Phylogenetic position of Bopyroides hippolytes, with comments on the rearrangement of the mitochondrial genome in isopods (Isopoda: Epicaridea: Bopyridae).

BACKGROUND: Classification of parasitic bopyrids has traditionally been based on morphological characteristics, but phylogenetic relationships have remained elusive due to limited information provided by morphological data and tendency for loss of morphological features as a result of parasitic lifestyle. Subfamily Argeiinae was separated from Bopyrinae based on morphological evidence, although the assignment of all genera has not been phylogenetically evaluated. Bopyroides hippolytes has been traditionally classified in Bopyrinae, but divergent morphological characters make this assignment questionable. To investigate the relationship of bopyrines, we sequenced the complete mitochondrial genome of B. hippolytes and four mitochondrial genes of two other Bopyrinae. RESULTS: The phylogenetic trees based on separate and combined cox1and 18S sequence data recovered Bopyridae as robustly monophyletic, but Bopyrinae as polyphyletic. Bopyroides hippolytes was a close sister to Argeia pugettensis, type species to Argeiinae. Mitochondrial phylogenomics also suggested that B. hippolytes was close to Argeiinae. We also found a novel gene order in B. hippolytes compared to other isopods. CONCLUSIONS: Bopyroides hippolytes should be excluded from the Bopyrinae and has a close affinity with Argeia pugettensis based on molecular and morphological data. The conserved syntenic blocks of mitochondrial gene order have distinctive characteristics at a subordinal level and may be helpful for understanding the higher taxonomic level relationships of Isopoda.

Two new species and a new record of Bopyrinae (Isopoda: Bopyridae) infesting Alpheidae and Hippolytidae, with comments on the genus Bopyrina Kossmann, 1881.

Two new bopyrids, Bopyrinina articulata n. sp. and Bopyrinella asymmetrica n. sp. are described from French Polynesia, the Red Sea, and the Philippines. Bopyrinina articulata n.sp. infests Salmoneus cf. gracilipes Miya, and is distinguishable from other species of this genus by the structure of the maxilliped, pleopods and oostegite 1. Bopyrinella asymmetrica n. sp. is most similar to Bopyrinella albida Shiino, 1958, but females differ from that species because all pereomeres on the short side have round dorsolateral bosses and its pleotelson is greatly distorted. Bopyrina ocellata (Czerniavsky, 1868) is newly recorded from the Western Atlantic, from Florida, USA. Review of the species of Bopyrina revealed that B. choprai Nierstrasz & Brender à Brandis, 1929 and B. sewelli Chopra, 1930 are intermediate in morphology between Bopyrina and Schizobopyrina, the taxonomic assignment of these two species needs further evaluation. Keys to Bopyrinella Nierstrasz & Brender à Brandis, 1925 and Bopyrina Kossmann, 1881 are presented. Hosts and distributions of the seven species of Bopyrinella are summarized.

Disrupted architecture and fast evolution of the mitochondrial genome of Argeia pugettensis (Isopoda): implications for speciation and fitness.

BACKGROUND: Argeia pugettensis is an isopod species that parasitizes other crustaceans. Its huge native geographic range spans the Pacific from China to California, but molecular data are available only for a handful of specimens from North-American populations. We sequenced and characterised the complete mitogenome of a specimen collected in the Yellow Sea. RESULTS: It exhibited a barcode (cox1) similarity level of only 87-89% with North-American populations, which is unusually low for conspecifics. Its mitogenome is among the largest in isopods (≈16.5 Kbp), mostly due to a large duplicated palindromic genomic segment (2 Kbp) comprising three genes. However, it lost a segment comprising three genes, nad4L-trnP-nad6, and many genes exhibited highly divergent sequences in comparison to isopod orthologues, including numerous mutations, deletions and insertions. Phylogenetic and selection analyses corroborated that this is one of the handful of most rapidly evolving available isopod mitogenomes, and that it evolves under highly relaxed selection constraints (as opposed to positive selection). However, its nuclear 18S gene is highly conserved, which suggests that rapid evolution is limited to its mitochondrial genome. The cox1 sequence analysis indicates that elevated mitogenomic evolutionary rates are not shared by North-American conspecifics, which suggests a breakdown of cox1 barcoding in this species. CONCLUSIONS: A highly architecturally disrupted mitogenome and decoupling of mitochondrial and nuclear rates would normally be expected to have strong negative impacts on the fitness of the organism, so the existence of this lineage is a puzzling evolutionary question. Additional studies are needed to assess the phylogenetic breadth of this disrupted mitochondrial architecture and its impact on fitness.

