Comparison of the Lipophosphoglycan 3 Gene of the Lizard- and Mammal-Infecting Leishmania

Limited yield and poor specificity are resulted in improving the PCR amplification of GC-rich DNA sequences. In this study, the Lipophosphoglycan 3 (LPG3) gene of the lizard- and mammalian Leishmania species was amplified under optimized PCR conditions, as well as the molecular characteristics of the predicted LPG3 amino acid sequence was described.
Genomic DNA extracted from Leishmania species was amplified by adding various additives in the reaction mixture to increase the PCR efficiency of GC-rich target sequence. The desired PCR products were then cloned and sequenced. Next, the Lipophosphoglycan 3 (LPG3) of the L. infantum was compared to the Lipophosphoglycan 3 (LPG3) of the lizard Leishmania at the amino acid sequence level by pairwise alignment and phylogenetic analysis.
The combination of betaine and 2-mercaptoethanol with bovine serum albumin as well as betaine in combination with bovine serum albumin could further promote PCR amplification yield and specificity relative to conditions using either one of the additives. The results may provide a simple modified PCR protocol which is capable of improving the efficiency of PCR amplification of DNA templates with high GC-content. Deduced amino acid alignment showed 95% identity between Leishmania infantum and lizard Leishmania. Leishmania infantum was also clustered with lizard Leishmania in the phylogenic tree. A significant spatial arrangement of secondary structure was observed in the LPG3 of both Leishmania species. Moreover, the prediction of tertiary structure indicated molecular homology.
Alignment and phylogenetic analysis suggest that the lizard Leishmania may be evolutionarily more close to Leishmania infantum.