Nuclear Integrants of Organellar DNA Contribute to Genome Structure and Evolution in Plants

The transfer of genetic material from the mitochondria and plastid to the nucleus gives rise to nuclear integrants of mitochondrial DNA (NUMTs) and nuclear integrants of plastid DNA (NUPTs). This frequently occurring DNA transfer is ongoing and has important evolutionary implications. In this review, based on previous studies and the analysis of NUMT/NUPT insertions of more than 200 sequenced plant genomes, we analyzed and summarized the general features of NUMTs/NUPTs and highlighted the genetic consequence of organellar DNA insertions. The statistics of organellar DNA integrants among various plant genomes revealed that organellar DNA-derived sequence content is positively correlated with the nuclear genome size. After integration, the nuclear organellar DNA could undergo different fates, including elimination, mutation, rearrangement, fragmentation, and proliferation. The integrated organellar DNAs play important roles in increasing genetic diversity, promoting gene and genome evolution, and are involved in sex chromosome evolution in dioecious plants. The integrating mechanisms, involving non-homologous end joining at double-strand breaks were also discussed.

Comparative Chloroplast Genomics of Fritillaria (Liliaceae), Inferences for Phylogenetic Relationships between Fritillaria and Lilium and Plastome Evolution

Fritillaria is a genus that has important medicinal and horticultural values. The study involved the most comprehensive chloroplast genome samples referring to Old and New World clades of Fritillaria for marker selection and phylogenetic studies. We reported and compared eleven newly sequenced whole-plastome sequences of Fritillaria which proved highly similar in overall size (151,652–152,434 bp), genome structure, gene content, and order. Comparing them with other species of Liliales (6 out of 10 families) indicated the same similarity but showed some structural variations due to the contraction or expansion of the inverted repeat (IR) regions. A/T mononucleotides, palindromic, and forward repeats were the most common types. Six hypervariable regions (rps16-trnQ, rbcL-accD, accD-psaI, psaJ-rpl33, petD-rpoA, and rpl32-trnL) were discovered based on 26 Fritillaria whole-plastomes to be potential molecular markers. Based on the plastome data that were collected from 26 Fritillaria and 21 Lilium species, a phylogenomic study was carried out with three Cardiocrinum species as outgroups. Fritillaria was sister to Lilium with a high support value, and the interspecies relationships within subgenus Fritillaria were resolved very well. The six hypervariable regions can be used as candidate DNA barcodes of Fritillaria and the phylogenomic framework can guide extensive genomic sampling for further phylogenetic analyses.

Complete plastome sequence of Croton laevigatus Vahl (Euphorbiaceae): an endemic species in Hainan, China

Croton laevigatus grows as an evergreen tree or shrub with 15 meters height. It is distributed in the dense or open forests of Hainan province, China. Here, we report and characterize the complete plastome of C. laevigatus in an effort to provide genomic resources useful for promoting its systematics research. The plastome of C. laevigatus is found to possess a total length 162,515 bp with the typical quadripartite structure of angiosperms, contains two Inverted Repeats (IRs) of 26,866 bp, a Large Single-Copy (LSC) region of 90,234 bp and a Small Single-Copy (SSC) region of 18,549 bp. The plastome contains 113 genes, consisting of 79 unique protein-coding genes, 30 unique tRNA genes and four unique rRNA genes. The overall A/T content in the plastome of C. laevigatus is 64.10%. The phylogenetic analysis indicated that C. laevigatus is close to C. tiglium within Euphorbiaceae in this study. The complete plastome sequence of C. laevigatus will provide a useful resource for the conservation genetics of this species as well as for the phylogenetic studies of Euphorbiaceae.

Complete plastome sequence of Euphorbia milii Des Moul. (Euphorbiaceae)

Euphorbia milii (Euphorbiaceae) grows as a scrambling shrub with many branches. Here, we report and characterize the complete plastome of E. milii in an effort to provide genomic resources useful for promoting its systematic research. The plastome of E. milii is found to possess a total length of 160,806 bp with the typical quadripartite structure of angiosperms, contains two Inverted Repeats (IRs) of 26,695 bp, a Large Single-Copy (LSC) region of 90,211 bp and a Small Single-Copy (SSC) region of 17,205 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA genes and four unique rRNA genes. The overall A/T content in the plastome of E. milii is of 64.10%. The phylogenetic analysis indicated that E. milii is close to E. tirucalli within Euphorbiaceae in this study. The complete plastome sequence of E. milii will provide a useful resource for the conservation genetics of this species as well as for the phylogenetic studies of Euphorbiaceae.

