Mitogenome Information Research Articles

Quantifying the effects of the mitochondrial genome on milk production traits in dairy cows: empirical results and modelling challenges

Significant advances in livestock traits have been achieved primarily through selection strategies targeting variation in the nuclear genome, with little attention given to mitogenome variation. We analyzed the influence of the mitogenome on milk production traits of Holstein cattle in Croatia based on strategically generated next-generation sequencing data for 109 cows pedigree-linked to 7115 milk production records (milk, fat and protein yield) from 3006 cows (first 5 lactations). Since little is known about the biology of the relationship between mitogenome variation and production traits, our quantitative genetic modeling was complex. Thus, the proportion of total variance explained by mitogenome inheritance was estimated using 5 different models: (1) cytoplasmic model with maternal lineages (CYTO), (2) haplotypic model with mitogenome sequences (HAPLO), (3) amino acid model with unique amino acid sequences (AMINO), (4) evolutionary model based on a phylogenetic analysis using Bayesian Evolutionary Analysis Sampling Trees phylogenetic analysis (EVOL), and (5) mitogenome SNP model (SNPmt). The polygenic autosomal and X chromosome additive genetic effects based on pedigree were modeled, together with the effects of herd-year-season interaction, permanent environment, location, and age at first calving. The estimated proportions of phenotypic variance explained by mitogenome in 4 different models (CYTO, HAPLO, AMINO, and SNPmt) were found to be substantial given the size of mitogenome, ranging from 5% to 7% for all 3 milk traits. At the same time, a negligible proportion of the phenotypic variance was explained by mitogenome with the EVOL model. Similarly, in all models, no proportion of phenotypic variance was explained by the X chromosome. Although our results should be confirmed in other dairy cattle populations, including a large number of sequenced mitogenomes and nuclear genomes, the potential of utilizing mitogenome information in animal breeding is promising, especially as the acquisition of complete genome sequences becomes cost-effective.

Determining Gene Order Patterns in the Suillus and Boletales through Comparative Analysis of Their Mitogenomes.

Suillus is one of the most important genera of ectomycorrhizal fungi. As a model for studying host specificity, its molecular fragments and nuclear genome have been analyzed. However, its mitochondrial genome has not yet been reported. In this study, we assembled five mitogenomes of Suillus and analyzed and compared their basic characteristics. Owing to the large number of introns as well as intergenic regions, the mitogenomic lengths of species of Suillus were greater than those of other species of Boletales. We identified two main patterns of gene order arrangement in the members of the order Boletales. The Ka/Ks values of 15 protein-coding genes were <1 for the mitochondrial genes of 39 Boletales species, indicating their conserved evolution. Phylogenetic trees, reconstructed using the mitogenomes, indicated that the genus Suillus was monophyletic. Phylogenetic results based on the internal transcribed spacer region and mitogenome were used to confirm the distribution of Suillus placidus in China. The results showed that the mitogenome was superior in distinguishing species compared with a single molecular fragment. This is the first study to investigate the mitogenome of Suillus, enriching the mitogenome information and providing basic data for the phylogeny, resource conservation, and genetic diversity of this genus.

The complete mitochondrial genome of a Biwa goby, Gymnogobius isaza (Tanaka, 1916)

We determined the complete mitochondrial DNA sequence of a Biwa goby, Gymnogobius isaza (Tanaka, 1916) using next-generation sequencing methods. The composition of its mitogenome is the same as that observed in most other vertebrates, comprising of 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and two control regions. Our molecular phylogenetic analysis confirmed the close phylogenetic relationship between G. isaza and G. petschiliensis. This mitogenome information will be useful for distribution surveys using environmental DNA and the development of conservation strategies for this species.

