Large buoyant particles dominated by cyanobacterial colonies harbor distinct bacterial communities from small suspended particles and free-living bacteria in the water column

Worldwide cyanobacterial blooms greatly impair ecosystems in many eutrophic lakes and impact the microbial environment. In particular, large cyanobacterial colonies that are buoyant on the water surface may provide a distinct habitat for bacteria from other small particles that are suspended stably in the water column. To test this hypothesis, bacterial communities (excluding cyanobacteria) attached to large particles dominated by cyanobacterial colonies (>120 μm, LA), small particles (3–36 μm, SA), and free‐living bacteria (0.2–3 μm, FL) were investigated monthly for a year in Lake Taihu, China. Results confirmed that the Shannon diversity index of LA was significantly lower than that of FL, which was lower than that of SA. Cytophagia and Alphaproteobacteria were specially enriched in LA. Although samples in each habitat collected during high‐ (May to November) and low‐bloom seasons (December to April) were separated, all samples in LA were clustered and separated from SA and FL, which were also clustered during the same sampling seasons. In addition, the bacterial communities in LA were correlated with nitrate level, whereas FL and SA were correlated with nitrate level and temperature. Mantel analysis revealed that bacterial composition significantly correlated with the cyanobacterial composition in LA and FL but not in SA. These results indicate that LA provides distinct niches to bacteria, whereas the differentiation of bacterial communities in FL and SA is seasonally dependent.

The complete chloroplast genome sequence of wild oat, Avena sterilis L. (Poaceae) and its phylogeny

Wild oat, Avena sterilis L. is a stout broad-leaved annual grass resembling cultivated oats in general appearance. In this study, we sequenced the complete chloroplast (cp) genome sequence of A. sterilis for the first time to investigate their phylogenetic relationship in the family Poaceae. The complete cp genome sequence is 135,887 bp in length with 38.5% overall GC content and exhibits a typical quadripartite structure comprising one pair of inverted repeats (21,603 bp) separated by a small single-copy region (12,575 bp) and a large single-copy region (80,106). The cp genome encodes 111 unique genes, 76 of which are protein-coding genes, four rRNA genes, 30 tRNA genes, and 18 duplicated genes in the inverted repeat region. The phylogenetic analysis indicated A. sterilis closely clustered with the cultivated oat, A. sativa L.

Complete chloroplast genome of an Endangered mangrove plant Hernandia nymphiifolia (C. Presl) Kubitzki (Hernandiaceae)

This study presents the chloroplast genome of Hernandia nymphiifolia (C. Presl) Kubitzki (Hernandiaceae) one Endangered mangrove species in China, which was assembled and analyzed by de novo assembly using whole chloroplast genome sequencing data. The accessing ID of reference sequence was MG838431. The size of the complete chloroplast genome was 157,762 bp in length with a large single-copy region (LSC) of 86,641 bp, a small single-copy region (SSC) of 18,603 bp, and two inverted repeat regions (IRS) (26,260 bp). The GC content of H. nymphiifolia is 39.3%. From the chloroplast genomes, 133 genes, including 83 protein-coding genes, 42 tRNA genes, and 8 rRNA genes, were predicted. Among them, 17 genes occur in IRS, containing 6 protein-coding genes, 7 tRNA genes and 4 rRNA genes. The phylogenetic analysis with 10 eudicots species and rice as the outgroup revealed that H. nymphiifolia was clustered with 6 Ranunculales species.

Complete chloroplast genome sequence of Heritiera angustata (Malvaceae): an endangered plant species

Heritiera angustata (Malvaceae) is an evergreen tree distributed in the Chinese provinces of Hainan and Yunnan and in Cambodia. In China, it is listed as 'Endangered' (EN) China Red List of Higher Plants, although it is not protected by law. The complete chloroplast (cp) genome sequence of this threatened species is reported in this study, based on high-throughput sequencing (Illumina). The complete cp genome is 168, 953 bp in length, containing a pair of inverted repeat regions (IRs) of 34,491 bp, a large single copy (LSC) region of 89,054 bp, and a small single copy (SSC) region of 10,917 bp. The cp genome contains 129 genes, consisting of 85 protein-coding genes, 36 tRNA genes and eight rRNA genes. The overall AT content in the cp genome of H. angustata is 63.2%. The phylogenetic analyses indicate that there is a close relationship between H. angustata and Firmiana pulcherrima.

