气泡室中"胚胎"气泡成长为可见气泡的模型建立及初步的理论计算

建立了气泡室中“胚胎”气泡成长为可见气泡模型.初步计算表明,“胚胎”气泡在成长为可见气泡的过程中,它不仅要从其周围吸收热量,而且还有分子进入到它的里面.理论上可以合理解释能量相同的中子和质子入射到气泡室所产生的径迹上的气泡半径是不同的,中子在气泡室中产生的径迹细长,而质子在气泡室中产生的径迹粗短;可以合理解释在同一径迹上某个区域内可以有半径大小相差不多的气泡存在;也可以合理解释电荷数较多的入射粒子较能量相同但电荷数不同的入射粒子,其在气泡室中径迹上气泡的半径要大;理论上预测入射粒子刚进入气泡室时,其径迹上有大气泡破裂现象发生.通过选择合适的工作物质可以提高气泡室的灵敏度和探测效率.     

稀土和微量元素对鸡胚生长发育影响的研究

研究了稀土和微量元素对鸡胚生长发育的影响及吸收分布情况。以海兰种蛋为实验材料,在稀土中按一定比例添加不同量的7种生物必需微量元素,注入种蛋进行孵化,实验发现,稀土与微量元素共用对鸡胚生长发育有一定影响;稀土剂量一定,加入不同量的微量元素,稀土和微量元素会产生最佳配比;最佳配比能使鸡胚正常生长发育,且稀土在各组织中的积累较使用同剂量的单一稀土少。     

电感耦合等离子体原子发射光谱法测定紫斑牡丹胚乳和胚中矿物质元素

为了给离体体细胞胚的人工胚乳配制提供矿物质元素种类和数量方面的参考,用浓硝酸-高氯酸(4∶1)的混合溶液消解紫斑牡丹的胚乳和胚样品,采用电感耦合等离子体-原子发射光谱法(ICP-AES)测定了样品中的(K、Na、Ca、Mg、Fe、Cu、Zn、Mn、Li、Ni、B、Ag、Cd、Pb)14种矿物质元素含量。结果表明:各元素的校准曲线的回归系数在0.9990～0.9999之间,线性良好;方法精密度高,能多元素同时分析;紫斑牡丹胚乳和胚中均含有植物生长必需的K、Ca、Mg 3种大量元素,Fe、Mn、Cu、Zn、Ni、B 6种微量元素,1种有益元素Na,及Li和Pb,Ag、Cd则未被检测到。在被检测到的12种元素中,Mg、Zn、Mn、Fe、K、Na、Li与Ni 8种元素在胚乳中的含量低于胚中的含量,Ca、Cu、Pb与B在胚乳中的含量则高于胚中的含量。     

异翅独尾草（百合科）的胚胎学研究

异翅独尾草子房内部结构特殊，子房壁内外表层细胞特化，腔内具贮水组织；胚珠外面覆以特殊附属物－假种皮；珠心组织在珠孔端及合点端细胞具明显的极性分化，胚囊为７细胞８核的蓼型结构。     

Micro-magnetic resonance imaging study of live quail embryos during embryonic development

Eggs containing live Japanese quail embryos were imaged using micro-magnetic resonance imaging (μMRI) at 24-h intervals from Day 0 to 8, the period during which the main body axis is being laid down and organogenesis is taking place. Considerable detail of non-embryonic structures such as the latebra was revealed at early stages but the embryo could only be visualized around Day 3. Three-dimensional (3D) changes in embryo length and volume were quantified and also changes in volume in the extra- and non-embryonic components. The embryo increased in length by 43% and nearly trebled in volume between Day 4 and Day 5. Although the amount of yolk remained fairly constant over the first 5 days, the amount of albumen decreases significantly and was replaced by extra-embryonic fluid (EEF). ¹H longitudinal (T₁) and transverse (T₂) relaxation times of different regions within the eggs were determined over the first 6 days of development. The T₂ measurements mirrored the changes in image intensity observed, which can be related to the aqueous protein concentrations. In addition, a comparison of the development of Day 0 to 3 quail embryos exposed to radiofrequency (rf) pulses, 7 T static magnetic fields and magnetic field gradients for an average of 7 h with the development of control embryos did not reveal any gross changes, thus confirming that μMRI is a suitable tool for following the development of live avian embryos over time from the earliest stages.     

Epigenetic game theory: How to compute the epigenetic control of maternal-to-zygotic transition

Epigenetic reprogramming is thought to play a critical role in maintaining the normal development of embryos. How the methylation state of paternal and maternal genomes regulates embryogenesis depends on the interaction and coordination of the gametes of two sexes. While there is abundant research in exploring the epigenetic interactions of sperms and oocytes, a knowledge gap exists in the mechanistic quantitation of these interactions and their impact on embryo development. This review aims at formulating a modeling framework to address this gap through the integration and synthesis of evolutionary game theory and the latest discoveries of the epigenetic control of embryo development by next-generation sequencing. This framework, named epigenetic game theory or epiGame, views embryogenesis as an ecological system in which two highly distinct and specialized gametes coordinate through either cooperation or competition, or both, to maximize the fitness of embryos under Darwinian selection. By implementing a system of ordinary differential equations, epiGame quantifies the pattern and relative magnitude of the methylation effects on embryogenesis by the mechanisms of cooperation and competition. epiGame may gain new insight into reproductive biology and can be potentially applied to design personalized medicines for genetic disorder intervention.     

Correlation of protoporphyrin metabolism in cell proliferation with embryonic development time: A spectroscopic investigation

The cell proliferation process in chick embryos was monitored using fluorometry. The 410 nm-excited emission spectra of albumin from controlled and incubated eggs were measured. A strong emission near 622 nm was observed, which is the characteristic emission of protoporphyrin IX (PPIX). It was found that the metabolic level of PPIX for the initial phase increases linearly with the embryonic development time (t) as M_PPIX^l(t)=M_PPIX⁰+αt, where α is a factor proportional to the rate of PPIX accumulation and M_PPIX⁰ is the initial value of M_PPIX^l(t), suggesting a possible method for estimating the stages of the organ development.     

Differential vitellin polypeptide processing in insect embryos

This review focuses on the current status of knowledge regarding the process of vitellogenin (Vg) uptake and vitellin (Vt) storage in insect oocytes. We also consider the overall morphology of the yolk sac as an embryonic organ allowing for both temporal and spatial differentiation of yolk degradation to provide the primary food supply for the embryo. In this context we describe the evidence that demonstrates the occurrence of Vt polypeptide processing and how it may be affected by maternally derived proteases stored in the yolk granules and by the ubiquitin–proteasome system in the cytosol. The extent of Vt polypeptide processing induced by these proteases will be correlated with the structural modifications affecting yolk granules and vitellophages in developing insect embryos. To accomplish these goals the ultrastructural and cytochemical composition of yolk granules during vitellogenesis and embryogenesis will be reviewed. Last but not the least, our current understanding of the role played by acidification of yolk granules in the activation of maternally derived proteases will also be examined.