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Biomedical subjects

M Schwerin

Publications and source records attributed to M Schwerin.

At least 73 records · Page 4Linked to original sources
PubMed1994

The bovine lactoferrin gene (LTF) maps to chromosome 22 and syntenic group U12.

Five overlapping lambda EMBL-clones, containing the complete bovine lactoferrin gene (LTF), have been used to map this gene by fluorescence in situ hybridization to bovine Chromosome (Chr) band 22q24. Primers derived from promoter and exon I sequences were applied in polymerase chain reactions (PCRs) to DNA samples of a previously characterized panel of somatic cell hybrid lines, allowing the assignment of the bovine lactoferrin locus to syntenic group U12. These results permit the assignment of syntenic group U12 to bovine Chr 22.

Animals↗
PubMed1994

Sex determination in spotted hyena (Crocuta crocuta ) by restriction fragment length polymorphism of amplified ZFX/ZFY loci.

We describe a quick and efficient method of determining the sex of DNA samples in the hyena. By choosing primers from sequences that are conserved between the human and bovine ZFY and ZFX genes, we amplified a 448 bp fragment from 1 male and 2 female hyenas. Using comparative sequencing, single base pair polymorphisms between the amplified ZFY and ZFX were established. Restriction fragment length polymorphism (RFLP) analysis with PstI and TaqI confirmed the sequence data and yielded specific banding patterns between the 2 sexes in the hyena.

Journal Article↗
PubMed1993

DNA fingerprinting of trait-selected mouse lines and linkage analysis in reference families.

The first aim of the study was the molecular genetic characterization of long-term trait-selected (growth, adaptability and fertility) lines of mice using multilocus DNA fingerprinting with the simple tandem repetitive oligonucleotide probes (GAA)6 and (GACA)4. Secondly polymorphic markers were screened for association with growth performance based on DNA fingerprint analysis in reference families. Pooled DNA samples of ten unrelated mice of trait-selected mouse lines (over 40 generations) and the unselected control lines were analyzed. Resulting differences in band patterns were reanalyzed comparing individual fingerprints of the animals included in the pooled DNA samples of the different lines. Between the mouse lines about 30% of analyzed fingerprint bands were polymorphic. Individuals of long-term selected mouse lines show only a few individual-specific bands. Most polymorphic bands observed in DNA mixes appear in all animals included in the DNA mix of the corresponding line. Line-specific DNA fingerprint bands were analyzed for their inheritance and linkage with growth performance in reference families using animals with extreme growth performance of the first backcross after crossing of growth-selected with unselected mice. Scanning the distribution of line-specific bands in the reference panel few bands were identified which are associated with growth performance. They appear as useful markers for growth selection. Nevertheless most line-specific bands result from genetic drift rather than from selection.

Adaptation, Physiological↗
PubMed1993

Short interspersed nuclear element (SINE) sequences of the Bovidae.

DNA sequences from Bovidae (cattle, goats and sheep) in the EMBL nucleotide database contain several short interspersed repeated sequences (SINEs). Three different SINEs have been found: Bov-A2, containing two 115-bp A elements; Bov-tA, a tRNA pseudogene coupled to an A element; and Bov-B of 560 bp or less and partially homologous to the A element. Bov-A2, Bov-tA and Bov-B occupy about 1.8%, 1.6% and 0.5%, respectively, of the bovine genome as represented in the nucleotide database. Apart from a tRNA-like sequence in both Bov-tA and the porcine SINEs, there was no similarity with the porcine SINEs. Apparently, the artiodactyle SINEs were established after the divergence leading to the Suidae and Bovidae but before the radiation within these families. Oligonucleotides were designed for a specific amplification of DNA from Bovidae.

Animals↗
PubMed1992

Mapping of repetitive bovine DNA sequences on cattle Y chromosomes.

Three male-specific PCR products of the sequences BC1.2, lambda ES6.0, and BRY.1 were used as probes for Southern blot analyses. Each of these probes generated a complex male-specific band pattern, which showed some quantitative variations among bulls. Hybridization patterns obtained with the BC1.2 and lambda ES6.0 PCR products were interrelated. Chromosomal locations of these repeats were determined by hybridizing the tritiated PCR products in situ to male metaphase spreads. The BC1.2 and lambda ES6.0 PCR products hybridized to Yp13-->p12, whereas the BRY.1 PCR product hybridized over the entire Y chromosome. In addition, the BC1.2 and lambda ES6.0 PCR products hybridized to the distal half of the acrocentric Y chromosome of Bos indicus, indicating that the short arm of the B. taurus Y chromosome is homologous with the telomeric end of the B. indicus Y and supporting the notion that the Y chromosomes of these two species differ by a pericentric inversion.

Animals↗
PubMed1991

Quantification of Y chromosome bearing spermatozoa of cattle using in situ hybridization.

An easy assay for quantification of Y chromosome-bearing sperm (Y-sperm) is needed, especially to monitor sperm separation techniques. In the present study a tritiated bovine male-specific DNA fragment was tested for identification of Y-sperm by in situ hybridization. A protocol for in situ hybridization to bovine sperm was developed and used to study the proportion of Y-sperm of 12 bulls. The usefulness of the method in optimization of sperm separation procedures is illustrated through analysis of fractions of sperm separated by Percoll density gradient centrifugation.

Animals↗
PubMed1989

Gene transfer experiments in cattle.

Various methods for gene transfer in cattle are described. Four vectors containing (1) the bovine papilloma virus DNA, (2) the alcohol dehydrogenase gene of Drosophila melanogaster, and the human (3) and the bovine (4) growth hormone gene were used for gene injection in bovine zygotes. The period between 78 and 82 h after prostaglandin treatment was determined as the optimum time for collection of bovine zygotes. A total of 802 eggs was obtained from 74 successfully superovulated heifers. The foreign DNA was injected into the pronuclei of 156 (Construct 1), 130 (Construct 2), 62 (Construct 3) and 250 (Construct 4) centrifuged zygotes. An average number of 12 zygotes per recipient heifer was transferred into one oviduct. The eggs were recovered after 14 days (Constructs 1 and 2) for analysis or after 7 days (Constructs 3 and 4) respectively for transfer into final recipients. After the transfer into 23 recipient heifers of 43 embryos (Construct 4), 14 calves were born and 1 fetal monster was isolated. According to dot-blot hybridization the total rate of efficiency of gene transfer was 3.2%, 6.9%, and 0.8% for Constructs 1, 2 and 4, respectively.

Animals↗