家燕与金腰燕染色体的比较研究

本文对家燕和金腰燕的核型、C带和Ag-NORs带进行了比较研究。结果表明,两者的核型基本一致。核型公式:2n=80=2M+4ST+zMwSM+2M+2ST+2SM+8 T+2M+56mT/D。但两者在染色体的相对长度、W染色体大小、G带带型、A g-NORs的数目和分布均存在着差异。文中在家燕No.1、7、W染色体和金腰燕No.1、 6、7染色体的形态划分,金腰燕W染色体的确定及其染色体数目等方面,均与卞小庄、李庆伟的结果不同。 Abstract:A comparative study on karyotype and C-band and Ag-NORs of house swallow and red-rumped swallow has been made.The result shows that the karyotype of them are similar,and their karyotypical formulae is 2n=80=2M+4ST+zMwSM+2M+2ST+8T+2M+56mT/D.But they are different in the relative length of chromosomes,the size of W chromosome,C-band patterns and the number and distribution of Ag-NORs.The chromosomes,the size of W chromosome,C-band patterns and the number and distribution of Ag-NORs.THE result in this paper is different from that of Mr.Bian and Mr.Li in the types of No.1,7,W chromosomes of house swallow and No.1,6,7 chromosomes of red-rumped swallow and the determination of W chromosome and diploid number of red-rumped swallow.     

赤链蛇染色体组型、C带和Ag-NORs的研究

以骨髓细胞为材料研究赤链蛇的染色体,结果表明该物种2n=46,由8对大型的和15对微小的染色体组成,AF=50.性染色体的大小介于3号和4号之间,为ZW型;8对大型染色体均显示着丝粒C带,1-6号还显示浅染端粒C带.W染色体为整条C带阳性;该物种一对NOR位于7号染色体近着丝粒区.不同地理分布群赤链蛇核型可能经历过Z与W染色体不等交换。 Abstract:The Karyotype,C-bands and Ag-NORs of Dinodon rufozonaturn (Cantor) reported is in this paper including the diploid number(2n=46)comprising 8 pairs of macro-and 15 pairs of microchromosomes,and AF=50 in the D.rufozonatum.The sex chromosome in size locates between the autochromosones No.3 and No.4,which belongs to ZW type.The C-banding technique revealed that the all macrochromosomes there are centromerc C band,the telomeric C band was only observed in Nos.1~6,while a whole W chromosome is constitutive heterochromatinization.Two NOR were observed on the pericentric of the No.7 chromosome.     

泰和乌骨鸡的核型与带型研究

采用外周血淋巴细胞培养--空气干燥法,对泰和乌骨鸡染色体核型和带型进行了研究。结果表明：泰和乌骨鸡体细胞染色体数目2n=78,染色体基本臂数AF=90,1、9号染色体及Z、W性染色体为中央着丝粒（m）染色体,2、4、7号染色体为亚中央着丝粒（sm）染色体,3、6、8、10号染色体为端着丝粒（t）染色体。G带研究表明：前10对大型染色体可分为29个区,190条带。C带处理发现,所有母鸡分裂相中W性染色体都出现C带并整条深染。Ag-NORs研究发现：Ag-NORs常定位于1、2号常染色体短臂和Z性染色体短臂端部;Ag-NORs数目分布范围为1～6;平均每个细胞的Ag-NORs数在雌、雄鸡中分别为2.94和2.96。 Abstract:This study made the chromosome slides of Taihe Silkies by the peripheral blood lymphocyte culture-drying method,and analyzed Taihe Silkies karyotype and band pattern.The results are as follow:The diploid chromosome number of Taihe Silkies was 2n=78,the basic number of chromosome arms was AF=90 and the sex chromosome type was ZZ(♂)/ZW(♀).According to the measured relative length,arm ratio and centromeric index,the first 10 pairs of macro-chromosomes are described as follows:No.1 ,9 and Z,W chromosomes were metacentrics,No.2,4,7 were submetacentrics,and No.3,6,8,10 were telocentrics.Studies on Taihe Silkies′ G-band showed that the first 10 pairs of macro-chromosomes can be divided into 29 zones and 190 bands.Being treated by C-banding technique,a totally dark-stained and easily indentified W-chromosome always showed up in the female metaphase configurations.Ag-NORs were located in the short arms′ telomere of No.1,2 euchromosomes and Z sexchromosome,the Ag-NORs number varied from 1-6. -NORs     

