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Positive Clones (positive + clone)
Selected AbstractsDevelopment and characterization of SSR markers in Ribes speciesMOLECULAR ECOLOGY RESOURCES, Issue 3 2002R. Brennan Abstract Eleven microsatellite loci were identified and characterized in blackcurrant (Ribes nigrum L.) and related species. An enriched library was constructed and screened with simple sequence repeat (SSR) oligonucleotides. Positive clones were sequenced and primers were designed flanking the repeat motifs. These 11 microsatellites produce amplification products polymorphic across a range of Ribes germplasm, predominantly from the Eucoreosma section of the genus. The number of alleles varied from 2 to 18 with levels of diversity ranging from 0.18 to 0.91. [source] Identification of tudor repeat associator with PCTAIRE 2 (Trap)FEBS JOURNAL, Issue 7 2000A novel protein that interacts with the N-terminal domain of PCTAIRE 2 in rat brain PCTAIRE 2 is a Cdc2-related kinase that is predominantly expressed in the terminally differentiated neuron. To elucidate the function of PCTAIRE 2, proteins that associate with PCTAIRE 2 were screened by the yeast two-hybrid system. A positive clone was found to encode a novel protein that could bind to PCTAIRE 2 in vitro as well as in vivo, and was designated as Trap (tudor repeat associator with PCTAIRE 2). The overall structure of Trap shows no significant homology to any proteins, but contains five repeated domains (the tudor-like domain), conserved in Drosophila tudor protein. Trap associates with the N-terminal domain of PCTAIRE 2 through its C-terminal domain, which contains two tudor-like domains. PCTAIRE 1, but not PCTAIRE 3, can also associate with Trap. Trap is predominantly expressed in brain and testis, and gradually increases during brain development throughout life, consistent with the expression pattern of PCTAIRE 2. Immunoreactivities for PCTAIRE 2 and Trap were colocalized to the mitochondria in COS 7 cells. Immunohistochemical analyses showed that PCTAIRE 2 and Trap were distributed in the same cell layer of the cerebral cortex and cerebellum. These findings suggest that Trap is a physiological partner of PCTAIRE 2 in terminally differentiated neurons. [source] Acute lymphoblastic leukemia without the Philadelphia chromosome occurring in chronic myelogenous leukemia with the Philadelphia chromosomeAMERICAN JOURNAL OF HEMATOLOGY, Issue 3 2003Hee Jin Huh Abstract The blast crisis in chronic myelogenous leukemia (CML) is related to the evolution of a Philadelphia chromosome (Ph)-positive clone. Secondary chromosomal abnormalities accompanied by t(9;22) are found in 70,80% of blast crises. Here we describe a patient with Ph-positive CML, who developed Ph-negative acute lymphoblastic leukemia (ALL). A 52-year-old man was diagnosed with CML with the Ph chromosome in the chronic phase. He achieved a partial cytogenetic response after 4 months of imatinib mesylate therapy. After 8 months, common ALL occurred. At that time his karyotype was normal and the Ph chromosome was not noted. Am. J. Hematol. 74:218,220, 2003. © 2003 Wiley-Liss, Inc. [source] Isolation of microsatellite loci in the pollinating fig wasp of Ficus hispida, Ceratosolen solmsiINSECT SCIENCE, Issue 4 2008Hao Yu Abstract Microsatellite loci were isolated for Ceratosolen solmsi, pollinator of the dioecious Ficus hispida. We developed nine polymorphic microsatellite loci based on the method of polymerase chain reaction isolation of microsatellite arrays (PIMA). Enrichment of genomic libraries was performed by random amplified polymorphic DNA (RAPD). A subset of 38 positive clones was sequenced; 15 clones showed microsatellite loci. We tested 15 designed primer pairs and nine of them produced polymorphic amplification in 48 individual wasps collected from different fruits of the dioecious host fig Ficus hispida in China. Among the 48 individuals, 49 alleles were obtained at the nine loci. The observed heterozygosity ranged between 0.357 and 0.634. [source] Microsatellite markers application on domesticated silkworm and wild silkwormINSECT SCIENCE, Issue 6 2005LIE ZHANG Abstract Twenty-seven sets of simple sequence repeat (SSR) primers were developed through hybridizing of (CA)n, (CT)n and (GT)n and sequencing the positive clones in libraries constructed by using p50 silkworm strain. Of those primer pairs, 26 sets of SSR primers amplified well in two regional wild silkworm strains. Ten domesticated silkworm strains and two regional wild silkworm strains were used for comparing the polymorphisms and for constructing a phylogenetic tree employing the UPGAM method. The result showed that the genetic distances within Japanese strains are closer than those of Chinese strains. And this result also implies that Japanese strains diverged from domesticated silkworm later than Chinese strains. According to the clustering result, the domesticated silkworm is firstly clustered in one class, but could be classified into two groups. Within a strain, the individual polymorphism of wild silkworm was significantly higher in abundance than those of domesticated silkworm. The S SR primers of domesticated silkworm could be used in genetic studies for wild silkworm. [source] Specific Fab fragments recovered by phage display technique recognizing human spermatozoaINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 5 2009Dorota Fiszer Summary Human hybridoma cell lines are often unstable and loose ability for antibody production. Sometimes, they show low and varying levels of heavy and light chains synthesis. Therefore it is reasonable to preserve generated specificities of light and heavy chains by cloning them to phagemid vector and creating phage display library. The aim of this study was to construct phage display library of Fab fragments recognizing sperm surface antigens. The source of mRNA constituted seven hybridoma cell lines producing antisperm antibodies which was proved by ELISA, and agglutination test as well as by inhibition of sperm to penetrate hamster oocytes. Fragments of cDNA encoding ,/, and , chains were cloned into pComb3HSS phagemid vector