I am trying to determinate dS and dN in Mega7 of my Sanger sequecing sequences. I determinated with jModelTest that the best model for my sequences is Tamura Nei (TrN) gamma distributed. But, when I change the substitutions type in Mega:

Nucleotide to Syn-Nonsynonymous I have not TrN model I have others:

Nei-Gojobori method, Modified Nei-Gojobori method, Liu-Wu-Lou Method, Pamilo Bianchi-Li method, Kumar method

What model is equivalence to Trn ?

Thanks in advantage.