Gene Arrangement Research Articles

Complete mitochondrial genome of <I>Clupeonella abrau</I> (Maliatsky, 1930) (Clupeiformes), an endemic species of freshwater fish from lake Abrau (Russia)

The Abrau sprat (Tyulka or Sardelka) Clupeonella abrau (Maliatsky, 1930) is an endemic fish of Lake Abrau (Krasnodar Territory). The full mitogenome of C. abrau (16650 bp in length, with a conservative gene arrangement for Clupeidae) demonstrates 98.8% similarity with the mitogenome of a related species, the Black Sea-Caspian tulka (C. cultriventris) from the Black Sea. The sequence of the COX1 gene was also studied in a museum specimen collected in Lake Abrau in 1938. Variability in modern Abrau sprat COX1 locus in about 0.15%, the difference between C. abrau and C. cultriventris is 1.2%, and the difference between the Museum and modern samples of tulka from Lake Abrau is 0.92%. It has been confirmed that the Abrau sprat is present in the fish community and capable of reproducing in the lake. Various alternative scenarios for the settlement of Lake Abrau have been proposed.

Phylogenomic analysis of glutamine synthetase gene family in Helianthus annuus L.

Glutamine synthetase is one of the predominant enzymes in nitrogen metabolism. In developing leaves, glutamine is mainly produced in chloroplasts by the activity of the GS2 isoenzyme. It catalyzes glutamine synthesis from glutamate and ammonia in an ATP-dependent reaction. The genes encoding glutamine synthetase play a crucial role in ammonia and glutamate detoxification, acid-base homeostasis, cell signaling, and cell proliferation. The gene family responsible for producing glutamine synthetase has been previously documented in model plants like Arabidopsis. Nevertheless, there has been no exploration into its existence and attributes in oilseed crops like sunflower (Helianthus annuus L.). This study thoroughly analyzes, gene structure, conserved motifs, chromosomal location, phylogenetic relationships, and expression patterns to identify the glutamine synthetase genes in H. annuus. Our findings unveiled 19 genes encoding glutamine synthetase within the H. annuus genome. These genes were distributed across 11 chromosomes of H. annuus. Furthermore, we examined the expression patterns of all the HaGS genes using RNA-seq datasets, specifically focusing on their response to biotic and abiotic stress conditions. Under biotic stress, H. annuus expresses genes for mycorrhizal fungi named Rhizoglomus irregulare at four days post inflorescence (dpi) and 16 dpi. Under abiotic stress, the effect of drought and hormones was investigated. In drought, one gene, HaGS6D, showed the highest expression in the leaf. Meanwhile, in roots, gene HaGS7B showed the highest expression. Under hormonal stress, the effects of auxin, brassinosteroid, and cytokinin were studied on the leaf. For auxin, the gene HaGS7C showed the highest expression. For brassinosteroid, the gene HaGS7D showed the highest expression; for cytokinin, the gene HaGS6E showed the highest expression. Thus, these findings can significantly contribute to our understanding of the arrangement of glutamine synthetase genes in H. annuus and offer valuable insights for developing of drought-resistant cultivars of this species.

Phylogenetic and divergence analysis of Pentatomidae, with a comparison of the mitochondrial genomes of two related species (Hemiptera, Pentatomidae).

Pentatomidae, the most diverse family of Pentatomoidea, is found worldwide. Currently, the phylogenetic relationships among Pentatomidae tribes remain unstable, and subfamily divergence has not been estimated. Here, we sequenced and analyzed the complete mitochondrial genomes of two species of Lelia, and studied the phylogenetic relationships among Pentatominae tribes. We also selected three available fossil as the calibration points in the family, and preliminarily discussed the divergence time of Pentatomidae. Trees of Pentatomidae were reconstructed using the Bayesian inference method. Divergence times of Pentatominae were estimated based on the nucleotide sequences of protein-coding genes with a relaxed clock log-normal model in BEASTv.1.8.2. The results showed that the gene arrangements, nucleotide composition, and codon preferences were highly conserved in Lelia. Further, a phylogenetic analysis recovered Eysarcorini, Strachiini, Phyllocephalini, and Menidini as monophyletic with strong support, however, the monophyly of Antestiini, Nezarini, Carpocorini, Pentatomini and Cappaeini were rejected. Moreover, Pentatominae diverged from Pentatomidae soon after the origin of the Cretaceous Period, at approximately 110.38 Ma. This study enriches the mitochondrial genome database of Pentatomidae and provides a reference for further phylogenetic studies, and provides a more accurate estimate of divergence time.

