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Large-cell lymphomas are newly-formed, often abnormal, tissue growths in the lymphatic system, and are members of a group of advanced, aggressive B-cell neoplasms, tumors which are often cancerous. Half the patients with large cell or mixed large- and small-cell lymphomas either go into remission or are totally cured by combined chemotherapy. Why the others do not respond has not been well understood. The role of genetic changes in B-cells, especially the 2p chromosome (bcl-2), was associated with recurrent lymphomas and a poor prognosis for patients suffering from this type of cancer in spite of multi-drug chemotherapy. Different defects in the chromosome were associated with different responses to therapy. The authors conclude that in large-cell lymphoma, multiple recurrent defects in the chromosome may be important is determining patient outcome.

A study was conducted to analyze the mapping of the prostaglandin-endoperoxide synthase 2 gene to chromosome 9 and bovine chromosome 16 of pigs. To this end, a common forward primer based on homologous regions of porcine and bovine DNA sequences was designed. Results indicated that the mapping of the gene to SSC9 promotes an evolutionary breakpoint in HSA1 in relation to SSC4 and SSC9.

The 46 DNA molecules that make up the diploid human genome are incredibly thin and very long, with a width of ~2 nanometers and a combined length of ~2 meters. […]

Myogenin is part of the helix-loop-helix family of skeletal muscle-specific transcription factors. The pig myogenin in chromosomal location 9q2.1.-q2.6 conforms with a segment of the human chromosome 1q31-qter which indicates its localization. It is determined through genetic mapping which shows the correspondence between the pig and human chromosomes. Such an analysis presents that myogenin physically maps to porcine chromosome 9q2.1-q2.6.

A bovine and rodent hybrid somatic cell panel aids the physical mapping of bovine microsatellites ILSTS001 (D7S3) and ILSTS011 (D14S2) and brain-specific protein eta amino chain (BSPN). BSPN, D14S2 and D7S3 mapped to the bovine syntenic groups/chromosomes U24/BTA 14 , U24/BTA 14 and U22/BTA 7, respectively. The allelic expressions of D14S2 and D7S3 enable their mapping to linkage maps, thus developing a correlation between linkage and physical maps.

The genes in E. coli involved in the formation of uroporphyrinogen III from aminolevulinate have been blocked, and heme, siroheme, vitamin B12 are all produced through the common tetrapyrrole pathway. The isolated strain with a mutation in heme E gene was located on an E. coli physical map. Strain W3110 was affected by lambda b221 cI857 Tn5 at 37 degrees centigrade and was plated on L agar consisting of a microgram of kanamycin per milliliter.

An Escherichia coli sequence, ECOPOTABCD, having 87% identity in 56-bp overlap with an area of the pepT sequence, has been discovered and mapped to nearly 25 units on the Salmonella chromosome. potABCD operon is found at 15 map units on the E. coli chromosome (3). The placement of ECOPOTABCD with the geometric restriction map depicts a clockwise placement of potABCD and a distance of 1 Kb between ECOPOTABCD and ECOPHOPQ.

Members of the Enterobacteriaceae family produce microcins that have low-molecular-weight peptide antibiotics. The min 4 area of the E. coli was genetically mapped by the chromosomal Tn5 insertion, leading to the complete blockage of the peptide antibiotic microcin 25. The introduction of Tn5 also disturbed the fhuA gene encoding the functional outer membrane receptor for the antibiotic albomycin, ferrichrome and colicin M, since microcin 25 and these agents make use of the same receptor.

DNA can undergo changes not only in sequence, but also by the addition or removal of chemical groups. Such 'epigenetic' changes affect gene regulation and are thought to be involved [...]

Pairing between wheat (Triticum turgidum and T. aestivum) homeologous chromosomes is prevented by the expression of the Phi locus on the long arm of chromosome 5B. The genome of Aegilops speltoides suppresses Phi expression in wheat X Ae. speltoides hybrids. Suppressors with major effects were mapped as Mendelian loci on the long arms of Ae. speltoides chromosomes 3S and 7S. The chromosome 3S locus was designated Su1-Ph1 and the chromosome 7S locus was designated Su2-Ph1. A QTL with a minor effect was mapped on the short arm of chromosome 5S and was designated QPh.ucd-5S. The expression of Su1-Ph1 and Su2-Ph1 increased homeologous chromosome pairing in T. aestivum X Ae. speltoides hybrids by 8.4 and 5.8 chiasmata/cell, respectively. Su1-Ph1 was completely epistatic to Su2-Ph1, and the two genes acting together increased homeologous chromosome pairing in T. aestivum X Ae. speltoides hybrids to the same level as Su1-Ph1 acting alone. QPh.ucd-5S expression increased homeologous chromosome pairing by 1.6 chiasmata/cell in T. aestivum X Ae. speltoides hybrids and was additive to the expression of Su2-Ph1. It is hypothesized that the products of Su1-Ph1 and Su2-Ph1 affect pairing between homeologous chromosomes by regulating the expression of Phl but the product of QPh.ucd-5S may primarily regulate recombination between homologous chromosomes.

