Year: 2017
Type: dissertation
Abstract: Mammary stem and progenitor cells in the bovine mammary gland are thought to influence milk production. However, little is known about these cell populations in the cow. This project sought to identify, isolate and characterise putative bovine mammary stem and progenitor populations from tissue samples and fresh milk samples. Cell surface markers in bovine mammary tissue were investigated using immunophenotyping strategies previously used in other species for stem (CD24, CD29 and CD49f positive) and progenitor (CD24, CD29 and CD61 positive) cells. These two enriched populations of cells were assayed for proliferative potential and demonstrated greater proliferative activities when compared to control un-enriched bovine mammary epithelial cell populations. The RNA from the putative stem and progenitor cell populations was sequenced (RNAseq), with a number of genes demonstrating significant changes in gene expression between enriched populations and control samples. These genes were associated with a number of pathways including nitrogen metabolism, phototransduction and calcium signalling. The cellular fraction of fresh milk samples was also investigated for stem and progenitor cell markers in addition to Ki67 (proliferation), CD44 (a cancer cell marker) and Nestin. A large proportion of cells were positive for these antibody markers in milk. The work in this thesis was successful in isolating populations of cells that demonstrate some functional and molecular qualities of bovine mammary stem and progenitor cells. Using these techniques in future work to investigate these populations may aid in understanding the underlying mechanisms of bovine mammary stem and progenitor cells and could be developed into opportunities to alter the lactation cycle to produce high milk yields and improve the welfare of dairy cows.
Author: Sebastian R. A. Bowman
Language: English
Subfield: Genetics
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2606542482