Comparative Mitogenomics Analysis Revealed Evolutionary Divergence among Purpureocillium Species and Gene Arrangement and Intron Dynamics of Ophiocordycipitaceae.

The species of Purpureocillium are cosmopolitan and multitrophic fungi that can infect a wide range of invertebrate hosts. This study reports the mitogenome of P. atypicola, a specialized spider pathogenic fungus. The 112,465 bp mitogenome encoded genes typically found in fungal mitogenomes, and a total of 52 introns inserted into seven genes. A comparison with three other Purpureocillium species revealed significant differences in length and intron number, primarily due to intron variation; however, there was no dynamic variation in the introns of the cox1 gene within the same species of the Purpureocillium genus. Different mitochondrial protein-coding genes showed variable degrees of genetic differentiation among these species, but they were all under purifying selection. Additionally, frequent intron loss or gain events were detected to have occurred during the evolution of the Ophiocordycipitaceae mitogenomes, yet the gene arrangement remains conserved. A phylogenetic analysis of the combined mitochondrial gene set gave identical and well-supported tree topologies. The estimated age of the crown of Ophiocordycipitaceae and Purpureocillium were around the Early Cretaceous period (127 Mya) and Late Cretaceous period (83 Mya), respectively. The results of this study advance our understanding of the genomics, evolution, and taxonomy of this important fungal group.

Characterization of the Complete Mitochondrial Genome of Pleurogenoides japonicus (Digenea, Pleurogenidae): Comparison With the Members of Microphalloidea and Phylogenetic Implications.

Pleurogenoides japonicus (Trematoda: Microphalloidea) is an important parasite in wood frogs with high infection rates and significant ecological, economic, and societal importance. The scarcity of molecular data for these parasites severely limits population genetics and phylogenetic studies. In the present study, for the first time, we determined and described the entire mitochondrial (mt) genome of P. japonicus as the first representative of the family Pleurogenidae. The entire mt genome of P. japonicus was circular, with 15,043 bp (GenBank accession number OR900118), containing 36 genes, comprising 12 protein-coding genes (cox1-3, nad1-6, nad4L, cytb, and atp6), two ribosomal RNA genes, 22 transfer RNA genes, and two non-coding regions. There were 23 intergenic spacers, ranging from 2 to 162 bp, and only one 40 bp overlap between nad4L and nad4 genes in the P. japonicus mt genome. The nucleotide composition of P. japonicus mt genome exhibited a strong AT bias with a 63.75% A + T content, while the AT- and GC-skews were - 0.435 and 0.407, respectively. Comparative analysis demonstrated that the P. japonicus mt genome shared the most common characteristics with Microphalloidea trematodes, and the cox1 gene was the longest and most conserved gene in Microphalloidea trematodes. The gene arrangements of Xiphidiata trematodes were of the same order based on protein-coding genes and rRNA genes, except for tRNA. More than two gene arrangement types exist in Echinostomata and Xiphidiata, and the gene rearrangement events mainly occurred in "trnE-trnG" and "trnG-trnE". Phylogenetic analysis suggested that trematodes of the family Pleurogenidae clustered more with Prosthogonimidae than Eucotylidae. The mt genome data of P. japonicus provide an accurate genetic marker for further studies of Xiphidiata trematodes.

