Analysis of the population structure and genetic diversity of the red swamp crayfish (Procambarus clarkii) in China using SSR markers

BACKGROUND: Procambarus clarkii produces high-quality, delicious meat that is high in protein, low in fat, and rich in calcium and phosphorus. It has become an important aquatic resource in China. Our objectives are (i) to analyze the level of genetic diversity of P. clarkii populations; (ii) to explore the genetic differentiation (Gst); and (iii) to propose appropriate strategies for the conservation. RESULTS: In this study, Shannon's index (I) and Nei's gene diversity index (H) for P. clarkii were high (I = 0.3462 and H = 0.2325 on average and I = 0.6264, H = 0.4377 at the species level) based on the SSR markers. The expected heterozygosity value of 17 microsatellite loci in 25 crayfish populations was 0.9317, the observed heterozygosity value was 0.9121, and the observed number of alleles per locus was 2.000; and the effective number of alleles per locus was 1.8075. Among the P. clarkii populations, the inbreeding coefficient within populations (Fis) was 0.2315, overall inbreeding coefficient (Fit) was 0.4438, genetic differentiation coefficient among populations (Fst) was 0.3145 and gene differentiation (Gst) was 0.4785 based on SSR analyses. The cluster analysis results obtained by unweighted pair-group method with arithmetic mean (UPGMA) analysis, principal coordinate analysis (PCoA) and STRUCTURE analysis were similar. A mantel test showed that the isolation-by-distance pattern was not significant. CONCLUSIONS: The high Gst among P. clarkii populations is attributed to genetic drift and geographic isolation. The results indicated that more P. clarkii populations should be collected when formulating conservation and aquaculture strategies.

Hydrogen sulfide alleviates chlorobenzene toxicity in soybean seedlings / Sulfeto de hidrogênio e clorobenzeno na toxicidade da soja

As a gas signaling molecule, endogenous hydrogen sulfide (H2S) plays a crucial role in the plant stress response. However, the role of H2S in the response to organic pollutants specifically has not been studied. Here, the effects of H2S addition on soybean (Glycine max) seedlings tolerance of 1,4-dichlorobenzene (1,4-DCB) were investigated. Under 1,4-DCB stress, the growth of soybean seedlings roots and stems was inhibited, while L-/D-cysteine desulfhydrase (LCD/DCD) activity was induced and endogenous H2S increased. When applied jointly with sodium hydrosulfide (NaHS), a H2S donor, root growth inhibition was effectively alleviated. Pre-treatment of seedlings with 0.4mmol L-1 NaHS reduced the malondialdehyde (MDA) and reactived oxygen species (ROS) content, mitigating root cell toxicity significantly. Further experiments confirmed that NaHS enhanced soybean seedlings peroxidase (POD) and superoxide dismutase (SOD) enzyme activities. In contrast, these effects were reversed by hypotaurine (HT), a H2S scavenger. Therefore, H2S alleviated 1,4-DCB toxicity in soybean seedlings by regulating antioxidant enzyme activity to reduce cell oxidative damage.(AU)

Tal como uma molécula de sinal de gás, sulfureto de hidrogenio endógena (H2S) desempenha um papel crucial na resposta ao stress das plantas. Mas não foi relatado o papel de H2S em plantas poluentes orgânicos stress. Este estudo sobre a variação de H2S envolvido em plântulas de soja tolerância 1,4-Diclorobenzeno foi investigada. Os resultados mostraram sob o 1,4-diclorobenzeno stress, que o crescimento da soja (Glycine max) de raiz de mudas e caule foram inibidas, L- / D-cisteína desulfhydrase (LCD / DCD) atividades enzimáticas foram empossados, em seguida, H2S endógeno aumentado. Quando aplicado com hidrossulfureto de sódio (NaSH), um doador de H2S, raiz de plântulas de soja, a inibição do crescimento pode ser melhorada. Tratamentos prévios com 0,4mmol L-1 NaHS, malondialdeído (MDA) e espécies de oxigênio reactivas conteúdo (ROS) foi reduzida, em seguida, a toxicidade celular da raiz foi reduzida significativamente. Outros experimentos confirmaram que NaSH melhorou a peroxidase de plântulas de soja (POD), superóxido dismutase (SOD) atividades enzimáticas. Em contraste, estes efeitos foram revertidos por hypotaurine (HT), um eliminador de H2S. Então H2S pode aliviar toxicidade 1,4-diclorobenzeno em plântulas de soja por meio da regulamentação das atividades de enzimas antioxidantes para manter a integridade da estrutura celular.(AU)

