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Cytogenetic analysis was carried out in the calves of the quintuplets (3 females and 2 males), triplets (3 females and 1 male), 5 pair of heterosexual twins. Metaphase chromosomes derived from leukocyte cultures of peripheral blood were examined in all calves at 1-2 weeks of age and in calves of the triplets additionally at 12 and 24 weeks. All the animals cytologically examined, except for one pair of twins, exhibited, sex-chromosomal chimerism. In three calves of the quintuplets (2 females and 1 male) there were more cells the 60,XX type (72-95%) and in the two remaining calves (male and female), there were more cells of the 60,XY type (82-94%). In the calves of triplets and twins only one cell type dominated, either 60,XX or 60,XY. The proportion of male : female cells in bovine triplets did not change with age. In the discussion was suggested the necessity of fertility evaluation of chimeric bulls before their employment as reproductors.
Analysis of skeletal malformations in embryos that died between day 17 and 21 of incubation obtained from two reproductive flocks of broiler chickens showed exencephaly to be the most common defect. It comprises about 48% of all diagnosed axial skeleton disorders. Analysis of the expression of Hoxa1 and Hoxd3 genes by real time PCR revealed upregulation of Hoxa1 in chicken embryos with exencephaly (16.8-fold higher), when compared with healthy birds. Upregulation of Hoxa1 suggests that this gene may be associated with exencephaly in chickens.
The studies conducted aimed at evaluating the frequency of chromosome abnormalities in early embryos of 8 breeds/varieties of geese originating from the Southern and Northern parts of Poland, since the seventies of the XX century, without selection, avoiding interrelations. In total 1927 eggs were evaluated, of which 485 were not fertile. The karyotypic survey was performed on 1442 embryos and showed that 65 of them (4.5%) had an abnormal karyotype. Among the chromosome abnormalities the principal were: 1AZ haploidy; haploid-diploid chimerism 1AZ/2AZZ, 1AZ/2AZW; mosaic 2AZZ/3AZZZ. One embryo proved to be a pure tetraploid 4A/ZZZZ. The translocation or inversion type of structural chromosome abnormalities were not observed. A considerable variability was observed in the frequency of chromosome abnormalities between the geese varieties examined: from 2.99% in the Pomeranian variety to 7.58% in the case of the Hunched Breed. In the remaining six breeds/varieties the per cent of karyotype changes ranged from 3.38 to 4.73.
Genetic analysis was conducted in chicken belonging to lines divergently selected for high or low frequency of skeletal defects (line H and L, respectively). The analysis was based on the DNA fingerprinting technique, using enzyme HinfI and Jeffrey’s 33.6 probe. Principal aims were: 1) to determine the effects of selection on the genetic variation within and between lines, and 2) to search for the presence of line-specific minisatellite alleles (as bands in the DNA fingerprinting pattern) which could be used as markers for the predisposition to skeletal defects. DNA fingerprinting pattern (DFP) displayed differences in position of bands, some of them appearing characteristic only for one out of two chicken lines studied.
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