MONOGENETIC TREMATODES FROM THE MIDDLE YANGTZE VALLEY:DACTYLOGYRUS PARASITIC ON ABRAMIDINAE FISHES

The present paper reports 43 species of Dactylogyrus found on fishes belonging tosubfamily Abramidinae in Chiayu (嘉鱼), Hupeh Province in the middle Yangtze valley.Among them, 7 are new species, 13 new host records, and with 1 species undetermined.The characteristics of the new species are briefly described as follows:     

鲤科四种鱼肠道菌群的相似性及其与系统进化的关系

在同一背景条件下,对草鱼、白鲢、团头鲂和鲤鱼等4种鱼的肠道菌群中好氧性菌或兼性厌氧菌进行分析鉴定,得到4种鱼之间的肠道菌群相似值.用UPGMA和NJ法构建鲤科的雅罗鱼亚科、鲢亚科、鳊亚科和鲤亚科等4种亚科的系统演化树.不同亚科的鱼间菌群分布有较大差异,但雅罗鱼亚科和鳊亚科在菌群分布方面有极显著的正相关性.哈夫尼亚菌属、致病杆菌属、气单胞菌属、柠檬酸菌属、假单胞菌属等在4种鱼肠道中均有分布,链球菌属、拉恩氏菌属、芽孢杆菌属、葡萄球菌属等属于共生菌.雅罗鱼亚科和鳊亚科相邻邻接为一个共同接点,该接点与鲤亚科连接为一个接点,鲤亚科可能是最原始的类型。 Abstract:This paper is an analysis and appraisal of aerobe and facultative anaerobe among intestinal bacterium of the following fishes:Ctenophar yngodomidellus,Hypophtha lmichthys molitrix,Megalorama ambly cephala Yih and Cyprinus carpio haematopterus under same surroundings.After that,We contain similarity values of intestinal bacteria were obtained between every two kinds of the four fishes.We constructed the revolutionary trees of in Cyprinidate,Leuciscinae,Abramidinae,Cyprininae and Hypophthalmi by NJ method and UPGMA method according to the similarity values.     

锯缘摄龟和齿缘摄龟的核型与Ag-NORs

本文分析了锯缘摄龟和齿缘摄龟的核型与Ag-NORs,结果：2FKn均为52,核型模式9+5+12。但锯缘摄龟AN=78, 其NOR位于A组No.4的长臂上,而齿缘摄龟AN=76,NOR位于A组的No.7的长臂。作者对这两种摄龟核型的结构特点和NOR位置差异的细胞分类学意义进行了讨论。G[2]G[-2] Abstract:In this paper, the karyotypes and Ag-NORs of FKPyxidea mouhtiiand FKCyclemys dentatafrom China were studies. It was found that the 2FKn=52, the karyotypic formula is 9+5+12 in this two species. But FKP. mouhtiihas AN=78, its NORs located on the No.4 q of group A, while AN=76, NORs located on No.7 q of group A in FKC. dentata. The cytotaxonomical value of the features of karyotypic structure and the positinal differentiation of NORs between this two spepies is preliminarily discussed.     

Experimental study of rat beta islet cells cultured under simulated microgravity conditions

To observe the effects of simulated microgravity on beta islet cell culture, we have compared the survival rates and the insulin levels of the isolated rat islet cells cultured at micro- and normal gravity conditions. The survival rates of the cells cultured were determined by acridine orange-propidium iodide double-staining on day 3, 7 and 14. The morphology of the cells was observed by electron microscopy. Insulin levels were measured by radio immuno assays. Our results show that the cell number cultured under the microgravity condition is significantly higher than that under the routine condition (P<0.01). Some tubular structure shown by transmission electron microscopy, possibly for the transport of nutrients, were formed intercellularly in the microgravity cultured group on day 7. There were also abundant secretion particles and mitochondria in the cytoplasm of the cells. Scanning electron microscopy showed that there were holes formed between each islet, possibly connecting with the nutrient trans     