and amplified in XL-1Blue. The library was panned against whole unfixed sperm cells. Three positive clones selected after fourth round of panning showed heavy chain belonging to VH4 family, two of them (G28, K61) possessed lambda chain from VL2 family and one (H43) kappa chain from VK1 family. As these Fabs revealed similarities to antibodies against some proteins involved in sperm motility and cell fusion it can be suggested that these Fabs may be a cause of infertility. Finally, we proved that it is feasible to preserve specificities produced by human hybridomas using phage display technique and we recovered some Fabs which may be of diagnostic and research value, and may also have some value for contraceptive vaccine. [source] Expression profile of genes identified in human spermatogonial stem cell-like cells using suppression subtractive hybridizationJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2010Jung Ki Yoo Abstract Spermatogenesis is the process by which testicular spermatogonial stem cells (SSCs) self-renew and differentiate into mature sperm in the testis. Maintaining healthy spermatogenesis requires proper proliferation of SSCs. In this study, we sought to identify factors that regulate the proliferation of SSCs. Human SSC (hSSC)-like cells were isolated from azoospermic patients by a modified culture method and propagated in vitro. After four to five passages, the SSC-like cells spontaneously ceased proliferating in vitro, so we collected proliferating (P)-hSSC-like cells at passage two and senescent (S)-hSSC-like cells at passage five. Suppression subtractive hybridization (SSH) was used to identify genes that were differentially expressed between the P-hSSC-like and S-hSSC-like cells. We selected positive clones up-regulated in P-hSSC-like cells using SSH and functionally characterized them by reference to public databases using NCBI BLAST tools. Expression levels of genes corresponding to subtracted clones were analyzed using RT-PCR. Finally, we confirmed the differential expression of 128 genes in positive clones of P-hSSC-like cells compared with S-hSSC-like cells and selected 23 known and 39 unknown clones for further study. Known genes were associated with diverse functions; 22% were related to metabolism. Fifteen of the known genes and two of the unknown genes were down-regulated after senescence of hSSC-like cells. A comparison with previous reports further suggests that known genes selected, SPP1, may be related to germ cell biogenesis and cellular proliferation. Our findings identify several potential novel candidate biomarkers of proliferating- and senescencet-hSSCs, and they provide potentially important insights into the function and characteristics of human SSCs. J. Cell. Biochem. 110: 752,762, 2010. © 2010 Wiley-Liss, Inc. [source] Isolation and characterization of highly polymorphic microsatellite loci for the garden tiger moth Arctia caja (Lepidoptera: Arctiidae)MOLECULAR ECOLOGY RESOURCES, Issue 1 2006SARAH J. ANDERSON Abstract A set of microsatellite markers was isolated from Arctia caja, a species that has been declining in UK for several decades. As has been found with other Lepidoptera species, this proved to be a difficult task. Eight enriched libraries identified 103 positive clones, and these yielded only seven polymorphic microsatellites. Allelic diversity ranged from 10 to 23 alleles per locus in a population of 30 individuals. Significant heterozygosity deficits were shown by three of these loci, presumably due to null alleles. The remaining four loci were in Hardy,Weinberg equilibrium and will be used to investigate the population genetic structure of A. caja. [source] Microsatellite DNA loci for Western Hemlock [Tsuga heterophylla (Raf.) Sarg]MOLECULAR ECOLOGY RESOURCES, Issue 3 2002Vindhya Amarasinghe Abstract Polymorphic microsatellite loci were developed for Western Hemlock [Tsuga heterophylla (Raf.) Sarg], a prominent forest tree species in Western North America. Microsatellite-enriched libraries were screened for (CA)n dinucleotide repeats from which 33 positive clones were sequenced. Polymerase chain reaction (PCR) primers for 16 microsatellite loci were prepared and tested against DNA from unrelated Western Hemlock trees. The 12 most informative microsatellite loci are reported here. From four to 22 alleles per locus were observed, with an average expected heterozygousity of 0.799. [source] Isolation of polymorphic microsatellite markers from the malaria vector Anopheles darlingiMOLECULAR ECOLOGY RESOURCES, Issue 4 2001Jan E. Conn Abstract High molecular weight DNA was extracted from the primary Neotropical malaria vector, Anopheles darlingi from Capanema, Pará, Brazil, to create a small insert genomic library, and then a phagemid library. Enriched sublibraries were constructed from the phagemid library using a microsatellite oligo primed second strand synthesis protocol. The resulting 242 760 individual clones were screened. The mean clone size of the positive clones was 302 bp. Flanking primers were designed for each suitable microsatellite sequence. Eight polymorphic loci were optimized and characterized. The allele size ranges are based on 253 samples of A. darlingi from eastern Amazonian and central Brazil. [source] Characterization of microsatellite loci for Trigona carbonaria, a stingless bee endemic to AustraliaMOLECULAR ECOLOGY RESOURCES, Issue 1-2 2001Catherine L. Green Abstract Microsatellite loci were isolated from Trigona carbonaria (family Apidae; tribe Meliponini), a stingless bee endemic to Australia, following the screening of a partial genomic library with several simple-repeat oligonucleotide probes. Polymerase chain reaction (PCR) primers were designed to DNA sequence flanking a selection of trinucleotide and dinucleotide repeat sequences within positive clones. Nine of 10 microsatellite loci were found to be polymorphic amongst 20 unrelated T. carbonaria workers, with observed heterozygosity estimates ranging from 0.168 to 0.800. For many of the primers, distinct polymorphic products were also amplified when used in reactions with DNA from a selection of other bee species. [source] |