Two complete mitochondrial genomes of extinct form of the Sevan trout Salmo ischchan danilewskii

The mitochondrial genomes from two individuals of the extinct subspecies of the Sevan trout Salmo ischchan danilewskii are published in this paper. The mitochondrial DNA (mtDNA) is 16,665 base pairs (bp) in length and contained 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. The overall base composition of the genome in descending order was 27.9% of A, 29.4% of C, 16.7% of G, and 26.0% of T without a significant AT bias of 53.9%.

Characterization of the complete chloroplast genome of the Eastern gamagrass, Tripsacum dactyloides

Tripsacum dactyloides, known as eastern gamagrass, is used as a donor of valuable traits. It grows naturally in the same region where maize is commercially cultured in the USA and has the ability to hybridize to maize. The wild genotype of eastern gamagrass is threaten by the gene flow from the transgenic maize. The circular genome is 141,050 bp in length and contains 120 genes, including 73 protein-coding genes (PCG), 39 transfer RNA genes (tRNA) and eight ribosomal RNA genes (rRNA). The overall nucleotide composition is: 30.8% A, 19.2% C, 19.3% G, 30.7% T, with a total G + C content of 38.5%. The phylogenetic tree was constructed to explore the taxonomic status of Tripsacum dactyloides, which contributes to phylogenetic studies and further conservation strategies for this species.

Characterization of the complete chloroplast genome of longan (Dimocarpus longan Lour.) using illumina paired-end sequencing

Longan (Dimocarpus longan Lour.), as a kind of commercial fruit tree in the family Sapindaceae, is widely cultivated in South Asia. In this study, we obtained the complete chloroplast genome sequence of longan using Illumina paired-end sequencing. It has 160,833 bp in length, containing a pair of IR regions (28,428 bp) separated by a small single-copy region (18,270 bp) and a large single-copy region (85,707 bp). The overall GC contents of the chloroplast genome were 37.8%. This circular genome contains 130 annotated genes, including 85 protein-coding genes, 37 tRNAs and 8 rRNAs. The phylogenetic analysis using maximum–likelihood (ML) and neighbour-joining (NJ) method showed that longan has the closest relationship with Litchi chinensis, Sapindus mukorossi and Dodonaea viscosa. This complete chloroplast genomes can be subsequently used for the genetic breeding of this valuable species.

The complete mitochondrial DNA sequence of endemic honeybee Apis nuluensis (Insecta: Hymenoptera: Apidae) inhabiting Mount Kinabalu in Sabah Province, Borneo Island

The cavity-nesting honeybee Apis nuluensis inhabits only the highlands of Mount Kinabalu of Sabah, Borneo Island. The mitochondrial genome is a circular molecule of approximately 1.6 kb that includes 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and one AT-rich control region. The average AT content was 84.5%. The start codons ATC, ATG, and ATT were found in one, three, and nine genes, respectively, whereas the stop codon TAA was observed in all genes. The phylogenetic relationship, inferred using 13 PCGs, was consistent with that reported in previous studies that predicted a sister taxon relationship between A. nuluensis and A. cerana.

De novo Assembly and Characterization of Cajanus scarabaeoides (L.) Thouars Transcriptome by Paired-End Sequencing

Pigeonpea [Cajanus cajan (L.) Millsp.] is a heat and drought resilient legume crop grown mostly in Asia and Africa. Pigeonpea is affected by various biotic (diseases and insect pests) and abiotic stresses (salinity and water logging) which limit the yield potential of this crop. However, resistance to all these constraints is not readily available in the cultivated genotypes and some of the wild relatives have been found to withstand these resistances. Thus, the utilization of crop wild relatives (CWR) in pigeonpea breeding has been effective in conferring resistance, quality and breeding efficiency traits to this crop. Bud and leaf tissue of Cajanus scarabaeoides, a wild relative of pigeon pea were used for transcriptome profiling. Approximately 30 million clean reads filtered from raw reads by removal of adaptors, ambiguous reads and low-quality reads (3.02 gigabase pairs) were generated by Illumina paired-end RNA-seq technology. All of these clean reads were pooled and assembled de novo into 1,17,007 transcripts using the Trinity. Finally, a total of 98,664 unigenes were derived with mean length of 396 bp and N50 values of 1393. The assembly produced significant mapping results (73.68%) in BLASTN searches of the Glycine max CDS sequence database (Ensembl). Further, uniprot database of Viridiplantae was used for unigene annotation; 81,799 of 98,664 (82.90%) unigenes were finally annotated with gene descriptions or conserved protein domains. Further, a total of 23,475 SSRs were identified in 27,321 unigenes. This data will provide useful information for mining of functionally important genes and SSR markers for pigeonpea improvement.