The Genome Structure of Ciprofloxacin-Resistant Mycoplasma Hominis Clinical Isolates

The genome structure of three ciprofloxacin-resistant Mycoplasma hominis clinical isolates was studied using next-generation sequencing on the Illumina platform. The protein sequences of the studied Mycoplasma strains were found to have a high degree of homology. Mycoplasma hominis (M45, M57, MH1866) was shown to have limited biosynthetic capabilities, associated with the predominance of the genes encoding the proteins involved in catabolic processes. Multiple single-nucleotide substitutions causing intraspecific polymorphism of Mycoplasma hominis were found. The genes encoding the efflux systems - ABC transporters (the ATP-binding cassette superfamily) and proteins of the MATE (multidrug and toxic compound extrusion) family - were identified. The molecular mechanism of ciprofloxacin resistance of the Mycoplasma hominis M45 and M57 isolates was found to be associated with the Ser83Leu substitution in DNA gyrase subunit A. In the Mycoplasma hominis MH1866 isolate it was related to the Lys144Arg substitution in topoisomerase IV subunit A.

Complete plastome sequence of Elaeagnus glabra (Elaeagnaceae): an Asian endemic plant species

Elaeagnus glabra is an evergreen vine or climbing shrub with 5 m height. It is widespread in southern China. It grows in the sunny forests or forest margins below 1000 m a.s.l. In this paper, we report and describe the complete plastome of E. glabra in order to provide useful genomic data for its systematic research. The complete plastome of E. glabra is 152,555 bp with a typical quadripartite structure of angiosperms. It contains two Inverted Repeats (IRs) of 25,918 bp, a large single-copy (LSC) of 82,408 bp, and a small single-copy (SSC) region of 18,311 bp. The complete plastome contains 129 genes, including 83 protein-coding genes, 38 tRNA genes, and eight rRNA genes. The overall A/T content in the chloroplast genome of E. glabra is 62.90%. The phylogenetic analysis indicated that E. glabra is close to E. loureirii within Elaeagnaceae. The complete plastome of E. glabra will provide useful resources for the development and utilization of this species and the phylogenetic study of Rosales.

The complete mitochondrial genome sequence and gene organization of Lepidotrigla Kanagashira (Scorpaeniformes, Triglidae) with phylogenetic consideration

The complete mitochondrial genome DNA sequence of Lepidotrigla kanagashira was 16,504 bp in length. It consists of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and one control region. Among 22 tRNA genes, 8 tRNAs were encoded on the L-strand. The overall base composition of the genome is 26.65% for A, 25.42% for T, 30.89% for C and17.04% for G. The phylogenetic tree suggested that L. kanagashira was genetically closest to L. microptera and Chelidonichthys kumu among 13 related species. This study could provide some valuable information for further studies on L. kanagashira.

Postglacial ecotype formation under outcrossing and self-fertilization in Arabidopsis lyrata

The formation of ecotypes has been invoked as an important driver of postglacial biodiversity, because many species colonized heterogeneous habitats and experienced divergent selection. Ecotype formation has been predominantly studied in outcrossing taxa, while far less attention has been paid to the implications of mating system shifts. Here, we addressed whether substrate-related ecotypes exist in selfing and outcrossing populations of Arabidopsis lyrata subsp. lyrata and whether the genomic footprint differs between mating systems. The North American subspecies colonized both rocky and sandy habitats during postglacial range expansion and shifted the mating system from predominantly outcrossing to predominantly selfing in a number of regions. We performed an association study on pooled whole-genome sequence data of 20 selfing or outcrossing populations, which suggested genes involved in adaptation to substrate. Motivated by enriched gene ontology terms, we compared root growth between plants from the two substrates in a common environment and found that plants originating from sand grew roots faster and produced more side roots, independent of mating system. Furthermore, single nucleotide polymorphisms associated with substrate-related ecotypes were more clustered among selfing populations. Our study provides evidence for substrate-related ecotypes in A. lyrata and divergence in the genomic footprint between mating systems. The latter is the likely result of selfing populations having experienced divergent selection on larger genomic regions due to higher genome-wide linkage disequilibrium.

