"One of the past arguments for evidence of biological evolution in the genome has been the concept of pseudogenes. These DNA sequences were once thought to be the defunct remnants of genes, representing nothing but mutated genomic “fossils” in the genomes of plants, animals, and humans.
*However, much research has been published over the past several decades showing that pseudogenes are not only functional but key to organism survival.
Pseudogenes come in three different forms depending on their DNA sequence characteristics. The group of pseudogenes that has the largest representation in the human genome is what is called a processed pseudogene (also called a retrogene). There are about 10,000 of these in humans, and this category is also the most highly studied for functionality.
It has been postulated by evolutionists that these processed pseudogenes were derived from an mRNA copy of a protein-coding gene that had its intervening sequences (introns) spliced out, which were then retro-transcribed into DNA and inserted back into the
genome—hence the moniker “processed.”
Pseudogenes come in three different forms depending on their DNA sequence characteristics. The group of pseudogenes that has the largest representation in the human genome is what is called a processed pseudogene (also called a retrogene). There are about 10,000 of these in humans, and this category is also the most highly studied for functionality.
It has been postulated by evolutionists that these processed pseudogenes were derived from an mRNA copy of a protein-coding gene that had its intervening sequences (introns) spliced out, which were then retro-transcribed into DNA and inserted back into the
Conventional scientists believe that this is why these types of pseudogenes lack introns and, in most cases, a promoter region similar to that of its protein-coding counterpart. In addition, a processed pseudogene is almost always located on a different chromosome than its alleged parent gene. Despite the seemingly accidental structure of these genes, many of them are being shown to have important functionality, including some with introns that also exhibit functionality.
A second category of pseudogenes are duplicated pseudogenes. These are believed to have been duplicated from a parent gene since they contain promoters and introns but have alterations in their DNA code that keep them from producing a protein.
A second category of pseudogenes are duplicated pseudogenes. These are believed to have been duplicated from a parent gene since they contain promoters and introns but have alterations in their DNA code that keep them from producing a protein.
Conventional scientists believe that these may have been derived during DNA replication due to an unequal crossing-over event during meiosis. However, this is pure speculation just as in the case of processed pseudogenes. In fact, this hypothetical explanation is even employed for the development of large gene families that do not include pseudogenes.
The third category of pseudogenes is rare in the genome and called a unitary pseudogene. These don’t necessarily have an obvious parent from which they are derived. Although, if they are part of a gene family, duplication will often be invoked as an evolutionary meme. These types of genes will often have DNA code alterations that prohibit a protein from being produced and are in most cases considered to be broken genes. However, the human beta-globin pseudogene, which was once considered to be a broken gene, has actually now been shown to be highly functional by producing long non-coding RNAs (lncRNAs) that help regulate the entire beta-globin gene network. Furthermore, this gene is highly intolerant of mutations, which can cause beta-thalassemia disease pathologies.
Pseudogenes work their functional expertise through a variety of molecular mechanisms and systems. In one of the leading systems, pseudogenes are thought to participate as biological regulators by functioning as competitive endogenous RNAs (ceRNAs).
The third category of pseudogenes is rare in the genome and called a unitary pseudogene. These don’t necessarily have an obvious parent from which they are derived. Although, if they are part of a gene family, duplication will often be invoked as an evolutionary meme. These types of genes will often have DNA code alterations that prohibit a protein from being produced and are in most cases considered to be broken genes. However, the human beta-globin pseudogene, which was once considered to be a broken gene, has actually now been shown to be highly functional by producing long non-coding RNAs (lncRNAs) that help regulate the entire beta-globin gene network. Furthermore, this gene is highly intolerant of mutations, which can cause beta-thalassemia disease pathologies.
Pseudogenes work their functional expertise through a variety of molecular mechanisms and systems. In one of the leading systems, pseudogenes are thought to participate as biological regulators by functioning as competitive endogenous RNAs (ceRNAs).
In a previous article, I showed that small RNAs called microRNAs (miRNAs) are produced from RNA copies of long DNA sequences (long primary miRNAs) and then are eventually processed into smaller mature miRNAs that are only about 19 to 25 nucleotides long. These miRNAs then bind to other RNA transcripts such as lncRNAs, protein-coding gene transcripts, and pseudogene transcripts at specific target sites called miRNA response elements (MREs). This competitive binding among populations of RNA transcripts and miRNAs is a complicated cellular system of titrating and fine-tuning gene regulation.
Another role of pseudogene function involves interactions between their lncRNAs and proteins. Part of the cell’s biology includes
specialized proteins that bind to RNAs called RNA-binding proteins or RBPs. These RBPs function as key regulators of a variety of posttranscriptional processes, including RNA splicing, transcript stability (protection from degradation), RNA transport to specific cellular addresses, and making proteins from the transcript, which functions as a template (translation). And just as miRNAs competitively function between pseudogenes and their protein-coding counterparts, so do RBPs, which bind to specific RNA-binding domain (RBD) sites on the RNAs. Several studies in humans have shown that proper functioning of pseudogene transcripts regulated by RBPs is key to maintaining healthy insulin levels and keeping cancer at bay.
Yet another fascinating aspect of some pseudogenes is their ability to harbor what are known as small interfering RNAs (siRNA), which are sequences that are processed out of the pseudogene transcripts. I discussed the role of siRNAs in a previous article. These siRNAs can regulate the pseudogene’s protein-coding counterparts by forming specific stem-loop structures that bind to corresponding sites on the transcripts of protein-coding genes, which can repress their activity as another means of gene regulation.
It is nearly impossible to imagine how pseudogene systems this complex could arise by naturalistic processes. And certainly, the term “pseudo” now appears to be a highly inaccurate description of these misunderstood types of genes that are now believed to be almost as plentiful in number as protein-coding genes in the genome. In reality, they are just another class of lncRNA genes. The only logical conclusion is that divine engineering by an omnipotent and wise creator is the source for this amazing biological and purposeful code."
Another role of pseudogene function involves interactions between their lncRNAs and proteins. Part of the cell’s biology includes
Yet another fascinating aspect of some pseudogenes is their ability to harbor what are known as small interfering RNAs (siRNA), which are sequences that are processed out of the pseudogene transcripts. I discussed the role of siRNAs in a previous article. These siRNAs can regulate the pseudogene’s protein-coding counterparts by forming specific stem-loop structures that bind to corresponding sites on the transcripts of protein-coding genes, which can repress their activity as another means of gene regulation.
It is nearly impossible to imagine how pseudogene systems this complex could arise by naturalistic processes. And certainly, the term “pseudo” now appears to be a highly inaccurate description of these misunderstood types of genes that are now believed to be almost as plentiful in number as protein-coding genes in the genome. In reality, they are just another class of lncRNA genes. The only logical conclusion is that divine engineering by an omnipotent and wise creator is the source for this amazing biological and purposeful code."
ICR
