Molecular insights into the catalytic mechanism of a phthalate ester hydrolase.

Phthalate esters (PAEs) are emerging hazardous and toxic chemicals that are extensively used as plasticizers or additives. Diethyl phthalate (DEP) and dimethyl phthalate (DMP), two kinds of PAEs, have been listed as the priority pollutants by many countries. PAE hydrolases are the most effective enzymes in PAE degradation, among which family IV esterases are predominate. However, only a few PAE hydrolases have been characterized, and as far as we know, no crystal structure of any PAE hydrolases of the family IV esterases is available to date. HylD1 is a PAE hydrolase of the family IV esterases, which can degrade DMP and DEP. Here, the recombinant HylD1 was characterized. HylD1 maintained a dimer in solution, and functioned under a relatively wide pH range. The crystal structures of HylD1 and its complex with monoethyl phthalate were solved. Residues involved in substrate binding were identified. The catalytic mechanism of HylD1 mediated by the catalytic triad Ser140-Asp231-His261 was further proposed. The hylD1 gene is widely distributed in different environments, suggesting its important role in PAEs degradation. This study provides a better understanding of PAEs hydrolysis, and lays out favorable bases for the rational design of highly-efficient PAEs degradation enzymes for industrial applications in future.

Genomic analysis of Cobetia sp. D5 reveals its role in marine sulfur cycling.

Dimethylsulfoniopropionate (DMSP) is one of the most abundant sulfur-containing organic compounds on the earth, which is an important carbon and sulfur source and plays an important role in the global sulfur cycle. Marine microorganisms are an important group involved in DMSP metabolism. The strain Cobetia sp. D5 was isolated from seawater samples in the Yellow Sea area of Qingdao during an algal bloom. There is still limited knowledge on the capacity of DMSP utilization of Cobetia bacteria. The study reports the whole genome sequence of Cobetia sp. D5 to understand its DMSP metabolism pathway. The genome of Cobetia sp. D5 consists of a circular chromosome with a length of 4,233,985 bp and the GC content is 62.56%. Genomic analysis showed that Cobetia sp. D5 contains a set of genes to transport and metabolize DMSP, which can cleave DMSP to produce dimethyl sulphide (DMS) and 3-Hydroxypropionyl-Coenzyme A (3-HP-CoA). DMS diffuses into the environment to enter the global sulfur cycle, whereas 3-HP-CoA is catabolized to acetyl CoA to enter central carbon metabolism. Thus, this study provides genetic insights into the DMSP metabolic processes of Cobetia sp. D5 during a marine algal bloom, and contributes to the understanding of the important role played by marine bacteria in the global sulfur cycle.

Marinobacter qingdaonensis sp. nov., a moderately halotolerant bacterium isolated from intertidal sediment.

A Gram-stain-negative, aerobic, rod-shaped and halotolerant bacterium, designated as strain ASW11-75T, was isolated from intertidal sediments in Qingdao, PR China, and identified using a polyphasic taxonomic approach. Growth of strain ASW11-75T occurred at 10-45 °C (optimum, 37 °C), pH 6.5-9.0 (optimum, pH 8.0) and 0.5-18.0 % NaCl concentrations (optimum, 2.5 %). Phylogenetic analyses based on 16S rRNA gene sequences and 1179 single-copy orthologous clusters indicated that strain ASW11-75T is affiliated with the genus Marinobacter. Strain ASW11-75T showed highest 16S rRNA gene sequence similarity to 'Marinobacter arenosus' CAU 1620T (98.5 %). The digital DNA-DNA hybridization and average nucleotide identity values between strain ASW11-75T and its closely related strains (Marinobacter salarius R9SW1T, Marinobacter similis A3d10T, 'Marinobacter arenosus' CAU 1620T, Marinobacter sediminum R65T, Marinobacter salinus Hb8T, Marinobacter alexandrii LZ-8T and Marinobacter nauticus ATCC 49840T) were 19.8-24.5 % and 76.6-80.7 %, respectively. The predominant cellular fatty acids were C16 : 0, C18 : 1 ω9c and C16 : 0 N alcohol. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminophospholipid and two unidentified lipids. The major isoprenoid quinone was ubiquinone-9. The genomic DNA G+C content was 62.2 mol%. Based on genomic and gene function analysis, strain ASW11-75T had lower protein isoelectric points with higher ratios of acidic residues to basic residues and possessed genes related to ion transport and organic osmoprotectant uptake, implying its potential tolerance to salt. The results of polyphasic characterization indicated strain ASW11-75T represents a novel Marinobacter species, for which the name Marinobacter qingdaonensis sp. nov. with the type strain ASW11-75T is proposed. The type strain is ASW11-75T (=KCTC 82497T=MCCC 1K05587T).