Mitochondrial Phylogenomics of Scoliidae from China, with Evidence to Challenge the Former Placement of the Colpa Group.

Scoliidae, also known as scarab hunters or flower wasps, are important in the biological control of scarabs and for pollination. Mitogenomic and phylogenetic studies are rare for this group. In this study, 10 mitochondrial genomes representing eight genera in two tribes of the family Scoliidae were determined. The general features and rearrangements of the mitochondrial genomes for 15 Scoliidae species representing all genera distributed in China were described and compared and the phylogenetic relationships among them were inferred using MrBayes and IQtree based on four data matrices. Most sequences of Scoliidae have one extra trnM gene. Species belonging to Campsomerini have lower A + T content than all Scoliini species except for Colpa tartara in this study. The AT-skew is positive in 7 out of 15 species. All 15 Scoliidae sequences have similar conserved gene arrangements with the same arrangements of PCGs and rRNA genes, except for Campsomeriella annulata. The tRNA genes have the highest frequency of rearrangement, and C. tartara is always rearranged as in its Scoliini counterparts. Our phylogenetic results support most of the relationships between genera and tribes of Scoliidae in former morphological studies. However, Colpa tartara is proved to be closer to Scoliini according to genome features, phylogenetic analyses and some morphological evidence, which challenges the former attribution of the Colpa group.

Mitochondrial Genome Characteristics and Phylogenetic Analysis of Fulmekiola serrata (Kobus) (Thysanoptera: Thripidae)

Sugarcane thrips, Fulmekiola serrata (Kobus) (Thysanoptera: Thripidae), is a common foliar pest that infests sugarcane and is found throughout tropical and subtropical countries. In this study, we obtained and analyzed the complete mitochondrial genome of F. serrata for the first time and explored the phylogenetic relationships of the higher-order elements of Thysanoptera members at the mitochondrial level. The complete mitochondrial genome of F. serrata is 16,596 bp in length and includes 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and 1 noncoding control region. A+T accounted for 75% of the total bases in the mitochondrial genome of F. serrata, revealing an obvious AT bias. Among the 13 PCGs, except for nad5, which had a start codon of TTG, the remaining genes had ATNs typical of insects (ATA, ATT, ATC, and ATG); nad1, nad2, nad3, and atp8 had incomplete termination codons of TA or T. The remaining nine PCGs were complete with the termination codon TAA. Of the 22 tRNA secondary structures, all were typical cloverleaf secondary structures except for trnS1, which was missing the DHU arm. Compared with the hypothetical ancestral gene arrangement of arthropods, F. serrata presented extensive gene rearrangement, with 23 translocated genes, 8 inverted genes, and 5 shuffled genes. Both maximum likelihood (ML) and Bayesian inference (BI) phylogenetic trees resulted in similar topologies: ((Thripidae + (Stenurothripidae + Aeolothripidae)) + Phlaeothripidae), with Thripidae, Aeolothripidae and Phlaeothripidae being monophyletic groups, whereas F. serrata is closely related to Thrips palmi, and the two are sister groups.

Full-Length Transcriptome Profiling of the Complete Mitochondrial Genome of Sericothrips houjii (Thysanoptera: Thripidae: Sericothripinae) Featuring Extensive Gene Rearrangement and Duplicated Control Regions.