大鳞副泥鳅ZZ/ZW型性别决定的细胞遗传学证据

大鳞副泥鳅是鲤形目、鳅科的鱼类。其2n数为48,核型组成为12m+4sm+32 t(雄性),11m+5sm+32t(雌性)。根据银染带和C带特征分析,证实大鳞副泥鳅为ZZ/ZW型性别决定。Z染色体为中部着丝粒染色体,在其长臂端部有Ag -NOR存在。 W染色体为亚中部着丝粒染色体,在其长臂末端也有Ag-NOR存在,同时还有一深染的居间C带,这是W染色体独有的带纹特征。 Abstract:Paramisgurnus dabryanus belongs to Cypriniformes,Cobitidae.Its 2n is 48.The karyotype formula is 12m+4sm+32t(in male),11m+5sm+32t(in female).According to the Ag-NORs band and C-band patterns,we consider that its sex determination is of ZZ/ZW type.The Z chromosome is a metacentric one with Ag-NORs located on its arm end.The W chromosome is a submetacentric with Ag-NORs located on the terminal of its long arm.There is a darkly stained C-band on the long arm of W chromosome.This band is a characteric of the W chromosome.     

三个家猪品种和rob易位群染色体分带多态性的比较

对家猪不同品种及家系间的染色体组型、C-带、Ag-NORs多态性进行的研究表明：杜洛克猪、约克夏猪、长白猪体细胞染色体数2n=38,核型2n=10sm+12m+4st+12t, 而13/17易位纯合子猪（36, rob. 13/17）的体细胞染色体数2n=36,核型2n=10sm+12m+6st+8t; 13/17易位杂合子猪（37,rob. 13/17）的体细胞染色体数目为 2n＝37,核型为2n=10sm+12m+5st+10t。5种家猪的C-带在13～18号染色体上存在大、中、小三种类型, 且呈多态性分布。杜洛克猪、约克夏猪、长白猪、13/17易位纯合子猪、13/17易位杂合子猪的Ag-NORs均数分别为2.05、2.06、2.00、1.99、1.98,说明Ag－NORs在品种、个体及细胞间具有多态性。 Abstract:The present experiment is carried out to make comparative stdy on polymorphism of chromosome Karyotypes, C-band ?and Ag-NORs of different breeds and strains in domestic Pigs. The results showed that the chromosome number of somatic cell in Duroc, Yorkshire and Landrace Pig Was 38 and the karyotype was 2n=10sm+12m+4st+12t. But in heterozygous Rob 13/17(37, rob. 13/17) Pig, the chromosome number of somatic cell was 37 andthe karyotype was 2n=10sm+12m+5st+10t, while in homozygousRob 13/17(36, rob. 13/17) Pig, the somatic cell chromosome number was 36 and the karyotype was 2n=10sm+12m+6st+8t. It was also showed that there were three C-band types in size on chromosome No. 13-18 showing polymorphism in three breeds and two strains of domestic Pigs. The average of Ag-NORs in Duroc, yorkshire,Landrace, homozygous Rob. 13/17 and heterozygous Rob. 13/17 Pig was 2.05, 2.06, 2.00, 1.99 and 1.98, respectively. It is suggested that Ag-NORs have polymorphism among strains, which can be used as a genetic index to analyse relationships among domestic animals with high reliability.     

Mapping of a BYDV resistance gene from Thinopyrum intermedium in wheat background by molecular markers

The wheat line H960642 is a homozygous wheat-Thinopyrum intermedium translocation line with resistance to BYDV by genomie in situ hybridization (GISH) and RFLP analysis. The genomie DNA of Th. intermedium was used as a probe, and eonunon wheat genomie DNA as a blocking in GISH experiment. The results showed that the chromosome segments of Th. intermedium were transferred to the distal end of a pair of wheat chromosomes. RFLP analysis indicated that the transloeation line H960642 is a T7DS·7DL-7XL translocation by using 8 probes mapped on the homoeologous group 7 in wheat. The tranalocation breakpoint is located between Xpsr680 and Xpsr965 about 90—99 cM from the centromere. The RFLP markers psr680 and psr687 were closoly linked with the BYDV resistance gene. The gene is located on the distal end of 7XL around Xpsr680 and Xpsr687.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

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     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

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.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

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).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

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.