Alteromonas arenosi sp. nov., a novel bioflocculant-producing bacterium, isolated from intertidal sand.

A novel Gram-stain-negative, strictly aerobic and bioflocculant-producing bacterium, designated as ASW11-36T, was isolated from an intertidal sand collected from coastal areas of Qingdao, PR China. Growth occurred at 15-40 °C (optimum, 30 °C), pH 7.0-9.0 (optimum, pH 7.5) and with 1.5-7.0% (w/v) NaCl (optimum, 2.5-3.0%). In the whole-cell fatty acid pattern prevailed C16:0 and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). The major isoprenoid quinone was determined to be Q-8 and the major polar lipids were phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), one unidentified aminolipid (AL), one unidentified glycolipid (GL), and two lipids (L1, L2). Based on the phylogenetic analyses of 16S rRNA gene sequences and 618 single-copy orthologous clusters, strain ASW11-36T could represent a novel member of the genus Alteromonas and was closely related to Alteromonas flava P0211T (98.4%) and Alteromonas facilis P0213T (98.3%). The pairwise average nucleotide identity and digital DNA-DNA hybridization values of the ASW11-36T genome assembly against the closely related species genomes were 71.8% and 21.7%, respectively, that clearly lower than the proposed thresholds for species. Based on phenotypic, phylogenetic, and chemotaxonomic analyses, strain ASW11-36T is considered to represent a novel species of the genus Alteromonas, for which the name Alteromonas arenosi sp. nov. is proposed. The type strain is ASW11-36T (= KCTC 82496T = MCCC 1K05585T). In addition, the strain yielded 65% of flocculating efficiency in kaolin suspension with CaCl2 addition. The draft genome of ASW11-36T shared abundant putative CAZy family related genes, especially involved in the biosynthesis of exopolysaccharides, implying its potential environmental and biological applications.

Cost-effective production of alginate oligosaccharides from Laminaria japonica roots by Pseudoalteromonas agarivorans A3.

BACKGROUND: Alginate oligosaccharides (AOs) are the degradation products of alginate, a natural polysaccharide abundant in brown algae. AOs generated by enzymatic hydrolysis have diverse bioactivities and show broad application potentials. AOs production via enzymolysis is now generally with sodium alginate as the raw material, which is chemically extracted from brown algae. In contrast, AOs production by direct degradation of brown algae is more advantageous on account of its cost reduction and is more eco-friendly. However, there have been only a few attempts reported in AOs production from direct degradation of brown algae. RESULTS: In this study, an efficient Laminaria japonica-decomposing strain Pseudoalteromonas agarivorans A3 was screened. Based on the secretome and mass spectrum analyses, strain A3 showed the potential as a cell factory for AOs production by secreting alginate lyases to directly degrade L. japonica. By using the L. japonica roots, which are normally discarded in the food industry, as the raw material for both fermentation and enzymatic hydrolysis, AOs were produced by the fermentation broth supernatant of strain A3 after optimization of the alginate lyase production and hydrolysis parameters. The generated AOs mainly ranged from dimers to tetramers, among which trimers and tetramers were predominant. The degradation efficiency of the roots reached 54.58%, the AOs production was 33.11%, and the AOs purity was 85.03%. CONCLUSION: An efficient, cost-effective and green process for AOs production directly from the underutilized L. japonica roots by using strain A3 was set up, which differed from the reported processes in terms of the substrate and strain used for fermentation and the AOs composition. This study provides a promising platform for scalable production of AOs, which may have application potentials in industry and agriculture.

