Transporter Gene Research Articles

RNA thermometers are widespread upstream of ABC transporter genes in bacteria

RNA thermometers are temperature-sensing non-coding RNAs that regulate the expression of downstream genes. A well-characterized RNA thermometer motif discovered in bacteria is the ROSE-like element (repression of heat shock gene expression). ATP-binding cassette (ABC) transporters are a superfamily of transmembrane proteins that harness ATP hydrolysis to facilitate the export and import of substrates across cellular membranes. Through structure-guided bioinformatics, we discovered that ROSE-like RNA thermometers are widespread upstream of ABC transporter genes in bacteria. X-ray crystallography, biochemistry, and cellular assays indicate that these RNA thermometers are functional regulatory elements. This study expands the known biological role of RNA thermometers to these key membrane transporters.

Enhancing Acetate Utilization in Phaeodactylum tricornutum through the Introduction of Acetate Transport Protein.

The diatom Phaeodactylum tricornutum, known for its high triacylglycerol (TAG) content and significant levels of n-3 long chain polyunsaturated fatty acids (LC-PUFAs), such as eicosapentaenoic acid (EPA), has a limited ability to utilize exogenous organic matter. This study investigates the enhancement of acetate utilization in P. tricornutum by introducing an exogenous acetate transport protein. The acetate transporter gene ADY2 from Saccharomyces cerevisiae endowed the organism with the capability to assimilate acetate and accelerating its growth. The transformants exhibited superior growth rates at an optimal NaAc concentration of 0.01 M, with a 1.7- to 2.0-fold increase compared to the wild-type. The analysis of pigments and photosynthetic activities demonstrated a decline in photosynthetic efficiency and maximum electron transport rate. This decline is speculated to result from the over-reduction of the electron transport components between photosystems due to acetate utilization. Furthermore, the study assessed the impact of acetate on the crude lipid content and fatty acid composition, revealing an increase in the crude lipid content and alterations in fatty acid profiles, particularly an increase in C16:1n-7 at the expense of EPA and a decrease in the unsaturation index. The findings provide insights into guiding the biomass and biologically active products production of P. tricornutum through metabolic engineering.

Identification and selection of reference genes for analysis of gene expression by quantitative real-time PCR in the euhalophyte Suaeda altissima (L.) Pall.

ABSTRACT Сoding sequences of seven housekeeping genes: actin SaACT7, ubiquitin-conjugating protein SaUBC10, glyceraldehyde-3-phosphate dehydrogenase SaGAPDH, protein of the large subunit of ribosomes SaL2, α-tubulin SaTUA, translation elongation factor SaeEF1α, and protein phosphatase SaPP2A were identified as candidate reference genes for expression analysis of target genes in the extremely salt tolerant plant Suaeda altissima (L.) Pall. The expression profiles of the genes differed. SaACT7 and SaeEF1α demonstrated the highest expression levels, while the lowest expression levels were found for SaPP2A and SaTUA. SaPP2A and SaeEF1α genes were the most stably expressed at different steady-state salinity levels and different nitrate concentrations in nutrient solutions (NSs). SaL2, SaPP2A, and SaeEF1α genes showed the greatest stability of expression when nitrate was added to nutrient solution of plants grown under conditions of nitrate deficiency. Less constant expression was demonstrated in this experiment by SaACT7 and SaTUA. SaL2, SaACT7, SaeEF1α, and SaUBC10 genes showed the smallest expression changes under salt shock. To validate the use of the most stably expressed genes for normalization of gene expression, we checked them as reference genes to study the expression of the nitrate transporter gene SaNPF6.3 in S. altissima roots under conditions of different salinity and different nitrate supply.

Genome-Wide Identification and Expression Pattern of Sugar Transporter Genes in the Brown Planthopper, Nilaparvata lugens (Stål).

