Speciation Genomics of Protein-Coding Genes Common to Mycoplasmatales
- *Corresponding Author:
- Dipaloke Mukherjee
Department of Food Science
Nutrition and Health Promotion
Mississippi State University, MS 39762, USA
E-mail: [email protected]
Received Date: December 22, 2016; Accepted Date: January 09, 2017; Published Date: January 13, 2017
Citation: Mukherjee D, Diehl WJ (2017) Speciation Genomics of Protein-Coding Genes Common to Mycoplasmatales. J Phylogenetics Evol Biol 5:175. doi: 10.4172/2329-9002.1000175
Copyright: © 2017 Mukherjee D, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Identifying regions of a genome that evolve by natural selection, particularly as species diverge, has been a matter of considerable interest. The genomes of 12 species in the eubacterial order Mycoplasmatales were compared to test the hypothesis that natural selection targets genes by function and/or at given moments in the phylogenetic history of the species. These species possess some of the smallest genomes known, and analyses on the set of protein-coding genes common to all species in the study will shed light on the evolution of some of the most critical genes to living organisms. Genes that control cellular processes showed greater evidence of natural selection than genes of unknown function or genes associated with information processing and storage or metabolism. Moreover evidence of natural selection was only detected in the deepest branches of the Mycoplasmatales phylogeny, including one node where a host shift from land plants to insects likely occurred and another node where a host shift from land plants/insects to land vertebrates likely occurred. Many of the genes that showed the strongest evidence of natural selection (e.g. secA, secY, ftsH, ftsY, yidC, lepA, dnaK) encode proteins that are components of the Sec-dependent secretory pathway, which regulates the extracellular translocation of proteins. The Sec-dependent secretory pathway is proposed to play a role in speciation of Mycoplasmatales by altering the type and amount of secreted proteins, thereby affecting virulence of Mycoplasma sp. in response to infection of novel hosts.