Complete plastome sequence of Magnolia omeiensis (W.C. Cheng) Dandy (Magnoliaceae)

Magnolia omeiensis is an evergreen tree with 25 meters heights. It is distributed in tropical 1200-1300 m. Mount Emei. And it has been ranked as a CR (Critically Endangered) species in China. Here, we report and characterize the complete plastome of M. omeiensis in an effort to provide genomic resources useful for promoting its systematics research. The plastome of M. omeiensis is found to possess a total length 160,021 bp with the typical quadripartite structure of angiosperms, contains two Inverted Repeats (IRs) of 26,336 bp, a Large Single-Copy (LSC) region of 88,061 bp and a Small Single-Copy (SSC) region of 19,288 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA genes and 4 unique rRNA genes. The overall A/T content in the plastome of M. omeiensis is 60.70%. The phylogenetic analysis indicated that M. omeiensis is close to Magnolia yunnanensis within Magnoliaceae in this study. The complete plastome sequence of M. omeiensis will provide a useful resource for the conservation genetics of this species as well as for the phylogenetic studies of Magnoliaceae.

Unique structure (construction and configuration) and evolution of the array of small serum protein genes of Protobothrops flavoviridis snake

The nucleotide sequence of Protobothrops flavoviridis (Pf) 30534 bp genome segment which contains genes encoding small serum proteins (SSPs) was deciphered. The genome segment contained five SSP genes (PfSSPs), PfSSP-4, PfSSP-5, PfSSP-1, PfSSP-2, and PfSSP-3 in this order and had characteristic configuration and constructions of the particular nucleotide sequences inserted. Comparison between the configurations of the inserted chicken repeat-1 (CR1) fragments of P. flavoviridis and Ophiophagus hannah (Oh) showed that the nucleotide segment encompassing from PfSSP-1 to PfSSP-2 was inverted. The inactive form of PfSSP-1, named PfSSP-1δ(Ψ), found in the intergenic region (I-Reg) between PfSSP-5 and PfSSP-1 had also been destroyed by insertions of the plural long interspersed nuclear elements (LINEs) and DNA transposons. The L2 LINE inserted into the third intron or the particular repetitive sequences inserted into the second intron structurally divided five PfSSPs into two subgroups, the Long SSP subgroup of PfSSP-1, PfSSP-2 and PfSSP-5 or the Short SSP subgroup of PfSSP-3 and PfSSP-4. The mathematical analysis also showed that PfSSPs of the Long SSP subgroup evolved alternately in an accelerated and neutral manner, whereas those of the Short SSP subgroup evolved in an accelerated manner. Moreover, the ortholog analysis of SSPs of various snakes showed that the evolutionary emerging order of SSPs was as follows: SSP-5, SSP-4, SSP-2, SSP-1, and SSP-3. The unique interpretation about accelerated evolution and the novel idea that the transposable elements such as LINEs and DNA transposons are involved in maintaining the host genome besides its own transposition natures were proposed.

Complete plastome sequence of Ilex asprella (Hooker and Arnott) Champion ex Bentham (Aquifoliaceae), a Chinese folk herbal medicine

The complete chloroplast genome of Ilex asprella, a species of Aquifoliaceae is reported for the first time in this study. The complete chloroplast genome of I. asprella is 157,856 bp in length with a typical quadripartite structure, consisting of a large single-copy region (LSC, 87,258 bp), a single-copy region (SSC, 18,441 bp) and a pair of inverted repeats (IRs, 26,082 bp). There are 114 genes annotated, including 85 unique protein-coding genes, four unique ribosomal RNA genes, and 30 transfer RNA genes. To investigate the evolution status of T. concolor, as well as Scrophulariaceae, we build a phylogenetic tree with I. asprella and other eight species based on their complete chloroplast genomes. According to the phylogenetic topologies, I. asprella was closely related to I. wilsonii.

