MOLECULAR PHYLOGENETIC ANALYSIS OF CONSERVED GENES ACROSS EUKARYOTIC SPECIES

Abstract

This paper reports a full-blown molecular phylogenetic analysis of the conserved proteins of different eukaryotic organisms to explain the evolutionary correlation and sequence preserved pattern. A high-quality collection of 32 representative species that represent four major eukaryotic groups, including the Animalia, Plantae, Fungi, and Protists, was assembled on the basis of high-quality sequences on the NCBI and Ensembl databases. As molecular markers, they chose 4 genes that were highly conserved, which include 18S rRNA, cytochrome c oxidase subunit I (COX1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB). The MUSCLE method was used in multiple sequence alignment and Maximum Likelihood method was used in phylogenetic tree reconstruction based on General Time Reversible (GTR) model. Bootstrap analysis of 1000 replicas was conducted to guarantee the statistical soundness of the study. These findings show that 18S rRNA is highly conserved in all of the studied lineages, thereby confirming it as a good universal phylogenetic marker. Contrastingly, protein coding genes had moderate sequence divergence and this indicated functional adaptations that depend on lineages. Phylogenetic clusters provided evidence of the tendency towards closer evolutionary relationship between animal and fungal species as established theories of evolution would predict, however plant and protist lineages revealed different patterns of divergence. On the whole, this research will represent a multi-gene view on eukaryotic evolution and underscore the efficacy of integrating ribosomal and protein-coding genome in solidusing phylogenetic inferencing in comparison genomics.