Sugar transporters play important roles in controlling carbohydrate transport and are responsible for mediating the movement of sugars into cells in numerous organisms. In insects, sugar transporters not only play a role in sugar transport but may also act as receptors for virus entry and the accumulation of plant defense compounds. The brown planthopper, Nilaparvata lugens, inflicts damage on rice plants by feeding on their phloem sap, which is rich in sugars. In the present study, we identified 34 sugar transporters in N. lugens, which were classified into three subfamilies based on phylogenetic analysis. The motif numbers varied from seven to eleven, and motifs 2, 3, and 4 were identified in the functional domains of all 34 NlST proteins. Chromosome 1 was found to possess the highest number of NlST genes, harboring 15. The gut, salivary glands, fat body, and ovary were the different tissues enriched with NlST gene expression. The expression levels of NlST2, 3, 4, 7, 20, 27, 28, and 31 were higher in the gut than in the other tissues. When expressed in a Saccharomyces cerevisiae hexose transporter deletion mutant (strain EBY.VW4000), only ApST4 (previously characterized) and NlST4, 28, and 31 were found to transport glucose and fructose, resulting in functional rescue of the yeast mutant. These results provide valuable data for further studies on sugar transporters in N. lugens and lay a foundation for finding potential targets to control N. lugens.

Characterization and Expression Analysis of Sugar Transporters through Partial Least Square Structural Equation Model (PLS-SEM) Revealed Their Role in Pepper (Capsicum annuum L.).

Pepper (Capsicum annuum L.) is one of the most important economic crops in the world. By controlling the transport and distribution of photosynthetic products between cells and organs, sugar transporters are widely involved in growth and development, environmental adaptation, and microbial interactions. The present study was carried out at the genome-wide level to systematically characterize sugar transporters. As a result, 50 MST, 3 SUT, and 29 SWEET genes were identified and classified. The expression pattern of sugar transporters in pepper was analyzed by transcriptomic data. The expression properties of sugar transporters were further explored in pepper varieties with significant differences in weight, shape, and pungency. It was shown that the pepper sugar transporter genes had obvious spatiotemporal specific expression characteristics and exhibited variety-specific expression preferences. We focus on analyzing candidate genes that may be involved in fruit development and expansion. We further explore the response of pepper sugar transporters to adversity stress using a structural equation model. Finally, we found that the MST, SUT, and SWEET families are collectively involved in balancing pepper resistance to abiotic stress by coordinating the expression strengths of different family members. Our study may contribute to the functional study of pepper sugar transporter genes and create the prospect of utilizing sugar transporter gene resources to improve pepper variety.

Nitric oxide has diverse effects on head and neck cancer cell proliferation and glycolysis.

Glycolysis is a key energy-providing process and one of the hallmarks of cancer. Nitric oxide (NO), a free radical molecule, regulates glycolysis in various cancers. NO can alter the cell cycle and apoptosis in head and neck squamous cell carcinoma (HNSCC) cells. However, the effect of NO on glycolysis in HNSCC cells remains unresolved. The present study investigated the effects of NO on cell proliferation, glucose transporter (GLUT) gene expression and glycolytic indicators in HNSCC cell lines. Two pairs of isogenic HNSCC cell lines, HN18/HN17 and HN30/HN31, were treated with a NO donor, diethylamine NONOate (DEA-NONOate), for 24, 48 and 72 h. Cell proliferation was assessed using MTT assay and NO concentration was measured using the Griess Reagent System. GLUT1, GLUT2, GLUT3, and GLUT4 gene expression was analyzed using reverse transcription-quantitative PCR. Furthermore, hexokinase (HK) activity and lactate production were measured in NO-treated cells using colorimetric assay. NO exhibited concentration-dependent pro- and anti-proliferative effects on the HNSCC cell lines. Lower NO concentrations (5-200 µM) had pro-proliferative effects, whereas NO >200 µM had an anti-proliferative effect on HNSCC cells. NO (5 µM) promoted proliferation and glycolysis in HN18 cells by upregulating GLUT1 and GLUT2 gene expression and increasing HK activity and lactate levels. At 5-20 µM, NO-induced HN17 and HN30 cells demonstrated enhanced proliferation and GLUT2, GLUT3 and GLUT4 gene expression, whereas the glycolytic pathway was not affected. In conclusion, the present study demonstrated distinct proliferative effects of NO on HNSCC cells. NO may promote cell proliferation by stimulating glucose consumption and the glycolytic rate in HN18 cells. The effects of NO in other cell lines may be mediated by a non-glycolysis mechanism and require further investigation.

