世界森林昆虫学研究现状与发展趋势展望

森林昆虫学160多年来随着其它许多相关学科的发展不断成长和壮大，因而理论，防治方法和技术上取得了长足发展，该文回顾了迄今世界森林昆虫学研究的现状,从七个方面阐述了森林昆虫学突飞猛进的进展情况，文中第二部分对森林昆虫学在新世纪的发展趋势作了展望，这对我国林业的可持续发展和森林保护工作具有十分重要的借鉴意义。     

Interactions between metabolic status, pre-breeding protein supplementation, uterine pH, and embrionic mortality in ewes: Preliminary observations

The effect of prebreeding short-term protein supplementation level (PL) and body condition (BC) on fertility rate (FERT,%), uterine pH and embryonic mortality (EMORT,%) in sheep, was evaluated. Multiparous Rambouillet ewes at low BC (LC; n = 6, 62.7 ± 1.7 kg) or high BC (HC; n = 6, 71.9 ± 1.7 kg), received. within BC, one of two levels of ruminally undegradable protein: low (LP, 14 g/ewe per day) and high (HP, 30 g/ewe per day). Once the animals were euthanized, corpus luteum number (CLN), as an indicator of ovulation rate, was registered and uterine horns were irrigated to recover embryonic tissue plus associated membranes as well as to measure uterine pH (UpH). While EMORT-1 considered a nonadjusted relationship between the number of embryos and CLN, EMORT-2 considered an analysis of covariance using CLN as the covariate. The HP-supplemented ewes had the lowest FERT (p=0.06; 100% vs 50%) and the highest EMORT (EMORT-1, 16.6% vs 53.8%, p = 0.08; EMORT-2, 52.0% vs 14.5%, p = 0.07) when compared to the LP-supplemented ewes. Neither BC nor PL affected CLN, CL weight or P₄ release (p > 0.10). While the lowest UpH (p = 0.04) was observed in the HP-supplemented ewes, this group also showed the lowest fertility and the highest embryonic mortality.     

Primary study on the differentiation mechanism of embryonic stem cells to epidermal like cells induced by human amnion

AIM: To investigate the mechanism by which human amnion induced mouse embryonic stem (ES) cells to differentiate into epidermal like cells. METHODS: ES- BALB/ c cells were cocultured with human amnionintranswells for 4 - 5 days , andthose cultured alone without amnion were taken as control group. The morphological differentiation were observed . The committed differentiation of EScells into epidermal like cells were detected by integrin-β₁ , CK19 , CK15 andinvolucrin immunohistochemistry , respectively .RESULTS: After 4-5 days of coculture, ES cells differentiated into single layer of epidermal like cells, fitted tightly, with polyhedral in shape. The immunohistochemical staining results showed that, most of the cells were integin-β₁ positive, only a few cells were CK19 and CK15 positively stained. Most of the cells in control group died, the survived ones were different in morphological shapes, and no integrin-β₁, CK19 and CK15 positive cells were found. CONCLUSION: Soluble substances secreted by human amnion may play an important role in inducing the differentiation of mouse ES cells into epidermal like cells.     

Supportive effects of human aorta-gonad-mesonephero stromal cells on the directed differentiation of embryonic stem cells into hematopoietic stem cells

AIM: To direct embryonic stem cells (ESCs) into hematopoietic stem cells (HSCs) in vitro by simulating the hematogenic microenvironment in human early embryonic aorta-gonad-mesonephero (AGM) region.METHODS: Murine E14 embronic stem cell line was used for two-step differentiation.In the first step of primary differentiation,E14 ESCs were seeded into semisolid methylcellulose-based medium containing bone morphogenesis protein 4 (BMP4) and vascular endothelial growth factor (VEGF) for embryoid body (EB) formation.On days 3,6,9,12 and 15,single EB cells were analyzed for Flk-1+ cells amount through flow cytometry.In the second step,single cell from EB containing most Flk-1+ cells was further co-cultured with human AGM stromal cells in non-contact system.On co-culture days of 3,6,9 and 12 days,cells were collected for cell count,flow cytometry for Sca-1+c-kit+ cells analysis,and colony forming cell assay.RESULTS: During the EB formation,BMP4+VEGF promoted Flk-1+ cell genesis on day 9 at peak pencentage value of 27.53%±2.84％,which was statistically higher than that in control group as 8.77±1.10 (P<0.05).Collagenase-disassociated single cell from day 9 EB was co-cultured with human AGM stromal cells of hAGMS3 or hAGMS4 for further hematopoietic differentiation.On day 6 Sca-1+c-kit+ cells got to peak value as 7.31%±1.21％ ［(2.57±0.48) folds］ and 7.62%±1.52％ ［(2.35±0.36) folds］ in hAGMS3 and hAGMS4 feeder systems,respectively,both of which were greater than those values of no-stroma groups at the same culture duration (P<0.05).Colonogenic cell assay showed that these Sca-1+c-kit+ cells had ability of forming multiple lineage hematopoietic colonies.CONCLUSION: BMP4 in combination with VEGF promotes Flk-1+ cell genesis during EB formation in vitro.Stromal cells from early human embryonic AGM region further enhance the directed differentiation of these primitive cells into HSCs.This two-step induction differentiation model can be used for molecular mechanism study of ESCs hematopoietic differentiation.     