The mitochondrial genome (mitogenome) of Thysanoptera has extensive gene rearrangement, and some species have repeatable control regions. To investigate the characteristics of the gene expression, transcription and post-transcriptional processes in such extensively gene-rearranged mitogenomes, we sequenced the mitogenome and mitochondrial transcriptome of Sericothrips houjii to analyze. The mitogenome was 14,965 bp in length and included two CRs contains 140 bp repeats between COIII-trnN (CR1) and trnT-trnP (CR2). Unlike the putative ancestral arrangement of insects, S. houjii exhibited only six conserved gene blocks encompassing 14 genes (trnL2-COII, trnD-trnK, ND2-trnW, ATP8-ATP6, ND5-trnH-ND4-ND4L and trnV-lrRNA). A quantitative transcription map showed the gene with the highest relative expression in the mitogenome was ND4-ND4L. Based on analyses of polycistronic transcripts, non-coding RNAs (ncRNAs) and antisense transcripts, we proposed a transcriptional model of this mitogenome. Both CRs contained the transcription initiation sites (TISs) and transcription termination sites (TTSs) of both strands, and an additional TIS for the majority strand (J-strand) was found within antisense lrRNA. The post-transcriptional cleavage processes followed the "tRNA punctuation" model. After the cleavage of transfer RNAs (tRNAs), COI and ND3 matured as bicistronic mRNA COI/ND3 due to the translocation of intervening tRNAs, and the 3' untranslated region (UTR) remained in the mRNAs for COII, COIII, CYTB and ND5. Additionally, isoform RNAs of ND2, srRNA and lrRNA were identified. In summary, the relative mitochondrial gene expression levels, transcriptional model and post-transcriptional cleavage process of S. houjii are notably different from those insects with typical mitochondrial gene arrangements. In addition, the phylogenetic tree of Thripidae including S. houjii was reconstructed. Our study provides insights into the phylogenetic status of Sericothripinae and the transcriptional and post-transcriptional regulation processes of extensively gene-rearranged insect mitogenomes.

Characterization and phylogenetic analysis of the complete mitochondrial genome of Cotylorhiza tuberculata assembled using next-generation sequencing

In this study, the complete mitochondrial genome (mitogenome) of Cotylorhiza tuberculata (Scyphozoa; Rhizostomeae; Cepheidae) was assembled by the next-generation sequencing data. The complete mitogenome spanned 16,590 bp and contained 14 protein-coding genes, two transfer RNA genes, and two ribosomal RNA genes. Total AT% content was 67.7%, comprising A 30.22%, C 16.16%, G 17.05%, and T 36.56%. The gene arrangement exhibited consistency with the known mitogenomes of other jellyfish species. Furthermore, the phylogenetic relationship of C. tuberculata was investigated based on analysis of the 13 common protein-coding genes. Results indicated a close relationship between C. tuberculata and both Cassiopea xamachana and Cassiopea andromeda. These findings provide a valuable reference for advancing understanding of the phylogenetic relationships, taxonomic classification, and phylogeography of jellyfish species.

Complete mitochondrial genome and phylogenetic analysis of Mancinella alouina.

The Muricidae family in the Class Gastropoda comprises numerous species with a vast range of morphological features and a worldwide presence. The phylogeny of the Muricidae has been analyzed in previous studies; however, the evolutionary relationships among the main branches of the Muricidae remain unknown. In the present study, the mitochondrial genome of Mancinella alouina was sequenced. The mitochondrial genome was found to be 16,671bp in length and made up of 37 genes (13 protein-coding genes, 22 transfer RNA and 2 ribosomal RNA genes). The genome has an A-T-rich region (66.5% A + T content) and all of the PCGs use the ATN start codon and the TAG or TAA stop codons. The mitochondrial gene arrangement of Mancinella alouina is similar to that of other Muricidae, except for Ocinebrellus inornatus and Ceratostoma burnetti. On the basis of a flexible molecular clock model, time-calibrated phylogenetic results indicate that the genus Mancinella diverged roughly 18.09Mya, and that the family Muricidae emerged in the Late Cretaceous. This study reveals the structural and sequence information features of the mitochondrial genome of Mancinella alouina. This study provides evidence for the relationships within the family Muricidae at the molecular level, and infer the divergence time. The results of phylogenetic analyses strongly support the current classification.

Exploring the mitochondrial genomes and phylogenetic relationships of trans-Andean Bryconidae species (Actinopterygii: Ostariophysi: Characiformes).