Correction: Deng et al. Distinct Roles of Ena ATP Family Proteins in Sodium Accumulation, Invasive Growth, and Full Virulence in Colletotrichum gloeosporioides. J. Fungi 2023, 9, 566.

In the original publication [...].

Structural and molecular basis for urea recognition by Prochlorococcus.

Nitrogen (N) is an essential element for microbial growth and metabolism. The growth and reproduction of microorganisms in more than 75% of areas of the ocean are limited by N. Prochlorococcus is numerically the most abundant photosynthetic organism on the planet. Urea is an important and efficient N source for Prochlorococcus. However, how Prochlorococcus recognizes and absorbs urea still remains unclear. Prochlorococcus marinus MIT 9313, a typical Cyanobacteria, contains an ABC-type transporter, UrtABCDE, which may account for the transport of urea. Here, we heterologously expressed and purified UrtA, the substrate-binding protein of UrtABCDE, detected its binding affinity toward urea, and further determined the crystal structure of the UrtA/urea complex. Molecular dynamics simulations indicated that UrtA can alternate between "open" and "closed" states for urea binding. Based on structural and biochemical analyses, the molecular mechanism for urea recognition and binding was proposed. When a urea molecule is bound, UrtA undergoes a state change from open to closed surrounding the urea molecule, and the urea molecule is further stabilized by the hydrogen bonds supported by the conserved residues around it. Moreover, bioinformatics analysis showed that ABC-type urea transporters are widespread in bacteria and probably share similar urea recognition and binding mechanisms as UrtA from P. marinus MIT 9313. Our study provides a better understanding of urea absorption and utilization in marine bacteria.

Genomic analysis of Marinomonas algicola SM1966T reveals its role in marine sulfur cycling.

Dimethylsulfoniopropionate (DMSP) is a ubiquitous organosulfur molecule in marine environments with important roles in global sulfur and nutrient cycling, which is mainly produced by marine phytoplankton and macroalgae. Marinomonas algicola SM1966T, a Gram-negative, aerobic and rod-shaped bacterium, was isolated from the surface of Ulva pertusa (Chlorophyta) algal sample collected off the coastal areas of Rongcheng, China. Here, we report the complete genome sequence of strain SM1966T and its genomic characteristics to utilize DMSP, which may be produced by Ulva pertusa. The genome of strain SM1966T contains one circular chromosome (4.3 Mbp) and one circular plasmid (149,271 bp). Genomic analysis showed that strain SM1966T possesses a set of genes involved in DMSP transport, DMSP cleavage and the catabolism of acrylate, one product of DMSP cleavage. The results indicated that strain SM1966T has the capacity to utilize DMSP and produce dimethyl sulfide (DMS), a volatile infochemical with important roles in global sulfur cycling. This study provides genetic insights into DMSP catabolism by algae-associated bacteria.

Distinct Roles of Ena ATP Family Proteins in Sodium Accumulation, Invasive Growth, and Full Virulence in Colletotrichum gloeosporioides.

Colletotrichum gloeosporioides, a significant fungal pathogen of crops and trees, causes large economic losses worldwide. However, its pathogenic mechanism remains totally unclear. In this study, four Ena ATPases (Exitus natru-type adenosine triphosphatases), homology of yeast Ena proteins, were identified in C. gloeosporioides. Gene deletion mutants of ΔCgena1, ΔCgena2, ΔCgena3, and ΔCgena4 were obtained through the method of gene replacement. First, a subcellular localization pattern indicated that CgEna1 and CgEna4 were localized in the plasma membrane, while the CgEna2 and CgEna3 were distributed in the endoparasitic reticulum. Next, it was found that CgEna1 and CgEna4 were required for sodium accumulation in C. gloeosporioides. CgEna3 was required for extracellular ion stress of sodium and potassium. CgEna1 and CgEna3 were involved in conidial germination, appressorium formation, invasive hyphal development, and full virulence. The mutant of ΔCgena4 was more sensitive to the conditions of high concentrations of ion and the alkaline. Together, these results indicated that CgEna ATPase proteins have distinct roles in sodium accumulation, stress resistance, and full virulence in C. gloeosporioides.