Mitogenome information in cattle breeding and conservation genetics: Developments and possibilities of the SNP chip

In contrast to nuclear markers routinely used for genomic selection, mitogenome information has been underutilized for breeding and biodiversity management of cattle populations. Our main goal was to promote the efficient use of mitogenome SNPs contained in commercial high-throughput SNP arrays. In collaboration with NEOGEN Genomics (Lincoln, NE, USA), we integrated 310 SNPs into the commercial GGP Bovine 100K SNP array. In doing so, we demonstrated how mitogenome SNPs can be used in high-throughput arrays to (i) analyze population structure and diversity, (ii) classify bovine haplogroups and identify introgression and/or upgrading, (iii) screen and identify pedigree defects, (iv) impute mitogenome information on maternal lineages to increase statistical power in estimating the effects of mitogenome variation on quantitative production traits, and (v) identify deleterious mutations found in humans. In addition, we have developed protocols and pipelines integrated with the Magellan v2.0 software to enable efficient and routine use of mitogenome information in cattle breeding and genetic diversity management. Finally, we have highlighted some other interesting opportunities for the use of mitogenome information in the near future.

The complete mitochondrial genome of Neoporphyra dentata (Bangiales, Rhodophyta)

Neoporphyra dentata (Kjellman) L.-E. Yang & J. Brodie, 2020 is an economically valuable species in seaweed aquaculture in the southwest coastal regions of Korea. Here, we report the complete mitogenome information of N. dentata using Illumina Miseq platform permitted assembly of a circular mitochondrial genome of 26,807 bp from N. dentata consisting of 29.9% GC contents, 9 protein coding genes (PCGs), 2 ribosomal RNA genes (12S rRNA and 16S rRNA), 23 transfer RNA (tRNA) genes, and a non-coding region. The overall nucleotide composition was A: 38%, T: 32%, C: 14.7%, and G: 15.2%. The mitochondrial genome of N. dentata contributes to revealing the phylogenetic relationships among species of the Bangiaceae family.

Complete Mitochondrial Genome of Two Ectoparasitic Capsalids (Platyhelminthes: Monogenea: Monopisthocotylea): Gene Content, Composition, and Rearrangement.

The capsalid monogeneans are important pathogens that generally infect marine fishes and have a substantial impact on fish welfare in aquaculture systems worldwide. However, the current mitogenome information on capsalids has received little attention, limiting the understanding of their evolution and phylogenetic relationships with other monogeneans. This paper reports the complete mitochondrial genomes of Capsala katsuwoni and Capsala martinieri for the first time, which we obtained using a next-generation sequencing method. The mitogenomes of C. katsuwoni and C. martinieri are 13,265 and 13,984 bp in length, respectively. Both species contain the typical 12 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region. The genome compositions show a moderate A+T bias (66.5% and 63.9% for C. katsuwoni and C. martinieri, respectively) and exhibit a negative AT skew but a positive GC skew in both species. One gene block rearrangement was found in C. katsuwoni in comparison with other capsalid species. Instead of being basal to the Gyrodactylidea and Dactylogyridea or being clustered with Dactylogyridea, all species of Capsalidea are grouped into a monophyletic clade. Our results clarify the gene rearrangement process and evolutionary status of Capsalidae and lay a foundation for further phylogenetic studies of monogeneans.

Characterization of the complete mitochondrial genome of Ixodes granulatus (Ixodidae) and its phylogenetic implications.

Ticks are deemed to be second only to mosquitoes as the most common vector of human infectious diseases worldwide that give rise to human and animal diseases and economic losses to livestock production. Our understanding of the phylogenetic analysis between tick lineages has been restricted by the phylogenetic markers of individual genes. Genomic data research could help advance our understanding of phylogenetic analysis and molecular evolution. Mitochondrial genomic DNA facilitated the phylogenetic analysis of eukaryotes containing ticks. In this study, we sequenced and assembled the circular complete mitogenome information of Ixodes granulatus. The 14,540-bp mitogenome consists of 37 genes, including 13 protein-coding genes (PCGs), two genes for ribosomal RNA (rRNAs), and 22 genes for transfer RNA (tRNAs), and the origin of the L-strand replication region. The directions of the coding strand and component genes in the non-Australasian Ixodes mitochondrial genome were similar to those found in most other Australasian Ixodes, except for the loss of a lengthy control region. The phylogenetic tree based on maximum likelihood (ML) and Bayesian inference (BI) computational algorithms showed that I. granulatus exhibits a close relationship with I. hexagonus and I. ricinus. To our knowledge, this is the first study exploring the complete mitogenome for the species I. granulatus. Our results provide new insights for further research on the evolution, population genetics, systematics, and molecular ecology of ticks.

