In species with large effective population sizes, highly expressed genes tend to be encoded by codons with highly abundant cognate tRNAs to maximize translation rate. However, there has been little evidence for a similar bias of synonymous codons in highly expressed human genes. Here, we ask instead whether there is evidence for the selection for codons associated with low abundance tRNAs. Rath...

The genetic code is degenerate; thus, protein evolution does not uniquely determine the coding sequence. One of the puzzles in evolutionary genetics is therefore to uncover evolutionary driving forces that result in specific codon choice. In many bacteria, the first 5-10 codons of protein-coding genes are often codons that are less frequently used in the rest of the genome, an effect that has b...

The association between scrapie and polymorphism of the prion protein (PrP) gene was studied in the Icelandic sheep breed. Polymorphism of the three codons, 136, 154 and 171, that are important for scrapie susceptibility was determined. A BspHI restriction analysis was used to study the alleles of codons 136 and 154, while density gradient gel electrophoresis (DGGE) was used to analyse codon 17...

The genetic code is the cellular translation table for the conversion of nucleotide sequences into amino acid sequences. Changes to the meaning of sense codons would introduce errors into almost every translated message and are expected to be highly detrimental. However, reassignment of single or multiple codons in mitochondria and nuclear genomes, although extremely rare, demonstrates that the...

Objective: The Rifampicin resistance and susceptibility of Mycobacterium tuberculosis are caused by mutations in the 81-base pair region of the rpoB gene encoding the b-subunit of RNA polymerase. Methods: Isoniazid resistance of M. tuberculosis is related to mutations in inha , oxyR and ahpC genes which 30 to 90 percent of Isoniazid resistance is occurred in 3015 codons of kat...

To further study the characteristics of peach codon usage, this analyzed usage biases and patterns genome, based on statistical calculations related GC content, effective number codons (ENC) relative synonymous (RSCU) from 26 873 coding sequences. The results showed that there were obvious in peach, 4 out 61 (UCA, ACA, GCA GAA) defined as optimal codons, all which end with Adenine at third posi...

objective(s): haemostasis prevents blood loss following vascular injury. it depends on the unique concert of events involving platelets and specific blood proteins, known as coagulation factors. the clotting system requires precise regulation and coordinated reactions to maintain the integrity of the vasculature. clotting insufficiency mostly occurs due to genetically inherited coagulation fact...