Identification and characterisation of ROS modulator 1 in Lampetra japonica

Wheat male-sterile 2 reduces ROS levels to inhibit anther development by deactivating ROS modulator 1

Ms2 is an important dominant male-sterile gene in wheat, but the biochemical function of Ms2 and the mechanism by which it causes male sterility remain elusive. Here, we report the molecular basis underlying Ms2-induced male sterility in wheat. We found that activated Ms2 specifically reduces the reactive oxygen species (ROS) signals in anthers and thereby induces termination of wheat anther development at an early stage. Furthermore, our results indicate that Ms2 is localized in mitochondria, where it physically interacts with a wheat homolog of ROS modulator 1 (TaRomo1). Romo1 positively regulates the ROS levels in humans but has never been studied in plants. We found that single amino acid substitutions in the Ms2 protein that rescue the ms2 male-sterile phenotype abolish the interaction between Ms2 and TaRomo1. Significantly, Ms2 promotes the transition of TaRomo1 proteins from active monomers to inactive oligomers. Taken together, our findings unravel the molecular basis of Ms2-induced male sterility and reveal a regulatory mechanism in which ROS act as essential signals guiding the anther development program in wheat.

Dose-Dependent Molecular Responses of Labeo rohita to Triphenyl Phosphate

Triphenyl phosphate (TPhP) is a broad-spectrum organophosphate compound widely used as an additive in several products to prevent ignition. However, its utilization produces a hazardous impact on various organisms. So far, very few studies have investigated the acute toxicity of TPhP at environmentally relevant concentrations in nontarget aquatic species. This study aimed to assess whether the short-term exposure of TPhP (4, 20, and 100 μg L^-1) affects the oxidative stress, antioxidant activity, biomolecule metabolism, DNA stability, chromosomal integrity, apoptosis, and pathological changes in various organs of Labeo rohita fingerlings. The results illustrated that the reactive oxygen species (ROS) production and lipid peroxidation (LPO) rates were significantly higher in tissues (brain, liver, and kidney) of TPhP-treated groups. Interestingly, superoxide dismutase (SOD) and catalase (CAT) activities were remarkably decreased in tissues following TPhP exposure. The levels of protein, glucose, total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) in various tissues were also found to be significantly altered in TPhP-exposed fish fingerlings. These significant alterations in the antioxidant system and biochemical profile induced genotoxic responses such as DNA and chromosomal damage in the fish fingerlings. Furthermore, the incidence of the observed genotoxic responses was also found to be dose-dependent. Likewise, the apoptotic responses were also significantly altered following TPhP acute exposure in L. rohita fingerlings. The subsequent effects on oxidative stress, antioxidant inhibition, dysregulated biomolecule metabolism, and genotoxicity might be the possible reason for the observed pathological changes in various tissues of L. rohita. Taken together, the present findings showed that the toxicity of TPhP is principally associated with exposure concentrations. Therefore, this study illustrates the toxicity risks of TPhP to vertebrate organisms at real-world concentrations.

Evolutionary history and functional characterization of Lj-TICAM-a and Lj-TICAM-b formed via lineage-specific tandem duplication in lamprey (Lampetra japonica)

Toll/interleukin-1 receptor domain-containing adaptor molecule (TICAM) genes respond to infections. We identified TICAM-a and TICAM-b in Lampetra japonica and investigated their evolutionary history and potential function via comparative genomics and molecular evolution analyses. They are arranged in tandem and evolved from a multi-exon to a single-exon structure. Lj-TICAM-a and Lj-TICAM-b might be the ancestral gene of the vertebrate TICAM genes. Lj-TICAM-b arose via a lamprey-specific tandem duplication event. Both genes are expressed in many tissues during an immune response, and exhibit different responses to peptidoglycan, indicating their functional divergence. Simultaneous overexpression of both proteins activated nuclear factor κB expression and co-immunoprecipitation assays indicated that they might form a complex for signal transduction. However, unlike in mammals, the TICAM-dependent signaling pathway in lamprey might rely on TRAF3 rather than on TRAF6. These results suggest that both Lj-TICAM-a and Lj-TICAM-b play a role in host defenses.