Comparative Mitogenomics of True Frogs (Ranidae, Anura), and Its Implications for the Phylogeny and Evolutionary History of Rana.

Simple SummaryThe true frogs of the genus Rana are a complex and diverse group. Many new species have been discovered with the help of molecular markers and morphological traits. However, the evolutionary history in Rana were not well understood. In this study, we sequenced and annotated the complete mitochondrial genome of R. longicrus and R. zhenhaiensis. In 13 protein codon genes, the COI was the most conserved, and ATP8 had a fast rate of evolution. The Ka/Ks ratio analysis among Rana indicated the protein-coding genes were suffering purify selection. There were three kinds of gene arrangement patterns found. This study provides mitochondrial genetic information, improving our understanding of mitogenomic structure and evolution, and recognizes the phylogenetic relationship and taxonomy among Rana.The true frogs of the genus Rana are a complex and diverse group, containing approximately 60 species with wide distribution across Eurasia and the Americas. Recently, many new species have been discovered with the help of molecular markers and morphological traits. However, the evolutionary history in Rana was not well understood and might be limited by the absence of mitogenome information. In this study, we sequenced and annotated the complete mitochondrial genome of R. longicrus and R. zhenhaiensis, containing 22 tRNAs, 13 protein-coding genes, two ribosomal RNAs, and a non-coding region, with 17,502 bp and 18,006 bp in length, respectively. In 13 protein codon genes, the COI was the most conserved, and ATP8 had a fast rate of evolution. The Ka/Ks ratio analysis among Rana indicated the protein-coding genes were suffering purify selection. There were three kinds of gene arrangement patterns found. The mitochondrial gene arrangement was not related to species diversification, and several independent shifts happened in evolutionary history. Climate fluctuation and environmental change may have played an essential role in species diversification in Rana. This study provides mitochondrial genetic information, improving our understanding of mitogenomic structure and evolution, and recognizes the phylogenetic relationship and taxonomy among Rana.

Characterization of the complete mitochondrial genome of Haemaphysalis (Alloceraea) kolonini (Ixodidae) and its phylogenetic implications.

Ticks transmit diverse pathogens that cause human and animal diseases, leading to an increasing number of new challenges around the world. Genomic data research could help advance our learning of phylogenetic analysis and molecular evolution. Mitochondrial genome DNA has been helpful in illustrating the phylogenetic analysis of eukaryotes containing ticks. In this research, we sequenced and assembled the circular complete mitogenome information of Haemaphysalis kolonini. The 14,948-bp mitogenome consists of 37 genes which included 13 genes for protein-coding, two genes for ribosomal RNA, 22 genes for transfer RNA, and two control regions (D-loops). Overall, the composition and arrangement of genes were compared with Haemaphysalis ticks previously recorded in Genbank. The phylogenetic tree based on Maximum likelihood (ML) and Bayesian inference (BI) computational algorithms showed that H. kolonini has a close relationship with Haemaphysalis inermis. The complete mitogenome data provide a preferable perception to the phylogenetic relationship than the single-gene data analysis. To our knowledge, this is the first research exploring the complete mitogenome for the species H. kolonini. Our results provide new insights for further research on the evolution, population genetics, systematics, and molecular ecology of ticks.

