MC1R是控制鸡黑色素形成的候选主效基因

黑素皮质素受体1 (melanocortin 1-receptor, MC1R)基因是控制动物黑色素合成的重要基因.采用多聚酶链反应-单链构象多态性分析(PCR-SSCP)以及DNA测序的方法,在由丝羽乌骨鸡与明星肉鸡为亲本建立的中国农业大学资源家系群体鸡MC1R基因的编码区检测到3个单核苷酸多态位点,并对该单核苷酸多态性进行了分析.结果显示,鸡MC1R基因编码区引物3扩增片段多态性是由G→A（867位）点突变引起的,引物5扩增片段的多态性是由C→T（1 292位）与C→G（1 377位）两个点突变引起的,最后对单核苷酸多态性与肤色、肉色、胫色与内脏膜色等黑色素性状进行了卡方独立性分析,结果显示,MC1R基因编码区867处突变与鸡的肤色性状显著相关（P＜0.05）,1 292处突变与鸡的活体胫色性状显著相关（P＜0.05）,1 377处突变与鸡的肉色性状显著相关（P＜0.05）.研究表明,MC1R基因可能是鸡黑色素性状的主效基因或者与鸡控制黑色素性状的主效基因连锁.     

MicroRNA expression and regulation in mouse uterus during embryo implantation

MicroRNAs (miRNAs) are 21-24-nucleotide non-coding RNAs found in diverse organisms. Although hundreds of miRNAs have been cloned or predicted, only very few miRNAs have been functionally characterized. Embryo implantation is a crucial step in mammalian reproduction. Many genes have been shown to be significantly changed in mouse uterus during embryo implantation. However, miRNA expression profiles in the mouse uterus between implantation sites and inter-implantation sites are still unknown. In this study, miRNA microarray was used to examine differential expression of miRNAs in the mouse uterus between implantation sites and inter-implantation sites. Compared with inter-implantation sites, there were 8 up-regulated miR-NAs at implantation sites, which were confirmed by both Northern blot and in situ hybridization. miR-21 was highly expressed in the subluminal stromal cells at implantation sites on day 5 of pregnancy. Because miR-21 was not detected in mouse uterus during pseudopregnancy and under delayed implantation, miR-21 expression at implantation sites was regulated by active blastocysts. Furthermore, we showed that Reck was the target gene of miR-21. Our data suggest that miR-21 may play a key role during embryo implantation.     

Rice XA21 binding protein 3 is a ubiquitin ligase required for full Xa21-mediated disease resistance

XA21 is a receptor-like kinase protein in rice (Oryza sativa) that confers gene-for-gene resistance to specific races of the causal agent of bacterial blight disease, Xanthomonas oryzae pv oryzae. We identified XA21 binding protein 3 (XB3), an E3 ubiquitin ligase, as a substrate for the XA21 Ser and Thr kinase. The interaction between XB3 and the kinase domain of XA21 has been shown in yeast and in vitro, and the physical association between XB3 and XA21 in vivo has also been confirmed by coimmunoprecipitation assays. XB3 contains an ankyrin repeat domain and a RING finger motif that is sufficient for its interaction with the kinase domain of XA21 and for its E3 ubiquitin ligase activity, respectively. Transgenic plants with reduced expression of the Xb3 gene are compromised in resistance to the avirulent race of X. oryzae pv oryzae. Furthermore, reduced levels of Xb3 lead to decreased levels of the XA21 protein. These results indicate that Xb3 is necessary for full accumulation of the XA21 protein and for Xa21-mediated resistance.     

不同品种菠菜叶肉及叶柄中硝态氮累积与硝酸还原酶活性的关系

盆栽试验条件下,菠菜体内的硝态氮含量及硝酸还原酶（NR）活性因品种和部位而异。硝态氮含量以短缩茎中最高,叶和叶柄中次之,根中最低,且根,冠比越大的品种,其整体植株中的硝态氮含量越低;根尤其是侧根NR活性较高;叶肉和叶柄中硝态氮含量均与根中以内、外源硝酸盐为底物的NR活性呈一定的负相关。     

Intermedin 1-53 in central nervous system elevates arterial blood pressure in rats

Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene-related peptide (CGRP) family identified from human and other vertebrate tissues. Preprointermedin can generate various mature peptides by proteolytic cleavage. Amino acid sequence analysis showed cleavage sites located between two basic amino acids at Arg93-Arg94 resulting in the production of prepro-IMD(95-147), namely IMD(1-53). The present study was designed to determine the effects of the IMD(1-53) fragment in the central nervous system (CNS) on mean arterial blood pressure and heart rate in normal rats and its possible mechanism. Rats were given doses of adrenomedullin (ADM) or IMD(1-53), intracerebroventricularly or intravenously, respectively, with continuous blood pressure and heart rate monitoring for 45min. Analysis with CGRP receptor antagonist CGRP(8-37), ADM receptor antagonist ADM(22-52), and anti-prepro-IMD antibody showed that 0.1, 0.5, and 1.0 nmol/kg IMD(1-53), caused a dose-dependent elevation in blood pressure, which was more prominent than the increase with equivalent IMD(1-47) or ADM. As well, IMD(1-53) caused a persistent increase in heart rate. The CNS action of IMD(1-53) could be blocked by ADM(22-52), CGRP(8-37), or prepro-IMD antibody. In contrast to the CNS action, intravenous administration of IMD(1-53) induced a depressor effect. These results suggest that IMD(1-53) is an important regulatory factor in mean arterial blood pressure and heart rate through its central and peripheral bioaction.     

