سالم مرمضی

Background: Milk proteins genes have been the focus of the researches as the candidate target genes that play a decisive role when animal breeding is desired. Objectives: In the present study, the transcriptional levels of Beta-lactoglobulin (BLG) and Alpha S1 casein (CSN1S1) genes were investigated during prenatal, milking and drying times in mammary glands of the Adani goats which showed high and low breeding values. Materials and Methods: The breeding values of the animals were estimated first by applying multi-trait random regression model. Using the biopsy gun, the mammary gland samples were taken and real-time PCR was applied to search the expression of the genes. Fixed factors of the model were the breeding value groups, sampling times and their interactions. Results: The interactions were significant for both genes. At milking time, the high breeding value group exhibited more transcriptional levels for BLG and less transcriptional levels for CSN1S1 gene compared with the low breeding value group. The expression patterns of these genes were also different between the two breeding value groups. The maximum level of BLG and CSN1S1 transcriptions were found to occur at drying time. Conclusions: A difference in the gene expression was observed between the two groups which indicate the change in the nucleotide sequence for transcription factor binding sites, or miRNA binding sites, otherwise in the coding regions. Therefore, the variations in the coding and promoter regions of this gene should be investigated in the further studies.