^(14)C,^(59)Fe双标记样品的测量

本试验通过^(14)C和^(59)F双标记固相模拟样品,依据两种核素的衰变特性和不同仪器对它们的探测灵敏度,确立两种简便的测量双标记示踪样品的方法。结果表明,该方法测量的数据与给出参考值在4％以内符合。

Genetic Diversity of Maize (Zea mays L.) Landraces from Southwest China Based on SSR Data

Genetic diversity of 54 maize landraces from southwest China was tested using bulk DNA samples and 42 microsatellite （SSR） loci distributed on 10 chromosomes of maize. A total of 256 alleles were detected among the landraces. At each locus, the number of alleles varied from 2 to 9, with an average of 6.1. On the basis of the genetic similarity coefficients, clustering analysis separated the landraces into four groups. The landraces collected from the same region were mostly grouped together. To reveal the genetic structure and genetic diversity within landraces, 165 individuals from 11 landraces were analyzed. Individual DNA samples proved to be superior to bulk DNA samples in identifying genetic diversity of landraces. A total of 330 alleles were detected in the 11 landraces. According to the results of the individual DNA sampling analysis, estimates of the mean number of alleles ‘A’, the effective allelic number ‘Ae’, the observed heterozygosity ‘Ho’, and expected heterozygosity ‘He’ were 7.86, 3.90, 0.69, and 0.37, respectively. An obvious genetic deviation from Hardy-Weinberg expectation was observed both among and within landraces and a considerable genetic variation was revealed within rather than among landraces. In addition, genetic diversity of landraces was greater in Sichuan than in the other three regions. It can be concluded that maize landraces in southwest China were initially introduced to Sichuan and from there to adjacent areas.

Rapid and Sensitive Identification of Horse and Donkey Meat in Iraqi Markets Using SSR and PCR-RFLP Based on Mitochondrial DNA Cytochrome B Gene

This study was carried out at the Genetic Engineering Lab, College of Agriculture, University of Basrah. DNA was extracted from samples containing meat of commercial products in the Basrah markets. The products subjected to analysis using polymerase chain reaction （PCR） with species specific repeat （SSR） and polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） techniques based on the sequence of the mitochondrial DNA cytochrome b gene （mtDNA cyt b gene）. Then digestion with the Alu l restriction enzyme to establish a differential diagnosis detects and discriminates between meat species and adulteration in the products. SSR primers were applied, has been detected amplification of the encoded gene product, generated 221 bp in some imported minced and canned meat samples. The results show that SSR analysis produced a pattern that allowed a direct identification of horse and donkey meats in some imported minced and canned meat samples （Hana, Monde and Bavaria）. The amplified 359 bp gene of mtDNA cyt b gene from samples in different product was cut using Alu 1 restriction enzyme resulting in restriction fragment length polymorphism （RFLP）. Alu 1 was used to distinguish between the animals meat that belong to the family or one species. The digestion of the PCR product showed differences between products. Where the fragment length generated were 74, 76 and 189 bp. It belonged to horse meat. The fraud was detected in Hana, Monde and Bavaria products available in Basrah markets showing the presence of horse meat in these products that labeled as beef meats 100%. This revealed mtDNA cyt b gene as highly conserved and consequently a good molecular marker for diagnostic studies. Thus, this technique can be applied to food authentication for the identification of different species of animals in food products.

Assessment of Genetic Diversity and Relationships among Maize （Zea mays L,） Varieties in Iraq Using Random Amplified Polymorphic DNA （RAPD） Markers

RAPD （random amplified polymorphic DNA） markers were performed to fingerprint 20 varieties of maize. Twenty operon primers generated informative RAPD patterns and selected for further RAPD analysis. These 20 primers yielded 291 of main bands, out of which 169 were polymorphic bands across tested varieties. Each selected primer produced between 59 bands （OPC-01） to 142 bands （OPX-04）. Amplification products （DNA amplicons） and fragments size ranged from 260 bp （OPT-06） to 2,365 bp （OPP-05）. The largest number of polymorphic bands （20 bands） was produced by primer OPX-04 while, the lowest number of polymorphic bands （1 band） was produced by primer OPA-03. The primers of the most interest of this purpose were those that produced more variety specific DNA profiles, such as OPD-03, OPE-18, OPF-05, OPL-11 and OPX-04. The primer efficiency ranged from 0.20 in primer OPA-12 to 0.01 in primer OPA-03. The highest polymorphism and value of discrimination in this study were obtained with primers OPX-04, while, the lowest polymorphism and value of discrimination were obtained with primers OPA-03. The lowest genetic distance was 0.1941 between varieties Manlcet and Biotech Bag, while, the highest genetic distance was 0.6433 between varieties Pio 3751 and Buhooth 106. Cluster analysis （phylogenetic tree） by UPGMA （unweighted pair-group method of arithmetic means） based dendrogram revealed that they were four main genetic groups. The overall analysis of the results reveals that the genetic relationships among the maize varieties were related to some of their morphological characters as well as to their geographical origins at the molecular genetics.

抗体芯片技术研究进展

抗体芯片是蛋白质组学的新兴技术，属于蛋白芯片的一个分支，具有高通量、高特异性、平行性分析的优点。目前抗体芯片技术在癌症标记物发现、药物发展、毒素检测、细胞因子研究、信号转导、表达产物分析、RNAs检测以及其它的基础和应用蛋白质组学研究等领域具有广泛的应用，并且在临床上有补充或取代传统免疫学方法的趋势。