Impact of tillage practices on soil bacterial diversity and composition under the tobacco-rice rotation in China

Tobacco-rice rotation is a common farming system in south China, and many tillage practices such as straw mulching, dolomite dust, and quicklime application have been adopted to improve crop production. These agricultural management practices alter soil physical and chemical properties and affect microbial life environment and community composition. In this research, six tillage practices including no tobacco and rice straw mulching (CK), tobacco and rice straw mulching (TrSr), rice straw returning fire (TrSc), tobacco and rice straw mulching with dolomite dust (TSD), rice straw returning fire and quicklime (TSQ), and rice straw returning fire, quicklime and reduced fertilizer (TSQf) were conducted to detect changes in soil bacterial diversity and composition using Illumina sequencing. The results showed that the total number of operational taxonomic units (OTUs) from the six treatments was 2030, and the number of mutual OTUs among all samples was 550. The TrSc treatment had the highest diversity and richness, while TSQf had the lowest. Soil physio-chemical properties and microbial diversity can influence each other. Proteobacteria and Actinobacteria had the greatest proportion in all treatments. The abundance of Nitrospirae was the highest in the TrSc treatment. The TSQf treatment had the highest abundance of Firmicutes. The abundance of Nitrospira in the TrSc treatment was 2.29-fold over CK. Streptomyces affiliated with Firmicutes improved by 37.33% in TSQf compared to TSQ. TSQf treatment was considered to be the most important factor in determining the relative abundance at the genus level.

Complete mitochondrial DNA sequence of the invasive hornet Vespa velutina (Insecta, Hymenoptera) found in Japan

In this study, we analyzed the complete mitochondrial genome of the invasive Asian hornet Vespa velutina from Japan. The mitochondrial genome of V. velutina was identified as a circular molecule of 16,765 bp, similar to that in other hornet species. It was predicted to contain 13 protein-coding, 20 tRNA, and two rRNA genes, along with one A + T-rich control region. The initiation codons ATC was found in one, ATG in four, ATT in five, and ATA in three genes, while TAA was the termination codon in all these genes. The average AT content of 13 protein-coding was 82%.

Stress and the microbiome: linking glucocorticoids to bacterial community dynamics in wild red squirrels

Bacterial diversity within animals is emerging as an essential component of health, but it is unknown how stress may influence the microbiome. We quantify a proximate link between the oral microbiome and hypothalamic-pituitary-adrenal (HPA) axis activity using faecal glucocorticoid metabolites (FGM) in wild red squirrels (Tamiasciurus hudsonicus). Not only was bacterial diversity lower at higher levels of FGM, but also between capture periods a change in bacterial relative abundance was related to an increase in FGM. These linkages between the HPA axis and microbiome communities represent a powerful capacity for stress to have multi-dimensional effects on health.

Transcriptome Analysis and Identification of Major Detoxification Gene Families and Insecticide Targets in Grapholita Molesta (Busck) (Lepidoptera: Tortricidae)

The oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), is an important pest of most stone and pome fruits and causes serious damage to the fruit industry worldwide. This insect pest has been primarily controlled through the application of insecticides; as a result, G. molesta has developed resistance to many different types of insecticides. To identify detoxification genes, we have, de novo, sequenced the transcriptome of G. molesta (Lepidoptera: Tortricidae) and yielded 58,970 unigenes of which 26,985 unigenes matched to known proteins. In total, 2,040 simple sequence repeats have been identified. The comprehensive transcriptome data set has permitted us to identify members of important gene families related to detoxification in G. molesta, including 77 unigenes of putative cytochrome P450s, 28 of glutathione S-transferases, 46 of Carboxylesterases, and 31 of insecticide targets. Orthologs of some of these unigenes have shown to play a pivotal role in insecticide resistance in other insect species and those unigenes likely have similar functions in G. molesta.

