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81.
Magnolia grandiflora is an important medicinal,ornamental and horticultural plant species.The chloroplast(cp) genome of M.grandiflora was sequenced using a 454 sequencing platform and the genome structure was compared with other related species.The complete cp genome of M.grandiflora was 159623 bp in length and contained a pair of inverted repeats(IR) of 26563 bp separated by large and small single copy(LSC,SSC) regions of 87757 and 18740 bp,respectively.A total of 129 genes were successfully annotated,18 of which included introns.The identity,number and GC content of M.grandiflora cp genes were similar to those of other Magnoliaceae species genomes.Analysis revealed 218 simple sequence repeat(SSR) loci,most composed of A or T,contributing to a bias in base composition.The types and abundances of repeat units in Magnoliaceae species were relatively conserved and these loci will be useful for developing M.grandiflora cp genome vectors.In addition,results indicated that the cp genome size in Magnoliaceae species and the position of the IR border were closely related to the length of the ycf1 gene.Phylogenetic analyses based on 66 shared genes from 30 species using maximum parsimony(MP) and maximum likelihood(ML) methods provided strong support for the phylogenetic position of Magnolia.The availability of the complete cp genome sequence of M.grandiflora provides valuable information for breeding of desirable varieties,cp genetic engineering,developing useful molecular markers and phylogenetic analyses in Magnoliaceae.  相似文献   
82.
通过显微注射法构建ES细胞(MESPU 13)嵌合小鼠   总被引:3,自引:1,他引:3  
为了研究一个新建的小鼠胚胎干细胞系(ES细胞系)MESPU 13,我们将ES细胞显微注射到C57BL/6J小鼠的囊胚中构建嵌合鼠。在注射了2-9个ES细胞的136个囊胚中,127个囊胚(93%)经过3个小时的培养后重新出现囊胚腔。当把119个恢复的囊胚移植到假孕雌鼠的子宫内时,获得63只(52.9%)出生鼠。在59只存活到可以判断毛色阶段的小鼠中,有21只(35.6%)被判定为嵌合鼠。显示了该ES细胞系具有较高的嵌合能力。  相似文献   
83.
中国成都地区汉族人群DHFRP2位点的遗传多态性研究   总被引:4,自引:0,他引:4  
用扩增片断长度多态性技术分析短串联重复序列(STR)DHFRP2位点的DNA多态性, 在156个中国成都地区汉族无关个体中发现6个等位基因,19种基因型,并首次发现一重复单元数不是4的整数倍的等位基因,该等位基因按孟德尔遗传规律遗传。观察的基因型分布符合Hardy-Weinberg定律,其个人鉴别力(DP)为0.87,杂合度为67.3%,多态性信息量(PIC)为0.68,非父排除率(CE)为45.5%,家系分析结果表明, 该位点符合孟德尔遗传法则。 Abstract: Analyzes polymorphism of short tandem repeat locus (DHFRP2) by using Amp-FLP. Six alleles and nineteen genotypes were observed in 156 unrelated individuals of Chinese Hans in Chengdu. Meanwhile, we first discovered a new allele, its repeat monomers is not integral times of four, which is in conformity with Mendelian inheritance. The allelic discriminating power (DP), observed heterozygocity (h), polymorphism information content (PIC) and chances of paternity exclusion (CE) are 0.87, 67.3%, 0.68 and 45.5% respectively. The distribution of its genotypes tally with Hardy-Weinberg equilibrium and family study manifested that the locus is in conformity with medelian inheritance.  相似文献   
84.
陆地棉产量性状的遗传效应及其与环境互作的分析   总被引:23,自引:0,他引:23  
本研究根据加性-显性与环境互作的遗传模型, 分析了陆地棉10个杂交亲本和20个F1皮棉产量、单株铃数、单铃重、衣分和前期收花率的两年资料,估算了各项遗传方差分量和成对性状间各项遗传效应的相关。方差分析结果表明,衣分受基因型×环境互作效应影响较小,其它4个性状受基因型×环境互作影响较大,其中皮棉产量、单株铃数和前期收花率受显性×环境互作效应影响较大。遗传相关分析表明,皮棉产量与单株铃数、衣分和前期收花率加性相关系数值较大,皮棉产量与单株铃数、单铃重和前期收花率间存在较强的加性与环境互作负相关。皮棉产量与单株铃数、单铃重和前期收花率间存在显著的显性正相关,但与单株铃数、单铃重间存在显性与环境互作相关。 Abstract:Ten parents and their 20 F1s of upland cotton were analyzed for five yield traits in two years by a genetic model of additive-dominance with interaction effects.Genetic variance components and correlations were estimated.It was indicated that the gene by year effects interaction were small for lint percentage,but large for the other four traits,the dominance by year effects interaction were very large for lintvield,boll number and first picking percentage,especially.The additive correlation between lint yield with boll number,lint percentage and first picking percentage were significantly and high.The dominance correlations between lint yield and boll number,and between boll weight and first picking percentage were significantly too.The correlation of additive by year interaction between lint yield and boll number,boll weight and first picking percentage and those of dominance interaction by year between lint yield and boll number,boll weight were significant and large.The dominance correlation between boll number and boll weight were large too.  相似文献   
85.