Exogenous melatonin improves growth in hulless barley seedlings under cold stress by influencing the expression rhythms of circadian clock genes.

BACKGROUND: Melatonin is a hormone substance that exists in various living organisms. Since it was discovered in the pineal gland of cattle in 1956, the function of melatonin in animals has been roughly clarified. Nevertheless, in plants, the research on melatonin is still insufficient. Hulless barley (Hordeum vulgare L. var. nudum hook. f.) is a crop that originates from cultivated barley in the east, usually grown on the Qinghai-Tibet Plateau, becoming the most important food crop in this area. Although the genome and transcriptome research of highland barley has gradually increased recently years, there are still many problems about how hulless barley adapts to the cold climate of the Qinghai-Tibet Plateau. METHODS: In this study, we set three temperature conditions 25°C, 15°C, 5°C hulless barley seedlings, and at the same time soaked the hulless barley seeds with a 1 µM melatonin solution for 12 hours before the hulless barley seeds germinated. Afterwards, the growth and physiological indicators of hulless barley seedlings under different treatment conditions were determined. Meanwhile, the qRT-PCR method was used to determine the transcription level of the hulless barley circadian clock genes under different treatment conditions under continuous light conditions. RESULTS: The results showed the possible mechanism by which melatonin pretreatment can promote the growth of hulless barley under cold stress conditions by studying the effect of melatonin on the rhythm of the circadian clock system and some physiological indicators. The results revealed that the application of 1 µM melatonin could alleviate the growth inhibition of hulless barley seedlings caused by cold stress. In addition, exogenous melatonin could also restore the circadian rhythmic oscillation of circadian clock genes, such as HvCCA1 and HvTOC1, whose circadian rhythmic phenotypes were lost due to environmental cold stress. Additionally, the results confirmed that exogenous melatonin even reduced the accumulation of key physiological indicators under cold stress, including malondialdehyde and soluble sugars. DISCUSSION: Overall, these findings revealed an important mechanism that exogenous melatonin alleviated the inhibition of plant vegetative growths either by restoring the disrupted circadian rhythmic expression oscillations of clock genes, or by regulating the accumulation profiles of pivotal physiological indicators under cold stress.

The complete chloroplast genome of Agrostis capillaris L.

Agrostis capillaris is a cool-season turf grass species that is found worldwide in temperate countries, and a good Pb phytostabilizer. In this study, the entire chloroplast genome sequence of A. capillaris was determined by Illumina sequencing. The complete chloroplast genome was circular and composed of 136,396 bp nucleotides with a GC content of about 38.5%. There were a large single-copy region (LSC, 81,659bp), a small single-copy region (SSC, 12,593bp), and a pair of reverse repeat regions (IRs, 42,144bp) in the chloroplast genome. In total, the A. capillaris chloroplast genome contained 144 genes, including 96 protein-coding genes, 40 tRNA genes, and 8 rRNA genes. Phylogenetic analysis revealed that A. capillaris was closely related to A. gigantean. The sequence data of A. capillaris chloroplast genome could provide useful genetic information for the studies on phylogenetic and evolutionary of Agrostidinae.

The complete chloroplast genome of Securigera varia (L.) Lassen.

