3788

3579

كارشناسي ارشد

علوم دامي

اصفهان : دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1386

يازده، 53، [II] ص.: مصور، جدول،نمودار

ص.ع. به فارسي و انگليسي

محمد علي ادريس، حميد رضا رحماني

بدرالدين ابراهيم سيد طباطبايي، مسعود عليخاني

4/10/86

نفيسه نيلي، بهرام شريف نبي

مهندسي كشاورزي

ID3579

به فارسي و انگليسي :قابل رؤيت در نسخه ديجيتال

Relationship of Pit 1 gene polymorphism and milk yield of Holstein cows in IsfahanAbstractsIn the last decade molecular marker information has been directly used in animal breeding plans It has been expected that molecular marker could speed up the rate of genetic trends up to 30 Genetic markers which are related to genes and traits of interest could be used as a marker forselection It is already stated that milk and reproduction traits are controlled by many genes When the aim is selection by makers it is not necessary to map the quantitative trait loci Findingmakers related to the trait and selection on the basis of marker information could be enough Then finding a candidate gene as a genetic marker for increase milk yield is quite important inanimal Genetic polymorphism in candidate genes which has significant effects on productiontraits is widely used In this study Pit 1 transcription factor gene was used as a candidate gene Transcription factor Pit 1 gene positively regulates the expression of growth hormone prolactinand thyrotrophin subunit genes It also plays a role in pituitary cell differentiation andproliferation Association studies have shown that Pit 1 is associated with growth rate carcasstraits and milk production in domestic animals In cattle Pit 1 was found to be associated withbody weight and milk protein and fat yield Therefore the Pit 1 gene could be a good candidategene for genetic markers for milk production traits in dairy cattle Random blood samples of 262cows from 4 different dairy farms in Isfahan province were collected for extracting DNA Pedigree and yield information of sampled cows were collected from dairy farm database InPCR reaction a part of Pit 1 gene 451 bp was amplified Amplified fragments were affected byHinfI enzyme for digestion Non digested fragment 451 bp shows AA genotype whileappearing of non digested 451 bp as well as two digested fragments 244 bp and 207 bp wouldbe AB genotype However production of only two digested fragments 244 bp and 207 bp willbe BB genotype Frequency of A and B alleles were 0 27 and 0 73 respectively Genotypicfrequencies of AA AB and BB were calculated to be 0 04 0 45 and 0 51 respectively Genotypic frequencies of the collected samples for Pit 1 gene were in disagreement with Hardy Weinberg equilibrium p 0 01 Genotype was a significant source of variation for birth wt days in milk open days and fat and protein percent p 0 1 while gestation length dry days total milk yield kg and standard milk yield were not affected by genotype Birth wt dry days fat and protein percentage were highly significant p 0 01 and days in milk significantly p 0 05 was influenced by Herd management but total milk yield kg standard milk yield open days and gestation length were not influenced by this factor The only consideredcovariable in the model calving interval was not an effective covariate for birth wt andpercentage of protein despite of rest of the traits which were significantly affected by thiscovariable Overall it could be concluded that those AB genotype bearing animals are preferablefor milk traits while AA genotypic animals are better for reproductive point of view

محمد علي ادريس، حميد رضا رحماني

بدرالدين ابراهيم سيد طباطبايي، مسعود عليخاني

نفيسه نيلي، بهرام شريف نبي