beta thalassemia is the  most common autosomal recessive disorder. the present study reports a rare β globin gene mutation, hbb: c.180g>a: codon 59 (aag/aaa), in a patient from gilan province, northern iran. nucleotide sequencing of amplified dna belonging to a 35 years old man presenting mild hypochromia revealed a synonymous mutation due to a g>a conversion at the third position of codon 59 o...

In Escherichia coli (E. coli), a low-usage codon is defined as a codon that is used rarely or infrequently in the genome with usage frequency lower than the smallest value (or frequency cut-off) among the usage frequencies of non-degenerate codons (Met codon AUG and Trp codon UGG) and the optimal codons for amino acids Leu, Ile, Val, Ser, Pro, Thr, Ala, Arg, Gly and Gln that have 2 or more dege...

Codon usage biases are found in all genomes and influence protein expression levels. The codon usage effect on protein expression was thought to be mainly due to its impact on translation. Here, we show that transcription termination is an important driving force for codon usage bias in eukaryotes. Using Neurospora crassa as a model organism, we demonstrated that introduction of rare codons res...

Most amino acids are encoded by more than one codon. These synonymous codons are not used with equal frequency: in every organism, some codons are used more commonly, while others are more rare. Though the encoded protein sequence is identical, selective pressures favor more common codons for enhanced translation speed and fidelity. However, rare codons persist, presumably due to neutral drift....

Translation of Xenopus laevis Connexin41 mRNA is strongly controlled by the three upstream open reading frames (uORFs) in its 5' untranslated region. Mutation of uAUG1 into AAG induced a 100-fold increase in translation of a green fluorescent protein (GFP) reporter ORF. The termination codon of uORF1 was mutated and the uORF was linked in-frame with the GFP ORF, enabling visualisation of initia...

Alzheimer's disease (AD) is a neurodegenerative disorder with few biomarkers even though it impacts a relatively large portion of the population and is predicted to affect significantly more individuals in the future. Neuroimaging has been used in concert with genetic information to improve our understanding in relation to how AD arises and how it can be potentially diagnosed. Additionally, evi...

Despite many attempts to introduce evolutionary models that permit substitutions instantly alter more than one nucleotide in a codon, the prevailing wisdom remains such changes are rare and generally negligible or reflective of non-biological artifacts, as alignment errors. Codon continue posit only single change have non-zero rates. Here, we develop test simple hierarchy codon-substitution wit...