A recent focus of swine genomics research has been to sequence a significant number of the genes which are expressed in the pig. The most popular approach to accomplish this goal is to collect single-pass sequence data from cDNA clones. The sequence data obtained, often between 400 and 600 bases in length, are called expressed sequence tags (EST). A sequence search of these data in GenBank and the MARC swine EST data identified over 100 sequence files which contained a microsatellite repeat. Most repeat motifs detected were dinucleotide (CA/GT) repeats; however, a number of tri-, tetra-, penta- and hexa-nucleotide repeats were also detected. The selection criteria for testing a microsatellite marker was that it span more than 18 bases of uninterrupted sequence. There was a considerable level of redundancy in the sequences identified and some files did not contain enough data adjacent to the microsatellite repeat to yield useful primers for amplification. Fifty-eight pair of primers were ordered representing 44 di-, 7 tri-, 1 tetra-, 1 penta-, and 4 hexa-nucleotide repeats, as well as 1 compound (contained a di-, tri- and tetra-nucleotide repeat) repeat motif. Thirty-four markers were polymorphic in the MARC reference population, 13 markers were uninformative and 11 primer pairs failed to satisfactorily amplify genomic DNA. A comparison of di-nucleotide repeat versus markers with repeat motifs of 3-6 bases determined that 73% of the di-nucleotide markers were useful relative to only 8% for the other repeat motifs. The difference was due to a much higher percentage of monomorphic markers in the 3-6 base repeat motif markers than in the di-nucleotide markers (69% vs 9%). Either the higher order repeat motifs are less polymorphic in the porcine genome or our selection criteria was too low. The percentage of monomorphic di-nucleotide markers was slightly higher, and the rate of unsatisfactory amplification was double that observed when di-nucleotide markers were derived from genomic sequence. This increased amplification failure rate could be due to the presence of introns between primer sites or base calling errors in the EST sequence files. Nonetheless, the mapped markers not only add useful microsatellites to the porcine genetic map but they also provide valuable links between the porcine and human genome. Key Words: Porcine, EST, Microsatellite

The nucleotide mapping of porcine microsatellites that are linked with an x-gene has exhibited codominance traits. Six polymorphic alleles were detected and SO511 was identified as the microsatellite locus of porcine. So511 locus was also detected with an x-linkage indicating a greater gene contribution from female alleles. Polymorphic alleles have sizes ranging from 152 to 178 bp and are inherited through codominance.

The analysis of the BamHI hybridized restriction enzyme revealed the presence of six polymorphic fragments. Polymorphic occurrences were also detected in TaqI, PstI and MspI gene loci. The polymorphic fragments were autosomally inherited among families in a span of three generations. The genetic fragments were isolated using agarose gel electrophoresis. The MUC5AC gene was probed using a homologous PGM-9B pig cDNA clones that encodes gastric mucin.

Studies on tumor-suppressors that disrupt the chromosome 9p21 in human tumors identify a multiple tumor-suppressor, MTS1, that maps to chromosomes 9p21 and encodes the protein P16. P16 protein is an effective tumor inhibitor as it blocks the activity of the cyclin-dependent kinases that promote cell growth. The germline mutations of MTS1 observed in a range of melanoma families confirm that MTS1 is a familial melanoma gene and highlights the importance of p16 in cancer.

A comprehensive map of the genome of cows enables the enhancement of artificial insemination and production of healthy breeds of cross. Researches of bovine genome are performed in Australia, the US, Israel and Germany. The production of healthier cows will yield more milk and throw light on the application of genome research to other mammals.

The location of the 7alpha-hydroxysteroid dehydrogenase gene (hdhA) is at 1715 to 1713 kbp on the physical map of the Escherichia coli chromomosome, as is determined by comparing the restriction map of Kohara et al and the restriction sites of the hdhA gene. Hybridization to the Kohara DNA library detects the location of the hdhA gene on the E. coli chromosome. Two clones, 9A1 (phage 315) and 6A5 (phage 314), hybridize with the probe which is the Pst I-Bam HI fragment of pSD3.