Junk DNA goodbye: creating limbs (Introduction)

by David Turell , Wednesday, May 26, 2021, 23:29 (1277 days ago) @ David Turell

Needs lots of 'junk' to work:

https://evolutionnews.org/2021/05/noncoding-junk-dna-is-important-for-limb-formation/

"A 2021 article in Nature, “Non-coding deletions identify Maenli lncRNA as a limb-specific En1 regulator,” reports important new functions for non-coding or “junk” DNA that underlie limb formation.

***

"The technical paper in Nature describes the research. The investigators examined the chromosomes of people who had naturally occurring limb malformation, and found that these people had deletions of DNA encoding long non-coding RNA sequences (lncRNAs) from human chromosome 2. They deleted corresponding DNA sequences in mice and found similar “severe congenital limb malformation,” suggesting these lncRNA sequences are functionally important:

"Here we show that genetic ablation of a lncRNA locus on human chromosome 2 causes a severe congenital limb malformation. We identified homozygous 27–63-kilobase deletions located 300 kilobases upstream of the engrailed-1 gene (EN1) in patients with a complex limb malformation featuring mesomelic shortening, syndactyly and ventral nails (dorsal dimelia). Re-engineering of the human deletions in mice resulted in a complete loss of En1expression in the limb and a double dorsal-limb phenotype that recapitulates the human disease phenotype. Genome-wide transcriptome analysis in the developing mouse limb revealed a four-exon-long non-coding transcript within the deleted region, which we named Maenli. Functional dissection of the Maenli locus showed that its transcriptional activity is required for limb-specific En1 activation in cis, thereby fine-tuning the gene-regulatory networks controlling dorso-ventral polarity in the developing limb bud.

***

"In the era of whole-genome sequencing, the findings described here underscore the need for a systematic annotation and functional characterization of lncRNA loci to interpret and classify non-coding genetic variants. They highlight the importance of elucidating the complex diversity of lncRNA modes of action to assess their role in organ development and disease.

***

"Another 2021 article in Nature shows why it’s no longer tenable for evolutionists to hide behind such an argument from ignorance. The article explains that over 130,000 functional “genomic elements, previously called junk DNA” have now been discovered, highlighting how important these “junk” segments have turned out to be: (my bold)

"t is now appreciated that the majority of functional sequences in the human genome do not encode proteins. Rather, elements such as long non-coding RNAs, promoters, enhancers and countless gene-regulatory motifs work together to bring the genome to life. Variation in these regions does not alter proteins, but it can perturb the networks governing protein expression With the HGP draft in hand, the discovery of non-protein-coding elements exploded. So far, that growth has outstripped the discovery of protein-coding genes by a factor of five, and shows no signs of slowing. Likewise, the number of publications about such elements also grew in the period covered by our data set. For example, there are thousands of papers on non-coding RNAs, which regulate gene expression."

Comment: All of these discoveries show that most human complaints about God's 'bad' designs are as my bold shows, arguments from ignorance. Human judgement is not God's judgement. What seems bad must be proven bad to have any honest discussion about God and His works.