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The availability of the draft genome sequence of Oryza sativa L ssp. indica has made it possible to study the rice tRNA genes. A total of 596 tRNA genes, including 3 selenocysteine tRNA genes and one suppressor tRNA gene are identified in 127551 rice contigs. There are 45 species of tRNA genes and the revised wobble hypothesis proposed by Guthrie and Abelson is perfectly obeyed. The relationship between codon usage and the number of corresponding tRNA genes is discussed. Redundancy may exist in the present list of tRNA genes and novel ones may be found in the future. A set of 33 tRNA genes is discovered in the complete chloroplast genome of Oryza sativa L. ssp. indica. These tRNA genes are identical to those in ssp. japonica identified by us independently from the origional annotation.  相似文献   

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Polycomb group proteins (PcG) play important roles in epigenetic regulation of gene expression. Some core PeG proteins, such as Enhancer of Zeste (E(z)), Suppressor of Zeste (12) (Su(z)12), and Extra Sex Combs (ESC), are conserved in plants. The rice genome contains two E(z)-Iike genes, OsiEZ1 and OsCLF, two homologs of Su(z)12, OsEMF2a and OsEMF2b, and two ESC-like genes, OsFIE1 and OsFIE2. OsFIE1 is expressed only in endosperm; the maternal copy is expressed while the paternal copy is not active. Other rice PcG genes are expressed in a wide range of tissues and are not imprinted in the endosperm. The two E(z)-Iike genes appear to have duplicated before the separation of the dicots and monocots; the two homologs of Su(z)12 possibly duplicated during the evolution of the Gramineae and the two ESC- like genes are likely to have duplicated in the ancestor of the grasses. No homologs of the Arabidopsis seed-expressed PcG genes MEA and FIS2 were identified in the rice genome. We have isolated T-DNA insertion lines in the rice homologs of three PcG genes. There is no autonomous endosperm development in these T-DNA insertion lines. One line with a T-DNA insertion in OsEMF2b displays pleiotropic phenotypes including altered flowering time and abnormal flower organs, suggesting important roles in rice development for this gene.  相似文献   

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Psoriasis(Ps)and psoriatic arthritis(Ps A)are genetically complex diseases with strong genetic evidence.Recently,susceptibility genes for Ps and Ps A have been identified within the late cornified envelop(LCE)gene cluster,especially the cluster 3(LCE3)genes.It is noteworthy that the deletion of LCE3B and LCE3C(LCE3C_LCE3B-del)is significantly associated with these two diseases.Gene-gene interactions between LCE3 genes and other genes are associated with Ps and Ps A.LCE3 genes also have pleiotropic effect on some autoimmune diseases,such as rheumatoid arthritis,atopic dermatitis and systemic lupus erythematosus.Further studies need to focus on the potential function of LCE3 genes in the pathogenesis of Ps and Ps A in the future.  相似文献   

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In gene expression profiling, nasopharyngeal carcinoma (NPC) 5-8F cells differ from 6-10B cells in terms of their high tumorigenicity and metastatic ability. Differentially expressed genes from the two cell types were analyzed by combining with MILANO (the automatic custom annotation of microarray results which is based on all the available published work in PubMed). The results showed that five genes, including CTSD, P63, CSEIL, BPAG1 and EGR1, have been studied or mentioned in published work on NPC.Subsequently, we revaluated the roles of these genes in the pathogenesis of NPC by combining the data of gene chips from NPCs versus NPs and pooled cells from 5-8F, 6-10B and CNE2 versus NPs. The results suggested that the roles of BPAG1 and EGR1 are possibly different from those reported in previous NPC studies. These five genes are likely to be involved in the proliferation, apoptosis, invasion and metastasis of NPC. A reexploration of the genes will further define their roles in the pathogenesis of NPC.  相似文献   

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Melanocortin-1 receptor gene variants in four Chinese ethnic populations   总被引:9,自引:0,他引:9  
INTRODUCTIONThe variation in human hall and skin color in~ geographic regions of the world is the result Of differences in two Principal forms Of melanin,the red-yellow phaeomelalilns and the bldebrowneUmelanins, which are present in the epidermallayer of hUman skin and hair[1, 2]. The type ofmelanin Produced is under the control of two genes,identified initially by the mouse mutation, extension and agouti. The eXtension gene is expressedin melanocytes, Producillg the melanocyte stimul…  相似文献   

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The complete sequence of Oxya chinensis (0. chinensis) mitochondrial genome is reported here. It is 15,443 bp in length and contains 75.9% A+T. The protein-coding genes have a similar A+T content (75.2%). The initiation codon of the cytochrome oxidase subunit I gene in the mitochondrial genome of O. chinensis appears to be ATC, instead of the tetranucleotides that have been reported in Locusta migratoria (L migratoria) mitochondrial genome. The sizes of the large and small ribosomal RNA genes are 1319 and 850 bp, respectively. The transfer RNA genes have been modeled and showed strong resemblance to the dipteran transfer RNAs, and all anticodons are identical to those of dipteran. The A+T-rich region is 562 bp, shorter than that of other known Orthoptera insects. The six conserved domains were identified within the A+T-rich region by comparing its sequence with those of other grasshoppers. The result of phylogenetic analysis based on the dataset containing 12 concatenated protein sequences confirms the close relation-ship of O. chinensis with L migratoria.  相似文献   

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The complete mitochondrial genome of Chinese Bombyx mandarina(ChBm) was determined.The cir-cular genome is 15682 bp long, and contains a typical gene complement, order, and arrangement iden-tical to that of Bombyx mori(B.mori) and Japanese Bombyx mandarina(JaBm) except for two addi-tional tRNA-like structures:tRNASer(TGA)-like and tRNAIle(TAT)-like.All protein-coding sequences are initi-ated with a typical ATN codon except for the COI gene, which has a 4-bp TTAG putative initiator codon.Eleven of 13 protein-coding genes(PCGs) have a complete termination codon(all TAA), but the re-maining two genes terminate with incomplete codons.All tRNAs have the typical clover-leaf structures of mitochondrial tRNAs, with the exception of tRNASer(TGA)-like, with a four stem-and-loop structure.The length of the A T-rich region of ChBm is 484 bp, shorter than those of JaBm(747 bp) and B.mori(494―499 bp).Phylogenetic analysis among B.mori, ChBm, JaBm, and Antheraea pernyi(Anpe) showed that B.mori is more closely related to ChBm than JaBm.The earliest divergence time estimate for B.mori-ChBm and B.mori-JaBm is about 1.08±0.18―1.41±0.24 and 1.53±0.20―2.01±0.26 Mya, respec-tively.ChBm and JaBm diverged around 1.11±0.16―1.45±0.21 Mya.  相似文献   

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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

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The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.  相似文献   

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鸡传染性法氏囊病病毒研究进展   总被引:3,自引:0,他引:3  
闫笑  李天宪 《中国病毒学》2003,18(2):191-195
传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.  相似文献   

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In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.  相似文献   

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Shen  Jia-Yuan  Li  Man  Xie  Lyu  Mao  Jia-Rong  Zhou  Hong-Ning  Wang  Pei-Gang  Jiang  Jin-Yong  An  Jing 《中国病毒学》2021,36(1):145-148
正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).  相似文献   

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Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.  相似文献   

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