The prevalence of canonic tautomers of nucleic acid bases can be influenced by factors such as temperature, pH, solvent conditions, and the specific environment in which they are present. The concept of canonic tautomers refers to the dominant or most stable forms of tautomeric species under normal physiological conditions.
At temperatures above 37 degrees Celsius (body temperature), the prevalence of tautomeric forms can vary for different nucleic acid bases. Generally, the keto forms are considered to be the more stable and prevalent tautomers for the nucleic acid bases adenine, guanine, and cytosine. The amino form is the more stable tautomer for thymine (in DNA) and uracil (in RNA).
It's important to note that the tautomeric equilibria in nucleic acid bases can be influenced by factors such as pH and solvent conditions. For example, at higher pH values, the keto-enol tautomeric equilibrium of cytosine can shift towards the enol form. Similarly, solvent effects can also impact the prevalence of different tautomers.
However, it is crucial to consult specific research literature or scientific studies to obtain the most up-to-date and accurate information on the prevalence of tautomeric forms of nucleic acid bases under specific temperature conditions. Experimental studies and computational modeling techniques are often employed to investigate the relative stabilities and prevalence of tautomers in nucleic acids.