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Abnormal segregation of prion protein octapeptide-repeat alleles in cattle

100%

Walawski K., Czarnik U., Wojciechowski R., Pareek C. S.

Journal of Applied Genetics

2003

vol. 44

issue 3

375-378

The study was conducted on full-families of Black-and-White cattle obtained as 25 AI sire families and 355 cows, as well as their progenies, mostly heifers at the age of 1-3 months. The sire group was composed by the casual qualification of 10 PRNP 6/6 and 15 PRNP 6/5 individuals on the basis of accessible young progenies. The randomly selected group of cows is characterised by a very high frequency of PRNP 6/6 (74.9%), followed by lower frequency of PRNP 6/5 (24.5%) and a very low frequency of PRNP 5/5 genotype (0.6%). The progenies represent all expected genotypes, such as: PRNP 6/6 (60.5%), PRNP 6/5 (35.8%) and PRNP 5/5 (3.7%), respectively. Taking into consideration the genotypes of parents and progenies, the segregation of PRNP 6 and PRNP 5 alleles was analysed. Results of the non-informative mating variant of male PRNP 6/6 ? female PRNP 6/6 (n = 87) are affected by the PRNP 6/6 progeny genotype in all cases. Subsequently, the results of mating variants male PRNP 6/6 ? female PRNP 6/5 (n = 29) and male PRNP 6/5 female PRNP 6/6 (n = 179) showed statistically non-significant differences in both above-mentioned alternations. The progeny group related from male PRNP 6/5 ? female PRNP 6/5 parental mating obtained fully informative and most valuable results based on the presented research concept. In the common group of 58 calves, the genotype PRNP 6/6 is represented by 26 individuals (44.8 %), PRNP 6/5 ? by 19 individuals (32.8 %) and PRNP 5/5 ? by 13 individuals (22.4 %). Therefore, the theoretical genotype rate (25% : 50% : 25%) is drastically deformed and the differentiation between the observed and expected numbers of animals is statistically highly significant (chi2= 12.72; 2 df.). These differences are affected by two times higher PRNP 6/6 homozygous (chi2 = 9.12; 1 df.) and responsively by the low number of PRNP 6/5 heterozygous animals (chi2 = 3.45; 1 df.). Further investigations are carried out to explain the genetic determination of abnormal PRNP octa-peptide repeat allele segregation, which suggests possible lethal cis-trans linkage effects.

Genetic suppresion of shrunken endosperm and low hordein content in Ris? mutant 18 (Hordeum vulgare L.)

86%

Kapala A.

Genetica Polonica

1994

vol. 35

issue 4

249-254

Data on segregation of the lys 3 b gene in the offsprings of crosses between the mutant Ris? 18 and the barley forms with plump kernels and high hordein content are presented.Hordein phenotype, and indirectly lysine, were determined by visual screening method.In the analysed materials all plump kernels were high-hordein (low lisine), and all shrunken kernels were low hordein (high-lysine).Genetic analysis showed a 3:1 Mendelian phenotypic ratio of normal and mutant F2 kernels in most of the analysed crosses.

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1 Genetica Polonica

1 Journal of Applied Genetics

1 2003

1 1994

1 Czarnik U.

1 Kapala A.

1 Pareek C. S.

1 Walawski K.

1 Wojciechowski R.

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Abnormal segregation of prion protein octapeptide-repeat alleles in cattle

Genetic suppresion of shrunken endosperm and low hordein content in Ris? mutant 18 (Hordeum vulgare L.)