变形能对奥氏体相变临界核胚尺寸的影响

针对利用变形诱导铁素体相变来细化晶粒这一材料研究领域的新方向 ,基于热力学原理 ,考虑变形诱导相变因素时 ,对奥氏体—铁素体相变在不同条件下形核的临界核胚尺寸进行了模拟计算 ,从相变时形核这一角度对变形诱导的铁素体相变进行了分析 ,比较了变形存储能对临界核胚尺寸的影响。计算表明 ,变形能的加入可以使临界核胚减小 。

铁镍基合金中蝶状马氏体核胚的研究

利用透射电子显微镜(TEM)在Fe-Ni-V-C合金中观察到一些马氏体核胚,核胚的结构为特殊的位错组态:Burgers矢量为1/2[011]fcc,且一端为封闭的发夹型位错,和在发夹型位错内塞税的、Burgers矢量为1/2[110]fcc的位错列。它们分别提供了马氏体相变所必须的二次切变。

等温马氏体转变的核胚数问题

通过对现有铁基合金等温马氏体转变动力学模型的分析，在肯定自促发形核机制的基础上，首次提出由自促作用所形成核胚数的瞬时值，使得动力学方程形式简单、意义明了，并结合实测数据进行了数值计算。结果表明：理论计算与实测情况一致。

兔移核重构胚再程序化相关基因片段的分离与鉴定

用单个植入前胚胎mRNA差别显示方法 (SinglePreimplantationEmbryonicmRNADifferentialDisplayReversePolymeraseReaction ,SPEDDRT PCR) ,以家兔移核重构发育至 2细胞、8细胞时期的胚胎及囊胚作为起始材料。研究家兔移核重构胚再程序化相关基因的表达。获得了 2 5个与再程序化相关的基因片段 ,完成了对所有片段的克隆、序列分析 ,其中 5个反向Northern证实的片段在从MⅡ到囊胚的发育阶段中呈现特异性表达的特点。这项研究为再程序化相关基因全长的分离以及功能研究奠定了良好的基础。

人精子2细胞胚微核实验方法建立与应用

人精子２细胞胚微核实验方法建立与应用李耒玉，黄天华，陈壁锋，林珏龙，郑巧玲，黄建民多年来，环境诱变剂对人类生殖细胞的诱变监测多通过人类体细胞或哺乳动物生殖细胞的研究来外推。因诱变剂对人类生殖细胞和体细胞效应的敏感性不同，对不同物种的效应也有差异。因此...

基于核微分同胚变换的实时剩余寿命预测

基于核密度估计的实时剩余寿命预测,不对数据分布形式做任何假设,而从数据本身出发研究其分布特征,避免了现有许多数据驱动方法需要进行模型结构假设及参数估计,但会导致寿命预测不够准确的问题,而传统核密度估计用于有界变量的概率密度估计时,会在区间边界处产生估计偏差,进而影响剩余寿命预测的准确性。针对以上问题,本文提出一种基于核微分同胚估计的实时剩余寿命预测方法。该方法利用微分同胚变换将有界随机变量变换到整个实数域,从而转换为传统意义上的核密度估计问题进行求解。最后,通过实例验证了该方法的可行性和有效性,并对最优初始样本数对实时剩余寿命预测准确性的影响进行了分析。

牛核供体胚发育阶段对核移植卵发育率的影响试验

本试验以体外培养６８、９２、１１６、１４０小时的体外受精卵为核供体胚，以体外培养成熟的卵母细胞为核受体进行了核移植试验。结果获得了８２％—９６％的融合率：将融合后的核移植卵与牛输卵管上皮细胞共同培养，７３％—８７％发育至２细胞期胚；２２％—５３％的核移植卵发育至８细胞期胚；以１１６小时组发育率最高，１４０小时组发育率最低；核移植卵发育至囊胚的比率分别为１３％（１３／１０２）、３％（２／７１）、３５％（３３／９５）和１２％（１２／９９），以９２小时组最低，１１６小时组最高。试验结果表明，核供体胚发育阶段及细胞周期对核移植卵的发育率有显著影响。