Stable and Conserved G-Quadruplexes in the Long Terminal Repeat Promoter of Retroviruses

Retroviruses infect almost all vertebrates, from humans to domestic and farm animals, from primates to wild animals, where they cause severe diseases, including immunodeficiencies, neurological disorders, and cancer. Nonhuman retroviruses have also been recently associated with human diseases. To date, no effective treatments are available; therefore, finding retrovirus-specific therapeutic targets is becoming an impelling issue. G-Quadruplexes are four-stranded nucleic acid structures that form in guanine-rich regions. Highly conserved G-quadruplexes located in the long-terminal-repeat (LTR) promoter of HIV-1 were shown to modulate the virus transcription machinery; moreover, the astonishingly high degree of conservation of G-quadruplex sequences in all primate lentiviruses corroborates the idea that these noncanonical nucleic acid structures are crucial elements in the lentiviral biology and thus have been selected for during evolution. In this work, we aimed at investigating the presence and conservation of G-quadruplexes in the Retroviridae family. Genomewide bioinformatics analysis showed that, despite their documented high genetic variability, most retroviruses contain highly conserved putative G-quadruplex-forming sequences in their promoter regions. Biophysical and biomolecular assays proved that these sequences actually fold into G-quadruplexes in physiological concentrations of relevant cations and that they are further stabilized by ligands. These results validate the relevance of G-quadruplexes in retroviruses and endorse the employment of G-quadruplex ligands as innovative antiretroviral drugs. This study indicates new possible pathways in the management of retroviral infections in humans and animal species. Moreover, it may shed light on the mechanism and functions of retrovirus genomes and derived transposable elements in the human genome.

Complete plastome sequence of Torenia concolor Lindley (Linderniaceae): an ornamental herb

In this study we firstly reported the complete chloroplast genome of Torenia concolor, a species of Linderniaceae. The complete chloroplast genome of T. concolor is 153,853 bp in length with a typical quadripartite structure, consisting of a large single-copy region (LSC, 85,446 bp), a single-copy region (SSC, 18,837 bp), and a pair of inverted repeats (IRs, 24,785 bp). There are 114 genes annotated, including 80 unique protein-coding genes, 4 unique ribosomal RNA genes, and 30 transfer RNA genes. To investigate the evolution status of T. concolor, as well as Linderniaceae, we constructed a phylogenetic tree with T. concolor and other 16 species based on their complete chloroplast genomes. According to the phylogenetic topologies, T. concolor was closely related to Pedicularis hallaisanensis.

Complete plastome sequence of Lysimachia congestiflora Hemsl. a medicinal and ornamental species in Southern China

Lysimachia congestiflora Hemsl. is a perennial herb of Primulaceae. It is mainly distributed in the provinces to the south of the Changjiang River and south of Shanxi, Gansu province and Taiwan. It is a plant that combines medicinal, ornamental, and economic values. To date no study has been carried out on the genome of L. congestiflora. Here, we report and characterize the complete plastid genome sequence of L. congestiflora in order to provide genomic resources useful for promoting its conservation. The complete chloroplast genome of L. congestiflora is 154,505 bp in length with a typical quadripartite structure, consisting of a large single-copy region (LSC, 84,606 bp), a single-copy region (SSC, 17,961 bp), and a pair of inverted repeats (IRs, 25,969 bp). There are 114 annotated genes, including 80 unique protein-coding genes, 4 unique ribosomal RNA genes, and 30 transfer RNA genes. To investigate the evolution status of L. congestiflora, as well as Primulaceae, we constructed a phylogenetic tree with L. congestiflora and other 11 species based on their complete chloroplast genomes. According to the phylogenetic topologies, L. congestiflora was closely related to L. coreana.

