The efficacy of DNA barcoding in the classification,genetic differentiation,and biodiversity assessment of benthic macroinvertebrates

Macroinvertebrates have been recognized as key ecological indicators of aquatic environment and are the most commonly used approaches for water quality assessment. However, species identification of macroinvertebrates (especially of aquatic insects) proves to be very difficult due to the lack of taxonomic expertise in some regions and can become time‐consuming. In this study, we evaluated the feasibility of DNA barcoding for the classification of benthic macroinvertebrates and investigated the genetic differentiation in seven orders (Insecta: Ephemeroptera, Plecoptera, Trichoptera, Diptera, Hemiptera, Coleoptera, and Odonata) from four large transboundary rivers of northwest China and further explored its potential application to biodiversity assessment. A total of 1,144 COI sequences, belonging to 176 species, 112 genera, and 53 families were obtained and analyzed. The barcoding gap analysis showed that COI gene fragment yielded significant intra‐ and interspecific divergences and obvious barcoding gaps. NJ phylogenetic trees showed that all species group into monophyletic species clusters whether from the same population or not, except two species (Polypedilum. laetum and Polypedilum. bullum). The distance‐based (ABGD) and tree‐based (PTP and MPTP) methods were utilized for grouping specimens into Operational Taxonomic Units (OTUs) and delimiting species. The ABGD, PTP, and MPTP analysis were divided into 177 (p = .0599), 197, and 195 OTUs, respectively. The BIN analysis generated 186 different BINs. Overall, our study showed that DNA barcoding offers an effective framework for macroinvertebrate species identification and sheds new light on the biodiversity assessment of local macroinvertebrates. Also, the construction of DNA barcode reference library of benthic macroinvertebrates in Eurasian transboundary rivers provides a solid backup for bioassessment studies of freshwater habitats using modern high‐throughput technologies in the near future.     

环境中胞内胞外抗性基因的分离检测、分布与传播

抗生素抗性基因(ARGs)传播对人类健康具有潜在的风险。胞内抗性基因(iARGs)和胞外抗性基因(eARGs)是抗生素抗性基因的两种存在形式,其在不同环境介质中的分布与传播过程具有截然不同的特征。本文首先基于ARGs赋存形态的差异,对染色体抗性基因、质粒抗性基因、噬菌体抗性基因等ARGs的胞内/胞外分类给予明确界定,并根据环境样品来源归纳了现有分离检测技术的应用场景,总结了iARGs和eARGs在养殖场、污水处理厂、河道、海洋、大气等环境中的分布特征,同时比较了其在传播方式和传播能力上的差异,以期为ARGs的分类阻控和健康风险评估提供理论参考。     

Comparative transcriptome analysis reveals the regulation network for fiber strength in cotton

Biotechnology Letters - Determine the effect of secondary cell wall (SCW) thickness and microcrystalline cellulose content (MCC) on mature fiber strength (FS) and reveal through comparative...     

Genetic variation and population structure of oriental migratory locust, Locusta migratoria manilensis, in China by allozyme, SSRP-PCR, and AFLP markers

Allozyme analysis, microsatellite primer PCR (SSRP-PCR), and amplified fragment length polymorphism (AFLP) techniques were used to assess genetic diversity and population structure of the Chinese oriental migratory locust, Locusta migratoria manilensis. A total of 299 PCR markers (67 SSRPs and 232 AFLPs) were detected in eight populations, of which 98.7% were polymorphic markers. The proportion of polymorphic loci (95.5-98.8%) by SSRP+AFLP markers indicated no significant differences between populations, and all populations exhibited a similar level of variability; results of the allozyme analysis demonstrated that 19 loci gave rise to a lower level of polymorphism (55.6-66.7%). The genetic distances between the populations were relatively low. Shannon's index and Nei's gene diversity showed low differentiation among the populations. Allozyme analysis, however, reflected greater similarity and smaller differentiation between the populations than those shown by SSRP and AFLP markers. Neighbor-joining dendrograms derived from both the allozyme and SSRP+AFLP markers showed that the genetic distances among Chinese oriental migratory locust populations were not greatly influenced by geographic distance and breeding habitats.     

