Serial nuclear transfer improves the development of interspecies reconstructed giant panda (Aluropoda melanoleuca) embryos

Interspecies somatic nuclear transfer (NT) may provide a new approach for preservation of the endangered rare species. Previous interspecies cloning studies have shown that a nucleus from a quiescent somatic cell supports early development of reconstructed embryos in the ooplasm from another species. In this study, we transferred nonquiescent somatic cells from a giant panda into the perivitelline space of the enucleated rabbit oocytes. After electrofusion (at the rate of 71.6%) and electrical activation, 4.2% of the panda-rabbit reconstructed embryos developed to blastocyst in vitro. For improving the development rate of reconstructed embryos, we used serial NT in this study, i.e. blastomeres from reconstructed morulae were transferred into the perivitelline space of the enucleated rabbit oocytes. The fusion rates in the groups of serial I, serial II and serial III were 79.5%, 84.1% and 78.0%, respectively, having no difference with that of somatic group. And the blastocyst rates in serial NT groups were 19.4%, 13.5% and 10.3%, respectively, which are significantly higher than that in somatic NT group. These results indicate that the nuclei from nonquiescent somatic cells can support early development of reconstructed embryos and serial NT can improve the development rate of interspecies reconstructed embryos. These authors contributed equally to this work.     

Mutations in Rab3a alter circadian period and homeostatic response to sleep loss in the mouse

Rab3a is the most abundant Rab (ras-associated binding) protein in the brain and has a regulatory role in synaptic vesicle trafficking. Mice with a targeted loss-of-function mutation in Rab3a have defects in Ca(2+)-dependent synaptic transmission: the number of vesicles released in response to an action potential is greater than in wildtype mice, resulting in greater synaptic depression and the abolishment of CA3 mossy-fiber long term potentiation. The effect of these changes on behavior is unknown. In a screen for mouse mutants with abnormal rest-activity and sleep patterns, we identified a semidominant mutation, called earlybird, that shortens the circadian period of locomotor activity. Sequence analysis of Rab3a identified a point mutation in the conserved amino acid (Asp77Gly) within the GTP-binding domain of this protein in earlybird mutants, resulting in significantly reduced levels of Rab3a protein. Phenotypic assessment of earlybird mice and a null allele of Rab3a revealed anomalies in circadian period and sleep homeostasis, providing evidence that Rab3a-mediated synaptic transmission is involved in these behaviors.     

Insertional mutagenesis in zebrafish rapidly identifies genes essential for early vertebrate development

To rapidly identify genes required for early vertebrate development, we are carrying out a large-scale, insertional mutagenesis screen in zebrafish, using mouse retroviral vectors as the mutagen. We will obtain mutations in 450 to 500 different genes--roughly 20% of the genes that can be mutated to produce a visible embryonic phenotype in this species--and will clone the majority of the mutated alleles. So far, we have isolated more than 500 insertional mutants. Here we describe the first 75 insertional mutants for which the disrupted genes have been identified. In agreement with chemical mutagenesis screens, approximately one-third of the mutants have developmental defects that affect primarily one or a small number of organs, body shape or swimming behavior; the rest of the mutants show more widespread or pleiotropic abnormalities. Many of the genes we identified have not been previously assigned a biological role in vivo. Roughly 20% of the mutants result from lesions in genes for which the biochemical and cellular function of the proteins they encode cannot be deduced with confidence, if at all, from their predicted amino-acid sequences. All of the genes have either orthologs or clearly related genes in human. These results provide an unbiased view of the genetic construction kit for a vertebrate embryo, reveal the diversity of genes required for vertebrate development and suggest that hundreds of genes of unknown biochemical function essential for vertebrate development have yet to be identified.     

黄河沉积物中重金属离子的形态转化及释放研究

以黄河包头段上游清洁河段的沉积物为吸附剂,以Pb^2 、Cu^2 、Zn^2 、Cd^2 等多离子溶液为吸附质,开展了重金属离子被黄河沉积物吸附后的再释放,以及吸附作用对重金属形态转化的影响等实验研究．结果表明,重金属离子被黄河沉积物吸附后,各元素均不转入残渣态,Cu^2 和Zn^2 主要向碳酸盐结合态及铁锰氧化物结合态转化,Pb^2 主要向碳酸盐结合态和可交换态转化;Cd^2 主要转入可交换态和碳酸盐结合态．吸附后的赋存形态决定了Cd^2 的释放量及释放能力远远大于其它3种重金属离子,由Cd^2 排放引起的污染不易消除且影响长久．     

Signal frequency based self－tuning fuzzy controller for semi－active suspension system

A new kind of fuzzy control scheme, based on the identification of the signal‘ s main frequency and the behavior of the ER damper, is proposed to control the semi-active suspension system. This method ad-justs the fuzzy controller to achieve the best isolation effect by analyzing the main frequency‘ s characters and inspecting the change of system parameters. The input of the fuzzy controller is the main frequency and the op-timal damping ratio is the output. Simulation results indicated that the proposed control method is very effec-tive in isolating the vibration.     

A novel long-chain acyl-derivative of epigallocatechin-3-O-gallate prepared and purified from green tea polyphenols

Lipophilic tea polyphenols (LTP) were prepared by catalytic esterifieation of green tea polyphenols (GRIP) with hexadeeanoyl chloride. A novel long-chain aeyl-derivative of epigalloeateehin-3-o-gallate(EGCG) was first isolated from purification of LTP by high-speed eountereurrent ehromatography (HSCCC)using a solvent system composed of n-hexane-ethyl acetate-methanol-water ( 1 : 1 : 1 : 1, v/v) . The moleeularstructure of the acyl-derivative, Epigallocatechin-3-O-gallate-4‘-O-hexadeeanate , was elucidated by meansof elemental analysis, IR, 1H-NMR and MS spectra.     

Is the PhyloCode better than Linnaean system?—— New development and debate on biologi-cal nomenclatural issues

The Linnaean system provides ultimate means governing biological nomenclature and classification.With series of modification,this system has admirably served biological sciences for some 250 years.The new PhyloCode,however,advocates the phylogenetic nomenclature that radically alternates the current nomenclatureal rules.The new proposals upset many systematic biologists and have provoked hot debate on nomenclatural issues.Binomial nomenclature and hierarchical classification are the key components of the Linnaean system.Proposed abandonment of these in the PhyloCode is widely criticized for it would not help to promote systematics but create chaos.It is not the Linnaean system but the phylogenetic nomenclature that should be abandoned.