Sensitivity of soil organic matter to climate and fire in a desert grassland

Biogeochemistry - Drylands contain a third of the organic carbon stored in global soils; however, the long-term dynamics of soil organic carbon in drylands remain poorly understood relative to...     

Length–weight relationships of seven fish species in the Yangtze River Estuary and its adjacent waters,Eastern China

The length–weight relationships (LWRs) for seven fish species belonging to five families in the Yangtze River Estuary and its adjacent waters are presented. Cynoglossus gracilis, Cynoglossus macrolepidotus, Ctenotrypauchen chinensis, Collichthys niveatus, Ophichthus apicalis and Erisphex potti were collected monthly in 2009 using trammel nets (the size of smaller mesh net was 1.5 m × 15 m × 4 panels with mesh sizes of 2.5, 3.4, 4.3 and 5.8 cm; the size of larger-mesh net was 2.4 m × 30 m × 4 panels with mesh sizes of 5.0, 6.0, 7.0 and 8.0 cm; soaking overnight). Lophiogobius ocellicauda were collected December in 2020 using shrimp trawl nets (mesh size 2.0 cm). The precision of measurement for the fish specimens is 0.1 cm total length and 0.1 g total weight. The estimated ranges of the parameters a and b for the seven fish species were from 0.0001 to 0.0289 and 2.718 to 3.541, respectively. Two new maximum total length were recorded for Ctenotrypauchen chinensis and Ophichthus apicalis.     

The involvement of bioactive factors in the self-renewal and stemness maintenance of spermatogonial stem cells

Molecular and Cellular Biochemistry - Spermatogenesis is usually accompanied throughout mammalian lifetime, transmitting genetic information to the next generation, which is mainly dependent on the...     

The role of exosomal microRNAs in central nervous system diseases

Molecular and Cellular Biochemistry - MicroRNAs (miRNA), endogenous non-coding RNAs approximately 22 nucleotides long, regulate gene expression by mediating translational inhibition or mRNA...     

Revisiting the phosphotyrosine binding pocket of Fyn SH2 domain led to the identification of novel SH2 superbinders.

Protein engineering through directed evolution is an effective way to obtain proteins with novel functions with the potential applications as tools for diagnosis or therapeutics. Many natural proteins have undergone directed evolution in vitro in the test tubes in the laboratories worldwide, resulting in the numerous protein variants with novel or enhanced functions. we constructed here an SH2 variant library by randomizing 8 variable residues in its phosphotyrosine (pTyr) binding pocket. Selection of this library by a pTyr peptide led to the identification of SH2 variants with enhanced affinities measured by EC50. Fluorescent polarization was then applied to quantify the binding affinities of the newly identified SH2 variants. As a result, three SH2 variants, named V3, V13 and V24, have comparable binding affinities with the previously identified SH2 triple‐mutant superbinder. Biolayer Interferometry assay was employed to disclose the kinetics of the binding of these SH2 superbinders to the phosphotyrosine peptide. The results indicated that all the SH2 superbinders have two‐orders increase of the dissociation rate when binding the pTyr peptide while there was no significant change in their associate rates. Intriguingly, though binding the pTyr peptide with comparable affinity with other SH2 superbinders, the V3 does not bind to the sTyr peptide. However, variant V13 and V24 have cross‐reactivity with both pTyr and sTyr peptides. The newly identified superbinders could be utilized as tools for the identification of pTyr‐containing proteins from tissues under different physiological or pathophysiological conditions and may have the potential in the therapeutics.     

History of safe exposure and bioinformatic assessment of phosphomannose-isomerase (PMI) for allergenic risk

Newly expressed proteins in genetically engineered crops are evaluated for potential cross reactivity to known allergens as part of their safety assessment. This assessment uses a weight-of-evidence approach. Two key components of this allergenicity assessment include any history of safe human exposure to the protein and/or the source organism from which it was originally derived, and bioinformatic analysis identifying amino acid sequence relatedness to known allergens. Phosphomannose-isomerase (PMI) has been expressed in commercialized genetically engineered (GE) crops as a selectable marker since 2010 with no known reports of allergy, which supports a history of safe exposure, and GE events expressing the PMI protein have been approved globally based on expert safety analysis. Bioinformatic analyses identified an eight-amino-acid contiguous match between PMI and a frog parvalbumin allergen (CAC83047.1). While short amino acid matches have been shown to be a poor predictor of allergen cross reactivity, most regulatory bodies require such matches be assessed in support of the allergenicity risk assessment. Here, this match is shown to be of negligible risk of conferring cross reactivity with known allergens.

     

自然保护地生态承载力时空分异研究——以大连金石滩为例

监测自然保护地生态承载力,对了解其时空分异规律及可持续发展有着重要意义。金石滩地质遗迹保护区是国家公园和风景名胜区的结合区域,是生态保护与地区发展间矛盾冲突所在之处,是多身份自然保护地的典型代表区域。以1998、2003、2007、2012、2015、2018年遥感影像和土地利用数据为基础,选取金石滩这个兼具保护与开发多种功能的自然保护地为研究区域,从弹性生态支撑系统、资源环境供容系统、社会经济协调系统3方面构建指标体系,运用模糊综合评价模型研究金石滩生态承载力的时空分异规律。结果表明：（1）在3个准则层中,弹性生态支撑力和资源环境供容力呈现出持续降低的剧烈下降趋势,社会经济协调力呈现先降后升、之后平稳发展的趋势。（2）金石滩生态承载力整体来看从强承载力演变为较弱承载力,1998-2018年自0.7572变为0.2940,近30年来承载力等级降低。（3）海陆生态承载力完全不同,陆地为强、较强承载力,海岸为弱、较弱承载力,自北部陆地向南部海岸逐渐减弱呈现极其不平衡的海陆空间分异。通过对金石滩1998-2018年生态承载力分析,能够反映区域的生态承载力变化情况,可为其他自然保护地的生态承载力评估和可持续发展提供参考。