新疆紫草细胞悬浮培养生产紫草宁衍生物的动态测定机理化因子调控

本文在本实验室提供的新疆紫草愈伤组织高产系A1的基础上，采用二步培养法，进行摇瓶悬浮培养，分别在生长及生产培养基中测定了细胞生长，次生产物合成，培养基的C源（蔗糖）消耗，溶氧，电导率和pH值的动态变化曲线，确定了各动态曲线之间的关系，为进一步的放大培养提供了参考依据。同时，还测定了与细胞生长密切相关的过氧化物酶及与产物合成密切相关的苯丙氨酸解氨酶(PAL)的活性的动态变化曲线，进一步将宏观参数的动态变化与微观参数的动态变化联系起来。 本文还对不同理化因子对生产培养基中悬浮培养的细胞的生长及紫草宁衍生物合成的影响进行了研究。结果表明：过高或过低的供氧水平均不利于细胞的生长及产物的合成;C源及N源有较好的协同作用，适当地提高C源及N源的水平能明显提高紫草宁衍生物的产量：接种前往培养基里加入一定量的前体苯丙氨酸( Phe)，能明显提高紫草宁衍生物的产量，而在培养中期添加则有一定的负致应;一定量的拜土及琼脂(agar)的添加，对产物的合成均具有正效应，并且作用大小和细胞的生理状态有关。高密度培养的研究表明，在合适的接种量和培养基浓度下，适当提高溶氧，较大幅度地提高产量是有可能的，这还有待于进一步的研究验证。

Evolution of genome organizations of squirrels (Sciuridae) revealed by cross-species chromosome painting

With complete sets of chromosome-specific painting probes derived from flow-sorted chromosomes of human and grey squirrel (Sciurus carolinensis), the whole genome homologies between human and representatives of tree squirrels (Sciurus carolinensis, Callosciurus erythraeus), flying squirrels (Petaurista albiventer) and chipmunks (Tamias sibiricus) have been defined by cross-species chromosome painting. The results show that, unlike the highly rearranged karyotypes of mouse and rat, the karyotypes of squirrels are highly conserved. Two methods have been used to reconstruct the genome phylogeny of squirrels with the laboratory rabbit (Oryctolagus cuniculus) as the out-group: ( 1) phylogenetic analysis by parsimony using chromosomal characters identified by comparative cytogenetic approaches; ( 2) mapping the genome rearrangements onto recently published sequence-based molecular trees. Our chromosome painting results, in combination with molecular data, show that flying squirrels are phylogenetically close to New World tree squirrels. Chromosome painting and G-banding comparisons place chipmunks ( Tamias sibiricus), with a derived karyotype, outside the clade comprising tree and flying squirrels. The superorder Glires (order Rodentia + order Lagomorpha) is firmly supported by two conserved syntenic associations between human chromosomes 1 and 10p homologues, and between 9 and 11 homologues.

Detecting positive darwinian selection in brain-expressed genes during human evolution

To understand the genetic basis that underlies the phenotypic divergence between human and non-human primates, we screened a total of 7176 protein-coding genes expressed in the human brain and compared them with the chimpanzee orthologs to identity genes

平顶猴TRIM5α基因变异影响其抗HIV-1功能

目的:解释平顶猴成为唯一能够被HIV-1感染的旧大陆猴以及在被SIV感染时出现较其他旧大陆猴严重临床症状的原因.方法:参考人TRIM5α基因的结构和序列合成引物,以平顶猴DNA 为模板,分别扩增其TRIM5α基因编码序列的所有外显子.利用生物学软件分析获得的编码序列,分析在已经明确与TRIM5α抗病毒功能密切相关的几个位点上是否发生可能影响其功能的突变.结果:在平顶猴基因组上CypA基因融合到TRIM5α基因第八外显子的下游,融合方式与在鹰猴中发现的CypA与TRIM5α的融合方式完全不同.恒河猴TRIM5α基因具有限制HIV-1复制的功能,第332位脯氨酸对其抗病毒功能非常重要,但在平顶猴的TRIM5α上,该氨基酸突变成谷氨酰胺;第335位以后8个氨基酸对恒河猴TRIM5α抗病毒功能也有重要影响,但在平顶猴的TRIM5α上,与其对应的氨基酸片段不仅缺失了两个氨基酸,还有两个氨基酸发生突变,附近区域还有另外两个发生突变.在平顶猴TRIM5α基因的Coiled-Coil结构域插入了13个氨基酸,但没有影响到编码框.结论:在平顶猴的基因组上CypA与TRIM5α的融合以及平顶猴TRIM5α基因抗病毒功能关键位点上的氨基酸突变可能影响其抗病毒功能,是其成为唯一能够被HIV-1感染的旧大陆猴以及在被SIV感染时出现较其他旧大陆猴严重临床症状的重要原因.

奶牛胚胎移植中GnRH、PGF_(2)#alpha#同期发情处理效果的比较

193头健康、经产的黑白花奶牛分为3个组,用3种不同的方法进行同期发情处理和胚胎移植。第1组:注射1次Lutalyse;第2组:注射2次Lutalyse;第3组:注射Fertagyl-Lutalyse-Fertagyl。结果表明:第1组和第2组之间的同期发情胚胎移植率无显著差异(P>0.05),分别为26.5%(21/79)和27.0%(18/68);第3组的同期发情胚胎移植率为60.9%(28/46),显著高于第1组和第2组(P<0.05)。

Opioid Withdrawal for 4 Days Prevents Synaptic Depression Induced by Low Dose of Morphine or Naloxone in Rat Hippocampal CA1 Area In Vivo

The formation of memory is believed to depend on experience- or activity-dependent synaptic plasticity, which is exquisitely sensitive to psychological stress since inescapable stress impairs long-term potentiation (LTP) but facilitates long-term depression (LTD). Our recent studies demonstrated that 4 days of opioid withdrawal enables maximal extents of both hippocampal LTP and drug-reinforced behavior; while elevated-platform stress enables these phenomena at 18 h of opioid withdrawal. Here, we examined the effects of low dose of morphine (0.5 mg kg(-1), i.p.) or the opioid receptor antagonist naloxone (1 mg kg(-1), i.p.) on synaptic efficacy in the hippocampal CA1 region of anesthetized rats. A form of synaptic depression was induced by low dose of morphine or naloxone in rats after 18 h but not 4 days of opioid withdrawal. This synaptic depression was dependent on both N-methyl-D-aspartate receptor and synaptic activity, similar to the hippocampal long-term depression induced by low frequency stimulation. Elevated-platform stress given 2 h before experiment prevented the synaptic depression at 18 h of opioid withdrawal; in contrast, the glucocorticoid receptor (GR) antagonist RU38486 treatment (20 mg kg(-1), s.c., twice per day for first 3 days of withdrawal), or a high dose of morphine reexposure (15 mg kg(-1), s.c., 12 h before experiment), enabled the synaptic depression on 4 days of opioid withdrawal. This temporal shift of synaptic depression by stress or GR blockade supplements our previous findings of potentially correlated temporal shifts of LTP induction and drug-reinforced behavior during opioid withdrawal. Our results therefore support the idea that stress experience during opioid withdrawal may modify hippocampal synaptic plasticity and play important roles in drug-associated memory. (C) 2009 Wiley-Liss, Inc.