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PARASITE VARIANT. “The latest such variant, discovered in a trypanosomatid (protist) symbiont of an insect by fossicking through symbiont sequences ‘contaminating’ the insect’s transcriptome. This non-canonical code is not only new and different, but also special because it may provide a glimpse into the intermediate stages of one of the rarest of changes in biology.” https://lnkd.in/d87ZWbH View in LinkedIn

FIXED STRINGS. "Although a substantial amount of research has been performed on variable-length strings and other structures, the majority of work with genetic algorithms is focussed on fixed-length character strings." http://www6.uniovi.es/ftp/pub/EC/FAQ/www/Q1_1.htm View in LinkedIn

ORIGIN INSIGHTS. “The nature of these non-canonical codes, as well as their distribution on the tree of life, give us a few insights into how translation may have originated, deep differences between translation systems in use today, and what forces keep the code so conserved.” https://lnkd.in/d87ZWbH View in LinkedIn

CANONICAL. “But the universal code is not quite universal — it is perhaps the most conserved feature of molecular biology, but even still some variants do exist (for which reason I prefer the term ‘canonical’ over ‘universal’).” https://lnkd.in/d87ZWbH View in LinkedIn

FRAGMENT FROM NATURE concludes this weekend on the theme of the (nearly) universal genetic code, and the deviations from this code. In a world where everything evolves and diversification is the common factor, having a highly conserved code is perplexing. And for sure, in the beginning, it was not how it is today. How did this arise? View in LinkedIn

PREDICTION FULFILLED. “Swart et al. recently reported evidence for just such a context-dependent process linked to a similar genetic code change in a ciliate, where UAR=Q and UGA=W or stop, depending on the downstream sequence. These codes are also exciting because they fulfill a central prediction of one of the models for how the genetic code evolves, the Ambiguous Intermediate model.” https://lnkd.in/d87ZWbH View in LinkedIn

MORE EXCEPTIONS. “It was the stand-out nature of stop codons that first alerted Zahonova et al. to the presence of the new non-canonical codes in Blastocrithidia. But digging deeper they encountered something more interesting. The most frequent nuclear code change is UAR=Q (stop codons UAA and UAG to encode glutamine). Zahonova et al. found instead that UAR=E and that UGA=W (which is common in bacteria).” https://lnkd.in/d87ZWbH View in LinkedIn

STILL TO FIND. “In contrast, a code where two amino acid-encoding codons were altered would appear in DNA sequence to be slightly divergent, but not obviously translated by a different genetic code. But it is therefore possible, even likely, that non-canonical genetic codes involving switches between amino acids have been observed but escaped our detection.” https://lnkd.in/d87ZWbH View in LinkedIn

STOP CODONS. “Because the code governs the translation of nucleotide to amino acid sequences, a code can in principle only be confirmed when both the gene and protein sequences are known. Stop codons stick out as a sore thumb in DNA sequence because they disrupt the coding region in a way that is difficult to overlook or misinterpret, so these codes can be strongly inferred from DNA sequence.” https://lnkd.in/d87ZWbH View in LinkedIn

VARIANT INFERENCE. “These characteristics may render such changes more statistically probable, less likely to be deleterious, or both. However, most non-canonical genetic codes are inferred from DNA sequence alone, or occasionally DNA sequences and corresponding tRNAs.” https://lnkd.in/d87ZWbH View in LinkedIn