H Ammer

Publications (6)9.54 Total impact

• Article: The use of genomic DNA probes for in-gel hybridization.

  T Wöhl, M Brecht, F Lottspeich, H Ammer
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  ABSTRACT: Hybridization within agarose gels using oligonucleotide probes has been described in several publications; genomic DNA probes, however, have been used rarely and only with limited success. Here we present a simple and convenient procedure for in-gel hybridization using radiolabeled genomic DNA fragments. The protocol was improved by the use of formamide in the hybridization as well as in the washing step. This method was compared with the conventional Southern blotting technique and was shown to produce good results in restriction pattern analysis, as well as in chromosomal localization with the help of pulsed field gel electrophoresis.
  Electrophoresis 06/1995; 16(5):739-41. · 3.30 Impact Factor
• Article: Exonic polymorphism vs intronic simple repeat hypervariability in MHC-DRB genes.

  H Ammer, F W Schwaiger, C Kammerbauer, M Gomolka, A Arriens, S Lazary, J T Epplen
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  ABSTRACT: Gene products encoded by the major histocompatibility complex often exhibit a high degree of polymorphism. In humans the HLA-DR polymorphism is due to more than 50 alleles with varying exon 2 sequences. Each group of DRB alleles contains a certain form of the basic simple repeat motif (gt)n(ga)m in intron 2. Identical alleles can be differentiated on the basis of the hypervariable repeat. In this study focused on cattle (Bos taurus) we identified different Bota-DRB alleles in a limited survey by amplification via polymerase chain reaction and sequencing. In addition DRB exon 2 sequences were also obtained from eight additional hoofed animal species (seven horned artiodactyls and one pig) revealing artiodactyl-specific polymorphic and nonpolymorphic substitutions. In the genus Bos the intronic simple repeat variability was compared with exonic DRB polymorphism. As in humans all Bota-DRB exons were always associated with specifically organized basic simple repeat structures. Yet the extent of simple repeat variability was lower in cattle compared to humans. Selective breeding in the process of domestication might be responsible for the diminished intronic hypervariability. Nevertheless, the hypermutable simple repeat sequences have been preserved in the same position and with the same principal structure for at least 70 x 10(6) years of evolution. Unexpectedly, the rate of intronic simple repeat and exonic changes appear quite similar.
  Immunogenetics 02/1992; 35(5):332-40. · 2.93 Impact Factor
• Article: Oligonucleotide fingerprinting to individualize ungulates.

  F W Schwaiger, M Gomolka, H Geldermann, H Zischler, J Buitkamp, J T Epplen, H Ammer
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  ABSTRACT: The optimal combination of restriction enzyme and oligonucleotide probe has been determined for the individualization of hoofed animal species (cattle, pig, goat, sheep, horse and camel). Four different restriction endonucleases were used as well as five synthetic oligonucleotide probes hybridizing to different simple tandem repeats for fingerprint analyses in unrelated cattle (Swiss and German Simmental of unknown relationship and three families): 4 x 10(15) cows and oxes would reveal different banding patterns after HinfI digestion using the probe (CAC)5/(GTG)5. The other species were investigated using HinfI (and HaeIII) and five different oligonucleotide probes specific for simple tandem repeats. Using (CAC)5/(GTG)5 the discrimination potential in sheep was about one order of magnitude lower than in cattle while in goats 6 x 10(10) specimen are easily differentiated with (CA)8/(GT)8. From an evolutionary standpoint it may be of interest that also in all other ungulate species tested, (CAC)5/(GTG)5 and (CA)8/(GT)8 exhibited the highest potential for individualization. Advantages of oligonucleotide fingerprinting are discussed.
  Applied and theoretical electrophoresis: the official journal of the International Electrophoresis Society 02/1992; 2(6):193-200.
• Article: Oligonucleotide fingerprinting using simple repeat motifs: a convenient, ubiquitously applicable method to detect hypervariability for multiple purposes.

  J T Epplen, H Ammer, C Epplen, C Kammerbauer, R Mitreiter, L Roewer, W Schwaiger, V Steimle, H Zischler, E Albert
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  ABSTRACT: A panel of simple repetitive oligonucleotide probes has been designed and tested for multilocus DNA fingerprinting in some 200 fungal, plant and animal species as well as man. To date at least one of the probes has been found to be informative in each species. The human genome, however, has been the major target of many fingerprinting studies. Using the probe (CAC)5 or (GTG)5, individualization of all humans is possible except for monozygotic twins. Paternity analyses are now performed on a routine basis by the use of multilocus fingerprints, including also cases of deficiency, i.e. where one of the parents is not available for analysis. In forensic science stain analysis is feasible in all tissue remains containing nucleated cells. Depending on the degree of DNA degradation a variety of oligonucleotides are informative, and they have been proven useful in actual case work. Advantages in comparison to other methods including enzymatic DNA amplification techniques (PCR) are evident. Fingerprint patterns of tumors may be changed due to the gain or loss of chromosomes and/or intrachromosomal deletion and amplification events. Locus-specific probes were isolated from the human (CAC)5/(GTG)5 fingerprint with a varying degree of informativeness (monomorphic versus truly hypervariable markers). The feasibility of three different approaches for the isolation of hypervariable mono-locus probes was evaluated. Finally, one particular mixed simple (gt)n(ga)m repeat locus in the second intron of the HLA-DRB genes has been scrutinized to allow comparison of the extent of exon-encoded (protein-) polymorphisms versus intronic hypervariability of simple repeats: adjacent to a single gene sequence (e.g. HLA-DRB1*0401) many different length alleles were found. Group-specific structures of basic repeats were identified within the evolutionarily related DRB alleles. As a further application it is suggested here that due to the ubiquitous interspersion of their targets, short probes for simple repeat sequences are especially useful tools for ordering genomic cosmid, yeast artificial chromosome and phage banks.
  EXS 02/1991; 58:50-69.
• Article: DNA fingerprinting in domestic animals.

  J Buitkamp, H Ammer, H Geldermann
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  ABSTRACT: DNAs of several species of domestic animals digested with the restriction endonucleases HinfI, AluI and HaeIII were hybridized with different synthetic probes. DNA fingerprint patterns were found in each investigated species by at least two of these probes. Furthermore, two probes gave sex-specific banding patterns in the chicken. Some applications of DNA fingerprinting in domestic animals are discussed.
  Electrophoresis 12(2-3):169-74. · 3.30 Impact Factor
• Article: Oligonucleotide fingerprinting using simple repeat motifs: A convenient ubiquitously applicable mthod to detect hypervariability for multiple purposes

  J T Epplen, H Ammer, C Epplen, C Kammerbauer, R Mitreiter, L Roewer, W Schwaiger, V Steimle, H Zischler, E Albert, [......], J Buitkamp, I Nanda, M Schmid, P Nürnberg, S. D. J. Peba, H Pöche, W. Sprecher, M Schartl, K Weising, A Yassouridis
  DNA Fingerprinting: Approaches and Applications, 50-69 (1991).