Recent progression and future perspectives in cotton genomic breeding

Upland cotton is an important global cash crop for its long seed fibers and high edible oil and protein content.Progress in cotton genomics promotes the advancement of cotton genetics,evolutionary studies,functional genetics,and breeding,and has ushered cotton research and breeding into a new era.Here,we summarize high-impact genomics studies for cotton from the last 10 years.The diploid Gossypium arboreum and allotetraploid Gossypium hirsutum are the main focus of most genetic and genomic studi...     

Four Endoplasmic Reticulum Resident Selenoproteins May Be Related to the Protection of Selenium Against Cadmium Toxicity in Chicken Lymphocytes

Cadmium could induce the damage of endoplasmic reticulum. In the present study, we investigated the effect of Cadmium on messenger RNA expressions of endoplasmic reticulum resident selenoproteins, selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T, in cultured chicken lymphocytes and the antagonistic effect of Selenium. Chicken splenic lymphocytes were treated with 10^?7 mol/L Selenium, 10^?6 mol/L Cadmium, and the mixture of 10^?6 mol/L Selenium and 10^?7 mol/L Cadmium in the culture medium for 12, 24, 36, and 48 h, respectively. Then, we detected the messenger RNA expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T by using real-time polymerase chain reaction method. The results indicated that Selenium significantly increased the expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T, which were reduced by Cadmium in chicken splenic lymphocytes. It indicated that endoplasmic reticulum was one target of Cadmium toxication, and Cadmium toxicity might be related to the reduced expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T in chicken lymphocytes. Selenium reserved the protective role by increasing the expressions of selenoprotein K, selenoprotein N, selenoprotein S, and selenoprotein T. The present study provided a useful clue to investigate the possible pathogenesis of Cadmium toxicity.     

TNF-α Mediated Increase of HIF-1α Inhibits VASP Expression,Which Reduces Alveolar-Capillary Barrier Function during Acute Lung Injury (ALI)

Acute lung injury (ALI) is an inflammatory disorder associated with reduced alveolar-capillary barrier function and increased pulmonary vascular permeability. Vasodilator-stimulated phosphoprotein (VASP) is widely associated with all types of modulations of cytoskeleton rearrangement-dependent cellular morphology and function, such as adhesion, shrinkage, and permeability. The present studies were conducted to investigate the effects and mechanisms by which tumor necrosis factor-alpha (TNF-α) increases the tight junction permeability in lung tissue associated with acute lung inflammation. After incubating A549 cells for 24 hours with different concentrations (0–100 ng/mL) of TNF-α, 0.1 to 8 ng/mL TNF-α exhibited no significant effect on cell viability compared with the 0 ng/mL TNF-α group (control group). However, 10 ng/mL and 100 ng/mL TNF-α dramatically inhibited the viability of A549 cells compared with the control group (*p<0.05). Monolayer cell permeability assay results indicated that A549 cells incubated with 10 ng/mL TNF-α for 24 hours displayed significantly increased cell permeability (*p<0.05). Moreover, the inhibition of VASP expression increased the cell permeability (*p<0.05). Pretreating A549 cells with cobalt chloride (to mimic a hypoxia environment) increased protein expression level of hypoxia inducible factor-1α (HIF-1α) (*p<0.05), whereas protein expression level of VASP decreased significantly (*p<0.05). In LPS-induced ALI mice, the concentrations of TNF-α in lung tissues and serum significantly increased at one hour, and the value reached a peak at four hours. Moreover, the Evans Blue absorption value of the mouse lung tissues reached a peak at four hours. The HIF-1α protein expression level in mouse lung tissues increased significantly at four hours and eight hours (**p<0.001), whereas the VASP protein expression level decreased significantly (**p<0.01). Taken together, our data demonstrate that HIF-1α acts downstream of TNF-α to inhibit VASP expression and to modulate the acute pulmonary inflammation process, and these molecules play an important role in the impairment of the alveolar-capillary barrier.