Complete mitochondrial genome of Proisotoma minuta (Collembola: Proisotominae)

The springtail Proisotoma minuta is a cosmopolitan species that can be found in many different habitats, especially in soil ecosystems. It is considered to be a good indicator of soil health. In this study, mitogenome information was obtained, which could lay a foundation for future fauna studies. The mitogenome of P. minuta is a circular module of 15,930 bp, including 13 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. The mitogenome of P. minuta is composed of 35.9% A, 28.5% T, 13.7% G, and 21.3% C. Phylogenetic analysis revealed that P. minuta was well grouped in the subfamily Proisotominae and had a closer relationship with Anurophorinae than Isotominae subfamily and other families.

Complete mitochondrial genome of the six-line wrasse Pseudocheilinus hexataenia (Labriformes, Labridae)

Here, we report the complete mitogenome information of the six-line wrasse Pseudocheilinus hexataenia (Bleeker, 1857). Genome sequencing using the Illumina HiSeq platform allowed the assembly of a circular mitochondrial genome of 17,111 bp from P. hexataenia, consisting of 54% AT nucleotides, 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a putative control region in the typical Labriformes gene composition. The gene order of the P. hexataenia mitochondrion was identical to that of the Labridae mitogenomes. Phylogenetic reconstruction places P. hexataenia with a close relationship with the mitogenome of the goldsinny wrasse, Ctenolabrus rupestris.

The complete mitochondrial genome of the terebellid polychaete Thelepus plagiostoma (Terebellida; Terebellidae)

Here, we report the complete mitogenome information of the terebellid polychaete, Thelepus plagiostoma (Schmarda, 1861). Genome sequencing by Illumina HiSeq platform permitted assembly of a circular mitochondrial genome of 15,628 bp from T. plagiostoma consisting of 67% AT nucleotides, 13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a non-coding region in the typical annelid gene composition. Gene order of the T. plagiostoma mitochondrion is identical to those of the Terebelliformia mitogenomes. Phylogenetic reconstruction places T. plagiostoma within the monophyletic subclass Sedentaria, a sister to Pista cristata in the suborder Terebelliformia.

Complete Mitochondrial Genome of Pseudocaranx dentex (Carangidae, Perciformes) Provides Insight into Phylogenetic and Evolutionary Relationship among Carangidae Family.

Pseudocaranx dentex (white trevally) which belongs to the Carangidae family, is an important commercial fishery and aquaculture resource in Asia. However, its evolution and population genetics have received little attention which was limited by the mitogenome information absence. Here, we sequenced and annotated the complete mitochondrial genome of P. dentex which was 16,569 bp in length, containing twenty-two tRNAs (transfer RNAs), thirteen PCGs (protein-coding genes), two rRNAs (ribosomal RNAs), and one non-coding region with conservative gene arrangement. The Ka/Ks ratio analysis among Carangidae fishes indicated the PCGs were suffering purify selection and the values were related to the taxonomic status and further influenced by their living habits. Phylogenetic analysis based on the PCGs sequences of mitogenomes among 36 species presented three major clades in Carangidae. According to the phylogenetic tree, we further analyzed the taxonomic confusion of Carangoides equula which was on the same branch with P. dentex but a different branch with Carangoides spp. We inferred Kaiwarinus equula should be the accepted name and belong to the independent Kaiwarinus genus which was the sister genus of Pseudocaranx. This work provides mitochondrial genetic information and verifies the taxonomic status of P. dentex, and further helps to recognize the phylogenetic relationship and evolutionary history of Carangidae.

The complete mitochondrial genome of Eoscarta assimilis (Hemipera: Cercopidae) and phylogenetic analysis of Cercopidae

The complete mitochondrial genome (mitogenome) of Eoscarta assimilis (Uhler, 1896) was sequenced in the current paper. The total length of the mitogenome is 17,231 bp and it consists of 37 genes including 22 transfer RNA (tRNAs), 13 protein-coding (PCGs) and 2 ribosomal RNA (rRNAs). The 13 PCGs initiated with the start codon ATN, but ND4 started with TTG. All of the PCGs ended with TAA, apart from COX3 which terminated by incomplete TAG. A ML tree based on sequences of 15 complete mitogenomes (13 Cercopidae and 2 outgroup) suggests that E. assimilis is more closely related to the genus Callitettix. The phylogenetic analysis supports the monophyly of the family Cercopidae and the genus Cosmoscarta, and the paraphyly of the subfamily Callitettixinae. This mitogenome information for E. assimilis could facilitate future evolutionary studies to related insects.