Most life history traits are positively influenced by body size, whereas disadvantages of large body size are poorly documented. To investigate presumed intrinsic costs of large size in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae), we established two replicates each of three body size laboratory selection lines (small, control and large; selection on males only), and subjected flies of the resulting extended body size range to various abiotic stresses. Response to selection was symmetrical in the small and large lines (realized h(2) = 0.16-0.18). After 24 generations of selection body size had changed by roughly 10%. Female size showed a correlated response to selection on male size, whereas sexual size dimorphism did not change. Development time also showed a correlated response as, similar to food limited flies, small line flies emerged earlier at smaller body size. At the lowest larval food limit possible, flies of all lines emerged at the same small body size after roughly the same development time; so overall phenotypic plasticity in body size and development time strongly increased following selection. Juvenile mortality increased markedly when food was extremely limited, large line flies showing highest mortality. Winter frost disproportionately killed large (line) flies because of their longer development times. Mortality at high temperatures was high but size-selective effects were inconsistent. In all environments the larger males suffered more. Initial growth rate was higher for males and at unlimited food. Small line individuals of both sexes grew slowest at unlimited larval food but fastest at limited larval food, suggesting a physiological cost of fast growth. Overall, extension of the natural body size range by artificial selection revealed some otherwise cryptic intrinsic juvenile viability costs of large size, mediated by longer development or faster growth, but only in stressful environments.  相似文献   
86.
Emerging studies support that RNA-binding proteins(RBPs)play critical roles in human biology and pathogenesis.RBPs are essential players in RNA processing and metabolism,including pre-mRNA splicing,polyadenylation,transport,surveillance,mRNA localization,mRNA stability control,translational control and editing of various types of RNAs.Aberrant expression of and mutations in RBP genes affect various steps of RNA processing,altering target gene function.RBPs have been associated with various diseases,including neurological diseases.Here,we mainly focus on selected RNA-binding proteins including Nova-1/Nova-2,HuR/HuB/HuC/HuD,TDP-43,Fus,Rbfox1/Rbfox2,QKI and FMRP,discussing their function and roles in human diseases.  相似文献   
87.
88.
The allozyme genetic variability of various species is correlated with a variety of morphological, physiological and fitness-related traits. In particular, temperature can affect the fitness of insects through its influence on enzyme function. We examined the seasonal (12 days over 1 year) and daily (nine samples over each day) allozyme variation at the phosphoglucomutase (PGM) locus in one population of yellow dung flies (Scathophaga stercoraria; Diptera: Scathophagidae). PGM is of central functional importance in the mobilization of glycogen reserves for flight, and has been shown to affect larval growth at different temperatures in the laboratory. Based on a sample of over 3000 flies, we found a quadratic relationship, with a minimum at approximately 12 degrees C, between the frequency of the most common allele and temperature, primarily mediated by seasonal temperature variation. This could be caused by behavioural responses over the short-term, but over the year either variable viability or sexual selection probably operates on this locus, maintaining the existing polymorphism. These results call for further work on the functional differences between PGM allozyme genotypes.  相似文献   
89.
We report an exceptionally high rate of infection by Haplorchis taichui (Nishigori, 1924) in human populations on Mindanao Island, southern Philippines. This intestinal fluke is seldom encountered, and this is the first report of high prevalence of infection (36%) in humans by H. taichui in the Philippines. The likely source of haplorchine infection has been linked to consumption of raw or undercooked freshwater fish containing infective metacercariae. The most common clinical symptoms appeared as upper abdominal discomfort or pain and borborygmi. Praziquantel (75 mg/kg divided in 3 doses in 1 day) was a well-tolerated and effective treatment for infection by H. taichui.  相似文献   
90.
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