In this study we want to characterize the selenoproteome and the machinery in charge of synthesizing it in the animal species Chelonoidis abingdonii, an extinct tortoise that lived in the Pinta Island (Galapagos, Ecuador).

The selenoproteome consists of all the selenoproteins present in a genome. Selenoproteins contain at least one selenocysteine (Sec). Sec residue is codified by the UGA codon, which normally acts as a stopping translation signal, and thus requires a specific machinery to be produced.

To correctly predict and assess the Chelonoidis abingdonii selenoproteome and the proteins related to its synthesis, we have studied the homology between the already described selenoproteins of Homo sapiens and the proteins encoded by the genes of the tortoise. To do this prediction, our team designed an automatic program that, using the data obtained through tBLASTn, applied Exonerate, GeneWise and T-Coffee to obtain the alignment between the predicted sequences of the selenoproteins in these species and the human (or lizzard) selenoproteins. The predicted genes were analysed through Seblastian to see if they could produce a selenoprotein. SECISearch3 was used to predict if the mRNA produced by our gene could contain any SECIS.

In our study we have predicted 23 selenoproteins, 10 Cys-containing homologous and 7 selenoprotein translation machinery proteins.