MAST4 regulates stem cell maintenance with DLX3 for epithelial development and amelogenesis

The asymmetric division of stem cells permits the maintenance of the cell population and differentiation for harmonious progress. Developing mouse incisors allows inspection of the role of the stem cell niche to provide specific insights into essential developmental phases. Microtubule-associated serine/threonine kinase family member 4 (Mast4) knockout (KO) mice showed abnormal incisor development with low hardness, as the size of the apical bud was decreased and preameloblasts were shifted to the apical side, resulting in amelogenesis imperfecta. In addition, Mast4 KO incisors showed abnormal enamel maturation, and stem cell maintenance was inhibited as amelogenesis was accelerated with Wnt signal downregulation. Distal-Less Homeobox 3 (DLX3), a critical factor in tooth amelogenesis, is considered to be responsible for the development of amelogenesis imperfecta in humans. MAST4 directly binds to DLX3 and induces phosphorylation at three residues within the nuclear localization site (NLS) that promotes the nuclear translocation of DLX3. MAST4-mediated phosphorylation of DLX3 ultimately controls the transcription of DLX3 target genes, which are carbonic anhydrase and ion transporter genes involved in the pH regulation process during ameloblast maturation. Taken together, our data reveal a novel role for MAST4 as a critical regulator of the entire amelogenesis process through its control of Wnt signaling and DLX3 transcriptional activity.

Sodium-dependent phosphate transporter NaPi2b as a candidate for targeted therapy: features of structure, function, and expression

The sodium-dependent phosphate transporter NaPi2b is an integral membrane protein of the SLC34 phosphate transporter family and is an attractive target for precision therapy of several human diseases. Together with other members of this family, the NaPi2b transporter is involved in maintaining phosphate homeostasis in the mammalian body. The NaPi2b transporter gene (SLC34A2) has a broad expression pattern in healthy tissues, including small intestinal epithelial cells, where NaPi2b plays a major role in the absorption of dietary phosphate. NaPi2b transports one divalentorthophosphoric acid residue into cells along with three sodium ions. NaPi2b transport is regulated by dietary phosphate, pH, hormones, and vitamins including vitamin D, estrogen, glucocorticoids, and epidermal growth factor. The NaPi2b transporter exists in two isoforms – 689 and 690 amino acid residues. The molecular weight of NaPi2b depends on the degree of glycosylation and varies from 70 to 100 kDa. According to various sources, the transporter has from 6 to 12 transmembrane domains, 2 co-transport domains, a large extracellular localization domain, as well as N- and C-terminal domains that face the inside of the cell. Impaired NaPi2b function leads to the development of several diseases, including pulmonary alveolar microlithiasis and hyperphosphatemia, and pulmonary alveolar microlithiasis is known to be associated with mutations in the SLC34A2 gene encoding NaPi2b. High levels of NaPi2b have been found in several malignant tumors, including ovary, lung, breast, thyroid, colon, bladder, liver, stomach, kidney, and in gliomas. The tumor-specific conformation of the large extracellular domain of the NaPi2b transporter, mutations, and features of expression of the transporter gene in normal and pathological conditions show that NaPi2b is a promising target for the development of highly selective targeted drugs against it for the treatment of cancer and metabolic disorders.

Developmental cascades from early childhood attachment security to adolescent level of personality functioning among high-risk youth.

This study examines associations between early childhood attachment security and adolescent personality functioning in a high-risk sample within a developmental psychopathology framework. Data from 2,268 children (1165 male; 1103 female) and caregivers participating in Future of Families and Child Well-Being Study (FFCWS) were used to examine (1) effects of genetic polymorphisms of the serotonin transporter (5-HTTLPR) and dopamine D4 receptor (DRD4) genes and adverse childhood experiences (ACEs) on attachment security and emotional and behavioral dysregulation in early childhood and (2) longitudinal associations and transactional relationships among attachment security, dysregulation, negative parenting attitudes and behaviors, social competence, and adolescent personality functioning. Results revealed that ACEs predicted attachment security over and above sex or the genetic risk, and gene × environment interactions did not increment prediction. Results of cascade models showed that greater early childhood attachment security predicted higher adolescent level of personality functioning via pathways through intermediary variables. Limitations and future research directions are discussed.

Genome-Wide Identification of the Sulfate Transporters Gene Family in Blueberry (Vaccinium spp.) and Its Response to Ericoid Mycorrhizal Fungi.

