Short form of α9 promotes α9β1 integrin-dependent cell adhesion by modulating the function of the full-length α9 subunit

The α9β1 integrin is a multifunctional receptor that interacts with a variety of ligands including vascular cell adhesion molecule 1, tenascin-C, and osteopontin. A 2.3-kb truncated form of α9 integrin subunit cDNA was identified by searching the Medline database. This splice variant, which we called the short form of α9 integrin (SFα9), encodes a 632-aa isoform lacking transmembrane and cytoplasmic domains, and its authentic expression was verified by PCR and Western blotting. SFα9 is expressed on the cell surface but cannot bind ligand in the absence of the full-length α9 subunit. Over-expression of SFα9 in cells expressing full-length α9 promotes α9-dependent cell adhesion. This promoting effect of SFα9 requires the authentic cytoplasmic domain of the co-expressed full-length α9 subunit. Thus, SFα9 is a novel functional modulator of α9β1 integrin by inside-out signaling.     

斑苦竹无性系种群克隆生长格局动态的研究

采用“例逐龄级累加法”（ＲＡＡ）研究了缙云山斑苦竹无性系种群的克隆生长格局动态,以及无性系分株克隆生长型的动态趋势．结果表明,作为复轴型的斑苦竹,其无性系种群随时间进程表现为聚集程度逐渐降低的集群分布格局．在自然条件下,斑苦竹更多地表现出单轴型的繁殖趋势．应用ＲＡＡ分析植物种群,尤其是竹类植物种群前期的克隆生长格局的动态,结果可靠,具有重要的应用价值．     

Circadian variations of plasma renin activity (PRA), aldosterone and electrolyte concentrations in plasma in pregnant and non-pregnant goats

The aim of this study was to estimate and analyse circadian variations of the renin-angiotensin-aldosterone system (RAA) activity in blood of goats and the influence of late pregnancy on the circadian variations of RAA system. The study was carried out on a group of 17 non-pregnant and 9 pregnant goats. The animals were kept in uniform environmental conditions, (9 h light/15 h darkness). Blood samples were collected seven times over a period of 24 h, every 4 h. Plasma renin activity (PRA), plasma aldosterone (PA), sodium, potassium and chloride concentrations were determined. PRA and PA of both groups changed during 24 h, with the highest values in the dark phase and with higher RAA system activity (especially during the night) in the pregnant goats. In the non-pregnant goats, no circadian changes in PRA and PA were observed. The circadian changes in PRA and PA found in pregnant goats had acrophases at 06:27 h and 01:13 h, respectively. Plasma electrolyte concentrations in both groups of goats also changed during 24 h. These results suggest that circadian changes of potassium concentration in plasma of goats during late pregnancy may be one of the main factors affecting the RAA system.     

重组酶介导扩增技术及其在病原微生物快速检测中的应用进展*

建立快速的病原学诊断方法对动物疫病的预防和控制、公共卫生安全等方面具有重要意义。重组酶介导扩增法(RAA)是一种新型恒温体外核酸扩增技术,在体外较低温度下就可以实现对DNA或RNA的快速扩增。RAA具有操作简便、快速、准确、节能、便捷等优点。重组酶、单链结合蛋白和DNA聚合酶是该技术的三大核心物质,利用这三种物质可替代传统PCR的热循环解链过程。该技术将会在病原微生物检测方面发挥重要作用。对RAA技术及其在病原检测方面的应用进行了综述,以期为相关领域的研究提供参考。