Month: September 2022

COUPLING FUNCTION. "The ultimate goal of these coupling reactions is to sort protein-coding RNAs (i.e. mRNA) from intergenic transcripts." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

CODING VS NON-CODING. "On average, protein-coding genes have eight introns, while the majority of annotated ENCODE intergenic transcripts tend not to be spliced." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

IDENTITY ELEMENTS. "These mRNA identity features activate coupling reactions, which in turn promote the further processing, nuclear export, and translation of a particular transcript. Likewise, other classes of functional RNAs (e.g., tRNAs and snRNAs) have their own identity elements." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

DESTRUCTION. "Transcripts that lack identity elements are targeted for degradation. In agreement with this model, intronless RNA molecules that have a random sequence are poorly exported from the nucleus and have a very short half-life." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

PROTECTIVE MARKER. "One would predict that lncRNAs contain a differential set of identity elements that not only serve to prevent their decay but also retain them in the nucleus. This would especially be critical for lncRNAs that are spliced." (LncRNAs = long non-coding RNAs). http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

MINOR TRANSCRIPTION. "Eukaryotes appear to have evolved an intricate network of coupling reactions that are required to cope with a large burden of junk RNA. These findings are consistent with the idea that eukaryotic genomes are filled with junk DNA that is transcribed at a low level." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

NEEDING EVIDENCE. "As stated by others, it is imperative that those who claim that the vast majority of intergenic transcription is functional test their hypotheses. In the absence of this evidence, the declaration that we are in the midst of a paradigm shift with regards to eukaryotic genomes and gene expression seems premature." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

IN TRANSITION. "However, evidence casting doubt that most of the human genome possesses a functional role has existed for some time. This is not to say that none of the nonprotein-coding majority of the genome is functional—examples of functional noncoding sequences have been known for more than half a century, and even the earliest proponents of “junk DNA” and “selfish DNA” predicted that further examples would be found." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

THE NEXT SECTION deals with major evolutionary transitions. These events have shaped life on earth, but our understanding of them is, as usual, rather scant. However, this is a very interesting topic, and some great thinkers have applied themselves to the topic. View in LinkedIn

SZATHMÁRY & MAYNARD SMITH. "There is no theoretical reason to expect evolutionary lineages to increase in complexity with time, and no empirical evidence that they do so. Nevertheless, eukaryotic cells are more complex than prokaryotic ones, animals and plants are more complex than protests, and so on. This increase in complexity may have been achieved as a result of a series of major evolutionary transitions. These involved changes in the way information is stored and transmitted." A classic paper. https://lnkd.in/eZ5-m7K View in LinkedIn