垣曲盆地始新世哺乳动物研究的新进展

简介了近几年来在垣曲盆地开展的地层古生物工作。在河南渑池任村和山西垣曲河堤、寨里等原有的化石点上通过筛洗和发掘,不仅找到了大量的以啮齿类为主的小哺乳动物,而且还发现了曙猿等珍贵的灵长类标本。新发现的火石坡化石点所产哺乳动物化石带明显的原始色彩,预示着垣曲盆地有可能存在中始新世伊尔丁曼哈期地层。按层位列出了迄今为止最为全面的垣曲盆地始新世哺乳动物名单。     

WOW培养法的研究

WOW培养法是目前培养胚胎的重要方法之一,在去透明带胚胎的培养上尤为重要.将拣卵针烧制成圆球状,在四孔板底烫制WOW,将不同时间去除透明带的牛孤雌激活胚培养于WOW中.结果显示:各组的卵裂率(78.9%、81.1%和78.9%)与对照组无显著差异(P＞0.05);移入6-DMAP中之前去除组的囊胚率(31.5%)与移入培养液中之前去除组(32.4%)无显著差异(P＞0.05),而且分别与对照组无差异显著(P＞0.05);移入离子霉素中之前去除组未得到囊胚.移入6-DMAP中之前去除组囊胚细胞数(113.8±10.1)与移入培养液中之前去除组囊胚细胞数(112.5±8.1)和对照组均无显著差异(P＞0.05).分别5枚、15枚和30枚为一组进行培养,对胚胎的后续发育无显著影响.     

Enhancement of phenol stress tolerance in transgenic <Emphasis Type="Italic">Arabidopsis</Emphasis> plants overexpressing glutathione S-transferase

Plant glutathione S-transferases (GSTs) are important for protecting plants against oxidative damage. We studied the function of a glutathione S-transferase family protein in Arabidopsis, AtGSTF2. Our results indicate the transgenic plants showed increased tolerance to oxidative stress caused by application of phenol. Under phenol stress, the lipid hydroperoxidation [the production of malondialdehyde (MDA)] of the leaves in overexpressing lines was suppressed compared with that of control plants. The antioxidative enzyme activities (SOD and POD) were higher in transgenic plants than in control. Furthermore, the residual phenol in medium was decreased more in transgenic plants than in control plants. These results indicate overexpressing GST protein reduce the damage of lipid hydroperoxidation and oxidative damage caused by phenol. Our findings also provide a suitable remediation strategy for sites contaminated by phenol.     

Artificial Gynogenesis and Sex Determination in Half-Smooth Tongue Sole (Cynoglossus semilaevis)

Half-smooth tongue sole (Cynoglossus semilaevis) is an important cultured marine fish as well as a promising model fish for the study of sex determination mechanisms. In the present study, a protocol for artificial gynogenesis of half-smooth tongue sole was developed in order to identify the sex determination mechanism and to generate all-female stock. The optimal UV-irradiation dose for genetically inactivating sea perch spermatozoa was determined to be ≥30 mJ/cm². The optimal initiation time for cold shock of gynogenetic embryos was determined to be 5 min after fertilization, while the optimal temperature and treatment duration were determined to be 20–25 min at 5°C. Chromosomes from common diploids, gynogenetic haploids, and diploids were analyzed. WW chromosomes were discovered in some of the gynogenetic diploids. The microsatellite marker was applied to analyze gynogenetic diploid fry. Among the 30 gynogenetic diploid fry, 11 fry contained only one allele, while 19 contained two alleles, which had the same genotype as their mother. The female-specific DNA marker was observed in four individuals out of ten gynogenetic diploid fry. Ploidy analysis of 20 putative gynogenetic fry showed them all to be diploid. Thus, a protocol for the induction of artificial gynogenesis has been developed for the first time in half smooth tongue sole, and the sex determination mechanism in the tongue sole was determined to be female heterogametic with the ZW chromosome.     

The role of cytoskeleton in glucose regulation

Cytoskeleton plays an important role in glucose regulation, mainly in the following three aspects. First, cytoskeleton regulates insulin secretion by guiding intracellular transport of insulin-containing vesicles and regulating release of insulin. Second, cytoskeleton is involved in insulin action by regulating distribution of insulin receptor substrate, GLUT4 translocation, and internalization of insulin receptor. In addition, cytoskeleton directs the intracellular distribution of glucose metabolism related enzymes including glycogen synthase and many glycolysis enzymes. Published in Russian in Biokhimiya, 2006, Vol. 71, No. 5, pp. 592–597.