Sulfur metabolism plays a major role in plant growth and development, environmental adaptation, and material synthesis, and the sulfate transporters are the beginning of sulfur metabolism. We identified 37 potential VcSULTR genes in the blueberry genome, encoding peptides with 534 to 766 amino acids. The genes were grouped into four subfamilies in an evolutionary analysis. The 37 putative VcSULTR proteins ranged in size from 60.03 to 83.87 kDa. These proteins were predicted to be hydrophobic and mostly localize to the plasma membrane. The VcSULTR genes were distributed on 30 chromosomes; VcSULTR3;5b and VcSULTR3;5c were the only tandemly repeated genes. The VcSULTR promoters contained cis-acting elements related to the fungal symbiosis and stress responses. The transcript levels of the VcSULTRs differed among blueberry organs and changed in response to ericoid mycorrhizal fungi and sulfate treatments. A subcellular localization analysis showed that VcSULTR2;1c localized to, and functioned in, the plasma membrane and chloroplast. The virus-induced gene knock-down of VcSULTR2;1c resulted in a significantly decreased endogenous sulfate content, and an up-regulation of genes encoding key enzymes in sulfur metabolism (VcATPS2 and VcSiR1). These findings enhance our understanding of mycorrhizal-fungi-mediated sulfate transport in blueberry, and lay the foundation for further research on blueberry-mycorrhizal symbiosis.

Dramatic Suppression of Lipogenesis and No Increase in Beta-Oxidation Gene Expression Are among the Key Effects of Bergamot Flavonoids in Fatty Liver Disease.

Bergamot flavonoids have been shown to prevent metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and stimulate autophagy in animal models and patients. To investigate further the mechanism of polyphenol-dependent effects, we performed a RT2-PCR array analysis on 168 metabolism, transport and autophagy-related genes expressed in rat livers exposed for 14 weeks to different diets: standard, cafeteria (CAF) and CAF diet supplemented with 50 mg/kg of bergamot polyphenol fraction (BPF). CAF diet caused a strong upregulation of gluconeogenesis pathway (Gck, Pck2) and a moderate (>1.7 fold) induction of genes regulating lipogenesis (Srebf1, Pparg, Xbp1), lipid and cholesterol transport or lipolysis (Fabp3, Apoa1, Lpl) and inflammation (Il6, Il10, Tnf). However, only one β-oxidation gene (Cpt1a) and a few autophagy genes were differentially expressed in CAF rats compared to controls. While most of these transcripts were significantly modulated by BPF, we observed a particularly potent effect on lipogenesis genes, like Acly, Acaca and Fasn, which were suppressed far below the mRNA levels of control livers as confirmed by alternative primers-based RT2-PCR analysis and western blotting. These effects were accompanied by downregulation of pro-inflammatory cytokines (Il6, Tnfa, and Il10) and diabetes-related genes. Few autophagy (Map1Lc3a, Dapk) and no β-oxidation gene expression changes were observed compared to CAF group. In conclusion, chronic BPF supplementation efficiently prevents NAFLD by modulating hepatic energy metabolism and inflammation gene expression programs, with no effect on β-oxidation, but profound suppression of de novo lipogenesis.

Fitness landscape of substrate-adaptive mutations in evolved amino acid-polyamine-organocation transporters.

The emergence of new protein functions is crucial for the evolution of organisms. This process has been extensively researched for soluble enzymes, but it is largely unexplored for membrane transporters, even though the ability to acquire new nutrients from a changing environment requires evolvability of transport functions. Here, we demonstrate the importance of environmental pressure in obtaining a new activity or altering a promiscuous activity in members of the amino acid-polyamine-organocation (APC)-type yeast amino acid transporters family. We identify APC members that have broader substrate spectra than previously described. Using in vivo experimental evolution, we evolve two of these transporter genes, AGP1 and PUT4, toward new substrate specificities. Single mutations on these transporters are found to be sufficient for expanding the substrate range of the proteins, while retaining the capacity to transport all original substrates. Nonetheless, each adaptive mutation comes with a distinct effect on the fitness for each of the original substrates, illustrating a trade-off between the ancestral and evolved functions. Collectively, our findings reveal how substrate-adaptive mutations in membrane transporters contribute to fitness and provide insights into how organisms can use transporter evolution to explore new ecological niches.