Complete plastome sequence of Torenia benthamiana Hance (Linderniaceae), an endemic herb in South China

Torenia benthamiana Hance is an endemic plant species distributed in southern China. In this study, we report and characterize the complete plastid genome sequence of T. benthamiana in order to provide genomic resources helpful for promoting its conservation and garden utilization. The complete plastome is 153,526 bp in length and contains the typical quadripartite structure of angiosperm plastome, including two inverted repeat (IR) regions of 24,638 bp, a large single-copy (LSC) region of 85,417 bp, and a small single-copy (SSC) region of 18,833 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA gene, and 4 unique rRNA genes. The overall A/T content in the plastome of T. benthamiana is 62.40%. The complete plastome sequence of T. benthamiana will provide a useful resource for the conservation and garden utilization of this species as well as for the phylogenetic studies of Linderniaceae.

Complete plastome sequence of Callicarpa nudiflora Vahl (Verbenaceae): a medicinal plant

Callicarpa nudiflora Vahl is a medicinal plant occurring in Guangdong, Guangxi, Hainan provinces of China. Here, we report and characterize the complete plastid genome sequence of C. nudiflora in an effort to provide genomic resources useful for promoting its conservation. The complete plastome is 154,080 bp in length and contains the typical structure and gene content of angiosperm plastome, including two inverted repeat (IR) regions of 25,657 bp, a large single-copy (LSC) region of 84,949 bp, and a small single-copy (SSC) region of 17,817 bp. There are 113 genes annotated, including 79 unique protein-coding genes, 4 unique ribosomal RNA genes, and 30 transfer RNA genes. To investigate the evolution status of C. nudiflora, as well as Verbenaceae, we constructed a phylogenetic tree with C. nudiflora and other 11 species based on their complete chloroplast genomes. According to the phylogenetic topologies, C. nudiflora was closely related to Lancea hirstua.

Systematic proteomics of endogenous human cohesin reveals an interaction with diverse splicing factors and RNA-binding proteins required for mitotic progression

The cohesin complex regulates sister chromatid cohesion, chromosome organization, gene expression, and DNA repair. Cohesin is a ring complex composed of four core subunits and seven regulatory subunits. In an effort to comprehensively identify additional cohesin-interacting proteins, we used gene editing to introduce a dual epitope tag into the endogenous allele of each of 11 known components of cohesin in cultured human cells, and we performed MS analyses on dual-affinity purifications. In addition to reciprocally identifying all known components of cohesin, we found that cohesin interacts with a panoply of splicing factors and RNA-binding proteins (RBPs). These included diverse components of the U4/U6.U5 tri-small nuclear ribonucleoprotein complex and several splicing factors that are commonly mutated in cancer. The interaction between cohesin and splicing factors/RBPs was RNA- and DNA-independent, occurred in chromatin, was enhanced during mitosis, and required RAD21. Furthermore, cohesin-interacting splicing factors and RBPs followed the cohesin cycle and prophase pathway of cell cycle-regulated interactions with chromatin. Depletion of cohesin-interacting splicing factors and RBPs resulted in aberrant mitotic progression. These results provide a comprehensive view of the endogenous human cohesin interactome and identify splicing factors and RBPs as functionally significant cohesin-interacting proteins.

Comparative analyses identify genomic features potentially involved in the evolution of birds-of-paradise

The diverse array of phenotypes and courtship displays exhibited by birds-of-paradise have long fascinated scientists and nonscientists alike. Remarkably, almost nothing is known about the genomics of this iconic radiation. There are 41 species in 16 genera currently recognized within the birds-of-paradise family (Paradisaeidae), most of which are endemic to the island of New Guinea. In this study, we sequenced genomes of representatives from all five major clades within this family to characterize genomic changes that may have played a role in the evolution of the group's extensive phenotypic diversity. We found genes important for coloration, morphology, and feather and eye development to be under positive selection. In birds-of-paradise with complex lekking systems and strong sexual dimorphism, the core birds-of-paradise, we found Gene Ontology categories for "startle response" and "olfactory receptor activity" to be enriched among the gene families expanding significantly faster compared to the other birds in our study. Furthermore, we found novel families of retrovirus-like retrotransposons active in all three de novo genomes since the early diversification of the birds-of-paradise group, which might have played a role in the evolution of this fascinating group of birds.

