Heterologous Expression of a Gibberellin 2-Oxidase Gene from <Emphasis Type="BoldItalic">Arabidopsis thaliana</Emphasis> Enhanced the Photosynthesis Capacity in <Emphasis Type="BoldItalic">Brassica napus</Emphasis> L.

Gibberellins (GAs) are endogenous hormones that play an important role in regulating plant stature by increasing cell division and promoting seed germination. The GA2-oxidase gene from Arabidopsis thaliana (AtGA2ox8) was introduced into Brassica napus L. by Agrobacterium-mediated floral-dip transformation with the aim of decreasing the amount of bioactive GA and hence reduced the plant height. As anticipated, the transgenic plant exhibited dwarf phenotype. Importantly, compared with the wild type, the transgenic plants had delayed the seed germination, increased the chlorophyll content (28.7–36.3%) and photosynthesis capacity (14.3–18.7%) in a single leaf. At the same time, the photosynthesis capacity of the whole plants was significantly enhanced (35.7–48.6%) due to the extra leaves and branches.     

Genetic parameters for body weight, carcass chemical composition and yield in a broiler-layer cross developed for QTL mapping

The objective of this study was to estimate genetic and phenotypic correlations of body weight at 6 weeks of age (BW6), as well as final carcass yield, and moisture, protein, fat and ash contents, using data from 3,422 F2 chickens originated from reciprocal cross between a broiler and a layer line. Variance components were estimated by the REML method, using animal models for evaluating random additive genetic and fixed contemporary group (sex, hatch and genetic group) effects. The heritability estimates (h(2)) for BW6, carcass yield and percentage of carcass moisture were 0.31 ± 0.07, 0.20 ± 0.05 and 0.33 ± 0.07, respectively. The h(2) for the percentages of protein, fat and ash on a dry matter basis were 0.48 ± 0.09, 0.55 ± 0.10 and 0.36 ± 0.08, respectively. BW6 had a positive genetic correlation with fat percentage in the carcass, but a negative one with protein and ash contents. Carcass yield, thus, appears to have only low genetic association with carcass composition traits. The genetic correlations observed between traits, measured on a dry matter basis, indicated that selection for carcass protein content may favor higher ash content and a lower percentage of carcass fat.     

The nucleoskeleton as a genome-associated dynamic 'network of networks'

In the cytosol, actin polymers, intermediate filaments and microtubules can anchor to cell surface adhesions and interlink to form intricate networks. This cytoskeleton is anchored to the nucleus through LINC (links the nucleoskeleton and cytoskeleton) complexes that span the nuclear envelope and in turn anchor to networks of filaments in the nucleus. The metazoan nucleoskeleton includes nuclear pore-linked filaments, A-type and B-type lamin intermediate filaments, nuclear mitotic apparatus (NuMA) networks, spectrins, titin, 'unconventional' polymers of actin and at least ten different myosin and kinesin motors. These elements constitute a poorly understood 'network of networks' that dynamically reorganizes during mitosis and is responsible for genome organization and integrity.     

Comparative analysis of oxygen transfer rate distribution in stirred bioreactor for simulated and real fermentation broths

Study of the distribution of the oxygen mass transfer coefficient, k _l a, for a stirred bioreactor and simulated (pseudoplastic solutions of carboxymethylcellulose sodium salt) bacterial (P. shermanii), yeast (S. cerevisiae), and fungal (P. chrysogenum free mycelia) broths indicated significant variation of transfer rate with bioreactor height. The magnitude of the influence of the considered factors differed from one region to another. As a consequence of cell adsorption to bubble surface, the results indicated the impossibility of achieving a uniform oxygen transfer rate throughout the whole bulk of the microbial broth, even when respecting the conditions for uniform mixing. Owing to the different affinity of biomass for bubble surface, the positive influence of power input on k _l a is more important for fungal broths, while increasing aeration is favorable only for simulated, bacterial and yeast broths. The influence of the considered factors on k _l a were included in mathematical correlations established based on experimental data. For all considered positions, the proposed equations for real broths have the general expression k_l a = aC_X^b ( \fracP_a V )^g v_S^d , k_{\rm l} a = \alpha C_{\rm X}^{\beta } \left( {{\frac{{P_{\rm a} }}{V}}} \right)^{\gamma } v_{\rm S}^{\delta } , exhibiting good agreement with experimental results (with maximum deviations of ±10.7% for simulated broths, ±8.4% for P. shermanii, ±9.3% for S. cerevisiae, and ±6.6% for P. chrysogenum).     

