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。     

Histological and immunohistochemical studies of the structure of lymph nodes in Kilis goats

Ten healthy adult Kilis goat mesenteric lymph nodes were used to examine the general structure of lymph nodes, lymphocytes, plasma cells, reticular cells and reticular fibers using histological methods. We also detected T lymphocytes using anti-CD3 [SP7], anti-CD4 [74-12-4], mouse anti-bovine CD4 [CC30] and mouse anti-bovine CD8 [CC63] monoclonal antibodies (mAb); and B lymphocytes using anti-CD79a [HM57] mAb, macrophages using anti-macrophage [MAC387] mAb and follicular dendritic cells using anti-S100 polyclonal antibody (pAb). The distribution of these cells also was studied. Although the primer antibodies we used for CD3, CD8, CD79a, MAC387 and S100 worked well, the primer antibodies for CD4 were ineffective for paraffin embedded goat lymph nodes.     

The role of tryptophan residues in the antigenic activity of carcinoembryonic antigen

Antigenic determinants of carcino-embryonic antigen (CEA) were spatially located using N-bromosuccinimide modification of tryptophan residues both in native (acetate buffer solution) and unfolded (guanidinium chloride solution) molecule of the antigen. Modification of exposed tryptophan residues failed to alter CEA antigenic activity and conformation of its protein portion as shown by CD spectroscopy. On the contrary, modification of buried tryptophan residues induced conformational changes of CEA protein portion connected with a considerable loss of its antigenic activity. It was shown that CEA antigenic activity depends on spatial structure of its protein moiety.     

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。     

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.     

Microsatellite loci variation and investigation of gene flow between two karyoforms of <Emphasis Type="Italic">Cricetulus barabensis</Emphasis> sensu lato (Rodentia,Cricetidae)

We examine the diversity of six microsatellite loci and partial RAG1 exon of “barabensis” and “pseudogriseus” karyoforms in Cricetulus barabensis sensu lato species complex. A total of 435 specimens from 68 localities ranging from Altai to the Far East are investigated. The results of the population structure analysis (factor analysis and NJ tree based on Nei genetic distances) support subdivision into two well-differentiated clusters corresponding to the two karyoforms. These karyoforms are also well differentiated by the level of microsatellite variability. In several “barabensis” specimens, we found microsatellite alleles that are common in “pseudogriseus” populations but are otherwise absent in “barabensis.” Most of these specimens originate from a single population in one of the zones of potential contact between karyoforms, Kharkhorin in Central Mongolia. These molecular results are consistent with previously published karyological data in suggesting that rare hybridization events between the two chromosomal races occur in nature.     

Quantitative trait loci analysis of individual and total isoflavone contents in soybean seeds

Soybean isoflavones play diverse roles in human health, including cancers, osteoporosis, heart disease, menopausal symptoms and pabulums. The objective of this study was to identify the quantitative trait loci (QTL) associated with the isoflavones daidzein (DC), genistein (GeC), glycitein (GlC) and total isoflavone contents (TIC) in soybean seeds. A population of 184 F_21:0 recombinant inbred lines derived from a ‘Xiaoheidou’ בGR8836’ cross was planted in pot and field conditions to evaluate soybean isoflavones. Twenty-one QTL were detected by composite interval mapping. Several QTL were associated with the traits for DC, GeC, GlC and TIC only. QDGeGlTIC4_1 and QDGlTIC12_1 are reported first in this study and were associated with the DC, GeC, GlC and TIC traits simultaneously. The QTL identified have potential value for marker-assisted selection to develop soybean varieties with desirable isoflavone content.     

K<Superscript>+</Superscript> Channels in Cardiomyocytes of the Pulmonate Snail <Emphasis Type="Italic">Helix</Emphasis>

We used the patch-clamp technique to identify and characterize the electrophysiological, biophysical, and pharmacological properties of K⁺ channels in enzymatically dissociated ventricular cells of the land pulmonate snail Helix. The family of outward K⁺ currents started to activate at –30 mV and the activation was faster at more depolarized potentials (time constants: at 0 mV 17.4 ± 1.2 ms vs. 2.5 ± 0.1 ms at + 60 mV). The current waveforms were similar to those of the A-type family of voltage-dependent K⁺ currents encoded by Kv4.2 in mammals. Inactivation of the current was relatively fast, i.e., 50.2 ± 1.8% of current was inactivated within 250 ms at + 40 mV. The recovery of K⁺ channels from inactivation was relatively slow with a mean time constant of 1.7 ± 0.2 s. Closer examination of steady-state inactivation kinetics revealed that the voltage dependency of inactivation was U-shaped, exhibiting less inactivation at more depolarized membrane potentials. On the basis of this phenomenon, we suggest that a channel encoded by Kv2.1 similar to that in mammals does exist in land pulmonates of the Helix genus. Outward currents were sensitive to 4-aminopyridine and tetraethylammonium chloride. The last compound was most effective, with an IC₅₀ of 336 ± 142 µmol l^–1. Thus, using distinct pharmacological and biophysical tools we identified different types of voltage-gated K⁺ channels. Present address for S.A.K.: Brigham and Womens Hospital, Cardiovascular Division, Harvard Medical School, 75 Francis St., Thorn 1216, Boston, MA 02115.