Comparative mitogenomics and its evolutionary relationships within Bryconidae remains largely unexplored. To bridge this gap, this study assembled 15 mitogenomes from 11 Bryconidae species, including five newly sequenced. Salminus mitogenomes, exceeding 17,700 bp, exhibited the largest size, contrasting with a median size of 16,848 bp in the remaining species (Brycon and Chilobrycon). These mitogenomes encode 37 typical mitochondrial genes, including 13 protein-coding, 2 ribosomal RNA, and 22 transfer RNA genes, and exhibit the conserved gene arrangement found in most fish species. Phylogenetic relationships, based on the maximum-likelihood method, revealed that the trans-Andean species (found in northwestern South America) clustered into two main sister clades. One clade comprised the trans-Andean species from the Pacific slope, Brycon chagrensis and Chilobrycon deuterodon. The other clade grouped the trans-Andean species from the Magdalena-Cauca Basin Brycon moorei and Salminus affinis, with their respective cis-Andean congeners (found in eastern South America), with Brycon rubricauda as its sister clade. Since the current members of Brycon are split in three separated lineages, the systematic classification of Bryconidae requires further examination. This study provides novel insights into mitogenome characteristics and evolutionary pathways within Bryconidae, standing as crucial information for prospective phylogenetic and taxonomic studies, molecular ecology, and provides a valuable resource for environmental DNA applications.

Global Distribution and Diversity of Haloarchaeal pL6-Family Plasmids.

Australian isolates of Haloquadratum walsbyi, a square-shaped haloarchaeon, often harbor small cryptic plasmids of the pL6-family, approximately 6 kb in size, and five examples have been previously described. These plasmids exhibit a highly conserved gene arrangement and encode replicases similar to those of betapleolipoviruses. To assess their global distribution and recover more examples for analysis, fifteen additional plasmids were reconstructed from the metagenomes of seven hypersaline sites across four countries: Argentina, Australia, Puerto Rico, and Spain. Including the five previously described plasmids, the average plasmid size is 6002 bp, with an average G+C content of 52.5%. The tetramers GGCC and CTAG are either absent or significantly under-represented, except in the two plasmids with the highest %G+C. All plasmids share a similar arrangement of genes organized as outwardly facing replication and ATPase modules, but variations were observed in some core genes, such as F2, and some plasmids had acquired accessory genes. Two plasmids, pCOLO-c1 and pISLA-c6, shared 92.7% nt identity despite originating from Argentina and Spain, respectively. Numerous metagenomic CRISPR spacers matched sequences in the fifteen reconstructed plasmids, indicating frequent invasion of haloarchaea. Spacers could be assigned to haloarchaeal genera by mapping their associated direct repeats (DR), with half of these matching Haloquadratum. Finally, strand-specific metatranscriptome (RNA-seq) data could be used to demonstrate the active transcription of two pL6-family plasmids, including antisense transcripts.

Comparative chloroplast genome analyses of cultivated and wild Capsicum species shed light on evolution and phylogeny

The chloroplast (cp.) genome, also known as plastome, plays crucial roles in plant survival, adaptation, and evolution. The stable genetic structure of cp. genomes provides an ideal system for investigating species evolution. We sequenced three complete cp. genome sequences of Capsicum species and analyzed them using sequences of various Capsicum species retrieved from the NCBI database. The cp. genome of Capsicum species maintains a well-preserved quadripartite structure consisting of two inverted repeats (IRs) flanked by a large single copy (LSC) region and a small single copy (SSC) region. The sizes of cp. genome sequences ranged from 156,583 bp (C. lycianthoides) to 157,390 bp (C.pubescens). A total of 127–132 unique genes, including 83–87 protein-coding, 36–37 tRNA, and eight rRNA genes, were predicted. Comparison of cp. genomes of 10 Capsicum species revealed high sequence similarity in genome-wide organization and gene arrangements. Fragments of trnT-UGU/trnL-UAA, ccsA, ndhD, rps12, and ycf1 were identified as variable regions, and nucleotide variability of LSC and SSC was higher than that of IR. Phylogenetic speciation analysis showed that the major domesticated C. annuum species were the most extensively divergent species and closely related to C. tovarii and C. frutescens. Analysis of divergent times suggested that a substantial range of speciation events started occurring ~ 25.79 million years ago (Mya). Overall, comparative analysis of cp. genomes of Capsicum species not only offers new insights into their genetic variation and phylogenetic relationships, but also lays a foundation for evolutionary history, genetic diversity, conservation, and biological breeding of Capsicum species.

