Mitochondrial genomes of five Hyphessobrycon tetras and their phylogenetic implications

Abstract

To date, the taxonomic status and phylogenetic affinities within Hyphessobrycon, even among other genera in Characidae, remain unclear. Here, we determined five new mitochondrial genomes (mitogenomes) of Hyphessobrycon species (H. elachys, H. flammeus, H. pulchripinnis, H. roseus, and H. sweglesi). The mitogenomes were all classical circular structures, with lengths ranging from 16,008 to 17,224 bp. The type of constitutive genes and direction of the coding strand that appeared in the mitogenomes were identical to those of other species in Characidae. The highest value of the Ka/Ks ratio within 13 protein‐coding genes (PCGs) was found in ND2 with 0.83, suggesting that they were subject to purifying selection in the Hyphessobrycon genus. Comparison of the control region sequences among seven Hyphessobrycon fish revealed that repeat units differ in length and copy number across different species, which led to sharp differences in mitogenome sizes. Phylogenetic trees based on the 13 PCGs did not support taxonomic relationships, as the Hyphessobrycon fish mixed with those from other genera. These data were combined to explore higher level relationships within Characidae and could aid in the understanding of the evolution of this group.

Novel gene rearrangement pattern in mitochondrial genome of Ooencyrtus plautus Huang & Noyes, 1994: new gene order in Encyrtidae (Hymenoptera, Chalcidoidea)

“…In addition, the Ka/Ks of atp8 is as high as 0.9389, which is the highest except for nad2. The high Ka/Ks phenomenon of nad2 and atp8 is also found in other species (Jia et al 2020;Guo et al 2021;Xu et al 2021). The reason for this phenomenon may be that the evolution speed of a gene is related to its function (Wang et al 2011).…”

Mitochondrial Genomes of two Lycosa spiders (Araneae, Lycosidae): Genome Description and Phylogenetic Implications

“…Although most mitogenomes were relatively stable, CR showed great variability because it is a non-coding region. The CR region may vary greatly among different species and even among individuals of the same species [2,39,40]. As shown in Figure 2, the size of the CR also affected the size of the spider mitogenome [36].…”

“…In general, the mitogenome of arthropods is a circular, double-stranded molecule, ranging in size from 14 to 20 kb, and typically containing a standard set of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and 1 control region (CR), also called the A + T-rich region. Mitochondria have their own genetic material and genetic system and have become excellent targets for studying the origin and phylogeny of species owing to their high evolutionary rate, matrilineal inheritance, and ease of amplification [2,3].…”

“…However, these mitochondrial sequences are much shorter than the complete mitogenome sequences and typically have limited phylogenetic information [8,9]. Additional reliable datasets, such as complete mitogenome sequences, can make phylogenetic reconstruction more efficient [2,9,10]. In addition, researchers can better judge phylogenetic relationships through complete mitogenome sequences because they can provide information that is lacking in fragments, such as gene rearrangement, tRNA secondary structure [11], genetic code changes, replication, and transcriptional regulation patterns.…”

Characterization of Five New Earthworm Mitogenomes (Oligochaeta: Lumbricidae): Mitochondrial Phylogeny of Lumbricidae

“…Consequently, earthworm identification based on mitochondrial genomes (mitogenome) might provide a solution to this issue [9]. The mitogenome is a highly conserved, typically double-stranded, circular molecule that Diversity 2021, 13, 580 2 of 8 is one of the most widely used tools in taxonomy, population genetics, and evolutionary biology [10][11][12].…”