Development and Validation of Prognostic Nomograms Based on Lymph Node Ratio for Young Patients with Gastric Cancer: A SEER-Based Study.

PURPOSE: To investigate the role of lymph node ratio (LNR) in young patients with gastric cancer (GC) and develop nomograms to predict the survival of young GC patients. METHODS: This retrospective study enrolled stage I-III GC patients before the age of 40 between 2010 and 2016 from the Surveillance, Epidemiology, and End Results (SEER) database. Cox proportional hazards models were used to determine the prognosticators and create the nomograms incorporating LNR to predict overall survival (OS) and cancer-specific survival (CSS). The discriminating superiority of the nomograms was examined using calibration curves, C-index, receiver operating characteristic (ROC) curves, decision curve analysis (DCA), and integrated discrimination improvement (IDI) by comparing with the TNM staging. The performance of the nomograms for risk stratification was analyzed by the Kaplan-Meier method. RESULTS: Based on the significant prognosticators identified in multivariate survival analysis, the nomograms were established and showed LNR as the third strongest predictor. The C-index of the nomograms for OS and CSS were higher than those of the TNM staging (OS: 0.773 vs 0.665; CSS: 0.769 vs 0.666). The ROC curves for the nomograms to predict survival exhibited superior sensitivity and specificity when compared with the TNM staging. The calibration plots, DCA curves, and IDI values of the nomograms also demonstrated adequate fit and ideal net benefit in prediction and clinical utility. The Kaplan-Meier analysis observed remarkable differences in patients divided into different risk subgroups (P < .001). CONCLUSIONS: These results found the clinical outperformance of the LNR-based nomograms for predicting survival in young stage I-III GC patients. Our nomograms may improve accuracy of survival risk prediction and facilitate individualized care of young stage I-III GC patients.

Complete genome sequence of Bacillus cereus 2-6A, a marine exopolysaccharide-producing bacterium isolated from deep-sea hydrothermal sediment of the Pacific Ocean.

Bacillus cereus 2-6A, was isolated from the sediments in the hydrothermal area of the Pacific Ocean with a water depth of 2628 m. In this study, we report the whole genome sequence of strain 2-6A and analyze that to understand its metabolic capacities and biosynthesis potential of natural products. The genome of strain 2-6A consists of a circular chromosome of 5,191,018 bp with a GC content of 35.3 mol% and two plasmids of 234,719 bp and 411,441 bp, respectively. Genomic data mining reveals that strain 2-6A has several gene clusters involved in exopolysaccharides (EPSs) and polyhydroxyalkanoates (PHAs) production and complex polysaccharides degradation. It also possesses a variety of genes for allowing strain 2-6A to cope with osmotic stress, oxidative stress, heat shock, cold shock and heavy metal stress, which could play a vital role in the adaptability of the strain to hydrothermal environments. Gene clusters for secondary metabolite production, such as lasso peptide and siderophore, are also predicted. Therefore, genome sequencing and data mining provide insights into the molecular mechanisms of Bacillus in adapting to hydrothermal deep ocean environments and can facilitate further experimental exploration.

Divergent projections of the prelimbic cortex mediate autism- and anxiety-like behaviors.

The comorbidity of autism spectrum disorder and anxiety is common, but the underlying circuitry is poorly understood. Here, Tmem74-/- mice showed autism- and anxiety-like behaviors along with increased excitability of pyramidal neurons (PNs) in the prelimbic cortex (PL), which were reversed by Tmem74 re-expression and chemogenetic inhibition in PNs of the PL. To determine the underlying circuitry, we performed conditional deletion of Tmem74 in the PNs of PL of mice, and we found that alterations in the PL projections to fast-spiking interneurons (FSIs) in the dorsal striatum (dSTR) (PLPNs-dSTRFSIs) mediated the hyperexcitability of FSIs and autism-like behaviors and that alterations in the PL projections to the PNs of the basolateral amygdaloid nucleus (BLA) (PLPNs-BLAPNs) mediated the hyperexcitability of PNs and anxiety-like behaviors. However, the two populations of PNs in the PL had different spatial locations, optogenetic manipulations revealed that alterations in the activity in the PL-dSTR or PL-BLA circuits led to autism- or anxiety-like behaviors, respectively. Collectively, these findings highlight that the hyperactivity of the two populations of PNs in the PL mediates autism and anxiety comorbidity through the PL-dSTR and PL-BLA circuits, which may lead to the development of new therapeutics for the autism and anxiety comorbidity.