Complete genome of the new bacilliform virus that causes Milky Hemolymph Syndrome in Chionoecetes bairdi (Rathbun, 1924)

The genome of a new member of the Nimaviridae family has been sequenced. The Chionoecetes bairdi bacilliform virus (CbBV) causes Milky Hemolymph Syndrome (MHS) in Chionoecetes bairdi populations of the Pacific coast of Kamchatka. The CbBV genome is represented by double-stranded DNA with a length of 245,567 nucleotides containing 120 ORFs. Of these, 85 proteins had significant matches in the NCBI database, and 57 genes encoded capsid, envelope, tegument and nonstructural proteins. Comparative analysis of the genomes of CbBV and a number of representatives of the class nuclear arthropod large DNA viruses (NALDVs) made it possible to isolate 49 evolutionarily conserved orthologue core genes. Among them, 5 were multicopy genes, and 44 were single-copy genes. There were ancestral genes characteristic of all Naldaviricetes − per os infectivity complex genes, one DNA polymerase gene and one thymidylate synthase gene.Phylogenetic analysis of representatives of the Nimaviridae family revealed that the CbBV and Chionoecetes opilio bacilliform virus (CoBV) form an independent clade within the family separate from the clade containing WSSV strains. This is supported by data on the order and arrangement of genes in the genomes of nimaviruses that were identical within each clade but differed between them. In addition, a high identity of the genomes and proteomes of CbBV and CoBV (approximately 99%) was shown, and their identity with WSSV strains was no more than 33%.The data on the structure of the genome of the new virus that causes MHS in C. bairdi indicate that it belongs to the family Nimaviridae, genus Whispovirus. Thus, the CbBV infecting the commercially important species of Tanner crab in populations of the Pacific coast of Kamchatka is the second “wild” representative of replicating nimaviruses whose genome has been characterized after the CoBV that causes MHS in C. opilio in populations of the Sea of Japan. The discovery of a new member of the family that infects decapods indicates the prevalence of nimaviruses in marine ecosystems. The information obtained is important for understanding the evolution of representatives of the class of nuclear arthropod large DNA viruses. The discovery of a new nimavirus that causes MHS in Chionoecetes crabs, in contrast to the white spot syndrome (WSS) caused by WSSV strains, makes it relevant to identify two variants and possibly species within the family, namely, WSSV and Milky Hemolymph Syndrome virus (MHSV).

The complete mitochondrial genome and microsatellite discovery of the Chilean kelp crab Taliepus dentatus (Brachuyra, Majoidea)

Abstract The complete sequence of the mitochondrial genome and fifteen microsatellite loci for the Chilean kelp crab Taliepus dentatus are reported for the first time. The DNA assembly obtained from an Illumina sequencing revealed a complete mitochondrial genome of 15 603 bp in length. The gene composition and arrangement were similar to that reported for most decapod crabs, containing 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and a non-coding region. A phylogeny performed with 10 species obtained from GenBank placed T. dentatus close to individuals of the Family Epialtidae. From the 6397 repeated sequences encountered in the data, 15 microsatellite loci primers were designed and five tested for variability in specimens obtained from two sampling sites separated by 300 km of distance. The mean number of alleles per locus was nine (5–15 alleles per locus) and the observed heterozygosities ranged from 0.34 to 0.8. Departure from Hardy–Weinberg equilibrium was observed in two out of the five microsatellites, while none of the loci exhibited significant linkage disequilibrium. This genetic resource will be useful for phylogeny, population genetics and parentage analysis of the commercial species T. dentatus.

