原、异位保存东乡野生稻主要农艺性状的比较研究

为了解原、异位保存东乡野生稻主要农艺性状的变化,对庵家山普通野生稻原、异位群体进行了考察和比较分析。结果表明,原、异位保存的东乡野生稻在每穗总粒数、每穗实粒数、结实率等方面存在较大的差异,如异位保存的东乡野生稻每穗总粒数平均为58.28粒,比原位多11.44粒,但其每穗实粒数却较少,为9.89粒,结实率降低了45.43%。从种植环境可以发现,异位保存圃的环境不适宜东乡野生稻的生长,应该选择与原生境相类似的种植环境,以便于东乡野生稻的保存、研究与利用。     

我国网络平台本土兰科植物贸易状况

我国兰科植物物种丰富, 很多具有极高的药用和观赏价值。随着网络平台的迅速发展, 兰科植物的线上交易越来越普遍。为了解国内网络平台的本土兰科植物贸易情况, 本文利用PyCharm Community软件爬取网络交易信息和人工浏览收集的方法, 分析了淘宝网、拼多多和中兰网的兰科植物贸易情况。调查发现: 网络贸易的本土兰科植物共计84属339种(含3变种), 包含45个中国特有种, 兰属(Cymbidium)和石斛属(Dendrobium)是最大的贸易对象。其中, 仅以观赏用途作为卖点的兰科植物309种(91.1%), 仅以药用价值作为卖点的兰科植物5种(1.5%), 以双用途作为卖点的兰科植物25种(7.4%)。本次调查共记录到336种(99.1%)野生兰科植物销售信息, 并发现部分销售者刻意包装野生兰科植物的现象。大部分淘宝网和拼多多的兰科植物最大销售量对应的价位为10-49元, 其中拼多多的价格更低且集中, 位于15-35元的占57.5%。商品货源地较集中, 主要包括云南省、广东省、广西壮族自治区、浙江省、福建省和四川省。进一步对本次记录的兰科植物进行濒危等级统计后发现: 受威胁兰科植物188种(55.5%), 其中极危(Critically Endangered, CR) 23种(6.8%), 濒危(Endangered, EN) 85种(25.1%), 易危(Vulnerable, VU) 80种(23.6%)。为加强我国野生兰科植物多样性保护, 强烈建议各网络平台依据最新《国家重点保护野生植物名录》制定兰科植物商品信息发布规则, 重点监督货源地集中的地区, 同时加强对公众的宣传教育, 相关部门应利用网络平台加强兰科资源的信息交流, 共同保护野生兰科植物。     

我国涉天鹅属鸟类死亡案件分析及防控对策研究

我国有分布的天鹅属所有种(Cygnusspp.)均为国家Ⅱ级重点保护野生动物,根据中华人民共和国刑法,非法猎捕、杀害珍贵濒危野生动物构成刑事犯罪。然而,天鹅死亡案件仍时有发生。本文分析2000至2016年有统计的我国天鹅死亡案件发现,每年11月至翌年1月是涉天鹅案件的高发时期;毒杀为致死主因;案件多发生于我国行政区划交界处。因此,应于迁徙越冬季节重点加强高案发地点的侦查监管;加强克百威(呋喃丹)为代表的高毒农药管控;建立迁徙季节多地区执法联动机制。     

Behavioral patterns of two fiddler crab species Uca rapax and Uca tangeri in a seminatural mangrove system

Zoos increasingly transform their exhibitions from traditional one‐species enclosures to more natural exhibits, that is, environments that capture part of an ecosystem including a selection of animals and plants that occur there. Thus, enhancing the experience of its human visitors while also allowing its residents to possibly show more natural behavior. In 2017 Royal Burger's Zoo (Arnhem, The Netherlands) created and opened a mangrove‐like environment containing fiddler crabs. Fiddler crabs display a broad range of behaviors, and this research examines which wild‐type behavior and behavioral patterns can be observed on a seminatural mudflat. The behavior shown by Uca rapax and Uca tangeri on the mudflat was counted each hour between 07:00 and 17:00. An asymmetric tidal regime was present in the enclosure including two high water periods. Various known fiddler crab behaviors, including waving and combat, were observed but no copulation. A clear pattern in exposed crabs on the mudflat was found, with low numbers visible in the early morning and the highest numbers present in the early afternoon, while number of visitors did not have a significant effect on this pattern. Interestingly, the highest abundances were not observed around the ebbing tide (07:00–09:00), as observed in the wild, but somewhat later, possibly due to the asymmetric tidal scheme or the interaction of tidal and daily rhythms. This study shows that in captivity, fiddler crabs indeed show a range of natural behaviors which is linked to the tidal and possibly daily rhythm as well.     