基因型HS86-11去雄穗细胞胚胎学观察

通过对基因型HS 86- 11去雄穗细胞胚胎学观察发现 ,该基因型具有兼性无融合生殖假配合特性 ,表现在 :( 1)有性生殖胚囊与无融合生殖胚囊同时存在 ,属于兼性无融合生殖类型。( 2 )在有性生殖胚囊中 ,可观察到完整的八核胚囊。 ( 3)在无融合生殖胚囊中 ,卵细胞、助细胞行单性生殖 ,在未受精的情况下 ,自主发育成胚。可观察到细胞分裂及幼胚发育的不同时期。( 4 )在同一卵器中 ,助细胞与助细胞、助细胞与卵细胞之间 ,发育并不一致 ,有时发现助细胞发育超前于卵细胞。 ( 5)极核细胞能自主融合成为一个次生大细胞 ,但未观察到融合后的细胞进一步分化。 ( 6)在所有切片中 ,尚未发现胚乳细胞形成。 ( 7)自主发育的卵细胞最大可发育到两核幼胚阶段 ,进而发现胚囊解体。估计与不能形成正常胚乳细胞 。

An Effective Method for Extracting Total RNA from Young Embryo of Seedless Litchi

A total RNA extraction method for young embryo of seedless litchi was introduced. CTAB, Phenol （saturated with water）, chloroform, Guanidine isothioeyanate were used as main extraction reagents. Polyphenolie compounds were removed effectively by added PVP into the extraction buffer solution. RNA was purified intensively by phenol, chloroform extraction, and ethanol deposition after deposited by LiCl. Both the results of formaldehyde denatured agarose gel eleetrophoresis and ultraviolet spectrophotometer analysis showed high integrity and purity of RNA. So the quality of extracted RNA could meet the demand of most molecular biology experiments that require higher quality RNA.

Development in vitro in Reconstitution of Embryo from Porcine Somatic Cell Nuclear Transfer

In present paper,a study on reconstitution of porcine oocytes by using nuclear transfer with cumulus cells(CC) and fibroblast cells(FC) was carried out.Reconstituted oocytes which were the fusion with CC and showed a cleavage rate of 56.7%,developed into morula (11.7%) and blastocysts (6.7%) phases which were higher than those derived from the fusion with FC( P <0.05).The results of this study also involved the effects of oocyte collection method,activation protocol and maturational age of recipient oocytes during the in vitro develpoment of nuclear transfer embryos which were reconstituted with cultured cumulus cells.The cumulus cells synchronized in G 0/G 1 phases through serum starvation culture,were transferred into enuclated oocytes which were collected by aspiration or dissection method and cultured for 33 or 44 h.Reconstituted embryos were activated with a combination of calcium ionophore A23187 or electric pulsation and 6 DMAP,and cultured for 6 days.As for the oocyte collection methods,activation treatment in the presence of cytochalasin B and activation protocols did not affect the developmental rate of embryos reconstituted with 44 h mature recipients.However,the development rate of reconstituted embryos with 33 h mature recipients were significantly higher( P <0.05) by activation with the combination of electric pulsation and 6 DMAP.These results suggest that the reconstituted porcine embryos derived from cultured cumulus cells can develop into the blastocyst stage and that the development of the former could be improved for the reconstitution with young oocyte cytoplast after the activation with the combination of electric pulsation and 6 DMAP.

棉籽油分和3种主要脂肪酸含量QTL分析

本研究对棉籽油分、棕榈酸、油酸和亚油酸含量进行了不同遗传体系的QTL分析,为相关性状挖掘出更多有用的基因信息。分别于2017年和2018年,利用陆地棉亲本HS46 (P_(1))和MARCABUCAG8US-1-88 (P2)所构建的188个重组近交系分别与双亲杂交构建F1群体BC (P_(1))和BC(P_(2))。基于这些回交群体种子,采用专为种子性状设计的母体和胚核基因组QTL定位的混合线性遗传模型及QTLNetwork-CL-2.0-Seed软件,对棉籽油分、棕榈酸、油酸和亚油酸含量进行QTL定位分析。共检测到7个控制棉籽油分含量、3个控制棕榈酸含量、2个控制油酸含量和3个控制亚油酸含量的QTL,均具有显著或极显著的源自母体和胚2个核基因组的加性主效应,其中有7个QTL的表型变异贡献率大于10%。研究结果可为这些性状的分子标记辅助选择育种提供更为可靠的参考,为这些性状的分子遗传机制研究提供理论基础。

Enhancement of insulin-producing cell differentiation from embryonic stem cells using pax4-nucleofection method