Characterization of the complete mitochondrial genome of Aphyocypris chinensis (Cypriniformes, Xenocyprididae), and its phylogenetic position in Cypriniformes

Aphyocypris chinensis Günther, 1868 is a small freshwater fish of the family Xenocyprididae (Cypriniformes). In this study, we determined its complete mitochondrial genome and phylogenetic position in Cypriniformes. The complete mitochondrial genome is 16,608 bp in size, containing 13 protein-coding genes, two RNAs, 22 tRNAs, and a control region. It has the typical vertebrate mitochondrial gene arrangement. Our mitogenomic phylogeny revealed that A. chinensis belongs to Xenocyprididae, rather than Danionidae. This mitogenome information could play an essential role in resolving the conflict over its current taxonomic status in Cypriniformes.

The complete mitochondrial genome of Platycheirus albimanus (Diptera: Syrphidae: Syrphinae) and phylogenetic analysis of the Syrphidae

The complete mitochondrial genome of Platycheirus albimanus (Fabricius, 1781) was sequenced. The length of the mitogenome is 16,648 bp and consists of 37 genes including 22 transfer RNA (tRNAs), 13 protein-coding (PCGs) and 2 ribosomal RNA (rRNAs). The 13 PCGs initiate with the start codon ATN, except for COX1 and ATP6 which use TTG. All of the PCGs ended with TAA, apart from ND4 and ND4L terminated by incomplete T––. The ML tree based on complete mitogenomes from 25 species (22 Syrphidae and 3 outgroup taxa) suggests that the tribe Melanostomini is more closely related to the Syrphini. The phylogenetic analysis supports the monophyly of Syrphinae, and the paraphyly of the Eristalinae. This mitogenome information for P. albimanus could facilitate future studies of evolutionarily related insects.

The complete mitochondrial genome of Homatula pycnolepis (Teleostei, Cypriniformes) in Lantsang River and its phylogenetic analysis

Homatula pycnolepis is a small-sized benthopelagic fish species in the family Nemacheilidae, superfamily Cobitidea. In this study, the entire mitogenome sequence of the H. pycnolepis has been sequenced by using sanger sequencing method. The circular mitochondrial genome was 16,570 bp in length and contained of 13 protein-coding genes, two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, an origin of light-strand replication (OL), and one displacement loop locus (D-loop). The overall base composition was 30.1% A, 26.4% T, 26.8% C, and 16.7% G with 56.6% AT content. Most genes were encoded on the heavy strand except for ND6 and eight tRNA genes. There were 11 regions of gene overlaps totaling 29 bp and 7 intergenic spacer regions totaling 37 bp. Its structure type was similar to the mitogenome of Cobitidea fishes. Phylogenetic analysis with 33 complete mitogenomes of Cobitidea and 2 Macrognathus fishes in the family of Mastacembelidae suggested that Homatula species clustered as one monophyletic clade and Homatula was closely related to Schistura. Mitogenome information from this study could be a useful basis for conservation and phylogenetics of this species.

The Phylogenetic Implications of the Mitochondrial Genomes of Macropsis notata and Oncopsis nigrofasciata.

