6418

5992

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1390

يازده،56ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

سعيد انصاري،غلامرضا قرباني

محمدعلي ادريس، بدرالدين طباطبائي

3/1/090

احمد رياسي، مجيد طالبي

مهندسي كشاورزي

ID5992

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

AbstractOxidised low density lipoprotein receptor 1 OLR1 is a type II membrane protein that belongs to C typelectin family that acts as a cell surface receptor for oxLDL This receptor is coded by OLR1 gene With regard tothe role of OLR1in lipid metabolism in degrading oxLDL and QTL studies for milk production traits OLR1 hasbeen regarded as a candidate gene related to milk production traits in dairy cattle One polymorphism SNP in3 untranslated region of this gene might control translation or stability of OLR1 mRNA This polymorphism isthe result of substitution of nucleotide adenine by cytosine in position 8232 OLR1g 8232 C A In the case ofbeing nucleotide C there will be restriction site for the restriction enzyme PstI and as a result alleles A and Cwill be recognizable as bands with length 270bp and 250bp respectively To hnvestigate this polymorphism andits relationship with milk production traits blood sample was randomly taken from 408 Holstein cattle in 5industrial dairy farms located in Isfahan province that had records for milk production and its composition forfirst parity Genotyping was done by PCR RFLP technique After extracting DNA determining the quality andquantity of extracted DNA amplification and digestion by restriction enzyme digestion product was observedon 2 5 agarose gel Both alleles A and C were observed in all 5 herds and wich their frequencies werw 0 5172and 0 4828 respectively totally Frequency of genotypes AA AC and CC werw also 0 289 0 456 and 0 255respectively All five herds and all of them were in Hardy Weinberg equilibrium Being in equilibrium can beowing to selecting animals according not to OLR1 gene Genetic analysis of the population was done by thesoftware PopGen32 Resulted indices indicates high diversity of this polymorphism and high inbreeding andgenetic relationship in the studied population To identify the effect of genotype on production traits thesoftware SAS procedure GLM was used In the analysis model the effects genotype and combined effect ofherd year and season of parturition were considered as fixed effects and days in lactation and open days wereconsidered as covariables Genotype had significant effect on fat and protein percentage and the breeding valueof milk fat production P 0 001 Individuals with genotype CC had statistically more milk fat percentage andbreeding value of milk fat production in comparison with genotypes AC and AA Also cows having genotypeAC showed more milk fat percentage compared to genotype AA This finding can be a reason that the effect ofthis polymorphism is additive Also individuals with genotype CC and AC had more milk protein percentage incomparison with genotype AA For traits milk fat percentage milk protein percentage and the breeding value ofmilk fat production the average effect of substitution of allele C was significant P 0 001 but dominanceeffect for the studied traits was not significant P 0 05 which indicates the effect of the polymorphism asadditive Regarding the relationship between the polymorphism and traits milk fat percentage milk proteinpercentage and the breeding value of milk fat production and also its hight diversity in the studied population the polymorphism can be used is selection for these traits Key words OLR1 Gene Holstein Cattle Genotype Polymorphism

سعيد انصاري،غلامرضا قرباني

محمدعلي ادريس، بدرالدين طباطبائي

احمد رياسي، مجيد طالبي