Securigera varia is an important leguminous forage grass species that is mainly distributed in arid and semi-arid land with water scarcity, and has outstanding drought resistance. In this study, Illumina sequencing was used to obtain the complete sequence of the S. varia chloroplast genome. The complete genome was 154,257 bp in length with 35.9% GC content. It was a circular genome containing a large single-copy region (LSC, 84,762 bp), a small single-copy region (SSC, 18,059 bp), and a pair of inverted repeat regions (IRs, 51,436 bp). A total of 128 genes were encoded, including 83 protein-coding genes, 37 tRNAs, and 8 rRNAs. Phylogenetic analysis revealed that S. varia was closely related to Robinia pseudoacacia. The sequence data of S. varia chloroplast genome could provide useful genetic information for the studies on phylogenetic and evolutionary of Leguminosae.

Hantaan virus can infect human keratinocytes and activate an interferon response through the nuclear translocation of IRF-3.

Hantaan virus (HTNV) is a rodent-borne virus that causes hemorrhagic fever with renal syndrome (HFRS) in Asia and can be transmitted to humans through bites or the inhalation of aerosolized urine, droppings, or saliva of infected rodents. Keratinocytes predominate in the epidermis and reportedly serve as a replication site for multiple vector-borne viruses, little is known about the susceptibility of human skin cells to HTNV infection. Therefore, we aimed to evaluate whether human keratinocytes support HTNV replication and elicit an immune response against HTNV infection. We found that a human keratinocyte cell line, HaCaT, supports HTNV replication. In addition, retinoic acid inducible gene-I (RIG-I) and melanoma differentiation associated gene-5 (MDA5) play key roles in the detection of HTNV infection in HaCaT cells and in the up-regulation of interferon (IFN)-ß expression, which subsequently leads to the production of a large amount of antiviral interferon-stimulated genes (ISGs) and other chemokines used for immune cell recruitment. Furthermore, we suggest that interferon regulatory factor (IRF)-3, as opposed to NF-κB/p65 or IRF-7, is translocated to the nucleus to induce IFN-ß. However, the early induction of chemokine CXCL10 was a direct result of HaCaT cells counteracting HTNV infection and was not due to the induction of IFN. Overall, our data demonstrate, for the first time, the permissiveness of human keratinocytes to HTNV infection.

Abnormal transsulfuration metabolism and reduced antioxidant capacity in Chinese children with autism spectrum disorders.

Autism spectrum disorder (ASD) is a neurological disorder that presents a spectrum of qualitative impairments in social interaction, communication, as well as restricted and stereotyped behavioral patterns, interests, and activities. Several studies have suggested that the etiology of ASD can be partly explained by oxidative stress. However, the implications of abnormal transsulfuration metabolism and oxidative stress, and their relation with ASD are still unclear. The purpose of this study was to evaluate several transsulfuration pathway metabolites in Chinese participants diagnosed with ASD, to better understand their role in the etiology of this disorder. Fifty children (39 male, 11 female) diagnosed with ASD and 50 age- and gender-matched non-ASD children (i.e., control group) were included in this study. This prospective blinded study was undertaken to assess transsulfuration and oxidative metabolites, including levels of homocysteine (Hcy), cysteine (Cys), total glutathione (tGSH), reduced glutathione (GSH), oxidized glutathione (GSSG), and glutathione ratio (GSH/GSSG). The clinical severity of ASD was evaluated with the Childhood Autism Rating Scale (CARS), and the autistic children's present behavior was measured by the Autism Behavior Checklist (ABC). The results indicated that Hcy and GSSG levels were significantly higher in children diagnosed with ASD, Cys, tGSH and GSH levels as well as the GSH/GSSG ratio showed remarkably lower values in ASD children compared to control subjects. Hcy levels correlated significantly with increasing CARS scores and GSSG levels in children with ASD. Our results suggest that an abnormal transsulfuration metabolism and reduced antioxidant capacity (i.e., hyperhomocysteinemia and increased oxidative stress), and Hcy level appears to have a potentially negative impact on clinical severity of autistic disorder.