Hydrogen sulfide alleviates chlorobenzene toxicity in soybean seedlings / Sulfeto de hidrogênio e clorobenzeno na toxicidade da soja

ABSTRACT: As a gas signaling molecule, endogenous hydrogen sulfide (H2S) plays a crucial role in the plant stress response. However, the role of H2S in the response to organic pollutants specifically has not been studied. Here, the effects of H2S addition on soybean (Glycine max) seedlings tolerance of 1,4-dichlorobenzene (1,4-DCB) were investigated. Under 1,4-DCB stress, the growth of soybean seedlings roots and stems was inhibited, while L-/D-cysteine desulfhydrase (LCD/DCD) activity was induced and endogenous H2S increased. When applied jointly with sodium hydrosulfide (NaHS), a H2S donor, root growth inhibition was effectively alleviated. Pre-treatment of seedlings with 0.4mmol L-1 NaHS reduced the malondialdehyde (MDA) and reactived oxygen species (ROS) content, mitigating root cell toxicity significantly. Further experiments confirmed that NaHS enhanced soybean seedlings peroxidase (POD) and superoxide dismutase (SOD) enzyme activities. In contrast, these effects were reversed by hypotaurine (HT), a H2S scavenger. Therefore, H2S alleviated 1,4-DCB toxicity in soybean seedlings by regulating antioxidant enzyme activity to reduce cell oxidative damage.

RESUMO: Tal como uma molécula de sinal de gás, sulfureto de hidrogenio endógena (H2S) desempenha um papel crucial na resposta ao stress das plantas. Mas não foi relatado o papel de H2S em plantas poluentes orgânicos stress. Este estudo sobre a variação de H2S envolvido em plântulas de soja tolerância 1,4-Diclorobenzeno foi investigada. Os resultados mostraram sob o 1,4-diclorobenzeno stress, que o crescimento da soja (Glycine max) de raiz de mudas e caule foram inibidas, L- / D-cisteína desulfhydrase (LCD / DCD) atividades enzimáticas foram empossados, em seguida, H2S endógeno aumentado. Quando aplicado com hidrossulfureto de sódio (NaSH), um doador de H2S, raiz de plântulas de soja, a inibição do crescimento pode ser melhorada. Tratamentos prévios com 0,4mmol L-1 NaHS, malondialdeído (MDA) e espécies de oxigênio reactivas conteúdo (ROS) foi reduzida, em seguida, a toxicidade celular da raiz foi reduzida significativamente. Outros experimentos confirmaram que NaSH melhorou a peroxidase de plântulas de soja (POD), superóxido dismutase (SOD) atividades enzimáticas. Em contraste, estes efeitos foram revertidos por hypotaurine (HT), um eliminador de H2S. Então H2S pode aliviar toxicidade 1,4-diclorobenzeno em plântulas de soja por meio da regulamentação das atividades de enzimas antioxidantes para manter a integridade da estrutura celular.