The complete mitochondrial genome of the Bermuda buckeye butterfly Junonia coenia bergi (Insecta: Lepidoptera: Nymphalidae)

The Bermuda buckeye, Junonia coenia bergi, is the only butterfly endemic to Bermuda, but is largely unstudied. Whole-genome Illumina sequencing was used to obtain a complete circular mitochondrial genome sequence of 15,221 bp consisting of 22 tRNAs, 13 protein-coding genes, 2 rRNAs and a control region. Mitogenome structure and organization was found to be very similar to that of other Junonia butterfly mitogenomes. Excluding ambiguous nucleotides, the J. coenia bergi mitogenome is 99.1% identical to the J. coenia coenia mitogenome. Parsimony and maximum-likelihood phylogenetic reconstruction revealed the monophyly of subfamily Nymphalinae, genus Junonia, and species J. coenia.

Expressed microRNA associated with high rate of egg production in chicken ovarian follicles

MicroRNA (miRNA) is a highly conserved class of small noncoding RNA about 19-24 nucleotides in length that function in a specific manner to post-transcriptionally regulate gene expression in organisms. Tissue miRNA expression studies have discovered a myriad of functions for miRNAs in various aspects, but a role for miRNAs in chicken ovarian tissue at 300 days of age has not hitherto been reported. In this study, we performed the first miRNA analysis of ovarian tissues in chickens with low and high rates of egg production using high-throughput sequencing. By comparing low rate of egg production chickens with high rate of egg production chickens, 17 significantly differentially expressed miRNAs were found (P < 0.05), including 11 known and six novel miRNAs. We found that all 11 known miRNAs were involved mainly in pathways of reproduction regulation, such as steroid hormone biosynthesis and dopaminergic synapse. Additionally, expression profiling of six randomly selected differentially regulated miRNAs were validated by quantitative real-time polymerase chain reaction (RT-qPCR). Some miRNAs, such as gga-miR-34b, gga-miR-34c and gga-miR-216b, were reported to regulate processes such as proliferation, cell cycle, apoptosis and metastasis and were expressed differentially in ovaries of chickens with high rates of egg production, suggesting that these miRNAs have an important role in ovary development and reproductive management of chicken. Furthermore, we uncovered that a significantly up-regulated miRNA-gga-miR-200a-3p-is ubiquitous in reproduction-regulation-related pathways. This miRNA may play a special central role in the reproductive management of chicken, and needs to be further studied for confirmation.

Sequencing of complete mitochondrial genome of brown algal Saccharina sp. ye-F

The complete sequence (37 657 bp) of the mitochondrial DNA (mtDNA) of the Saccharina sp. ye-F was determined using Illumina sequencing data (Illumina Inc., San Diego, CA). The genome contains 38 protein-coding genes (PCG), three ribosomal RNA (rRNA), and 25 transfer RNA (tRNA) genes that are typical of Saccharina mtDNA. A phylogenetic analysis based on the mitochondrial genomes of brown algae indicated that Saccharina sp. ye-F and Saccharina longissima, Saccharina japonica are the most closely related species, which strongly supports their close phylogenetic affinity.

Complete mitochondrial genome of Cacospongia mycofijiensis (Dictyoceratida: Demospongiae): the first report for the sponge family Thorectidae

We sequenced a complete mitochondrial genome of the marine sponge, Cacospongia mycofijiensis, which is the first report for the family Thorectidae in the class Demospongiae. The mitogenome was obtained from a de novo assembly of shotgun genome sequencing using Illumina Miseq technology, which reconstructed a circular genome with 97 × of sequence coverage. The assembled mitochondrial genome consisting of 16,227 bp includes 14 protein-coding genes, 2 rRNAs and 2 tRNAs. This complete mitogenome sequence will be useful especially for the phylogenic studies of Demospongiae.

Sequencing of complete mitochondrial genome of brown algal Saccharina sp. ye-W

The complete sequence (37 657 bp) of the mitochondrial DNA (mtDNA) of the Saccharina sp. ye-W was determined using Illumina sequencing data. The genome contains 38 protein-coding genes (PCG), three ribosomal RNA (rRNA), 25 transfer RNA (tRNA) genes that are typical of Saccharina mtDNA. Phylogenetic analysis based on the mitochondrial genomes of brown algae indicated that Saccharina sp. ye-W and Saccharina longissima, Saccharina japonica are the most closely related species, which strongly supports their close phylogenetic affinity.