The Characterization of the Mitochondrial Genome of Fulgoraria rupestris and Phylogenetic Considerations within the Neogastropoda.

Fulgoraria rupestris is a predatory marine gastropod belonging to Neogastropoda and possessing considerable taxonomic significance. However, research on this species remains limited. We acquired the complete mitochondrial genome of F. rupestris through second-generation sequencing and conducted an analysis of its genome structural features. The mitochondrial genome of F. rupestris spans a total length of 16,223 bp and encompasses 37 genes (13 protein-coding genes (PCGs), 22 transfer RNAs, and 2 ribosomal RNAs). Notably, most tRNAs exhibit the typical cloverleaf structure, but there is an absence of the Dihydrouridine (DHU) arm in the trnS1 and trnS2 genes. The A + T content is 68.67%, indicating a pronounced AT bias. Additionally, we conducted a selection pressure analysis on the mitochondrial genomes of four species within Volutidae, revealing that all PCGs are subjected to purifying selection. In comparison to other species within Neogastropoda, F. rupestris shares an identical gene arrangement. Additionally, based on mitochondrial genome sequences of the 13 PCGs from 50 species within Neogastropoda, we constructed a phylogenetic tree. The phylogenetic tree indicates F. rupestris forms a clade with species within the family Volutidae (Cymbium olla, Neptuneopsis gilchristi, and Melo melo). This study serves as a valuable reference for future research on F. rupestris, offering insights for the upcoming phylogenetic and taxonomic classification within Neogastropoda. Furthermore, the findings provide valuable information for the development of genetic resources in this context.

Organellar Genomes of Sargassum hemiphyllum var. chinense Provide Insight into the Characteristics of Phaeophyceae.

Sargassum hemiphyllum var. chinense, a prevalent seaweed along the Chinese coast, has economic and ecological significance. However, systematic positions within Sargassum and among the three orders of Phaeophyceae, Fucales, Ectocarpales, and Laminariales are in debate. Here, we reported the organellar genomes of S. hemiphyllum var. chinense (34,686-bp mitogenome with 65 genes and 124,323 bp plastome with 173 genes) and the investigation of comparative genomics and systematics of 37 mitogenomes and 22 plastomes of Fucales (including S. hemiphyllum var. chinense), Ectocarpales, and Laminariales in Phaeophyceae. Whole genome collinearity analysis showed gene number, type, and arrangement were consistent in organellar genomes of Sargassum with 360 SNP loci identified as S. hemiphyllum var. chinense and two genes (rps7 and cox2) identified as intrageneric classifications of Sargassum. Comparative genomics of the three orders of Phaeophyceae exhibited the same content and different types (petL was only found in plastomes of the order Fucales and Ectocarpales) and arrangements (most plastomes were rearranged, but trnA and trnD in the mitogenome represented different orders) in genes. We quantified the frequency of RNA-editing (canonical C-to-U) in both organellar genomes; the proportion of edited sites corresponded to 0.02% of the plastome and 0.23% of the mitogenome (in reference to the total genome) of S. hemiphyllum var. chinense. The repetition ratio of Fucales was relatively low, with scattered and tandem repeats (nine tandem repeats of 14-24 bp) dominating, while most protein-coding genes underwent negative selection (Ka/Ks < 1). Collectively, these findings provide valuable insights to guide future species identification and evolutionary status of three important Phaeophyceae order species.

