Multiple adaptive losses of alanine-glyoxylate aminotransferase mitochondrial targeting in fruit-eating bats

The enzyme alanine-glyoxylate aminotransferase 1 (AGT) functions to detoxify glyoxylate before it is converted into harmful oxalate. In mammals, mitochondrial targeting of AGT in carnivorous species versus peroxisomal targeting in herbivores is controlled by two signal peptides that correspond to these respective organelles. Differential expression of the mitochondrial targeting sequence (MTS) is considered an adaptation to diet-specific subcellular localization of glyoxylate precursors. Bats are an excellent group in which to study adaptive changes in dietary enzymes; they show unparalleled mammalian dietary diversification as well as independent origins of carnivory, frugivory, and nectarivory. We studied the AGT gene in bats and other mammals with diverse diets and found that the MTS has been lost in unrelated lineages of frugivorous bats. Conversely, species exhibiting piscivory, carnivory, insectivory, and sanguinivory possessed intact MTSs. Detected positive selection in the AGT of ancestral fruit bats further supports adaptations related to evolutionary changes in diet.     

地高辛精标记酪氨酸羟化酶RNA探针的制备研究

为制备用地高辛精（Ｄｉｇｏｘｉｇｅｎｉｎ,Ｄｉｇ）标记的酶氨酸羟化酶（ＴｙｒｏｓｉｎｅＨｙｄｒｏｘｙｌａｓｅ,ＴＨ）ＲＮＡ探针,本研究用分子生物学技术重组质粒ＰＧＥＭＴＨＩ,即分别将携带Ｔ７和Ｓｐ６启动子的ＰＧＥＭ－３ｚｆ质粒和携带ＴＨ基因的ＰＫＳＴＨ质粒用限制性内切酶消化并行分离纯化,得到带Ｔ７和ｓｐ６启动子的ＤＮＡ片段和ＴＨ基因片段;经Ｔ４ＤＮＡ连接酶连接后转入大肠杆菌,得到ｐＧＥＭＴＨ１重组克隆。经小量提取质粒井用酶切分析检测,证实其确有ＴＨ基因且方向正确。将此质粒再经限制性内切酶消化则得到线状ＤＮＡ片段,用Ｔ７ＲＮＡ聚合酶转录合成带有Ｄｉｇ标记的高比活度的单链ＲＮＡ探针;经斑点杂交试验证实该探针具有较高的可靠性。这将为基因治疗帕金森氏病动物模型的疗效检测提供有效手段。     

云南8种树蛙的染色体组型比较研究

本文报道了云南８种树桂的染色体组型,并对目前所已知的树蛙种类的染色体组型进行了比较。锯腿小树蛙Ｐｈｉｌａｕｔｕｓｃａｖｉｒｏｓｔｒｉｓ（Ｇｕｅｎｔｈｅｒ）的２ｎ＝２６,５对大染色体和８对小染色体,９Ｍ＋４ＳＭ,ＮＦ＝５２,Ｎｏ．７长臂近着丝粒处和Ｎｏ．８短臂端部备有一个次缢痕;白颊小树蛙Ｐｈｉ．ｐａｌｐｅｂｒａｌｉｓＳｍｉｔｈ的２ｎ＝２６,５对人染色体和８对小染色体,８Ｍ＋５ＳＭ,ＮＦ＝５２,Ｎｏ．６短臂近着丝粒处有一个次缢痕。白颌大树蛙Ｒｈａ．ｍａｘｉｍｕｓＧｕｅｎｔｈｅｒ的２ｎ＝２６,５对大染色体和８对小染色体,９Ｍ＋４ＳＭ,ＮＦ＝５２;棕褶树蛙Ｒｈａ．ｆｅａｅＢｏｕｌｅｎｇｅｒ的２ｎ＝２６,５对大染色体和８对小染色体,９Ｍ＋４ＳＭ,ＮＦ＝５２;黑蹼树蛙Ｒｈａ．ｒｅｉｎｗａｒｄｔｉｉ（Ｂｏｉｅ）的２ｎ＝２６,５对大染色体和８对小染色体,９Ｍ＋４ＳＭ,ＮＦ＝５２,Ｍｏ．１短臂近着丝粒处有一个次缢痕;红蹼树蛙Ｒｈａ．ｒｈｏｄｏｐｕｓＬｉｕｅｔＨｕ的２ｎ＝２６,５对大染色体,１对中染色体和７对小染色体,９Ｍ＋４ＳＭ,ＮＦ＝５２;斑腿泛树蛙Ｐｏｌｙｐｅｄａｔｅｓｍｅｇａｃｅｐｈａｌｕｓ的２ｎ＝２６,５对大染色体     