Gut Microbiota Community and Its Assembly Associated with Age and Diet in Chinese Centenarians

Increasing evidence suggests that gut microbiota underpin the development of health and longevity. However, our understanding of what influences the composition of this community of the longevous has not been adequately described. Therefore, illumina sequencing analysis was performed on the gut microbiota of centenarians (aged 100-108 years; RC) and younger elderlies (aged 85-99 years; RE) living in Bama County, Guangxi, China and the elderlies (aged 80-92 years; CE) living in Nanning City, Guangxi, China. In addition, their diet was monitored using a semiquantitative dietary questionary (FFQ 23). The results revealed the abundance of Roseburia and Escherichia was significantly greater, whereas that of Lactobacillus, Faecalibacterium, Parabacteroides, Butyricimonas, Coprococcus, Megamonas, Mitsuokella, Sutterella, and Akkermansia was significantly less in centenarians at the genus level. Both clustering analysis and UniFraq distance analysis showed structural segregation with age and diet among the three populations. Using partial least square discriminate analysis and redundancy analysis, we identified 33 and 34 operational taxonomic units (OTUs) as key OTUs that were significantly associated with age and diet, respectively. Age-related OTUs were characterized as Ruminococcaceae, Clostridiaceae, and Lachnospiraceae, and the former two were increased in the centenarians; diet-related OTUs were classified as Bacteroidales, Lachnospiraceae, and Ruminococcaceae. The former two were deceased, whereas the later one was increased, in the high-fiber diet. The age and high-fiber diet were concomitant with changes in the gut microbiota of centenarians, suggesting that age and high-fiber diet can establish a new structurally balanced architecture of gut microbiota that may benefit the health of centenarians.

Sequencing of complete mitochondrial genome of brown algal Saccharina sp. ye-G

The complete sequence (37,673 bp) of the mitochondrial DNA (mtDNA) of the Saccharina sp. ye-G was determined using Illumina sequencing data. The genome contains 38 protein-coding genes (PCG), 3 ribosomal RNA (rRNA), 25 transfer RNA (tRNA) genes that are typical of Saccharina mtDNA. A phylogenetic analysis based on the mitochondrial genomes of brown algae indicated that Saccharina sp. ye-G and Saccharina longissima, Saccharina japonica are the most closely related species, which strongly supports their close phylogenetic affinity.

MicroRNAs of the mesothorax in Qinlingacris elaeodes, an alpine grasshopper showing a wing polymorphism with unilateral wing form

MicroRNAs (miRNAs) are now recognized as key post-transcriptional regulators in regulation of phenotypic diversity. Qinlingacris elaeodes is a species of the alpine grasshopper, which is endemic to China. Adult individuals have three wing forms: wingless, unilateral-winged and short-winged. This is an ideal species to investigate the phenotypic plasticity, development and evolution of insect wings because of its case of unilateral wing form in both the sexes. We sequenced a small RNA library prepared from mesothoraxes of the adult grasshoppers using the Illumina deep sequencing technology. Approximately 12,792,458 raw reads were generated, of which the 854,580 high-quality reads were used only for miRNA identification. In this study, we identified 49 conserved miRNAs belonging to 41 families and 69 species-specific miRNAs. Moreover, seven miRNA*s were detected both for conserved miRNAs and species-specific miRNAs, which were supported by hairpin forming precursors based on polymerase chain reaction. This is the first description of miRNAs in alpine grasshoppers. The results provide a useful resource for further studies on molecular regulation and evolution of miRNAs in grasshoppers. These findings not only enrich the miRNAs for insects but also lay the groundwork for the study of post-transcriptional regulation of wing forms.

Effects of drought and salt-stresses on gene expression in Caragana korshinskii seedlings revealed by RNA-seq

BACKGROUND

Drought and soil salinity are major abiotic stresses. The mechanisms of stress tolerance have been studied extensively in model plants. Caragana korshinskii is characterized by high drought and salt tolerance in northwestern China; unique patterns of gene expression allow it to tolerate the stress imposed by dehydration and semi-desert saline soil. There have, however, been no reports on the differences between C. korshinskii and model plants in the mechanisms underlying their drought and salt tolerance and regulation of gene expression.