AIM： To enhance the differentiation of insulin producing cell （IPC） ability from embryonic stem （ES） cells in vitro. METHODS： Four-day embryoid body （EB）-formatted ES cells were dissociated as single cells for the followed plasmid DNA delivery. The use of NucleofectorTM electroporator （Amaxa biosystems, Germany） in combination with medium-contained G418 provided a high efficiency of gene delivery for advanced selection. Neucleofected cells were plated on the top of fibronectincoated Petri dishes. Addition of Ly294002 and raised the glucose in medium at 24 h before examination.The differentiation status of these cells was monitored by semi-quantitative PCR （SQ-PCR） detection of the expression of relative genes, such as oct-4, sox-17, foxa2, mixll, pdx-1, insulin 1, glucagons and somatostatin. The percentage of IPC population on d 18 of the experiment was investigated by immunohistochemistry （IHC）, and the content/secretion of insulin was estimated by ELISA assay. The mice with severe combined immunodeficiency disease （SCID） pretreated with streptozotocin （STZ） were used to eliminate plasma glucose restoration after pax4^＋ ES implantation. RESULTS： A high efficiency of gene delivery was demonstrated when neucleofection was used in the present study; approximately 70% cells showed DsRed expression 2 d after neucleofection. By selection of medium-contained G418, the percentage of DsRed expressing cells kept high till the end of study. The pancreatic differentiation seemed to be accelerated by pax4 nucleofection. When compared to the group of cells with mock control, foxa2, mixll, pdxl, higher insulin and somatostatin levels were detected by SQ-PCR 4 d after nucleofection in the group of pax4 expressing plasmid delivery. Approximately 55% of neucleofected cells showed insulin expression 18 d after neucleofection, and only 18% of cells showed insulin expression in mock control. The disturbance was shown by nucleofected pax4 RNAi vector; only 8% of cells expressed insulin 18 d after nucleofection. A higher IPC population was also detected in the insulin content by ELISA assay, and the glucose dependency was demonstrated in insulin secretion level. In the animal model, improvement of average plasma glucose concentration was observed in the group of pax-4 expressed ES of SCID mice pretreated with STZ, but no significant difference was observed in the group of STZ-pretreated SCID mice who were transplanted ES with mock plasmid. CONCLUSION： Enhancement of IPC differentiation from EB-dissociated ES cells can be revealed by simply using pax4 expressing plasrnid delivery. Not only more IPCs but also pancreatic differentiation-related genes can be detected by SQ-PCR. Expression of relative genes, such as foxa 2, mixl 1, pdx-1, insulin 1 and somatostatin after nucleofection, suggests that pax4 accelerates the whole differentiation progress. The higher insulin production with glucose dependent modulation suggests that pax4 expression can drive more mature IPCs. Although further determination of the entire mechanism is required, the potential of pax-4-nucleofected cells in medical treatment is promising.

Establishment of customized mouse stem cell lines by sequential nuclear transfer

Therapeutic cloning, whereby embryonic stem cells （ESCs） are derived from nuclear transfer （NT） embryos, may play a major role in the new era of regenerative medicine. In this study we established forty nuclear transfer-ESC （NTESC） lines that were derived from NT embryos of different donor cell types or passages. We found that NT-ESCs were capable of forming embryoid bodies. In addition, NT-ESCs expressed pluripotency stem cell markers in vitro and could differentiate into embryonic tissues in vivo. NT embryos from early passage RI donor cells were able to form full term developed pups, whereas those from late passage RI ES donor cells lost the potential for reprogramming that is essential for live birth. We subsequently established sequential NT-RI-ESC lines that were developed from NT blastocyst of late passage R 1 ESC donors. However, these NT-R I-ESC lines, when used as nuclear transfer donors at their early passages, failed to result in live pups. This indicates that the therapeutic cloning process using sequential NT-ESCs may not rescue the developmental deficiencies that resided in previous donor generations.

环磷酰胺体外对人精子诱变性研究

目的 :探讨环磷酰胺 (CP)在体外测试系统中对人精子的诱变性。 方法 :使用不同浓度的CP与人精子和代谢活化酶作用 3h ,再与地鼠卵体外授精 ,研究精子染色体和 2细胞胚微核诱变作用。 结果 :CP有损伤精子染色体和诱发 2细胞胚微核作用。 结论 :CP在代谢活化酶作用的离体测试系统中 ,对人精子有诱变性 。

Developmental competence and ultrastructural changes of heat-stressed mouse early blastocysts produced in vitro