芹菜胚性愈伤的诱导及高频植株再生体系的建立

通过对芹菜离体培养过程中激素配比、基因型、不定芽产生等条件的研究,建立了芹菜高频植株再生体系。研究表明,芹菜苗期的下胚轴最适于诱导愈伤组织,其愈伤组织诱导和继代培养的最佳培养基是MS+2,4-D1.0mg·L-1+KT1.0mg·L-1和MS+2,4-D0.5mg·L-1+BA0.2mg·L-1+CH500mg·L-1+4%甘露醇;基因型对愈伤组织和胚状体的诱导影响很大;60%以上的愈伤组织在继代培养基上可以从非胚性状态向半胚性和胚性状态转化。愈伤组织在1/2MS+1.5%蔗糖+CH500mg·L-1+KT0.25mg·L-1上获得不定芽或小试管苗;在无激素的MS或1/2MS固体培养基上继续培养不定芽或小试管苗,即可生根或长大,获得芹菜的完整再生植株。     

影响油桃叶片产生胚性愈伤组织的因素

以早熟油桃华光和曙光为试材,对影响早熟油桃叶片产生胚性愈伤的基本培养基、外源激素、碳源、环境(光照强度,温度,暗培养时间)等因素进行研究,结果表明:碳源对两种油桃叶片胚性愈伤的诱导影响不显著,其他影响因子对油桃叶片胚性愈伤的诱导均显著。其中华光和曙光在暗培养21d时,产生的有效愈伤较其他处理有极显著差异,有利于有效愈伤的产生;外源激素对诱导桃叶片产生胚性愈伤组织影响显著,NAA不是影响胚性愈伤产生的主效因子;基本培养基中,QL,1/2MS培养基有利于华光胚性愈伤的发育,QL,LP培养基有利于曙光胚性愈伤的发育;当温度在24￣27.5℃时,光照强度为2000lx,有利于胚性愈伤组织的诱导及生长;接种方式上,叶背横切,叶面贴于培养基表面的接种方法易产生胚性愈伤。实验中发现:叶背横切,叶面接于G+2.5mg/LBA+0.5mg/LIBA培养基上,暗培养21d,转入1/2MS+2.0mg/lTDZ+2.0mg/LBA+0.5mg/LNAA的培养基中,温度控制在24￣27.5℃,光照强度为2000lx时,愈伤组织发育良好,获得高频胚性愈伤,进一步分化产生8%的不定芽。     

利用动物胚胎干细胞生产转基因动物研究进展

介绍了利用动物胚胎干细胞生产转基因动物的程序和方法,并阐述了利用胚胎干细胞生产转基因动物的意义。     

N6培养基添加钙和烯效唑对玉米幼胚培养的作用

通过浓度筛选和比较试验,将以N6培养基为基础的诱导培养基和继代培养基的钙浓度,从1.13 mmol/L提高到5 mmol/L,并分别添加1.00 mg/L和0.50 mg/L 烯效唑（S-3307）,对玉米幼胚胚性愈伤组织的诱导和继代具有促进作用,而不影响胚性愈伤组织的分化再生。在分化培养基中添加低浓度（0.25 mg/L）S-3307,能显著提高分化再生率     

FGF18在脊椎动物胚胎发育中的表达和调控作用

成纤维细胞生长因子18(FGF18)是成纤维细胞生长因子家族的成员之一,参与调控一系列重要的生长发育过程,包括脑的发育、肢体和躯干的形成、骨骼生长发育和胚胎发育等。就FGF18在脊椎动物胚胎发育时期的神经系统、呼吸系统、骨骼、肢体及不对称发育等组织、器官中的表达和调控作用进行了综述,以期为药物开发提供理论依据。