A real-time PCR for detection of pathogens of anthracnose on Chinese fir using TaqMan probe targeting ApMat gene.

BACKGROUND: Anthracnose is one of the most widespread and destructive diseases on Chinese fir. Colletotrichum cangyuanense, Colletotrichum fructicola, Colletotrichum gloeosporioides, and Colletotrichum siamense are the causal agents of anthracnose on Chinese fir. A rapid and accurate diagnosis of different pathogens is critical for the disease management. RESULTS: Phylogenetic tree and sequence similarity analysis showed that the single-locus ApMat provides superior phylogenetic information and is an appropriate target to distinguish C. cangyuanense, C. fructicola, C. gloeosporioides, and C. siamense. The real-time PCR assays with the primer sets of MQ-F/R, 1#C-F/R, YK-F/R, and WZ-F/R, and corresponding TaqMan probes of MQ-P, 1#C-P, YK-P, and WZ-P were specific for C. cangyuanense, C. fructicola, C. gloeosporioides, and C. siamense, respectively. The sensitivity tests showed that the lowest amount of gDNA that the PCRs can detect was 1 ng of genomic DNA. The validity of the assays was confirmed by directly detecting the pathogens from both the fungal culture and infected Chinese fir. CONCLUSION: These results demonstrated the potential of the TaqMan real-time PCR targeting the ApMat gene to provide rapid, specific, and reliable molecular detection of C. fructicola, C. gloeosporioides, C. siamense, and C. cangyuanense, respectively. The data also provided a reference solution for the identification of species within Colletotrichum gloeosporioides species complex (CGSC), which share similar morphological characteristics. © 2022 Society of Chemical Industry.

Characterization of a Novel Alginate Lyase with Two Alginate Lyase Domains from the Marine Bacterium Vibrio sp. C42.

Alginate is abundant in the cell walls of brown algae. Alginate lyases can degrade alginate, and thus play an important role in the marine carbon cycle and industrial production. Currently, most reported alginate lyases contain only one functional alginate lyase domain. AlyC8 is a putative alginate lyase with two alginate lyase domains (CD1 and CD2) from the marine alginate-degrading strain Vibrio sp. C42. To characterize AlyC8 and its two catalytic domains, AlyC8 and its two catalytic domain-deleted mutants, AlyC8-CD1 and AlyC8-CD2, were expressed in Escherichia coli. All three proteins have noticeable activity toward sodium alginate and exhibit optimal activities at pH 8.0-9.0 and at 30-40 °C, demonstrating that both CD1 and CD2 are functional. However, CD1 and CD2 showed opposite substrate specificity. The differences in substrate specificity and degradation products of alginate between the mutants and AlyC8 demonstrate that CD1 and CD2 can act synergistically to enable AlyC8 to degrade various alginate substrates into smaller oligomeric products. Moreover, kinetic analysis indicated that AlyC8-CD1 plays a major role in the degradation of alginate by AlyC8. These results demonstrate that AlyC8 is a novel alginate lyase with two functional catalytic domains that are synergistic in alginate degradation, which is helpful for a better understanding of alginate lyases and alginate degradation.

Antibacterial activity of peptaibols from Trichoderma longibrachiatum SMF2 against gram-negative Xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight on rice.