Complete plastome sequences of Diospyros maclurei Merr. and Diospyros hainanensis Merr. (Ebenaceae): two endemic species in Hainan Province, China

Diospyros is the largest genus (about 485 species) in Ebenaceae. It is a deciduous or evergreen tree or shrub. It grows in pantropical and extending into temperate regions. Here, we report and characterize the complete plastid genome sequences of D. maclurei Merr. and D. hainanensis Merr. in an effort to provide genomic resources useful for promoting their systematics research and potential economic development. The complete plastome of D. maclurei is 157,946 bp in length, including two Inverted Repeat (IR) regions of 26,081 bp, a Large Single-Copy (LSC) region of 87,387 bp, and a Small Single-Copy (SSC) region of 18,397 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA genes, and four unique rRNA genes. The overall A/T content in the plastome of D. maclurei is 62.60%. The complete plastome of D. hainanensis is 157,999 bp in length, including two Inverted Repeat (IR) regions of 26,077 bp, a Large Single-Copy (LSC) region of 87,523 bp, and a Small Single-Copy (SSC) region of 18,322 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA genes, and four unique rRNA genes. The overall A/T content in the plastome of D. hainanensis is 62.60%. The complete plastome sequences of D. Maclurei and D. hainanensis will provide a useful resource for the conservation genetics of the two species as well as for the phylogenetic studies of Diospyros.

Complete plastome sequence of Piper laetispicum (Piperaceae): An endemic plant species in South China

Piper laetispicum is dioecious climbers woody with 10 m tall, which is an endemic species in China. It grows on trees or rocks in forests (100-600 m) in Guangdong and Hainan Province of China. Here, we report and characterize the complete plastid genome sequence of P. laetispicum in an effort to provide genomic resources useful for promoting its conservation. The complete plastome is 161,721 bp in length and contains the typical structure and gene content of angiosperm plastome, including two inverted repeat (IR) regions of 27,125 bp, a large single copy (LSC) region of 89,224 bp and a small single copy (SSC) region of 18,247 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA gene, and four unique rRNA genes. The overall A/T content in the plastome of P. laetispicum is 61.70%. The complete plastome sequence of P. laetispicum will provide a useful resource for the conservation genetics of this species as well as for the phylogenetic studies for Piper.

Complete plastome sequence of Hoya pottsii Traill and Hoya liangii Tsiang (Apocynaceae)

Hoya is the largest genus (about 350-450 species) within Apocynaceae. It is a subshrub or liana, epiphytic or epilithic. Most species grow in tropical and subtropical South and Southeast Asia. Here we report and characterize the complete plastid genome sequence of Hoya pottsii Traill and Hoya liangii Tsiang in an effort to provide genomic resources useful for promoting its systematics research. The complete plastome of H. pottsii is 161,565 bp in length, including two Inverted Repeat (IR) regions of 24,657 bp, a Large Single-Copy (LSC) region of 92,532 bp, and a Small Single-Copy (SSC) region of 19,719 bp. The plastome contains 115 genes, consisting of 81 unique protein-coding genes, 30 unique tRNA genes, and 4 unique rRNA genes. The overall A/T content in the plastome of H. pottsii is 62.40%. The complete plastome of H. liangii is 162,989 bp in length, including two IR regions of 24,841 bp, a LSC region of 93,292 bp, and a SSC region of 20,015 bp. The plastome contains 115 genes, consisting of 81 unique protein-coding genes, 30 unique tRNA genes, and 4 unique rRNA genes. The overall A/T content in the plastome of H. pottsii is 62.30%. The complete plastome sequence of H. pottsii and H. liangii will provide a useful resource for the conservation genetics of the two species as well as for the phylogenetic studies of Hoya.

The complete mitochondrial genome of Neopagetopsis ionah (Channichthyidae, neopagetopsis) with phylogenetic consideration

In this study, the complete mitochondrial genome of Neopagetopsis ionah was obtained, which was 17,634 bp including two ribosomal RNAs, 13 protein-coding genes, 22 transfer RNAs, and a non-coding control region. In 13 protein-coding genes, there types of initiation codon (ATC, ATG, and GTG) and four types of stop codons (TAA, TAG, TA, and T) were identified. Among the 22 transfer RNAs, eight tRNAs were encoded by L-strand. The length of D-loop was 1519 bp and its contents of A, T, C, and G were 26.9%, 27.6%, 17.5%, and 30%, respectively. The complete mtDNA sequences of N. ionah and other 13 species were used to reconstruct the phylogenetic tree suggested that N. ionah was closest to some species of Channichthyidae. The study would provide a basic data for further research on population structure, conservation genetics and molecular evolution of N. ionah.

