Nuclear localisation of the transcription factor Stat5b is associated with ovine milk protein gene expression during lactation but not during late pregnancy or forced weaning

In the Murine and Bovine Maternal Mammary Gland Signal Transducer and Activator of Transcription 3 is Activated in Clusters of Epithelial Cells around the Day of Birth

Signal transducers and activators of transcription (STAT) proteins regulate mammary development. Here we investigate the expression of phosphorylated STAT3 (pSTAT3) in the mouse and cow around the day of birth. We present localised colocation analysis, applicable to other mammary studies requiring identification of spatially congregated events. We demonstrate that pSTAT3-positive events are multifocally clustered in a non-random and statistically significant fashion. Arginase-1 expressing cells, consistent with macrophages, exhibit distinct clustering within the periparturient mammary gland. These findings represent a new facet of mammary STAT3 biology, and point to the presence of mammary sub-microenvironments.

Differential Expression of the Alpha S1 Casein and Beta-Lactoglobulin Genes in Different Physiological Stages of the Adani Goats Mammary Glands

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.