Identifikacijom pojedinih gena odgovornih za veličinu legla te njihovom primjenom u selekciji jedinki, možemo doprinijeti povećanju reprodukcijske učinkovitosti svinja. Estrogeni receptor (ESR) jedan je od kandidatnih gena povezanih s rastom i reproduktivnim svojstvima. Cilj ovog preliminarnog istraživanja bio je analizirati polimorfizam odsječka gena ESR-PvuII, utvrditi frekvencije različitih genotipova kao i veličinu legla za svakog od njih. Primjenom lančane reakcije polimerazom genotipizirano je 30 prvopraskinja hibrida Topigs 20. Polimorfizam estrogenog receptora utvrđen je primjenom restrikcijske endonukleaze PvuII. Analizirani su sljedeći reproduktivni pokazatelji: ukupan broj oprasenih odojaka (UOO), broj živooprasenih odojaka (ŽO), broj mrtvooprasenih odojaka (MO) i broj mumificiranih odojaka (MM). Izračunate su frekvencije alela i genotipova, te je χ2-testom analizirano odstupanje od Hardy-Weinbergove ravnoteže. Značajnost razlike u promatranim svojstvima između pojedinih genotipova testirana je analizom varijance. Utvrđena su tri genotipa sa sljedećom zastupljenošću: AA (13), AB (14) i BB (3). Frekvencija alela A iznosila je 0,67, a alela B 0,33, pri čemu nije utvrđeno odstupanje od Hardy-Weinbergove ravnoteže. U prvopraskinja genotipa BB utvrđen je najveći broj UOO (14,33) i MO (2,33) za razliku od genotipa AA s najvećim brojem ŽO (12,66) i MM (0,38) odojaka. Iako su pronađene pojedine razlike u veličini legla kod jedinki različitih genotipova, one nisu bile statistički značajne (p>0,05). Vjerujemo da će daljnje analize provedene na većem broju jedinki doprinijeti konkretnijim zaključcima o mogućoj povezanosti ESR-PvuII genotipa i veličine legla u krmača Topigs 20.Identification of individual genes controlling litter size and their use in selection programs could contribute to an increased reproductive rate in pig population. Estrogen receptor gene (ESR) is a candidate gene marker for reproductive traits and growth in pigs. The aim of this preliminary study was to investigate ESR gene polymorphism as well as the frequencies of different ESR-PvuII genotypes and their litter size in primiparous sows. The polymerase chain reaction-restriction fragment
length polymorphism (PCR-RFLP) method with the PvuII restriction enzyme was used on genotyping 30 primiparous Topigs 20 hybrid sows. The following reproductive traits of litter size were analyzed: Total Number of Born piglets (TNB), Number of piglets Born Alive (NBA), Number of Stillborn piglets (NSB) and Number of Mummified piglets (NMUM). Allele and genotype frequencies were calculated, and Hardy-Weinberg equilibrium was tested using χ2-test. The ANOVA test was used to analyze litter size differences between sows with different genotypes. Three genotypes were detected with absolute frequencies (AA (13), AB (14) and BB (3)), while the gene relative frequency was 0.67 for A allele and 0.33 for B allele. Study animals were in Hardy-Weinberg equilibrium. The primiparous sows with the BB genotype
showed highest TNB (14.33) and NSB (2.33), while NBA and NMUM were highest in primiparous sows with AA genotype (12.66 and 0.38, respectively). Although some differences were found in litter size according to genotypes they were not significant (P>0.05). Further investigations in a larger sample size will contribute to more
conclusive evaluation of the possible correlation between ESR-PvuII polymorphism and litter size in sows