Bacterial leaf blight caused by Gram-negative pathogen Xanthomonas oryzae pv. oryzae (Xoo) is one of the most destructive bacterial diseases on rice. Due to the resistance, toxicity and environmental issues of chemical bactericides, new biological strategies are still in need. Although peptaibols produced by Trichoderma spp. can inhibit the growth of several Gram-positive bacteria and plant fungal pathogens, it still remains unclear whether peptaibols have anti-Xoo activity to control bacterial leaf blight on rice. In this study, we evaluated the antibacterial effects of Trichokonins A (TKA), peptaibols produced by Trichoderma longibrachiatum SMF2, against Xoo. The in vitro antibacterial activity analysis showed that the growth of Xoo was significantly inhibited by TKA, with a minimum inhibitory concentration of 54 µg/mL and that the three TKs in TKA all had remarkable anti-Xoo activity. Further inhibitory mechanism analyses revealed that TKA treatments resulted in the damage of Xoo cell morphology and the release of intracellular substances, such as proteins and nucleic acids, from Xoo cells, suggesting the damage of the permeability of Xoo cell membrane by TKA. Pathogenicity analyses showed that the lesion length on rice leaf was significantly reduced by 82.2% when treated with 27 µg/mL TKA. This study represents the first report of the antibacterial activity of peptaibols against a Gram-negative bacterium. Thus, TKA can be of a promising agent in controlling bacterial leaf blight on rice.

Structural determination of the lipid A from the deep-sea bacterium Zunongwangia profunda SM-A87: a small-scale approach.

Zunongwangia profunda SM-A87 is a deep-sea sedimentary bacterium from the phylum Bacteroidetes, representing a new genus of Flavobacteriaceae. It was previously investigated for its capability of yielding high quantities of capsular polysaccharides (CPS) with interesting rheological properties, including high viscosity and tolerance to high salinities and temperatures. However, as a Gram-negative, Z. profunda SM-A87 also expresses lipopolysaccharides (LPS) as the main components of the external leaflet of its outer membrane. Here, we describe the isolation and characterization of the glycolipid part of this LPS, i.e. the lipid A, which was achieved by-passing the extraction procedure of the full LPS and by working on the ethanol precipitation product, which contained both the CPS fraction and bacterial cells. To this aim a dual approach was adopted and all analyses confirmed the isolation of Z. profunda SM-A87 lipid A that turned out to be a blend of species with high levels of heterogeneity both in the acylation and phosphorylation pattern, as well as in the hydrophilic backbone composition. Mono-phosphorylated tetra- and penta-acylated lipid A species were identified and characterized by a high content of branched, odd-numbered, and unsaturated fatty acid chains as well as, for some species, by the presence of a hybrid disaccharide backbone.

Genomic analysis of Thalassospira sp. SW-3-3 reveals its genetic potential for phthalate pollution remediation.

Thalassospira sp. SW-3-3 is a bacterial strain isolated from deep seawater of the Pacific Ocean at a water depth of 3112 m. It is a Gram-negative, aerobic, and curved rod-shaped bacterium belonging to the family Thalassospiraceae. In this study, we report the complete genome sequence of strain SW-3-3. It has a circular chromosome with a size of 4,764,478 bp and a G + C content of 54.7%. The genome contains 4296 protein-coding genes, 63 tRNA genes, and 12 rRNA genes. Genomic analysis shows that strain SW-3-3 contains genes and catalytic pathways relevant to phthalate metabolism. Phthalates are well-known emerging contaminants that are harmful to environments and human health. They are chemically stable compounds that are widely used in plastic products and are pervasive in our life. With the discharge of plastic pollutants, a huge number of phthalate compounds enter the ocean. The genetic information of strain SW-3-3 suggests that it has the potential to metabolize phthalates. There are 9 key enzymes in the metabolization pathway, and phthalates are finally catalyzed to produce succinyl-CoA which is further degraded through the tricarboxylic acid (TCA) cycle pathway. This genomic analysis will be helpful for further understanding of the applications of strain SW-3-3 in the remediation of phthalate pollution.

Maternal inheritance of glucose intolerance via oocyte TET3 insufficiency.

