Distinct genomic traits of acral and mucosal melanomas revealed by targeted mutational profiling

The incidence of melanoma is rising globally including China. Comparing to Caucasians, the incidence of non‐cutaneous melanomas is significantly higher in Chinese. Herein, we performed genomic profiling of 89 Chinese surgically resected primary melanomas, including acral (n = 54), cutaneous (n = 22), and mucosal (n = 13), by hybrid capture‐based next‐generation sequencing. We show that mucosal melanomas tended to harbor more pathogenic mutations than other types of melanoma, though the biological significance of this finding remains uncertain. Chromosomal arm‐level alterations including 6q, 9p, and 10p/q loss were highly recurrent in all subtypes, but mucosal melanoma was significantly associated with increased genomic instability. Importantly, 7p gain significantly correlated with unfavorable clinical outcomes in non‐cutaneous melanomas, representing an intriguing prognostic biomarker of those subtypes. Furthermore, focal amplification of 4q12 (KIT, KDR, and PDGFRα) and RAD51 deletion were more abundant in mucosal melanoma, while NOTCH2 amplification was enriched in acral melanoma. Additionally, cutaneous melanomas had higher mutation load than acral melanomas, while mucosal melanomas did not differ from other subtypes in mutation burden. Together, our data revealed important features of acral and mucosal melanomas in Chinese including distinctive driver mutation pattern and increased genomic instability. These findings highlight the possibilities of combination therapies in the clinical management of melanoma.     

Mild manifestations of COVID-19 in healthcare workers

Medical staff treating Coronavirus Disease 2019 (COVID-19) patients are at high risk for exposure to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), and many have been infected, which may cause panic among medical workers, their relatives, health professionals, and government leaders. We report the epidemiologic and clinical characteristics of healthcare workers and that the majority of infected medical staff had milder symptoms/conditions with a better prognosis than admitted patients. Timely improvement to medical staff’s working conditions such as allowing adequate rest and providing sufficient medical protection is extremely important.     

ATP binding cassette transporters ABCG1 and ABCG16 affect reproductive development via auxin signalling in Arabidopsis

Angiosperm reproductive development is a complex event that includes floral organ development, male and female gametophyte formation and interaction between the male and female reproductive organs for successful fertilization. Previous studies have revealed the redundant function of ATP binding cassette subfamily G (ABCG) transporters ABCG1 and ABCG16 in pollen development, but whether they are involved in other reproductive processes is unknown. Here we show that ABCG1 and ABCG16 were not only expressed in anthers and stamen filaments but also enriched in pistil tissues, including the stigma, style, transmitting tract and ovule. We further demonstrated that pistil‐expressed ABCG1 and ABCG16 promoted rapid pollen tube growth through their effects on auxin distribution and auxin flow in the pistil. Moreover, disrupted auxin homeostasis in stamen filaments was associated with defective filament elongation. Our work reveals the key functions of ABCG1 and ABCG16 in reproductive development and provides clues for identifying ABCG1 and ABCG16 substrates in Arabidopsis.     

剑叶龙血树内生放线菌活性菌株的筛选和鉴定

为筛选具有抗菌抗肿瘤活性的药用植物内生菌资源,该文对300余株分离自中国云南西双版纳及越南地区剑叶龙血树的内生放线菌采用琼脂块扩散法进行抗病原细菌活性筛选、平板对峙法进行抗真菌活性筛选、SRB法测定菌株的细胞毒活性及PCR扩增方法筛选非核糖体肽合成酶NRPS基因及聚酮合酶PKS-I、PKS-Ⅱ基因;对得到的优势菌株经8种培养基进行发酵,采用10种病原细菌、3种病原真菌及2种人肿瘤细胞株测试其发酵粗提物的抗菌及抗肿瘤活性以确定最佳发酵培养基;用16S rRNA基因测序方法初步鉴定5株优势菌株的分类地位。结果表明:初筛得到5株抗菌活性、体外细胞毒活性及NRPS、PKS相关基因表达阳性的菌株S01-S05,其中4株(S01-S04)属于链霉菌属、1株(S05)属于类诺卡氏菌属;菌株经不同培养基发酵后产物的抗菌和抗肿瘤活性不同,其中Streptomyces sp. S04在7种培养基中的发酵提取物对8种测试病原菌均有较强抑制作用,且该菌株用Medium C的发酵提取物对人肝癌Hep G2细胞株抑制率达到100%,为剑叶龙血树内生菌活性成分挖掘及新型抗菌药物筛选奠定了基础。     