RESULTS

Three sequencing libraries from drought and salt-treated whole-seedling- plants and the control were sequenced to investigate changes in the C. korshinskii transcriptome in response to drought and salt stresses. Of the 129,451 contigs, 70,662 (54.12 %) were annotated with gene descriptions, gene ontology (GO) terms, and metabolic pathways, with a cut-off E-value of 10(-5). These annotations included 56 GO terms, 148 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and 25 Clusters of Orthologous Groups (COG). On comparison of the transcriptomes of the control, drought- and salt-treated plants, 1630 and 1521 contigs showed significant differences in transcript abundance under drought and salt stresses. Compared to the differentially expressed genes (DEGs) in drought- or salt-treated Arabidopsis in the database, 542 DEGs in drought-treated C. korshinskii and 529 DEGs in salt-treated samples were presumably unique to C. korshinskii. The transcription profiles revealed that genes related to transcription factors, protein kinases, and antioxidant enzymes are relevant to the tolerance of drought and salt stress in this species. The expression patterns of 38 randomly selected DEGs were confirmed by quantitative real-time PCR and were essentially consistent with the changes in transcript abundance identified by RNA-seq.

CONCLUSIONS

The present study identified potential genes involved in drought and salt tolerance in C. korshinskii, as well as many DEGs uniquely expressed in drought- or salt-treated C. korshinskii samples compared to Arabidopsis. To our knowledge, this study is the first exploration of the C. korshinskii transcriptome under drought and salt conditions, and these results will facilitate the discovery of specific stress-resistance-related genes in C. korshinskii, possibly leading to the development of novel plant cultivars through genetic engineering.

Postoperative Changes in Fecal Bacterial Communities and Fermentation Products in Obese Patients Undergoing Bilio-Intestinal Bypass

We assessed the gut microbial ecology of 11 severely obese patients before and after bilio-intestinal bypass (BIB). Fecal samples were evaluated for microbial communities using 16S rDNA Illumina sequencing, real-time PCR targeting functional genes, and gas chromatography of short chain fatty acids (SCFAs). At 6 months after surgery, subjects exhibited significant improvements in metabolic markers (body weight, glucose, and lipid metabolism) compared with baseline. The fecal microbiota of post-surgery individuals was characterized by an overall decrease of bacterial diversity, with a significant reduction in Lachnospiraceae, Clostridiaceae, Ruminococcaceae, Eubacteriaceae, and Coriobacteriaceae. On the contrary, there were significant increases of genera Lactobacillus, Megasphaera, and Acidaminococcus and the family Enterobacteriaceae. The pH was decreased in fecal samples from patients after BIB and SCFA profiles were altered, with lower percentages of acetate and propionate and higher levels of valerate and hexanoate. Some changes in the bacterial populations were associated with variations in the patients' metabolic health parameters, namely Gemmiger and glucose, Lactobacillus and glucose, and Faecalibacterium and triglycerides. The results from this study of BIB patients furthers our understanding of the composition of gut microbiota and the functional changes that may be involved in improving obesity-related conditions following weight-loss surgery.

Sequencing of complete mitochondrial genome of brown algal Saccharina sp. ye-C5

The complete genome (37 635 bp) mitochondrial DNA (mtDNA) of the Saccharina sp. ye-C5 was determined, which contains 38 protein-coding genes (PCG), three ribosomal RNA (rRNA) and 25 transfer RNA (tRNA) genes that are consistent in Saccharina genus. The phylogenetic tree that was established based on the mitochondrial genomes of brown algae, which indicated that Saccharina sp. ye-C5 and Saccharina longissima are the most closely related species.

Sequencing of complete mitochondrial genome of brown algal Saccharina sp. ye-C2

The complete sequence (37 657 bp) of the mitochondrial DNA (mtDNA) of the Saccharina sp. ye-C2 was determined. About 38 protein-coding genes (PCG), 3 ribosomal RNAs (rRNA) and 25 transfer RNA (tRNA) genes were annotated in the genome. The phylogenetic analysis strongly supports the close phylogenetic affinity of Saccharina sp. ye-C2 and Saccharina japonica based on the mitochondrial genomes of other brown algae.