Diabetes mellitus is prevalent among women of reproductive age, and many women are left undiagnosed or untreated1. Gestational diabetes has profound and enduring effects on the long-term health of the offspring2,3. However, the link between pregestational diabetes and disease risk into adulthood in the next generation has not been sufficiently investigated. Here we show that pregestational hyperglycaemia renders the offspring more vulnerable to glucose intolerance. The expression of TET3 dioxygenase, responsible for 5-methylcytosine oxidation and DNA demethylation in the zygote4, is reduced in oocytes from a mouse model of hyperglycaemia (HG mice) and humans with diabetes. Insufficient demethylation by oocyte TET3 contributes to hypermethylation at the paternal alleles of several insulin secretion genes, including the glucokinase gene (Gck), that persists from zygote to adult, promoting impaired glucose homeostasis largely owing to the defect in glucose-stimulated insulin secretion. Consistent with these findings, mouse progenies derived from the oocytes of maternal heterozygous and homozygous Tet3 deletion display glucose intolerance and epigenetic abnormalities similar to those from the oocytes of HG mice. Moreover, the expression of exogenous Tet3 mRNA in oocytes from HG mice ameliorates the maternal effect in offspring. Thus, our observations suggest an environment-sensitive window in oocyte development that confers predisposition to glucose intolerance in the next generation through TET3 insufficiency rather than through a direct perturbation of the oocyte epigenome. This finding suggests a potential benefit of pre-conception interventions in mothers to protect the health of offspring.

Molecular cytogenetic characterization of 2q deletion and Xq duplication associated with nasal bone dysplasia in prenatal diagnosis: A case report and literature review.

OBJECTIVE: We report a prenatal case of male fetus with a 2q13 deletion and an Xq27.3q28 duplication, presenting nasal bone dysplasia by ultrasound examination. And we compare the similarities of clinical features of cases consisting of similar 2q deletion and Xq duplication. CASE REPORT: A 30-year-old woman was referred for prenatal diagnosis and genetic counseling at 24 weeks of gestation. Prenatal ultrasound showed nasal bone dysplasia of the fetus. Amniocentesis revealed the karyotype of the fetus as 46, XY and the results of chromosomal microarray analysis was arr[GRCh37] 2q13(110467258-111370025)x1, arr[GRCh37]Xq27.3q28(144050780-149748782)x2. The parents both have normal karyotypes. The couple chose to continue the pregnancy and finally delivered a male infant at 39 weeks of gestation. His weight was 2850 g and length was 50 cm. Physical examination of the newborn revealed no apparent anomalies. Until the boy was one year old, there was no abnormalities in his growth and development. The long-term follow-up till adulthood for the healthy infant is necessary. CONCLUSION: The development of CMA plays a critical role in prenatal diagnosis and genetic counseling for unidentified chromosomal anomalies. More clinical information and further studies of patients with these anomalies will identify the pathogenicity of the involving genes and improve the understanding of the phenotype-genotype correlation.

A Novel Gelatinase from Marine Flocculibacter collagenilyticus SM1988: Characterization and Potential Application in Collagen Oligopeptide-Rich Hydrolysate Preparation.

Although the S8 family in the MEROPS database contains many peptidases, only a few S8 peptidases have been applied in the preparation of bioactive oligopeptides. Bovine bone collagen is a good source for preparing collagen oligopeptides, but has been so far rarely applied in collagen peptide preparation. Here, we characterized a novel S8 gelatinase, Aa2_1884, from marine bacterium Flocculibacter collagenilyticus SM1988T, and evaluated its potential application in the preparation of collagen oligopeptides from bovine bone collagen. Aa2_1884 is a multimodular S8 peptidase with a distinct domain architecture from other reported peptidases. The recombinant Aa2_1884 over-expressed in Escherichia coli showed high activity toward gelatin and denatured collagens, but no activity toward natural collagens, indicating that Aa2_1884 is a gelatinase. To evaluate the potential of Aa2_1884 in the preparation of collagen oligopeptides from bovine bone collagen, three enzymatic hydrolysis parameters, hydrolysis temperature, hydrolysis time and enzyme-substrate ratio (E/S), were optimized by single factor experiments, and the optimal hydrolysis conditions were determined to be reaction at 60 ℃ for 3 h with an E/S of 400 U/g. Under these conditions, the hydrolysis efficiency of bovine bone collagen by Aa2_1884 reached 95.3%. The resultant hydrolysate contained 97.8% peptides, in which peptides with a molecular weight lower than 1000 Da and 500 Da accounted for 55.1% and 39.5%, respectively, indicating that the hydrolysate was rich in oligopeptides. These results indicate that Aa2_1884 likely has a promising potential application in the preparation of collagen oligopeptide-rich hydrolysate from bovine bone collagen, which may provide a feasible way for the high-value utilization of bovine bone collagen.