Conclusions
The aim of this project was to identify and annotate all selenoprotein genes, their Cys homologues and the genes coding for the machinery required for their synthesis in Paroedura picta’s genome. After performing and discussing all the bioinformatic analysis from a total of 43 proteins this is the final characterization that was obtained:
- Sel15, SelH, SelT, GPx1, GPx2, DI1, DI3, Rdx, SelT, SelM, SelO, TR1, TR2, TR3, SelI, SelP, SelU1 (a Cys-containing homologue in Homo sapiens), SelR1 and SPS2 are all the selenoproteins we have found and annotated in Paroedura picta.
- SelN, GPx3_GPx4_GPx5_GPx6_GPx7_GPx8 (which are only two genes in P. picta), SelW2, MsrA, SelU2 and SelR2_SelR3 (separated genes in Homo sapiens) are all cysteine-containing genes found in P. picta which are homologous to selenoproteins in other species.
- SelW1, DI2 are proteins which appear to be homologous to the corresponding selenoproteins in Homo sapiens, but do not align the Sec with a Cys and rather align Sec with other amino acids.
- SPS1, PSTK, SecS, SBP2, SECp43, eEFSec are the genes coding for selenoprotein synthesis machinery, which are conserved between humans and Paroedura picta.
- SelV, SelK, SelS, SelU3 could not be predicted in our analysis, therefore we consider they do not exist in Paroedura picta.
Taking into account the 43 reference sequences from the human genome that belonged to the selenoprotein-related gene family, we conclude that a majority of selenoproteins are conserved between humans and P. picta, as well as all the machinery-related genes. Four of them could not be predicted under our criteria and others display duplication/deletion events throughout the evolution of Homo sapiens and Paroedura picta.
To reach these conclusions, an automated program was used to predict and obtain the information on the genome localization of each of these genes, if they existed, in Paroedura picta; using the selenoproteome of Homo sapiens as a reference. Nevertheless, some aspects, such as a mismatching in methionine as the first amino acid of our predicted proteins in P. picta, could be an indication that some of our predicted genes may not be complete or may not become expressed due to a lack of a translation initiation codon.
We consider it would be worth to conduct further studies to analyze those uncertainties, as well as to further analyze the selenoproteins which could not be found in Paroedura picta, since it is possible that our criteria was too strict for us to be able to predict existing selenoproteins. Furthermore, using another more closely-related species to P. picta for our analysis could have been helpful to overcome these uncertainties, and therefore we consider that further studies in this direction could be performed to compare its results with ours.
To sum up, we have been able to provide for the first time the annotation of Paroedura picta’s selenoproteome and contribute to the knowledge of the scientific community.