Papers are showing mostly co-culture of human fibroblasts and murine gall bladder epithelial primary cell culture .But reasons or explanations are not there .
There are various purposes for the use of a feeder layer, including to facilitate proliferation, increase plating efficiency and keep ES cells undifferentiated. If an autologous feeder layer (murine gall bladder fibroblasts inactivated with MMC or high dose ionizing irradiation) can give mouse primary gall bladder epithelial cell cultures growth advantage to an extent similar to or greater than human gall bladder fibroblasts, inactivated murine gall bladder fibroblasts may serve as a feeder layer. However, when you proceed to the molecular analyses, e.g., gene expression changes: if autologous system is use, it is difficult to differentiate the contamination of human and mouse genes in the sample.