Lamprey: a model for vertebrate evolutionary research

Lampreys belong to the superclass Cyclostomata and represent the most ancient group of vertebrates. Existing for over 360 million years, they are known as living fossils due to their many evolutionally conserved features. They are not only a keystone species for studying the origin and evolution of vertebrates, but also one of the best models for researching vertebrate embryonic development and organ differentiation. From the perspective of genetic information, the lamprey genome remains primitive compared with that of other higher vertebrates, and possesses abundant functional genes. Through scientific and technological progress, scientists have conducted in-depth studies on the nervous, endocrine, and immune systems of lampreys. Such research has significance for understanding and revealing the origin and evolution of vertebrates, and could contribute to a greater understanding of human diseases and treatments. This review presents the current progress and significance of lamprey research.

Identification of functional genes involved in Cd(2+) response of Chinese surf clam (Mactra chinensis) through transcriptome sequencing

The Chinese surf clam Mactra chinensis is an economically important bivalve species in the coastal waters of Liaoning and Shandong Province, China. In this study, we carried out transcriptome sequencing to develop molecular resources for M. chinensis and conducted an acute test of Cd(2+) stimulation through quantitative real-time PCR (qRT-PCR) to analyze the relative expression of six functional genes. A total of 100,839 transcripts and 56,712 unigenes were obtained from 39.9 million filtered reads and 21,305 unigenes were annotated by hitting against NCBI database. According to the results of qRT-PCR, heat shock protein 22 (Hsp22) and cytochrome P450 (CYP450(2C31)) were inhibited in the low concentration, and induced in the high concentration of Cd(2+); thioredoxin peroxidase (TPx-A) was at normal level in low concentration, but induced in high concentration of Cd(2+); glutathione peroxidase A (GPA), glutathione peroxidase 1 (GPA1) and Mn superoxide dismutase gene (MnSOD) were down-regulated when exposed to any treatment groups. Expression levels of the six functional genes following Cd(2+) exposure indicated that these genes were linked to environmental stress. Moreover, the present work enriched the molecule genetic data of M. chinensis.

Genomic characterization, expression analysis, and antimicrobial function of a glyrichin homologue from rock bream, Oplegnathus fasciatus

Antimicrobial peptides are important innate effector molecules, playing a vital role in antimicrobial immunity in all species. Glyrichin is a transmembrane protein and an antibacterial peptide, exerting its functions against a wide range of pathogenic bacteria. In this study, cDNA and a BAC clone harboring the glyrichin gene were identified from rock bream and characterized. Genomic characterization showed that the OfGlyrichin gene exhibited a 3 exon-2 intron structure. OfGlyrichin is a 79-amino-acid protein with a transmembrane domain at (22)GFMMGFAVGMAAGAMFGTFSCLR(44). Pairwise and multiple sequence alignments showed high identity and conservation with mammalian orthologues. Phylogenetic analysis showed a close relationship with fish species. Higher levels of OfGlyrichin transcripts were detected in the liver from healthy rock bream which were induced by immunogens like lipopolysaccharide, poly I:C, rock bream irido virus, Edwardsiella tarda and Streptococcus iniae. The synthetic peptide (pOf19) showed antibacterial activity against Escherichia coli, E. tarda, and S. iniae. Analysis of the bacterial morphological features after pOf19 peptide treatment showed breakage of the cell membrane, affirming that antibacterial function is accomplished through membrane lysis. The pOf19 peptide also showed antiviral activity against RBIV infection. The high conservation of the genomic structure and protein, together with the antimicrobial roles of OfGlyrichin, provide evidence for the evolutionary existence of this protein playing a vital role in innate immune defense in rock bream.