Concerted and Independent Evolution of Control Regions 1 and 2 of Water Monitor Lizards (Varanus salvator macromaculatus) and Different Phylogenetic Informative Markers

Duplicate control regions (CRs) have been observed in the mitochondrial genomes (mitogenomes) of most varanids. Duplicate CRs have evolved in either concerted or independent evolution in vertebrates, but whether an evolutionary pattern exists in varanids remains unknown. Therefore, we conducted this study to analyze the evolutionary patterns and phylogenetic utilities of duplicate CRs in 72 individuals of Varanus salvator macromaculatus and other varanids. Sequence analyses and phylogenetic relationships revealed that divergence between orthologous copies from different individuals was lower than in paralogous copies from the same individual, suggesting an independent evolution of the two CRs. Distinct trees and recombination testing derived from CR1 and CR2 suggested that recombination events occurred between CRs during the evolutionary process. A comparison of substitution saturation showed the potential of CR2 as a phylogenetic marker. By contrast, duplicate CRs of the four examined varanids had similar sequences within species, suggesting typical characteristics of concerted evolution. The results provide a better understanding of the molecular evolutionary processes related to the mitogenomes of the varanid lineage.

Ancient Mitogenomes Suggest Stable Mitochondrial Clades of the Siberian Roe Deer

The roe deer (Capreolus spp.) has been present in China since the early Pleistocene. Despite abundant fossils available for detailed morphological analyses, little is known about the phylogenetic relationships of the fossil individuals to contemporary roe deer. We generated near-complete mitochondrial genomes for four roe deer remains from Northeastern China to explore the genetic connection of the ancient roe deer to the extant populations and to investigate the evolutionary history and population dynamics of this species. Phylogenetic analyses indicated the four ancient samples fall into three out of four different haplogroups of the Siberian roe deer. Haplogroup C, distributed throughout Eurasia, have existed in Northeastern China since at least the Late Pleistocene, while haplogroup A and D, found in the east of Lake Baikal, emerged in Northeastern China after the Mid Holocene. The Bayesian estimation suggested that the first split within the Siberian roe deer occurred approximately 0.34 million years ago (Ma). Moreover, Bayesian skyline plot analyses suggested that the Siberian roe deer had a population increase between 325 and 225 thousand years ago (Kya) and suffered a transient decline between 50 and 18 Kya. This study provides novel insights into the evolutionary history and population dynamics of the roe deer.

Phylogeny and age of cockroaches: a reanalysis of mitogenomes with selective fossil calibrations

In spite of big data and new techniques, the phylogeny and timing of cockroaches remain in dispute. Apart from sequencing more species, an alternative way to improve the phylogenetic inference and time estimation is to improve the quality of data, calibrations and analytical procedure. This study emphasizes the completeness of data, the reliability of genes (judged via alignment ambiguity and substitution saturation), and the justification for fossil calibrations. Based on published mitochondrial genomes, the Bayesian phylogeny of cockroaches and termites is recovered as: Corydiinae + (((Cryptocercidae + Isoptera) + ((Anaplectidae + Lamproblattidae) + (Tryonicidae + Blattidae))) + (Pseudophyllodromiinae + (Ectobiinae + (Blattellinae + Blaberidae)))). With two fossil calibrations, namely, Valditermes brenanae and Piniblattella yixianensis, this study dates the crown Dictyoptera to early Jurassic, and crown Blattodea to middle Jurassic. Using the ambiguous ‘roachoid’ fossils to calibrate Dictyoptera+sister pushes these times back to Permian and Triassic. This study also shows that appropriate fossil calibrations are rarer than considered in previous studies.

Contribution to the knowledge of Chinese Gryllacrididae (Orthoptera) IV: New additions of Chinese Furcilarnaca Gorochov, 2004

Based on the specimens from Guangxi and Yunnan deposited in the Guangxi Normal University, the paper is firstly reported the female sex of two known species from China, viz. Furcilarnaca armata (Bey-Bienko, 1957) and Furcilarnaca forceps (Bey-Bienko, 1962). The female of Furcilarnaca armata (Bey-Bienko, 1957) is very similar to Furcilarnaca chiangdao in seventh abdominal tergite and subgenital plate, and they may belong to the same species. After examining the female subgenital plate of Furcilarnaca chirurga (Bey-Bienko, 1962), we treat Furcilarnaca hirta as a valid species. Mitochondrial genomes of six specimens of three Furcilarnaca species were sequenced and annotated in this study. The organization and gene content of new sequenced mitogenomes were conserved, except for significant variation of the control region. All the PCGs started with the typical ATN codons and most ended with complete TAA or TAG codons. Combined with five mitogenomes in NCBI, a total of twelve specimens (including one outgroup) were used in phylogenetic analysis based on 13 PCGs. The result revealed that Furcilarnaca was a monophyletic group. These data will provide more meaningful genetic information and validate the phylogenetic relationships within the Gryllacrididae.

The complete mitochondrial genomes of Notiophilus quadripunctatus Dejean, 1826 and Omophron limbatum (Fabricius, 1777): New insights into the mitogenome phylogeny of the Carabidae (Insecta, Coleoptera)

The Carabidae is by far the largest family of the Adephaga, with more than 40,000 described species. Whereas their phylogeny has been extensively studied, convergences and reversals in morphological traits prevent a robust phylogenetic concept so far. In this study, we sequenced the complete mitochondrial genomes of Notiophilus quadripunctatus (Nebriinae) and Omophrom limbatum (Omophroninae) using high-throughput sequencing. Both mitogenomes consisted of a single circular DNA molecule that encoded the typical 13 protein-coding genes, two subunits of mitochondrial RNAs, 22 tRNAs and a putative control region. Our phylogenetic study placed Omophrom limbatum as sister taxon to all other analyzed ground beetle species whereas Notiophilus quadripunctatus was identified as sister to Nebria brevicollis as part of the Nebriinae. The analyses also support the monophyly of the Cicindelidae but place Trachypachus holmbergi (Trachypachidae) within the Carabidae. Nevertheless, almost all carabid subfamilies with more than one analyzed species were identified as monophyla.

Long-read sequencing reveals atypical mitochondrial genome structure in a New Zealand marine isopod

Most animal mitochondrial genomes are small, circular and structurally conserved. However, recent work indicates that diverse taxa possess unusual mitochondrial genomes. In Isopoda , species in multiple lineages have atypical and rearranged mitochondrial genomes. However, more species of this speciose taxon need to be evaluated to understand the evolutionary origins of atypical mitochondrial genomes in this group. In this study, we report the presence of an atypical mitochondrial structure in the New Zealand endemic marine isopod, Isocladus armatus. Data from long- and short-read DNA sequencing suggest that I. armatus has two mitochondrial chromosomes. The first chromosome consists of two mitochondrial genomes that have been inverted and fused together in a circular form, and the second chromosome consists of a single mitochondrial genome in a linearized form. This atypical mitochondrial structure has been detected in other isopod lineages, and our data from an additional divergent isopod lineage (Sphaeromatidae) lends support to the hypothesis that atypical structure evolved early in the evolution of Isopoda . Additionally, we find that an asymmetrical site previously observed across many species within Isopoda is absent in I. armatus , but confirm the presence of two asymmetrical sites recently reported in two other isopod species.