Complete plastome sequence of Hydnocarpus hainanensis Merr (Achariaceae): an endemic 'vulnerable' tree in South China

Hydnocarpus hainanensis Merr. is an evergreen tree with a height of 6–12 m and a diameter at breast height of 50 cm. It is distributed in Guangxi, Guizhou, Hainan, South of Yunnan Province of China. Here, we report and characterize the complete plastid genome sequence of H. hainanensis in an effort to provide genomic resources useful for promoting its conservation and systematics research. The plastome of H. hainanensis is found to possess a total length 163,330 bp with the typical quadripartite structure of angiosperms, containing two inverted repeats (IRs) of 26,870 bp, a large single copy (LSC) region of 91,510 bp and a small single copy (SSC) region of 18,080 bp. The plastome contains 111 genes, consisting of 78 unique protein-coding genes (seven of which are duplicated in the IR: rps12, rps7, ndhB, ycf2, rpl23, rpl2, and rps19), 29 unique tRNA genes (seven of which are duplicated in the IR, i.e. trnN^GUU, trnR^ACG, trnA^UGC, trnl^GAU, trnV^GAC, trnL^CAA, and trnl^CAU) and four unique rRNA genes (5S rRNA, 4.55S rRNA, 23S rRNA, and 16S rRNA). The overall A/T content in the plastome of H. hainanensis is 63.70%. The phylogenetic analysis indicated that H. hainanensis is close to Salix rorida within Malpighiales. The complete plastome sequence of H. hainanensis will provide a useful resource for the conservation genetics of the one species as well as for the phylogenetic studies of Achariaceae.

Complete plastome sequence of Vatica mangachapoi (Dipterocarpaceae): a vulnerable (VU) plant species in Southeast Asia

Vatica mangachapoi is a tree up to 20 m tall with white resinous. It is distributed in China (Hainan province), Indonesia, Malaysia (N Borneo), Philippines, Thailand, and Vietnam. It grows in forests on hills and mountain slopes below 700 metres. Its durable wood is used for making boats and building bridges and houses. It has been ranked as a VU (Vulnerable) species in China. Here we report and characterize the complete plastid genome sequence of V. mangachapoi in an effort to provide genomic resources useful for promoting its conservation and phylogenetic research. The complete plastome is 151,538 bp in length and contains the typical structure and gene content of angiosperm plastome, including two Inverted Repeat (IR) regions of 23,921 bp, a Large Single-Copy (LSC) region of 83,587 bp and a Small Single-Copy (SSC) region of 20,109 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA gene, and 4 unique rRNA genes. The overall A/T content in the plastome of V. mangachapoi is 62.80%. The phylogenetic analysis indicated that V. mangachapoi and V. odorata is closely related and as an independent branch in Malvales in our study. The complete plastome sequence of V. mangachapoi will provide a useful resource for the conservation genetics of this species and for the phylogenetic studies for Vatica.

The complete mitochondrial genome of Chionodraco rastrospinosus (Notothenioidei: Channichthyidae) with phylogenetic consideration

In this study, the complete mitochondrial genome of Chionodraco rastrospinosus was obtained, which was 17598 bp including 2 ribosomal RNAs, 13 protein-coding genes, 22 transfer RNAs, and a non-coding control region. The length of D-loop was 1332 bp and its contents of A, T, C, and G were 30.3%, 27.6%, 26.8%, and 15.3%. The complete mtDNA sequences of C. rastrospinosus and other 14 species were used to reconstruct the phylogenetic tree, suggested that C. rastrospinosus was closest to two species of Chionodraco. The study would provide a basic data for further research on population structure, conservation genetics and molecular evolution of C. rastrospinosus.