Foetal microchimerism occurs in pigs

2 In 1893, Georg Schmorl initially reported FMc, when he discovered placental trophoblast cells in women who died of eclampsia. 3 Foetal cells are now well proven to enter the maternal bloodstream throughout both human and rodent gestations. 4,5 Foetal cells can be detected in multiple organs of the mother, including bone marrow, 6 kidney, 7 liver, 8 heart 9 and brain. 10,11 Foetal cells have multilineage potential and can differentiate into different cell types in maternal organs such as blood, 12 skin 13 and the central nervous system. 14 The purpose of foetal cells in maternal tissues is unclear, while numerous ideas include cancer encouragement, 15 immune surveillance protection 16 and tissue repair participation, 17,18 which may be governed by the phenotype acquired by these cells. [...]13 piglets were born naturally from three surrogates (Figure 1E and Method S3). After lysis of the red blood cells, the peripheral blood mononuclear cells (PBMC) were used for testing by flow cytometry (Method S4). More GFP positive cells were found in immune organs such as the spleen and lymph nodes, and small numbers of GFP positive cells were observed in the lungs, liver, intestine, brain and heart, no obvious presence of GFP positive cells was observed in kidney tissues (Figure 1I). Since the genetic material of these cloned GFP piglets was derived from male foetal fibroblasts and the SRY gene was only expressed in boars, any foetal cells that entered the mother can be identified by SRY detection.