Two Phenol Sulfotransferase Species from One cDNA: Nature of the Differences

A phenol sulfotransferase from rat liver (EC 2.8.2.9), expressed inEscherichia colifrom a single cDNA, was purified as two separable but catalytically active proteins. The proteins appeared to be identical to each other and to the natural liver sulfotransferase by comparison of their amino acid constitution, amino-terminal end group, and interaction with a polyclonal antibody raised against the liver enzyme. Each of the recombinant forms, α and β, catalyzed the sulfuryl group transfer from 4-nitrophenylsulfate to an acceptor phenol, a reaction in which 3′-phospho-adenosine 5′-phosphate (PAP) is a necessary intermediate. Only form β, however, catalyzes the physiological transfer of a sulfuryl group from 3′-phosphoadenosine 5′-phosphosulfate (PAPS) to the free phenol. Evidence is presented that sulfotransferase α, but not β, has 1 mol of PAP tightly bound per enzyme dimer. The ability to utilize PAPS as a sulfate donor could be altered: form α could be treated and purified as form β to acquire the ability to use PAPS, whereas form β was treated by extended incubation with PAP, lost its ability to use PAPS, and was purified as form α.     

细毛樟愈伤组织培养

从富含香叶醇的细毛樟（ＣｉｎｎａｍｏｍｕｍｔｅｎｕｉｐｉｌｕｍＫｏｓｔｅｒｍ）叶片外植体诱导出愈伤组织。愈伤组织生长较合适的培养基为ｐＨ５．８附加ＩＡＡ２ｍｇ／Ｌ和ＫＴ０１ｍｇ／Ｌ的ＭＳ培养基,在２５℃下暗培养。愈伤组织无性系继代培养到第６代后芳香成分初步分析结果表明主成分仍为香叶醇。     

红毛五加叶的三萜皂甙

红毛五加（ＡｃａｎｔｈｏｐａｎａｘｇｉｒａｌｄｉｉＨａｒｍｓ）系五加科五加属植物,分布于河北、河南、四川、陕西、甘肃等省,有祛风湿、通关节、强筋骨、治痿痹等功效［１］。其化学成分未见报道。本文报道红毛五加叶的５个三萜皂甙（甙Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ）的分离鉴定。它们均首次从该属植物发现,其结构如下：　　　　　　　　　　　　　Ｒ１　　　　　　　　　　　　　　Ｒ２　　　　　　　　Ⅰ　ｒｈａｍ－（１→２）－ａｒａ　　　　　Ｈ　　　　　　　Ⅱ　Ｈ　　　ｒｈａｍ－（１→４）－ｇｌｃ－（１→６）－ｇｌｃ　　　　　…     

青海湖裸鲤寄生舌状绦虫的空间格局研究

舌状绦虫裂头蚴只寄生在体长小于２２０ｍｍ的青海湖裸鲤中,其种群在宿主种群中呈聚集分布。其聚集分布的强度随寄生虫种群平均密度的增加而降低。由于舌状绦虫在宿主体腔生长,产生明显的空间拥挤效应,可能导致宿主死亡或被食鱼鸟类捕食而转移到终末宿主中。在体长小于１２０ｍｍ的宿主中,密度依赖的死亡过程可能是使聚集强度降低的原因;而体长１４０－２００ｍｍ的鱼中,则是非密度依赖的全死过程使聚集强度增加．     

The mechanism underlying the effects of the cell surface ATP synthase on the regulation of intracellular acidification during acidosis

The F1F0 ATP synthase has recently become the focus of anti‐cancer research. It was once thought that ATP synthases were located strictly on the inner mitochondrial membrane; however, in 1994, it was found that some ATP synthases localized to the cell surface. The cell surface ATP synthases are involved in angiogenesis, lipoprotein metabolism, innate immunity, hypertension, the regulation of food intake, and other processes. Inhibitors of this synthase have been reported to be cytotoxic and to induce intracellular acidification. However, the mechanisms by which these effects are mediated and the molecular pathways that are involved remain unclear. In this study, we aimed to determine whether the inhibition of cell proliferation and the induction of cell apoptosis that are induced by inhibitors of the cell surface ATP synthase are associated with intracellular acidification and to investigate the mechanism that underlines the effects of this inhibition, particularly in an acidic tumor environment. We demonstrated that intracellular acidification contributes to the cell proliferation inhibition that is mediated by cell surface ATP synthase inhibitors, but not to the induction of apoptosis. Intracellular acidification is only one of the mechanisms of ecto‐ATP synthase‐targeted antitumor drugs. We propose that intracellular acidification in combination with the inhibition of cell surface ATP generation induce cell apoptosis after cell surface ATP synthase blocked by its inhibitors. A better understanding of the mechanisms activated by ecto‐ATP synthase‐targeted cancer therapies may facilitate the development of potent anti‐tumor therapies, which target this enzyme and do not exhibit clinical limitations. J. Cell. Biochem. 114: 1695–1703, 2013. © 2013 Wiley Periodicals, Inc.