2016; 7: 12923 DOI: 10.1038/NCOMMS12923 More.

See also: Formerly thought “junk DNA,” lncRNA guides development of heart muscle cells

and

The latest in functional junk DNA

Follow UD News at Twitter!

Comments

Neo-Darwinists, OTOH, limiting themselves to only ‘coding’ DNA, have thrown science off the proper track of discovering where ‘disease’ lies. Apparently, it’s not with the “genes,” but with the ‘enhancers.’
You are pretty good at the destroying these strawmen, maybe you should step up to critiquing the actual science. Neo-Darwinists have never limited themselves to protein coding genes. King and Wilson were already concluding that much evolution ocurred by altering gene regulation in 1975. Once we started being able to study evo-devo in the 1990s, it became increasingly clear that cis-regulatory evolution was indeed important. The methods used to discoved gene-disease associations (GWAS, or earlier linkage mapping) are agnostic as to wether a disease-causing variant is protein coding or not. So, even if those big bad Darwinists had been misleading everyone, they wouldn't have prevented people from finding disase-associated alleles in non-coding sequences.wd400_{October 7, 2016
October
10
Oct
7
07
2016
09:57 PM
9
09
57
PM
PDT}

Origines, If we have found thousands of enchancers then we probably weren't discounting all non-coding sequences as junk... right?
Or is there another method — besides knocking out the heart enhancers in the genome and look at heart function — to establish that these genetic regions are heart enhancers?
Sequence motifs associated with cardiac transcription factors, conserved motifs near to known cardiac genes, homology to variants in model species, molecular interaction data from lab experiments...wd400_{October 7, 2016
October
10
Oct
7
07
2016
09:41 PM
9
09
41
PM
PDT}

Origenes, Part of the reason for the study is to find new ways to identify enhancers. This site talks about it, and references the study in the op: http://newscenter.lbl.gov/2014/03/24/new-technique-for-identifying-gene-enhancers/ If the way of identifying them was by disabling part of the genome then only a few would be known instead of thousands. But, true, you can't be really sure until disabling that part of the genome, and right now it seems to be the only way to know what would happen if the enhancer was disabled. That's why they were curious as to what would happen, because it had never been done before for any heart enhancer. But the point is that there were never just two categories of dna, stuff that directly codes for dna, and junk, as the op implies.goodusername_{October 7, 2016
October
10
Oct
7
07
2016
07:17 PM
7
07
17
PM
PDT}

This study conclusively links enhancers to proper heart function. Maybe the 'genes' (sequences that code) are critical to there being a heart in the first place, but 'enhancers' are what make it work 'properly.' I suppose if you have a bad heart, you might not leave so many descendants. IOW, it is wrong to ignore non-coding DNA when considering "selective" events. IDists have been saying this now for decades. Neo-Darwinists, OTOH, limiting themselves to only 'coding' DNA, have thrown science off the proper track of discovering where 'disease' lies. Apparently, it's not with the "genes," but with the 'enhancers.' From the end of the study's "Discussion":
Overall, this study highlights the important role enhancers play in cardiac health and provides a valuable compendium of human heart enhancers that can be easily integrated into cardiovascular disease studies.
Just think: in humans we have 20,000 'genes,' and, for just the 'heart', we have 80,000 possible 'enhancers.' Don't these two numbers tell us a lot?PaV_{October 7, 2016
October
10
Oct
7
07
2016
06:49 PM
6
06
49
PM
PDT}

Goodusername, How can anyone know that these regions are heart enhancers, prior to doing the experiment that shows that these regions are heart enhancers? Or is there another method — besides knocking out the heart enhancers in the genome and look at heart function — to establish that these genetic regions are heart enhancers? If so, reference please.Origenes_{October 7, 2016
October
10
Oct
7
07
2016
06:30 PM
6
06
30
PM
PDT}

Origenes, Leave out the "despite the fact" and your statement makes perfect sense. They wanted to know what would happen if they disabled heart enhancers, so they disabled the parts of the genome that are heart enhancers. What part of that is odd?goodusername_{October 7, 2016
October
10
Oct
7
07
2016
06:11 PM
6
06
11
PM
PDT}

Goodusername: These regions were already KNOWN to be enhancers, i.e they weren’t thought to be junk dna.
So these regions were already known to be (heart) enhancers, despite the fact that “prior to this work, no study had looked at what happens to heart function as a result of knocking out the heart enhancers in the genome”? I find that odd.Origenes_{October 7, 2016
October
10
Oct
7
07
2016
05:08 PM
5
05
08
PM
PDT}

Origenes, These regions were already KNOWN to be enhancers, i.e they weren't thought to be junk dna. The person who wrote the article apparently believed that despite being known enhancers that they were still believed to be junk DNA "because they do not code for specific proteins."goodusername_{October 7, 2016
October
10
Oct
7
07
2016
04:25 PM
4
04
25
PM
PDT}

Goodusername, “Prior to this work, no study had looked at what happens to heart function as a result of knocking out the heart enhancers in the genome”, indicate that these heart enhancers were (wrongly) assumed to be part of "junk-DNA".Origenes_{October 7, 2016
October
10
Oct
7
07
2016
03:56 PM
3
03
56
PM
PDT}

Easy there Origenes. wd400 is a neutralist like Moran. Their love for junk DNA runs deep. You might as well talk bad about his mother rather than talk bad about junk DNA.bornagain77_{October 7, 2016
October
10
Oct
7
07
2016
03:42 PM
3
03
42
PM
PDT}

Surely, those thousands of mapped enhancers were not considered junk-DNA.
I'm glad you realize that, but I'm not sure that the person who wrote the article does.goodusername_{October 7, 2016
October
10
Oct
7
07
2016
03:40 PM
3
03
40
PM
PDT}

wd400,
Enhancers were discovered in the 1970s, and we have mapped thousands of enhancers in the human genome. Do you really think anyone that thinks most of the genome is junk included enhancers is that tally?
That's the wrong question. Surely, those thousands of mapped enhancers were not considered junk-DNA. The question is: how about the enhancers which were not mapped? Today, with respect to the heart alone "80,000 candidate heart enhancers in the human genome" have been identified.
"Prior to this work, no study had looked at what happens to heart function as a result of knocking out the heart enhancers in the genome," said Dickel. "What was surprising to me was that outwardly, the knockout mice seemed fine. If you just looked at them, you wouldn't necessarily see anything wrong." Echocardiograms used to image the hearts from the two groups of mice confirmed that the heart tissue of mice with a disabled enhancer was pumping with less power than normal, consistent with the signs of human cardiomyopathy. [Sciencedaily.com]
Origenes_{October 7, 2016
October
10
Oct
7
07
2016
03:12 PM
3
03
12
PM
PDT}

It's kind amazing how predictably terrible press releases that use the "once considered junk..." meme are. Enhancers were discovered in the 1970s, and we have mapped thousands of enhancers in the human genome. Do you really think anyone that thinks most of the genome is junk included enhancers is that tally?wd400_{October 7, 2016
October
10
Oct
7
07
2016
02:26 PM
2
02
26
PM
PDT}

Prev 1 2 3

You must be logged in to post a comment.

Leave a Reply