Phenolic and anthocyanin fractions from wild blueberries (V. angustifolium) differentially modulate endothelial cell migration partially through RHOA and RAC1

The present study investigates the effect of anthocyanin (ACN), phenolic acid (PA) fractions, and their combination (ACNs:PAs) from wild blueberry powder (Vaccinum angustifolium) on the speed of endothelial cell migration, gene expression, and protein levels of RAC1 and RHOA associated with acute exposure to different concentrations of ACNs and PAs. Time-lapse videos were analyzed and endothelial cell speed was calculated. Treatment with ACNs at 60 μg/mL inhibited endothelial cell migration rate ( P ≤ 0.05) while treatment with PAs at 0.002 μg/mL ( P ≤ 0.0001), 60 μg/mL ( P ≤ 0.0001), and 120 μg/mL ( P ≤ 0.01) significantly increased endothelial cell migration rate compared with control. Moreover, exposure of HUVECs to ACNs:PAs at 8:8 μg/mL ( P ≤ 0.05) and 60:60 μg/mL increased ( P ≤ 0.001) endothelial cell migration. Gene expression of RAC1 and RHOA significantly increased 2 hours after exposure with all treatments. No effect of the above fractions was observed on the protein levels of RAC1 and RHOA. Findings suggest that endothelial cell migration is differentially modulated based on the type of blueberry extract (ACN or PA fraction) and is concentration-dependent. Future studies should determine the mechanism of the differential action of the above fractions on endothelial cell migration.     

Knockout of Nr2e3 prevents rod photoreceptor differentiation and leads to selective L-/M-cone photoreceptor degeneration in zebrafish

Mutations in the photoreceptor cell-specific nuclear receptor gene Nr2e3 increased the number of S-cone photoreceptors in human and murine retinas and led to retinal degeneration that involved photoreceptor and non-photoreceptor cells. The mechanisms underlying these complex phenotypes remain unclear. In the hope of understanding the precise role of Nr2e3 in photoreceptor cell fate determination and differentiation, we generated a line of Nr2e3 knockout zebrafish using CRISPR technology. In these Nr2e3-null animals, rod precursors undergo terminal mitoses but fail to differentiate as rods. Rod-specific genes are not expressed and the outer segment (OS) fails to form. Formation and differentiation of cone photoreceptors is normal. Specifically, there is no increase in the number of UV-cone or S-cone photoreceptors. Laminated retinal structure is maintained. After normal development, L-/M-cones selectively degenerate, with progressive shortening of OS that starts at age 1 month. The amount of cone phototransduction proteins is concomitantly reduced, whereas UV- and S-cones have normal OS lengths even at age 10 months. In vitro studies show Nr2e3 synergizes with Crx and Nrl to enhance rhodopsin gene expression. Nr2e3 does not affect cone opsin expression. Our results extend the knowledge of Nr2e3's roles and have specific implications for the interpretation of the phenotypes observed in human and murine retinas. Furthermore, our model may offer new opportunities in finding treatments for enhanced S-cone syndrome (ESCS) and other retinal degenerative diseases.     

