荷花成熟胚的组织培养

以荷花成熟胚为材料,研究不同消毒剂、培养基对荷花离体培养的影响.结果表明:0.1%HgCl2消毒8 min,污染率为0,成活率86.63%是有效消毒方式;根据不同浓度植物激素的培养基对成活率,萌发率及生长状况分析,MS+0.5 mg.L-16-BA+0.5 mg.L-1NAA为适宜诱导荷花成熟胚萌发的培养基;以MS+1.0 mg.L-16-BA+1.0 mg.L-1NAA为培养基所生成的根数、芽数相对较高.     

花生(Arachis hypogea L.)体细胞胚胚性特异蛋白的研究

花生萌发３ｄ的胚叶在诱导培养基上出现高频率的体细胞胚发生．ＳＤＳ－ＰＡＧＥ分析结果表明：在体细胞胚发生过程中，诱导第三天开始出现３条新的蛋白谱带，７ｄ后出现２条新带，１５ｄ后又出现３条；而在非胚性组织中检测到抑制性的特异蛋白条带．     

Effects of retinoic acid on embryonic development of mice in culture

Summary The effects of all-trans-retinoic acid (RA) (tretinoin) on the craniofacial development of mouse embryos were examined using whole embryo culture. In day 8 embryos cultured for 48 h, embryonic growth was inhibited concentration-dependently by all-trans-RA treatment. Most of the treated embryos exhibited hypoplasia of the primary palatal processes and a reduction in the development of the first viscreral arches. In day 10 embryos cultured for 48 h, although embryonic growth was not inhibited at any concentrations of all-trans-RA, median cleft lip (93%), hypoplasia of the primary palatal processes (37%) and limb reduction deformities (48%) occurred commonly. Furthermore, RA treatment greatly reduced the size of the secondary palatal processes. The incorporation of³H-thymidine in the treated maxillary processes was decreased to 65% of the control value at 1.0×10^–7 M alltrans-RA. These findings indicate that all-trans-RA is teratogenic in mouse whole embryo culture.     

双酚A对鸡胚中枢免疫器官发育影响的形态学观察

为进一步研究双酚A(BPA)的毒性作用,本试验对9日龄AA鸡胚和SPF鸡胚尿囊腔注射双酚A,待鸡胚孵化至22日龄,取鸡胚法氏囊和胸腺进行下述各项指标测定和形态学观察。结果显示,与对照组相比较,试验组鸡胚孵出率显著降低,法氏囊指数明显变小(p<0.05);染毒组法氏囊淋巴滤泡个数显著少于对照组(p<0.01),胸腺皮质、髓质厚度极显著小于对照组(p<0.01);光镜观察发现,双酚A染毒组法氏囊淋巴滤泡和胸腺髓质中的髓细胞明显多于对照组,扫描电镜下可见细胞间隙明显增大,显现针孔样结构。研究结果表明,双酚A对AA鸡胚和SPF鸡胚中枢免疫器官有毒性作用,对鸡胚法氏囊和胸腺的发育有显著的抑制作用。     

斑马鱼模型在药物早期安全性评价中的应用

在药物研发领域,建立经济、有效的药物早期安全性评价技术已成为当前国内外的迫切需求。斑马鱼作为常用的三大模式动物之一,是一种理想的药物早期安全性评价模型。采用该模型对新药进行早期安全性评价可以提高药物早期毒性预测的可靠性和灵敏度,缩短新药研发周期,降低新药研发成本,提高新药研发成功率。本文综述了斑马鱼模型在药物早期安全性评价,如一般毒性评价、发育毒性评价、神经毒性评价、器官毒性评价、生殖毒性评价等中的作用。随着生物与医药技术的发展,斑马鱼在药物研发的早期安全性评价领域将发挥更大的作用,并推动药物研发的进程。     

苍耳子提取物对斑马鱼的发育及运动行为的毒性研究

为研究苍耳子提取物对斑马鱼胚胎发育及运动行为的影响,取受精后12/24 h斑马鱼胚胎,将胚胎分别置于不同浓度苍耳子提取物溶液中,在作用不同时间后,显微镜下统计孵化率、死亡率和心率;取受精后120 h斑马鱼胚胎,用不同浓度苍耳子提取物处理60 min后,利用行为学分析系统统计各组斑马鱼在0~10、10~20、20~30 min内行为轨迹,基于游行距离与游行时间得到游行速度,并统计转圈值。结果表明,苍耳子提取物对受精后12 h斑马鱼胚胎的发育有毒性,使斑马鱼胚胎的孵化率降低,在提取物浓度大于15μg/mL时,孵化率低于40%;0.93μg/mL苍耳子提取物可提高24 h斑马鱼胚胎的心率(P≤0.01),当提取物浓度大于7.5μg/mL时,心率显著性降低(P≤0.01);在行为学分析中发现,当苍耳子提取物浓度大于3μg/mL时,游行速度与转圈均值明显增加。研究认为,苍耳子提取物对斑马鱼胚胎发育有毒性作用,能够兴奋斑马鱼胚胎心率并增加其游行速度。     

利用斑马鱼模型评价Vc和异Vc-Na抑制黑色素的生物活性

利用斑马鱼模型,通过表型观察、色素面积计算、酪氨酸酶活性测定三方面参数来评价Vc和异Vc-Na的抑制黑色素活性。首先利用已知的具有抑制黑色素活性的天然化合物熊果苷来验证该方法的可行性,获得预期结果后,再开展Vc和异Vc-Na的实验。实验结果表明,Vc水溶液在非致死的浓度范围内(0.01~5 mmol/L),对斑马鱼黑色素的形成未见明显影响,较高浓度的异Vc-Na水溶液能够显著抑制斑马鱼黑色素的形成(p≤0.05),而高浓度的异Vc-Na水溶液(≥0.3 mol/L)容易导致斑马鱼的形态学畸形。     

Induction of cranial and posterior trunk neural crest by exogenous retinoic acid in zebrafish

Retinoic acid (RA) plays an important role in development of vertebrate embryos. We demonstrate impacts of exogenous RA on the formation of neural crest cells in zebrafish using specific neural crest markers sox9b and crestin. Treatment with all -trans RA at 10₋₇ mmol/L at 50% epiboly induces sox9b expression in the forebrain and crestin expression in the forebrain and midbrain, resulting in significant increase of pigment cells in the head derived from the cranial neural crest. In addition, RA treatment induces expression of sox9b and crestin in the caudal marginal cells of the neuroectoderm during early segmentation. Earlier commitment of these cells to the neural crest fate in the posterior margins leads to abnormal development of the posterior body, probably by preventing mingling of ventral derived and dorsal-derived cells during the formation of the tailbud.