Genome-wide identification and expression analysis of Gossypium RING-H2 finger E3 ligase genes revealed their roles in fiber development,and phytohormone and abiotic stress responses

Background： RING H2 finger E3 ligase （RH2FE3） genes encode cysteine rich proteins that mediate E3 ubiquitin ligase activity and degrade target substrates. The roles of these genes in plant responses to phytohormones and abiotic stresses are well documented in various species, but their roles in cotton fiber development are poorly understood. To date, genome wide identification and expression analyses of Gossypium hirsutum RH2FE3 genes have not been reported. Methods： We performed computational identification, structural and phylogenetic analyses, chromosomal distribution analysis and estimated KJKs values of G hirsutum RH2FE3 genes. Orthologous and paralogous gene pairs were identified by all versus all BLASTP searches. We predicted cis regulatory elements and analyzed microarray data sets to generate heatmaps at different development stages. Tissue specific expression in cotton fiber, and hormonal and abiotic stress responses were determined by quantitative real time polymerase chain reaction （qRT PCR） analysis. Results： We investigated 140 G hirsutum, 80 G. orboreum, and evolutionary mechanisms and compared them with orthologs 89 G. roimondii putative RH2FB genes and their in Arobidopsis and rice. A domain based analysis of the G hirsutum RH2FE3 genes predicted conserved signature motifs and gene structures. Chromosomal localization showed the genes were distributed across all G hirsutum chromosomes, and 60 duplication events （4 tandem and 56 segmental duplications） and 98 orthologs were detected, cis elements were detected in the promoter regions of G hirsutum RH2FE3 genes. Microarray data and qRT PCR analyses showed that G hirsutum RH2FE3 genes were strongly correlated with cotton fiber development. Additionally, almost all the （brassinolide, gibberellic acid （GA）, indole 3-acetic acid drought, and salt）. dentified genes were up regulated in response to phytohormones （IAA）, and salicylic acid （SA）） and abiotic stresses （cold, heat, Conclusions： The genome wide identification, comprehensive analysis, and characterization of conserved domains and gene structures, as well as phylogenetic analysis, cis element prediction, and expression profile analysis of G hirsutum RH2FE3 genes and their roles in cotton fiber development and responses to plant hormones and abiotic stresses are reported here for the first time. Our findings will contribute to the genome wide analysis of putative RH2FE3 genes in other species and lay a foundation for future physiological and functional research on G hirsutum RH2FE3 genes.

RING3表达沉默细胞系的构建及其对Cyclin A的诱生

应用RNA干扰技术,建立了RING3(reallyinteresting gene3)表达沉默的细胞系,研究了RING3内生水平的表达与其可能的靶基因Cyclin A之间的关系.结果表明,在血清饥饿的成纤维细胞NI H/3T3中,用血清刺激后会引起细胞周期蛋白Cyclin A的表达;当用RNAi技术使RING3表达抑制后,Cyclin A的表达受到相应影响,可见Cyclin A的表达受到RING3的调节,其转录激活受到RING3和E2F-1等因子的共同调控,表明RING3与肿瘤发生之间的关系可能与Cyclin A的表达有关.

子宫内膜癌抑癌基因研究进展

子宫内膜癌是妇女常见的恶性肿瘤之一,发病率有逐年上升的趋势。随着分子生物学和免疫学的发展,关于子宫内膜癌分子水平的致癌机制研究日益深入,如癌基因、抑癌基因、DNA错配修复基因、雌激素代谢酶相关基因、甾体激素受体基因和细胞周期调控蛋白等。综述目前研究热点——抑癌基因的进展,为进一步探讨子宫内膜癌的发生发展、临床治疗及预后的判断提供重要依据。

SF3B1基因突变在骨髓增生异常综合征伴环形铁粒幼细胞增多中的研究进展

剪接体突变在骨髓增生异常综合征(MDS)的发生、发展中发挥重要作用,包括SF3B1、U2AF1(U2AF35)、SRSF2、ZRSR2、SF1、SF3A1及U2AF2相关基因突变等。进一步了解mRNA剪接对MDS的靶向治疗及改善患者预后具有指导作用。70%~85%低危骨髓增生异常综合征伴环形铁粒幼细胞增多(MDS-RS)患者存在SF3B1基因突变。多项研究结果表明,MDS-RS患者预后与SF3B1基因突变具有显著相关性关系。笔者拟就SF3B1突变基因与MDS-RS的关系,以及伴SF3B1突变基因的MDS-RS患者的治疗及预后的最新研究进展进行综述。

巴戟天中环烯醚萜苷和蒽醌在电喷雾离子源负离子模式下的质谱裂解行为

利用电喷雾-四极杆-飞行时间串联质谱(ESI-Q-TOF MS/MS)技术,在负离子模式下,探讨巴戟天中4种环烯醚萜苷和2种蒽醌成分的质谱裂解途径。通过[M-H]-获得化合物的相对分子质量信息,进一步对[M-H]-进行碰撞诱导解离,获得相应化合物的裂解途径。结果表明,环烯醚萜苷主要的裂解途径是首先脱去母环上的功能基团,如中性丢失H_2O、CO_2、CH_3COOH和糖单元等部分;其次是二氢吡喃环和糖环的断裂,m/z113、101为环烯醚萜苷母环断裂的特征碎片离子。蒽醌类化合物的裂解行为是连续失去CO,也可以失去CO_2。这些质谱裂解行为的研究有助于环烯醚萜苷和蒽醌类化合物的结构解析,也可为其他同类化合物的鉴定提供依据。