Phenotypic plasticity induced using high ambient temperature during embryogenesis in domesticated zebrafish,Danio rerio

Ambient temperature during early stages of life has a substantial effect on physiological processes, eliciting phenotypic plasticity during zebrafish developmental stages. Zebrafish are known to possess a noteworthy ability to modify their phenotype in dependence of environmental factors. However, there is a poor understanding of the effects of temperature during embryogenesis, which influences the biological functions such as survival ability and masculinization in later developmental stages. Since the middle embryonic phase (pharyngula period) is genetically the most conserved stage in embryogenesis, it is very susceptible to embryonic lethality in developmental processes of vertebrates. Here, we tested the effect of transient perturbations (heat shock) during early development (5–24 hr post‐fertilization; hpf) at 35°C compared to control group at 28°C, on survival ability of zebrafish to study the embryonic and post‐embryonic mortality. We studied the variation of heat‐induced masculinization among and across the families in response to high temperature. Furthermore, morphometric traits of adult zebrafish at different developmental time points were measured in order to estimate the temperature × sex interaction effect. We found the highest embryonic mortality around the gastrula and segmentation periods in both experimental groups, with significantly lower survival ability in the temperature‐treated group (73.30% ± 0.58% vs. 70.19% ± 0.57%, respectively). A higher hatching success was observed in the control group (71.08% ± 0.61%) compared to the heat‐induced group (67.95% ± 0.60%). A distinct reduction in survival ability was also observed in both experimental groups during the first two weeks after hatching, followed by a reduced level of changes thereafter. We found sex ratio imbalances across all families, with 25.2% more males under temperature treatment. Our study on growth performance has shown a positive effect of increased temperature on growth plasticity, with a greater impact on female fish in response to high ambient temperature.     

鸭MyoG基因编码区的克隆及其在鸭心肌组织发育中的表达研究

肌细胞生成素(myogenin,MyoG)在胚胎发育中发挥作用,并能与在心脏发育过程中起重要作用的MEF2基因家族协同促进肌肉的分化,而其在心肌发育中的作用却鲜有报道。为研究其在胚胎心肌组织发育过程中的作用,本研究扩增了鸭MyoG基因CDS序列,并采用实时荧光定量PCR法检测了MyoG在鸭E10、E14、E18、E22、E27 d及出生后1周雏鸭(P7 d)心肌组织中共6个阶段的表达变化。基因扩增得到鸭MyoG基因CDS序列共684bp,编码227个氨基酸,预测其含有碱性螺旋-环-螺旋(bHLH)结构域。结果表明:MyoG在鸭E10 d中的表达量最高,显著高于E14、E18、E22和E27 d(P0.05);E14 d与E18 d,E22 d和E27 d之间的表达差异不显著(P0.05);MyoG在鸭出壳前心肌组织中的表达量整体呈现下降趋势,出生后1周,表达量又明显上升,与E22 d和E27 d差异显著(P0.05)。MyoG在鸭心肌组织的发育中起作用,其机理可能是通过MyoG的bHLH结构域直接或以MEF2基因家族介导间接实现对心脏发育的调控。     

苜蓿原生质培养及体细胞杂交技术的应用

阐述了植物原生质体培养和体细胞杂交技术以及苜蓿Medicago spp.体细胞胚胎发生特性,综述了该技术在苜蓿育种研究中的应用状况,同时介绍了我国苜蓿研究领域原生质体培养和体细胞杂交技术的研究进展.     

小白菜小孢子培养胚状体的诱导

21个小白菜品种小孢子培养结果表明:适宜的花蕾长为2.5~3.5mm,花瓣与花药长度比为1/2~3/4;0.05~0.10 mg.L-1的细胞分裂素能促进小孢子胚的发生,高于此浓度的细胞分裂素对小孢子胚的产生有抑制作用,并使小孢子胚向畸形化发展;0.05mg.L-16-BA 0.10 mg.L-1NAA的配比可以明显提高成熟胚的比例。     

体细胞胚胎发生杂种马褂木造林密度试验

在福建省将乐国有林场,通过连续3a对引自南京林业大学培育的体细胞胚胎发生杂种马褂木密度试验幼林进行观测研究.结果表明体细胞胚胎发生杂种马褂木适生性强,3a生林分保存率达到99%以上.林分生长良好,3a生时平均树高、胸径分别为2.26 m和2.3 cm,具有良好的推广应用前景.不同造林密度对体细胞胚胎发生杂种马褂木幼林生长总体而言有着显著影响,这种影响在林分2a生后开始得以体现,3a生时影响达到极显著水平.     

大白菜游离小孢子培养技术高效体系的研究

以大白菜吉红82、#534DH 群体及#438 群体为试材，研究了利用细胞破碎仪机械提取小孢子与人工挤压提取小孢子对大白菜游离小孢子活力及提取量的影响。结果表明：机械提取替代人工挤压可在短时间内同时提取多份样品，并可快速调整小孢子的培养浓度。收集40 个适期花蕾于5 mL 离心管内，3 000 r·min-1 破碎10 s，将提取的小孢子定容于25 mL NLN-13 培养基，可确保小孢子浓度在适宜培养范围内，并成功诱导胚胎发生。     

高等植物小孢子胚胎发生的细胞和分子生化机制研究进展

小孢子胚胎发生的细胞学研究已取得了显著进展,并分离鉴定出一些小孢子胚胎发生表达的胚胎专一基因,但小孢子胚胎发生的机理尚未完全明确。综述了高等植物小孢子胚胎发生的细胞学以及分子和生物化学方面的最新研究进展,旨为进一步揭示小孢子的胚胎发生机理提供十分有用的信息。     

落叶松体细胞胚胎发生研究进展

综述了欧洲落叶松、日本落叶松、欧日和日欧杂种落叶松、西部落叶松和华北落叶松体细胞胚胎发生的研究进展，对胚性培养物的超低温保存、原生质体培养和基因转化等技术进行了介绍，并对落叶松体细胞胚胎发生的研究趋势作了展望。     

花楸树体细胞胚与合子胚的发生发育

利用花楸树人工控制授粉后的未成熟合子胚进行体细胞胚的诱导培养,通过石蜡切片、扫描电镜和透射电镜对合子胚和体细胞胚的发生发育过程进行组织、细胞观察。结果表明:1)体细胞胚发生进程与合子胚相似,均经历了球形期、心形期、鱼雷形期,最终发育成成熟胚;2)直接发生和间接发生在愈伤组织表面的体细胞胚均为单细胞起源,间接发生在愈伤组织内部的体细胞胚存在单细胞起源,同时还存在可能的多细胞起源;3)子叶和愈伤组织表面发生的体细胞胚在发育早期均具明显的胚柄,鱼雷形胚期胚柄退化;4)愈伤组织内部发生的体细胞胚没有胚柄;5)与合子不同,胚性细胞的第1次分裂为均等分裂;6)多细胞原胚周围降解的细胞具有细胞程序性死亡的形态特征。