Optimized silicon fertilization regime weakens cadmium translocation and increases its biotransformation in rice tissues

In acidic paddy fields of South China, rice (Oryza sativa L.) faces the dual challenges of cadmium (Cd) toxicity and silicon (Si) deficiency. Although previous studies have highlighted the functions of Si application timing and strategies in mitigating Cd-stressed rice, the precise mechanisms underlying the health restoration of Cd-toxic rice and the assurance of grain safety remain elusive. This study explored Cd translocation and detoxification in the shoots of rice regulated by various Si fertilization regimes: Si(T) (all Si added before transplanting), Si(J) (all Si added at jointing), and Si(TJ) (half Si added both before transplanting and at jointing). The findings revealed that the regime of Si(TJ) was more beneficial to rice health and grain safety than Si(T) and Si(J). The osmotic regulators such as proline, soluble sugars, and soluble proteins were significantly boosted by Si(TJ) compared to other Si treatments, and which enhanced membrane integrity, balanced intracellular pH, and increased Cd tolerance of rice. Furthermore, Si(TJ) was more effective than Si(T) and Si(J) on the Cd sequestration in the cell wall, Cd bio-passivation, and the down-regulated expression of the Cd transport genes. The concentrations of Cd in the xylem and phloem treated with Si(TJ) were reduced significantly. Additionally, Si(TJ) facilitated much more Cd bound with the outer layer proteins of grains, and promoted Cd chelation and complexation by phytic acid, phenolics, and flavonoids. Overall, Si (TJ) outperformed Si(T) and Si(J) in harmonizing the phycological processes, inhibiting Cd translocation, and enhancing Cd detoxification in rice plant. Thereby the split Si application strategy offers potential for reducing Cd toxicity in rice grain.

Effects of foliar spraying different sizes of zinc fertilizer on the growth and cadmium accumulation in rice.

Nanotechnology has been widely applied in agricultural science. During the process of reducing metal toxicity and accumulation in rice, nanomaterials exhibit size effects. However, there is limited knowledge regarding these size effects. We aim to explore the impact of fertilizer with various sizes of ZnO nanoparticles (ZnO-NPs) on rice growth and cadmium (Cd) accumulation and to elucidate the potential mechanism of Cd reduction in rice. Foliar applications of different concentrations (0.5 and 2 mmol L-1) and different sizes (30 and 300 nm ZnO-NPs) of zinc (Zn) fertilizer (Zn(NO3)2) were performed to investigate the effects on rice growth, Cd accumulation and subcellular distribution, and the expression of Zn-Cd transport genes. The results suggested that all the foliar sprayings can significantly reduce the Cd concentrations in rice grains by 41-61% with the highest reduction in the application of ZnO-NPs with large size and low concentration. This is related to the enhancement of Cd fixation in leaf cell walls and downregulation of Cd transport genes (OsZIP7, OsHMA2, OsHMA3) in stem nodes. Foliar ZnO-NPs applications can increase the Zn concentration in grains by 9-21%. Foliar applications of Zn(NO3)2 and small-sized ZnO-NPs promoted plant growth and rice yield, while the application of large-sized ZnO-NPs significantly reduced rice growth and yield. The study suggests that the rice yield and Cd reduction are dependent on the size and concentration of foliar spraying and the use of large-sized ZnO-NPs is the most effective strategy when considering both yield and Cd reduction comprehensively. © 2024 Society of Chemical Industry.

Occurrence and spatiotemporal distribution of arsenic biotransformation genes in urban dust

Microbially-mediated arsenic biotransformation plays a pivotal role in the biogeochemical cycling of arsenic; however, the presence of arsenic biotransformation genes (ABGs) in urban dust remains unclear. To investigate the occurrence and spatiotemporal distributions of ABGs, a total of one hundred and eighteen urban dust samples were collected from different districts of Xiamen city, China in summer and winter. Although inorganic arsenic species, including arsenate [As(V)] and arsenite [As(III)], were found to be predominant, the methylated arsenicals, particularly trimethylarsine oxide [TMAs(V)O] and dimethylarsenate [DMAs(V)], were detected in urban dust. Abundant ABGs were identified in urban dust via AsChip analysis (a high-throughput qPCR chip for ABGs), of which As(III) S-adenosylmethionine methyltransferase genes (arsM), As(V) reductase genes (arsC), As(III) oxidase genes (aioA), As(III) transporter genes (arsB), and arsenic-sensing regulator genes (arsR) were the most prevalent, collectively constituting more than 90 % of ABGs in urban dust. Microbes involved in arsenic methylation were assigned to bacteria (e.g., Actinomycetes and Alphaproteobacteria), archaea (e.g., Halobacteria), and eukaryotes (e.g., Chlamydomonadaceae) in urban dust via the arsM amplicon sequencing. Temperature, a season-dependent environmental factor, profoundly affected the abundance of ABGs and the composition of microbes involved in arsenic methylation. This study provides new insights into the presence of ARGs within the urban dust.

