Phylogeny and evolution of Bacillariophycidae (Bacillariophyceae) based on mitochondrial genome

Abstract

Diatoms are one of the most important primary producers in coastal and marine ecosystems and are involved in carbon, nitrogen, and silicate exchanges between the water column and sediments. In the Bacillariophyceae, Bacillariales and Naviculales are representative orders that are ubiquitous and rich in species, ca. 5,000 and 1,100 spp, respectively. However, systematics and evolutionary studies have largely relied on morphological and ultrastructural characteristic and a handful nuclear and plastid genes (i.e., LSU and SSU rRNA, and rbcL). In present study, we determined ten new mitochondrial genomes (mtDNA) from both orders and compiled all available diatoms dataset (total 22 mtDNA) to establish a robust phylogeny of the Bacillariophyceae. The dataset encompassed 33 protein coding genes (7,968 amino acids) of 16 species from both bacillariophycean orders and 10 putative relatives. The best phylogeny reveals a monophyly of Bacillariales and Naviculales with maximum support values and basal position of Fragilariales within the class. We demonstrated and discussed the implication of mtDNA data to understand the diatoms diversity and evolution.lales are representative orders that are ubiquitous and rich in species, ca. 5,000 and 1,100 spp, respectively. However, systematics and evolutionary studies have largely relied on morphological and ultrastructural characteristic and a handful nuclear and plastid genes (i.e., LSU and SSU rRNA, and rbcL). In present study, we determined ten new mitochondrial genomes (mtDNA) from both orders and compiled all available diatoms dataset (total 22 mtDNA) to establish a robust phylogeny of the Bacillariophyceae. The dataset encompassed 33 protein coding genes (7,968 amino acids) of 16 species from both bacillariophycean orders and 10 putative relatives. The best phylogeny reveals a monophyly of Bacillariales and Naviculales with maximum support values and basal position of Fragilariales within the class. We demonstrated and discussed the implication of mtDNA data to understand the diatoms diversity and evolution.