Mouse early blastocysts were exposed to temperatures of 39℃ and 41℃ for 2 h, respectively, to determine their developmental competence and ultrastructural changes. The results showed that heat stress at 41 ℃ for 2 h, significantly reduced the percentages of expanded and hatched blastocysts, but not at 39℃ for 2 h. The average cell numbers in expanded blastocysts, which developed from early blastoeysts heat-stressed at temperatures of 39℃ and 41 ℃, were significantly reduced. The average cell numbers in hatched blastocysts subjected to heat stress were no different from those in the control group cultured at 37 ℃ . The mitochondria of the early blastocysts heat-stressed at 39℃ for 2 h, were slightly swollen, but they had recovered after culturing at 37 ℃ for 2 h. However, the mitochondria in the blastocysts heat stressed at 41 ℃ for 2 h were severely swollen, and their number increased. The ribosomes shed from the rough endoplasmic reticulum, and the number of secondary lysosomes in the plasma increased. The integrity of desmosomes was disrupted. The space between the nuclear envelope and the perivitelline membrane enlarged. The fibre fraction and the particulate fraction of nueleoli were separated. The heterochromatin in nueleoli was also increased in its quantity. There were some lamellar-shape structures and heterogeneous dense materials exhibiting in the cytoplasm. The ultrastructural changes induced by heat shock at 41 ℃ for 2 h were not reversible. In conclusion, the damage of heat stress to mitoehondria, lysosomes, ribosomes and cell nucleus, may be one of the most important factors that inhibit the normal development of mouse early blastoeysts .

Embryonic stem cells generated by nuclear transfer of human somatic nuclei into rabbit oocytes

To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at ages of 5, 42, 52 and 60 years, and nuclear transfer (NT) embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells are human based on karyotype, isogenicity, in situ hybridization, PCR and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintain the capability of sustained growth in an undifferentiated state, and form embryoid bodies, which, on further induction, give rise to cell types such as neuron and muscle, as well as mixed cell populations that express markers representative of all three germ layers. Thus, ntES cells derived from human somatic cells by NT to rabbit eggs retain phenotypes similar to those of conventional human ES cells, including the ability to undergo multilineage cellular differentiation.

Arg-X Protease-Sensitive in Supramolecular Structures of Interphase Cell Nucleus during Growth Morphogenesis Mature Germs of Wheat

Abstract： In the present study was investigated Arg-X protease-sensitive in supramolecular-genome compartments （nucleoplasm, chromatin, nuclear matrix）, during the period of the transcriptional activation of chromatin when the growth processes was initiated in the mature germs of winter and transformed from it spring wheat. The germs have been separated from endosperm from 0 h （air-dry seed） up to 21 h in each 3 h after the start of seeds soaking. Cell nucleus have been allocated from germs and cleared, and then from them supramolecular-genome compartments were extracted by increasing ionic strength of solution. The Arg-X （tryptase） activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine in all nuclear fractions. In the present study have shown what Arg-X protease-sensitives zones can be located on the supramolecular structures of chromatin matrix in processes of realization of ontogenetic programs of development in mature germs of the winter and transformed from it spring wheat. Arg-X protease-sensitive can translocate and coordinated in heteropolymer structures on the same genetic matrix. Questions of epigenetic mechanisms are discussed.

培养基中能量底物对猪胚胎发育的影响

旨在探讨丙酮酸和乳酸对猪(Susscrofa)胚胎早期发育的影响,将NCSU-23培养基中的5.56mmol/L葡萄糖替换为0.2mmol/L丙酮酸、5.7mmol/L乳酸,并将此培养基命名为mNCSU-23。根据实验设计,孤雌胚及核移植胚转移到mNCSU-23或NCSU-23中培养。激活第2天统计孤雌胚及核移植胚中的5～8细胞胚胎数。激活第6天统计孤雌胚及核移植胚囊胚形成率及囊胚细胞数。实验结果表明,mNCSU/NCSU处理组的5～8细胞胚胎数及囊胚数显著高于对照组(P<0.05);单纯使用mNCSU培养猪胚胎时,囊胚率最低,发育结果最差(P<0.05)。本研究证实,在体外培养前两天,用乳酸和丙酮酸代替培养基中的葡萄糖对胚胎发育有利。

Assessing the Germplasm of Laminaria (Phaeophyceae) with Random Amplified PoLymorphic DNA (RAPD) Method

Eighteen gametophytes includingL. japonica, L. ochotensisandL. longissima, were verified with random amplified polymorphic DNA (RAPD) technique. Eighteen ten-base primers were chosen from 100 primers selected for final amplification test. Among the total of 205 bands amplified, 181 (88.3%) were polymorphic. The genetic distance among different strains ranged from 0.072 to 0.391. The dendrogram constructed by unweighted pair-group method with arithmetic (UPGMA) method showed that the female and male gametophytes of the same cell lines could be grouped in pairs respectively. It indicated that RAPD analysis could be used not only to distinguish different strains ofLaminaria, but also to distinguish male and female gametophyte within the same cell lines. There is ambiguous systematic relationship if judged merely by the present data. It seems that the use of RAPD marker is limited to elucidation of the phylogenetic relationship among the species ofLaminaria.