Search for genes gained by horizontal gene transfer in an entomopoxvirus, with special reference to the analysis of the transfer of an ABC transporter gene

Although it is generally believed that large DNA viruses capture genes by horizontal gene transfer (HGT), the detailed manner of such transfer has not been fully elucidated. Here, we searched for genes in the coleopteran entomopoxvirus (EV) Anomala cuprea entomopoxvirus (ACEV) that might have been gained by ACEV by HGT. We classified the potential source organisms for HGT into three categories: the host A. cuprea; other organisms, including viruses unrelated to EVs; and organisms with uncertain host attribution. Of the open reading frames (ORFs) of the ACEV genome, 2.1 % were suggested to have been gained from the host by ACEV or its recent ancestor via HGT; 8.7 % were possibly from organisms other than the host, and 3.7 % were possibly from the third category of organisms via HGT. The analysis showed that ACEV contains some interesting ORFs obtained by HGT, including a large ATP-binding cassette protein (ABC transporter) ORF and a tenascin ORF (IDs ACV025 and ACV123, respectively). We then performed a detailed analysis of the HGT of the ACEV large ABC transporter ORF—the largest of the ACEV ORFs. mRNA sequences obtained by RNA-seq from fat bodies—sites of ACEV replication—and midgut tissues—sites of initial infection—of the virus's host A. cuprea larvae were subjected to BLAST analysis. One type of ABC transporter ORF from the fat bodies and two types from the midgut tissues, one of which was identical to that in the fat bodies, had the greatest identity to the ABC transporter ORF of ACEV. The two types from the host had high levels of identity to each other (approximately 95 % nucleotide sequence identity), strongly suggesting that the host ABC transporter group consisting of the two types was the origin of ACV025. We then determined the sequence (12,381 bp) containing a full-length gene of the A. cuprea ABC transporter. It turned out to be a transcription template for the abovementioned mRNA found in both tissues. In addition, we determined a large part (ca. 6.9 kb) of the template sequence for the mRNA found only in the midgut tissues. The results showed that the ACEV ABC transporter ORF is missing parts corresponding to introns of the host ABC transporter genes, indicating that the ORF was likely acquired by HGT in the form of mRNA. The presence of definite duplicated sequences adjacent to the ACEV ABC transporter genes—a sign of LINE-1 retrotransposon-mediated HGT—was not observed. An approximately 2-month ACV025 transcription experiment suggested that the transporter sequence is presumed to be continuously functional. The amino acid sequence of ACV025 suggests that its product might function in the regulation of phosphatide in the host-cell membranes.

The efficient synthesis strategy of bacillomycin D in Bacillus amyloliquefaciens fmbJ

The cyclic lipopeptide bacillomycin D exhibits potent antifungal activity against a wide range of fungi, particularly filamentous fungi, thereby exhibiting significant potential for application in food preservation. However, the limited yield obtained from wild strains hinders the practical application of bacillomycin D. In this study, we used different strategies to modify the original strain Bacillus amyloliquefaciens fmbJ, including promoter replacement, competitive synthetic gene knockout, and overexpression of the lipopeptide transporter gene. Subsequently, we analyzed changes in the production and expression of bacillomycin D genes in the engineered strain. The results demonstrated that PbacA exhibits the highest promoter activity, leading to a significant increase (2.05-fold) in bacillomycin D production compared with control group. Additionally, deletion of the epsA-O gene cluster also significantly enhances the synthesis of bacillomycin D. However, when amyloid gene cluster tasA-sipW-yqxM was deleted,bacillomycin D accumulation time was shortened, resulting in no significant increase in bacillomycin D production. In addition, lipopeptide transporters SwrC, KrsE and YcxA did not promote bacillomycin D production. Finally, by replacing the promoter PbacA, we successfully disrupted the epsA-O gene cluster, and bacillomycin D production increased by 2.55 times compared to the initial bacillomycin D strain. In conclusion, this study indicated that genetic engineering of regulatory genes was an effective strategy to improve the yields of bacillomycin D and provided promising strains for industrial production of bacillomycin D.

