PHENOTYPIC VARIABILITY OF FERTILITY TRAITS OF PURE BREED SOWS IN FIRST THREE FARROWINGS**

**Original scientific paper (originalni naucni rad) Abstract: Investigation of the phenotypic variability of fertility traits was performed on Swedish Landrace sows (926 sows) deriving from single herd in Serbia. Data was processed by method of least squares (Harvey, 1990), and following fixed factors were included into the model: sire, season, litter genotype and order of farrowing, as well as regression effect of age at first farrowing, duration of lactation and number of reared (raised) piglets per litter. Traits of litter size varied (P<0.01) under the influence of sire and order of parities (first two parities). Number of still born as well as reared piglets per litter depended on the litter genotype (P<0.01). Year and season had no effect on variation of litter size traits except LWW (first two and three parities). Age of sows at first farrowing demonstrated linear effect (P<0.01) on size of their litter at farrowing (first three parities). Litter size and weight at weaning were under regression effect of lactation duration as well as corrected litter size (CLS) or number of weaned piglets (NW)

Characterization of a novel 21-kb deletion, CFTRdele2,3 (21kb), in the CFTR gene: a cystic fibrosis mutation of a Slavic origin common in Central and East Europe.

We report a large genomic deletion of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, viz., a deletion that is frequently observed in Central and Eastern Europe. The mutation, termed CFTRdele2,3(21 kb), deletes 21,080 bp spanning introns 1-3 of the CFTR gene. Transcript analyses have revealed that this deletion results in the loss of exons 2 and 3 in epithelial CFTR mRNA, thereby producing a premature termination signal within exon 4. In order to develop a simple polymerase chain reaction assay for this allele, we defined the end-points of the deletion at the DNA sequence level. We next screened for this mutation in a representative set of European and European-derived populations. Some 197 CF patients, including seven homozygotes, bearing this mutation have been identified during the course of our study. Clinical evaluation of CFTRdele2,3(21 kb) homozygotes and a comparison of compound heterozygotes for \u394F508/CFTRdele2,3(21 kb) with pairwise-matched \u394F508 homozygotes indicate that this deletion represents a severe mutation associated with pancreatic insufficiency and early age at diagnosis. Current data show that the mutation is particularly common in Czech (6.4% of all CF chromosomes), Russian (5.2%), Belorussian (3.3%), Austrian (2.6%), German (1.5%), Polish (1.5%), Slovenian (1.5%), Ukrainian (1.2%), and Slovak patients (1.1%). It has also been found in Lithuania, Latvia, Macedonia and Greece and has sporadically been observed in Canada, USA, France, Spain, Turkey, and UK, but not in CF patients from Bulgaria, Croatia, Romania or Serbia. Haplotype analysis has identified the same extragenic CF-haplotype XV-2c/KM. 19 'A' and the same infrequent intragenic microsatellite haplotype 16-33-13 (IVS8CA-IVS17bTA-IVS17bCA) in all examined CFTRdele2,3(21 kb) chromosomes, suggesting a common origin for this deletion. We conclude that the 21-kb deletion is a frequent and severe CF mutation in populations of Eastern- and Western-Slavic descent