小脑症蛋白ASPM和钙调蛋白的复合物的纯化和表征

常染色体隐性小脑症(Autosomal recessive primary microcephaly, MCPH)是一种与大脑缩小和智力缺陷有关的神经发育障碍。 ASPM(abnormal spindle-like microcephaly-associated)是最常见的MCPH的致病基因,但其潜在机制尚不清楚。我们发现钙调蛋白(calmodulin, CaM)通过与ASPM的IQ区域相互作用而对ASPM的功能有重要的调控作用。我们纯化了ASPM IQ区域和CaM的复合物,并通过分子排阻色谱结合多角度静态光散射（SEC-MALS）和圆二光谱（CD）实验发现了ASPM和apo_CaM的结合比例为1：8。有趣的是,在Ca2+存在时,ASPM的IQ区域与Ca2+_CaM的结合比例变为了1：7。此外,通过比较不同条件下（Ca2+存在与否）的CD光谱,ASPM-CaM复合物显示出Ca2+依赖性的热稳定性变化。综上所述,我们的研究揭示了Ca2+诱导的ASPM-CaM相互作用的调节机制。     

利用外源γ-氨基丁酸调控海洋绿藻亚心形四爿藻淀粉积累

微藻被看作第三代生物质能源的来源。微藻淀粉结构与高等植物的高度相似性使其可以作为粮食作物的替代,在生物能源领域有广泛的应用。γ-氨基丁酸(GABA)被认为是一种信号分子,可以调节植物细胞的生长代谢。本研究在缺氮培养条件下添加外源GABA调控海洋绿藻亚心形四爿藻生理代谢和淀粉积累。结果表明,添加外源GABA可以抑制细胞生长,降低光合作用效率;OJIP实验显示,GABA的添加增强了光合器官能量耗散,降低了光能利用效率,阻碍了电子传递,造成额外胁迫,从而促使细胞将碳流更多地分配到淀粉积累,导致藻细胞的淀粉含量、淀粉产量和淀粉产率提高。添加10 mmol/L GABA获得最大淀粉含量39%DW,比未添加GABA的对照组淀粉含量提高39%;同时获得最大淀粉产量和产率为1.72 g·L^-1和0.36 g·L^-1·d^-1,分别比未添加GABA的对照组提高39%和50%。以上结果表明在缺氮条件下添加外源GABA是一种调控亚心形四爿藻细胞代谢并提高其淀粉生产的有效方法。     

基于多源数据的福州市中心城区人居环境质量评价

城市内部居住环境的客观性评价有助于发现城市发展中暴露出的问题,有针对性地进行调整进而改善城市环境。以福州市中心城区为研究区,居住区为研究单元,利用气象监测数据、遥感影像数据、地图兴趣点数据、国土规划数据等多源数据,从环境健康舒适性、交通便捷性、城市安全性和生活方便性4方面构建城市人居环境监测体系,并使用优劣解距离法进行人居环境质量综合评价。结果表明: 福州市中心城区人居环境水平差异性较大,整体上呈现出中心区域高、边缘地区低的特点。城区中部人居环境指数较高,东部和南部区域较低,西部和北部区域人居环境高值与低值混杂分布。各指标层中,交通便捷性和生活方便性的高-高集聚以及低-低集聚特征与人居环境高低值聚类分布较为一致,便捷的交通以及完备的服务设施对人居环境评价的影响较大;环境健康舒适性呈现城市内部低、边缘高的特点,而城市安全性呈现内部高、边缘低的特点。     

干旱胁迫下喷施外源植物激素对甘薯生理特性和产量的影响

为探讨不同时期干旱胁迫下喷施外源植物激素对甘薯生理特性和产量的影响,明确喷施外源植物激素的最佳时期,在人工控水条件下研究了移栽后20(前期)、60(中期)和100 d(后期)干旱胁迫下喷施6-苄氨基嘌呤(6-BA)、α-萘乙酸(NAA)和脱落酸(ABA)对甘薯内源激素含量、光合荧光特性和产量的影响。结果表明: 与喷清水相比,喷施外源植物激素均能显著提高甘薯产量,以6-BA增幅最大,其次是NAA和ABA;前期喷施效果好于中期和后期。不同时期干旱胁迫下,喷施外源植物激素可显著提高甘薯叶片的光合和叶绿素荧光参数,缓解因干旱引起的玉米素核糖核苷(ZR)和生长素(IAA)含量下降的现象。逐步回归分析表明,内源激素和光合特性是影响甘薯产量的关键指标。通径分析表明,前期干旱胁迫下喷施外源植物激素主要通过影响净光合速率(P_n)、IAA、ZR、最大光化学效率和光化学性能指数来影响甘薯产量。生长前期喷施6-BA可调控甘薯内源激素含量,提高光合特性,有效缓解干旱造成的产量损失。