Sequence- and seed-structure-dependent polymorphic fibrils of alpha-synuclein

Synucleinopathies comprise a diverse group of neurodegenerative diseases including Parkinson's disease (PD), dementia with Lewy bodies, and multiple system atrophy. These share a common pathological feature, the deposition of alpha-synuclein (a-syn) in neurons or oligodendroglia. A-syn is highly conserved in vertebrates, but the primary sequence of mouse a-syn differs from that of human at seven positions. However, structural differences of their aggregates remain to be fully characterized. In this study, we found that human and mouse a-syn aggregated in vitro formed morphologically distinct amyloid fibrils exhibiting twisted and straight structures, respectively. Furthermore, we identified different protease-resistant core regions, long and short, in human and mouse a-syn aggregates. Interestingly, among the seven unconserved amino acids, only A53T substitution, one of the familial PD mutations, was responsible for structural conversion to the straight-type. Finally, we checked whether the structural differences are transmissible by seeding and found that human a-syn seeded with A53T aggregates formed straight-type fibrils with short protease-resistant cores. These results suggest that a-syn aggregates form sequence-dependent polymorphic fibrils upon spontaneous aggregation but become seed structure-dependent upon seeding.     

Methylglyoxal accumulation de-regulates HoxA5 expression,thereby impairing angiogenesis in glyoxalase 1 knock-down mouse aortic endothelial cells

Impaired angiogenesis leads to long-term complications and is a major contributor of the high morbidity in patients with Diabetes Mellitus (DM). Methylglyoxal (MGO) is a glycolysis byproduct that accumulates in DM and is detoxified by the Glyoxalase 1 (Glo1). Several studies suggest that MGO contributes to vascular complications through mechanisms that remain to be elucidated. In this study we have clarified for the first time the molecular mechanism involved in the impairment of angiogenesis induced by MGO accumulation.Angiogenesis was evaluated in mouse aortic endothelial cells isolated from Glo1-knockdown mice (Glo1KD MAECs) and their wild-type littermates (WT MAECs). Reduction in Glo1 expression led to an accumulation of MGO and MGO-modified proteins and impaired angiogenesis of Glo1KD MAECs. Both mRNA and protein levels of the anti-angiogenic HoxA5 gene were increased in Glo1KD MAECs and its silencing improved both their migration and invasion. Nuclear NF-?B-p65 was increased 2.5-fold in the Glo1KD as compared to WT MAECs. Interestingly, NF-?B-p65 binding to HoxA5 promoter was also 2-fold higher in Glo1KD MAECs and positively regulated HoxA5 expression in MAECs. Consistent with these data, both the exposure to a chemical inhibitor of Glo1 “SpBrBzGSHCp2” (GI) and to exogenous MGO led to the impairment of migration and the increase of HoxA5 mRNA and NF-?B-p65 protein levels in microvascular mouse coronary endothelial cells (MCECs).This study demonstrates, for the first time, that MGO accumulation increases the antiangiogenic factor HoxA5 via NF-?B-p65, thereby impairing the angiogenic ability of endothelial cells.     

Nr5a1-Cre-mediated Tspo conditional knockout mice with low growth rate and prediabetes symptoms – A mouse model of stress diabetes

Translocator protein (TSPO) is a high-affinity cholesterol- and drug-binding mitochondrial protein. Nuclear receptor subfamily 5 group A member 1 or steroidogenic factor 1 (Nr5a1)-Cre mice were previously used to generate steroidogenic cell-specific Tspo gene conditional knockout (cKO) mice. TSPO-depleted homozygotes showed no response to adrenocorticotropic hormone (ACTH) in stimulating adrenal cortex corticosterone production but showed increased epinephrine synthesis in the medulla. No other phenotype was observed under normal growth conditions. During these studies, we noted that pairing two cKO mice resulted in the generation of small pups. These pups showed low growth rate at weaning, which has been linked to the development of type 2 diabetes (T2D) in adulthood. Experimental verification of T2D symptoms via blood testing of the adult mice, including glycated hemoglobin and insulin C-peptide measurements, showed that these Tspo cKO mice exhibited sustained hyperglycemia, a sign of prediabetes, likely due to the augmentation of hepatic glucose production mediated by the increased epinephrine. We also observed increased expression of the S100a8 gene, which is upregulated after chronic glucose stimulation. Taken together, the observed prediabetes phenotype and lack of response to ACTH indicate that Tspo cKO mice (Nr5a1-Cre^+/?, Tspo^fl/fl) could provide a useful model to study the link between diabetes and stress.