The first mitogenome of the subfamily Stenoponiinae (Siphonaptera: Ctenophthalmidae) and implications for its phylogenetic position

Fleas are the most important insect vectors that parasitize warm-blooded animals and are known vectors of zoonotic pathogens. A recent study showed that Stenoponia polyspina parasitizing Eospalax baileyi in Zoige County have carried Bartonella spp. and Spotted fever group Rickettsia (SFGR). Accurate identification and differentiation of fleas are essential for prevention and control of zoonotic pathogens. To understand phylogenetic relationship of the subfamily Stenoponiinae, we described morphological characteristics of S. polyspina and sequenced its mitogenome with 14,933 bp in size and high A + T content (~ 79%). The S. polyspina mitogenome retained the ancestral pattern of mitochondrial gene arrangement of arthropods without rearrangement. The start codons of 13 protein-coding genes (PCGs) are traditional ATN and the stop codons are TAA or TAG. Anticodon loops of all tRNA genes were 7 bp except for trnL2 and trnD had anticodon loops with 9 bp and the abnormal anticodon loops may be associated with frameshifting mutation. Genetic distance and Ka/Ks ratios indicated that all 13 PCGs of S. polyspina were subjected to purifying selection, with cox1 at the slowest rate and atp8 at the fastest rate. The mitogenomes of 24 species representing 7 families in the order Siphonaptera were selected to reconstruct phylogenetic tree based on concatenated nucleotide sequences of two datasets (PCGRNA matrix and PCG12RNA matrix) using Bayesian inference (BI) and Maximum likelihood (ML) methods. Phylogenetic tree supported that the superfamilies Ceratophylloidea, Vermipsylloidea, Pulicoidea were monophyletic and the superfamily Hystrichopsylloidea was paraphyletic. The family Ctenophthalmidae was monophyletic in PCGRNA-ML (codon partition) and paraphyletic in the remain trees. S. polyspina belongs to the subfamily Stenoponiinae was closely more related to the subfamily Rhadinopsyllinae. This paper explored phylogenetic position of diverse clades within the order Siphonaptera based on morphological and mitogenome data of S. polyspina. Our research enriched NCBI database of the order Siphonaptera.

Characterizing the complete mitogenome of Odontothrips phaseoli (Thysanoptera: Thripidae) and its mitochondrial phylogeny

Described originally from Heilongjiang, China, Odontothrips phaseoli is a potential pest of threatening bean plant in northern China. The complete mitochondrial genome of O. phaseoli was sequenced and assembled, with a total length of 15,540 bp. Within this genome, 37 genes have been identified: 13 PCGs, 22 tRNAs, two rRNAs, and two putative control regions. Most PCGs terminate with TAA, while four genes (atp8, nad1, nad2 and nad4) use an incomplete ‘T’ and nad6 employs TAG as the stop codon. Compared to the mitogenome of the ancestral insect, O. phaseoli displays significant gene rearrangement. However, it retains three conserved gene blocks in common with its related species, Megalurothrips usitatus, both of which belong to the Megalurothrips genus-group. The phylogenetic tree, constructed based on the entire mitogenome dataset of all thrips species available in NCBI, shows that the two species cluster closely together. This alignment might underscore the close link between gene arrangements and the phylogeny relationships.

Mitochondrial Genomes of Streptopelia decaocto: Insights into Columbidae Phylogeny.

In this research, the mitochondrial genome of the Streptopelia decaocto was sequenced and examined for the first time to enhance the comprehension of the phylogenetic relationships within the Columbidae. The complete mitochondrial genome of Streptopelia decaocto (17,160 bp) was structurally similar to the recognized members of the Columbidae family, but with minor differences in gene size and arrangement. The structural AT content was 54.12%. Additionally, 150 mitochondrial datasets, representing valid species, were amassed in this investigation. Maximum likelihood (ML) and Bayesian inference (BI) phylogenetic trees and evolutionary time relationships of species were reconstructed based on cytb gene sequences. The findings from the phylogenetic evaluations suggest that the S. decaocto was classified under the Columbinae subfamily, diverging from the Miocene approximately 8.1 million years ago, indicating intricate evolutionary connections with its close relatives, implying a history of species divergence and geographic isolation. The diversification of the Columbidae commenced during the Late Oligocene and extended into the Miocene. This exploration offers crucial molecular data for the S. decaocto, facilitating the systematic taxonomic examination of the Columbidae and Columbiformes, and establishing a scientific foundation for species preservation and genetic resource management.