Macropsinae are forest pests that feed on woody plants. They can damage the growth of trees and crops, and some species can also spread plant pathogens. Due to their widespread effects, these leafhoppers are of great economic significance, which is why there is a need to study their genomes. To fill the gap in the mitochondrial genomic data of the subfamily Macropsinae, we sequenced the complete mitochondrial genomes of Macropsis notata and Oncopsis nigrofasciata (which were 16,323 and 15,927 bp long, respectively). These two species are representative species of the leafhoppers group (Cicadellidae); the mitochondrial genomes of these species range from a length of 15,131 bp (Trocnadella arisana) to 16,811 bp (Parocerus laurifoliae). Both mitogenomes contained 37 typical insect mitochondrial genes and a control region; there were no long non-coding sequences. The genes within the mitogenome were very compact. The mitogenomes from both species contained two kinds of parallel repeat units in the control region. The whole mitogenomes of Macropsinae showed a heavy AT nucleotide bias (M. notata 76.8% and O. nigrofasciata 79.0%), a positive AT Skew (0.15 and 0.12), and a negative GC Skew (–0.14 and –0.08). Upon comparative ML and BI analysis, some clade relationships were consistent among the six trees. Most subfamilies were reconstructed into monophyletic groups with strong support in all analyses, with the exception of Evacanthinae and Cicadellinae. Unlike the results of previous research, it was shown that although all Deltocephalinae species are grouped into one clade, they were not the sister group to all other leafhoppers. Further, Cicadellinae and Evacanthinae were occasionally reconstructed as a polyphyletic and a paraphyletic group, respectively, possibly due to the limited numbers of samples and sequences. This mitogenome information for M. notata and O. nigrofasciata could facilitate future studies on the mitogenomic diversity and evolution of the related Membracoidea, and eventually help to control their effects on plants for the betterment of society at large.

The complete mitochondrial genome and phylogenetic analysis of Hiatella sp. J (Mollusca: Hiatellidae)

The genus Hiatella is one of most abundant and widespread marine bivalves. To date, its intra-generic phylogeny remains disputed and mitogenome information is therefore much needed. Here, we first report the complete circular mitogenome of Hiatella sp. J that is distributed in the coast of Asia Pacific. The total length of this mitochondrial genome is 21,233 base pairs. It consists of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a major noncoding region (MNR). Phylogenetic analysis of COI from 25 species (Hiatellidae) revealed that the Hiatella sp. J was closely related to Asian Hiatella in the family Hiatellidae. This Hiatella mitogenome provides new molecular data for the further taxonomic and phylogenetic studies of the genus Hiatella of marine bivalves.

Massively parallel sequencing of mitogenome sequences reveals the forensic features and maternal diversity of tai-kadai-speaking hlai islanders

As a single maternally inherited locus, human mitochondrial DNA (mtDNA) is geographically arranged and plays a key role in forensic applications. Hlai population has been evidenced as the most typical and unmixed representative of the Tai-Kadai-speaking populations via genome-wide analyses. However, forensic features and maternal diversity of the complete mitogenomes in this Tai-Kadai ancestrally related population are scarce. Thus, we sequenced the complete mitogenomes in 127 Hainan Hlais and found 109 distinct haplotypes belonging to 43 terminal haplogroups resulting in the haplotype diversity of 0.9970. Our results of comprehensive population comparisons showed that Hlai islanders had a close genetic affinity with Tai-Kadai-speaking populations from Southeast Asia, which is consistent with the back-migration of Chinese Neolithic farmers into this region via the inland route. Besides, maternally genetic evidence further revealed a close genetic relationship between Tai-Kadai-speaking and Austronesian-speaking populations when only East Asian dataset was considered, which is consistent with the common origin from Yangtze rice farmers and then spread southward along the inland and coastal routes, respectively. In the reconstructed phylogenetic tree and median-joining networks, the vast majority of Hlais were clustered in exclusive clades, which demonstrated that Hlai people probably had undergone founder effect or genetic bottleneck in their history, and remained genetically isolated for a long time. Collectively, Hainan Hlai did not exhibit detectable maternal gene flow from surrounding or incoming populations. Mitogenome information generated in this study is a contribution in mitigating the underrepresentation of Chinese data in forensic mitogenetics and will assist geography-, metapopulation-, as well as phylogeny-based queries.