On the phylogeny of Mustelidae subfamilies: analysis of seventeen nuclear non-coding loci and mitochondrial complete genomes

Background  

Mustelidae, as the largest and most-diverse family of order Carnivora, comprises eight subfamilies. Phylogenetic relationships among these Mustelidae subfamilies remain argumentative subjects in recent years. One of the main reasons is that the mustelids represent a typical example of rapid evolutionary radiation and recent speciation event. Prior investigation has been concentrated on the application of different mitochondrial (mt) sequence and nuclear protein-coding data, herein we employ 17 nuclear non-coding loci (>15 kb), in conjunction with mt complete genome data (>16 kb), to clarify these enigmatic problems.     

Maternal inheritance of plastids and mitochondria in Cycas L. (Cycadaceae)

Cycas is often considered a living fossil, thereby providing a unique model for revealing the evolution of spermatophytes. To date, the genetic inheritance of these archaic plants is not fully understood. The present study seeks to document the process of organelle inheritance in an interspecific cross of Cycas species. Extranuclear organelle DNA from chloroplasts and mitochondria was analyzed using both polymerase chain reaction-restriction fragment length polymorphism analysis and microscopy. Here, we show that the chloroplasts and mitochondria in the progeny of interspecific crosses between Cycas taitungensis and Cycas ferruginea were exclusively inherited from the female parent. Epifluorescence microscopic analyses of the pollen cells from Cycas elongata indicated that there was a significant degradation of organelle DNA in male reproductive cells following maturation; the DNA fluorescent signals were only seen after pollen mitosis two, but not detectable at mature stage. Lack of organelle DNA fluorescent signal in prothallial cells was confirmed by the absence of plastids and mitochondria in electronic microscopic images. In conclusion, these data suggest that the maternal plastid and mitochondrial inheritance in Cycas, native to the old world, are the same as seen in seed plants.     

GRPR在宫颈疾病中的表达及临床意义

目的：研究胃泌素释放肽受体（GRPR）在正常宫颈组织、宫颈上皮内瘤样病变（CIN）、宫颈癌中的表达,探讨GRPR在促癌发生和癌生长等方面的生物学功能。方法：采用免疫组化SP法检测GRPR在28例宫颈癌、51例宫颈上皮内瘤变和15例正常宫颈组织中的表达情况,其中以正常宫颈组织作为对照。结果：在正常宫颈和宫颈癌组织中,GRPR阳性表达率分别为20%和92.9%。GRPR在CINⅠ、CINⅡ、CINⅢ中阳性表达呈上升趋势,差别无统计学意义。宫颈癌组的不同临床分期、有无淋巴结转移组间比较,GRPR的阳性表达率均有显著性差异,并随病情严重程度的增加,阳性率增高,其表达强度呈显著正相关。结论：GRPR的过度表达与宫颈癌的发生、发展有关,是宫颈癌发生的早期事件,其检测可作为评估宫颈癌恶性程度、判断预后及指导治疗的重要参考指标。     

NaCl胁迫对甘草生长及抗氧化酶活性的影响

目的：通过分析不同浓度NaCl胁迫下甘草生长和抗氧化酶活性的变化探讨甘草对盐分胁迫的适应性机理;方法：采用不同浓度的NaCl溶液（配成Hoagland液）处理盆栽一年生甘草,分别于35d、70d和105d取样,测定甘草株高、地上部分鲜、干重、根鲜、干重及甘草叶片SOD、POD、CAT活性,分析各生长指标与抗氧化酶活性的相关性;结果：NaCl胁迫70d和105d,0．6％和0．9％处理组的株高、地上部分鲜、干重及根鲜、干重均显著低于CK,SOD、POD及CAT活性均显著高于CK,经相关性分析得知,SOD、POD及CAT活性与各生长指标均负相关,其中POD活性与各生长指标极显著负相关;结论：甘草对NaCl胁迫的响应有胁迫时间和浓度的依赖性,在遭遇胁迫时,通过改变自身的生长和提高抗氧化酶活性,来提高机体的抗盐能力。