β-环糊精包合雨生红球藻皂化产物可行性研究

本文以雨生红球藻皂化产物中虾青素含量为评价指标,对β-环糊精包合雨生红球藻皂化产物可行性进行了实验研究。试验结果表明,当雨生红球藻粉在优选的实验条件下皂化产物经β-环糊精包合后,HPLC检测主要成分组成未见明显变化,包合率可达到90%。于温度40℃,湿度75%条件下进行稳定性加速实验,结果表明,经皂化后包合物中虾青素稳定性较好,达到了药物和保健食品原料的稳定性要求,说明该方法可行。     

Higher-order folding of heterochromatin: protein bridges span the nucleosome arrays.

In interphase eukaryotic nuclei, chromatin is divided into two morphologically distinct types known as heterochromatin and euchromatin. It has been long suggested that the two types of chromatin differ at the level of higher-order folding. Recent studies have revealed the features of chromatin 3D architecture that distinguish the higher-order folding of repressed and active chromatin and have identified chromosomal proteins and their modifications associated with these structural transitions. This review discusses the molecular and structural determinants of chromatin higher-order folding in relation to mechanism(s) of heterochromatin formation and genetic silencing during cell differentiation and tissue development.     

低能离子束辐照下水稻中与ABA相关基因的差异表达

本文检测了用基因芯片筛选出水稻种子被低能N＋辐照后引起的差异表达的ABA代谢和信号途径相关基因。结果显示,与ABA合成相关的ZDS、Lyc-β、ZEP、NCED、SDR这五种酶的基因表达量均为上调;受ABA调控的的H＋-ATPase、NR、Rubisco的基因表达变化显著;ABA依赖的逆境应答蛋白DREB和ASR的表达量上调;受ABA信号转导调控的蛋白LEA的表达量下调,GAD和P5CS的表达量上调。这些结果表明,6×1017N＋·cm-2剂量的辐照可能促进了ABA的合成和幼苗气孔的开放,同时促进了ABA信号系统并激活或抑制了一些相关基因的表达。     

Molecular phylogeny and divergence times of Hormaphidinae (Hemiptera: Aphididae) indicate Late Cretaceous tribal diversification

The aphid subfamily Hormaphidinae is a good candidate for the study of the evolution of insect – plant relationships. Most hormaphidine species depend on woody primary host plants and woody or herbaceous secondary host plants, and represent high host specificity, especially to their primary hosts. No detailed molecular phylogeny of Hormaphidinae has been reported, and the taxonomic positions of some taxa in this group remain unclear. To reconstruct major phylogenetic relationships and to understand the evolution of host association patterns for major lineages, we present the first detailed molecular phylogeny of Hormaphidinae, as inferred from nuclear and mitochondrial DNA sequences, using maximum parsimony, maximum likelihood, and Bayesian methods. The monophyly of Hormaphidinae and its three traditional tribes was supported, and a sister relationship between Hormaphidini and Nipponaphidini was suggested. Most inner relationships within tribes were also supported, and some novel relationships were revealed. Two subtribes of Cerataphidini are proposed. Divergence times estimated using a Bayesian approach indicate that tribal diversifications occurred during the Late Cretaceous and were coincident with the appearance of their primary host plants. The current pattern of secondary host association for the three tribes may have evolved in different time ranges. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 73–87.     

Paternal care behaviour of the giant water bug Kirkaldyia deyrolli (Heteroptera: Belostomatidae) against ants

1. Although potentially vulnerable to predators, the offspring of subsocial insects are effectively protected by their parent(s). The female giant water bug Kirkaldyia deyrolli lays its egg masses on the vegetation above the water surface in aquatic environments and the males supply the eggs with water and guard them against cannibalistic females until hatchling dispersal. Field observations showed that egg masses are attacked by ants if the attending males are not present. 2. Laboratory experiments were conducted to evaluate the effects of paternal care by K. deyrolli against the ant Tetramorium tsushimae by means of four treatments: attending male with ant approach (WM‐WA); no attending male with ant approach (NoM‐WA); attending male without ant approach (WM‐NoA); and no attending male without ant approach (NoM‐NoA). 3. The rate of offspring survival was lower in the NoM‐WA group (45.3%) than in any other group, which showed similar offspring survival (WM‐WA = 80.4%, WM‐NoA = 75.1%, NoM‐NoA = 80.3%). Moreover, there were a total of 44 interactions between the attending male and ants in WM‐WA, and of these, a chemical compound was released by the attending male four times; this probably deterred ants from attacking because the ants went back to their colony. 4. In conclusion, the attending male can protect its eggs from ant predators and its care has an important role. To the best of the authors' knowledge, this is the first report of Lethocerinae males protecting their egg masses from ants by means of physical and chemical defence.     

锂对铅引起的大鼠海马CA1区长时程增强效应（LTP）损伤的修复作用

应用离体脑片记录技术,记录大鼠海马CA1区的兴奋性突触后电位(EPSPs),研究了锂对铅引起的大鼠海马CA1区长时程增强效应(long-termpotentiation,LTP)损伤的修复作用。结果表明:对照组大鼠海马CA1区LTP幅度为194.42±14.05%(n=10);铅处理组LTP的幅度为147.06±9.55%(n=13);而锂加铅处理组LTP的幅度为193.45±14.91%(n=15)。与对照组相比,铅处理组LTP的幅度降低了47.36%,而锂几乎完全修复了铅对大鼠海马CA1区LTP幅度的损伤。锂和铅处理后对大鼠海马CA1区的双脉冲易化(paired-pulsefacilica-tion,PPF)都有一定的抑制作用,在脉冲间隔为50ms时,这种抑制效应最大:对照组为155.58±6.35%(n=7);铅暴露组为150.26±13.74%(n=8);锂加铅处理组为140.59±15.42%(n=8)。结果表明:锂对铅引起大鼠海马CA1区LTP的损伤有一定的修复作用。