From parents to children: associations of traffic risks with impulsivity, family relationships and serotonin transporter genotype.

Road traffic injuries are the leading cause of death for young adults, and parents play a major role in shaping their traffic behaviour. Higher impulsivity (predictor of higher traffic risk) has been shown to be dependent on family relations and the serotonin transporter gene promoter polymorphism (5-HTTLPR). The specific mechanisms for the inheritance of risky traffic behaviour from parents to children are not clear, and the genetic aspect has not been studied before. We used data of Estonian Children Personality Behaviour and Health Study subjects (n = 596, mean age = 25.2 ± 0.6) and their parents (mothers, n = 460, mean age = 52.1 ± 5.8; fathers, n = 339, mean age = 54.1 ± 6.5). Family relationships scale, traffic risk questionnaires and Adaptive and Maladaptive Impulsivity Scale were filled out. The increased risk-taking behaviour of parents and worse quality of family relationship were significant predictors of higher traffic risk among subjects. Family support and impulsivity of fathers significantly predicted the subjects' traffic risk score in interaction with 5-HTTLPR genotype: l'/l' homozygous subjects with adaptively impulsive fathers had higher traffic risk, whereas for s'-allele carrying subjects family support was more significant. Parental role modelling and family relationships are significant predictors of future traffic behaviour of the child. Whether the behavioural example of the father or the influence of family relationships is more important in predicting future risky traffic behaviour, depends on the 5-HTTLPR genotype of the child.

Caste-specific development of the dopaminergic system in bumble bees (Bombus ignitus)

The dopaminergic system is involved in caste-specific behaviors in eusocial bumble bees. However, little is known about how the caste differences in dopaminergic system are formed during pupal stages in the brains of bumble bees. Thus, we investigated the levels of dopamine-related substances and expression of genes encoding enzymes involved in dopamine synthesis and metabolism, dopamine receptors, and a dopamine transporter in the brain of female Bombus ignitus. The levels of dopamine and dopamine-related substances in the brain were significantly higher in gynes than in workers from the late pupal stage to emergence, but the dynamics were similar between the castes. The relative expression levels of genes encoding enzymes involved in dopamine synthesis (BigTh and BigDdc) and dopamine metabolism (BigNat) increased significantly from pupal stage to emergence, but there were no differences in the relative expression levels of these genes between castes. A similar pattern was seen in the relative expression levels of four dopamine receptor genes (BigDop1, BigDop2, BigDop3, and BigDopEcR) and a dopamine transporter gene (BigDat). Compared with the honey bee Apis mellifera, the caste-specific dopaminergic system in the bumble bee is less differentiated, which might reflect the degree of behavioral specialization in these two species.

Identification of Polymorphisms in EAAT1 Glutamate Transporter Gene SLC1A3 Associated with Reduced Migraine Risk.

Dysfunction in ion channels or processes involved in maintaining ionic homeostasis is thought to lower the threshold for cortical spreading depression (CSD), and plays a role in susceptibility to associated neurological disorders, including pathogenesis of a migraine. Rare pathogenic variants in specific ion channels have been implicated in monogenic migraine subtypes. In this study, we further examined the channelopathic nature of a migraine through the analysis of common genetic variants in three selected ion channel or transporter genes: SLC4A4, SLC1A3, and CHRNA4. Using the Agena MassARRAY platform, 28 single-nucleotide polymorphisms (SNPs) across the three candidate genes were genotyped in a case-control cohort comprised of 182 migraine cases and 179 matched controls. Initial results identified significant associations between migraine and rs3776578 (p = 0.04) and rs16903247 (p = 0.05) genotypes within the SLC1A3 gene, which encodes the EAAT1 glutamate transporter. These SNPs were subsequently genotyped in an independent cohort of 258 migraine cases and 290 controls using a high-resolution melt assay, and association testing supported the replication of initial findings-rs3776578 (p = 0.0041) and rs16903247 (p = 0.0127). The polymorphisms are in linkage disequilibrium and localise within a putative intronic enhancer region of SLC1A3. The minor alleles of both SNPs show a protective effect on migraine risk, which may be conferred via influencing the expression of SLC1A3.