Design of signal peptide bombyxin and its effect on secretory expression efficiency and levels of Helicobacter pylori urease subunit B in silkworm cells and larvae

This study employed a Bac-to-Bac/Bombyx mori bioreactor to mass-produce immunogenic urease subunit B (UreB) from Helicobacter pylori. The signal peptide bombyxin from B. mori was used to promote secretory expression to improve expression levels and was designed and integrated into the UreB gene to generate the Bacmid/BmNPV/(signal peptide)-UreB baculovirus expression system. To determine whether the bombyxin signal peptide resulted in secretory expression of recombinant UreB (rUreB) and to determine the secretory efficiency, we tested the secretory expression level of rUreB in Bm5 cells using ELISA. To further investigate whether secretory expression affected cell viability, cells were evaluated using 0.4% trypan blue staining, and Bacmid/BmNPV/UreB without the signal peptide served as a control. The above recombinant bacmid constructs were injected to silkworm larvae, and the secretory expression level of rUreB was detected using SDS-PAGE and semi-quantitative western blot analysis. The results indicated that the bombyxin signal peptide directed the secretory expression of rUreB and that this expression improved the viability of Bm5 cells. Moreover, the results showed that the expression level of rUreB was 1.5 times higher with the Bacmid/BmNPV constructs containing the bombyxin signal sequence than those without the signal sequence. These results demonstrate that secretory expression can enhance rUreB expression levels and is likely to aid in the large-scale expression and yield of rUreB in silkworm larvae.

Image registration algorithm using Mexican hat function-based operator and grouped feature matching strategy.

Feature detection and matching are crucial for robust and reliable image registration. Although many methods have been developed, they commonly focus on only one class of image features. The methods that combine two or more classes of features are still novel and significant. In this work, methods for feature detection and matching are proposed. A Mexican hat function-based operator is used for image feature detection, including the local area detection and the feature point detection. For the local area detection, we use the Mexican hat operator for image filtering, and then the zero-crossing points are extracted and merged into the area borders. For the feature point detection, the Mexican hat operator is performed in scale space to get the key points. After the feature detection, an image registration is achieved by using the two classes of image features. The feature points are grouped according to a standardized region that contains correspondence to the local area, precise registration is achieved eventually by the grouped points. An image transformation matrix is estimated by the feature points in a region and then the best one is chosen through competition of a set of the transformation matrices. This strategy has been named the Grouped Sample Consensus (GCS). The GCS has also ability for removing the outliers effectively. The experimental results show that the proposed algorithm has high registration accuracy and small computational volume.

26-Nor-25-isopropyl-ergosta-5,7,22E-trien-3beta-ol: a new C(29) sterol from the sponge Agelas sceptrum from Jamaica.

In addition to several known sterols, a new C(29) marine sterol with a normal ergosterol nucleus but a modified side chain, named 26-nor-25-isopropyl-ergosta-5,7,22E-trien-3beta-ol, was isolated from the Jamaican sponge Agelas sceptrum. The structures were assigned by spectroscopic methods including high-resolution 2D NMR techniques.

New antiinfective and human 5-HT2 receptor binding natural and semisynthetic compounds from the Jamaican sponge Smenospongia aurea.

In addition to the sesquiterpene-phenol aureols (1), 6'-chloroaureol (2), and aureol acetate (3), eight indole alkaloids including the new N-3'-ethylaplysinopsin (9) have been isolated from the Jamaican sponge Smenospongia aurea. Makaluvamine O (10), a new member of the pyrroloiminoquinone class, was also isolated. The structures were characterized by spectroscopic methods, and two new derivatives of aureol were prepared to optimize the biological activity. Aureol N,N-dimethyl thiocarbamate (1a) and 6-bromoaplysinopsin (7) exhibit significant antimalarial and antimycobacterial activity in vitro. Compound 6 showed activity against the Plasmodium enzyme plasmepsin II. The 6-bromo-2'-de-N-methylaplysinopsin (6), 6-bromoaplysinopsin (7), and N-3'-ethylaplysinopsin (9) displaced high-affinity [(3)H]antagonist ligands from cloned human serotonin 5-HT(2) receptor subtypes, whereas the other compounds tested did not. Remarkably, the 6-bromo-2'-de-N-methylaplysinopsin (6) showed a > 40-fold selectivity for the 5-HT(2C) subtype over the 5-HT(2A) subtype.