The comparison of the genome of Carettochelys insculpta with the Mus Musculus and Anolis carolinensis, both obtained from the Seleno DB database, have given us the following 12 selenoproteins: TR1, GPX1, GPX2, GPX4, SelP, Sel 15, MSRB 1, SEL T, SEL H, SEL I, SEL Na, SEL Nb.

On the other hand we have found one protein containing cysteine: SelU1 and six more proteins which are components of the selenoprotein forming machinery: eEFSec, SBP2, PSTK, SECS, SPS1 and SPS2.

Some of the results we’d like to mention are that we found a duplication, concretely of SEL N in the turtle’s genome and the deletion of GPX5, GPX6 and DI1 .

In order to consider a protein a Selenoprotein some criteria had to be accomplished: presence of a SECIS element and presence of selenocysteine in amino acid sequence. If both criteria weren’t met, we didn’t consider it a selenoprotein.

We must say that we found 18 from the 37 analyzed proteins (plus a duplication) in the turtle genome, which is not as much as we might have expected. We believe that this could be due to the fact that we compared it with the lizard (a closer species but with a not accurate annotated genome) and mouse genome (which was better annotated but phylogenetically further from our target species). So the lack of an accurate annotated genome of a phylogenetically closer species may have been related to the low number of identified proteins.

Regarding our study concretely, we find a series of limitations. We didn’t make the alignment with any other program which would have given us additional information and confirmation regarding our results, as well, the selection criteria of which protein scaffolds must be analyzed were established by us, and this means that some possible proteins could have been missed. All of this leads us to suggest more exhaustive studies on this matter.

In conclusion, with this project we have been able to provide for the first time, the annotation of the Carettochelys insculpta’s selenoproteome and contribute to the knowledge of the scientific community. This first study may lead to further investigations about Carettochelys insculpta’s genome and may open up doors to the presence of selenoproteins and their role in life.