Maternal microchimeric cell type estimation from gene expression pattern at single cell level.

Generally, animal body consists of its own cells that divide from a single fertilized egg (except for symbiotic microorganisms in the body). However, this does not apply to placental mammals, including humans and mice, as small numbers (around 1 in 100,000 cells in humans) of maternal cells obtained during pregnancy exist in our body. This phenomenon is called maternal microchimerism (MMc), which signifies a chimera of our own cells and small numbers of genetically and immunologically non-self, maternal cells. These maternal microchimeric cells (MMc cells) migrate into the body via the placenta (and through milk after birth) and are retained for decades after birth. Previous studies reported that various cell types have been observed as MMc cells in various situations, such as immune tolerance, inflammatory diseases and tissue repair. However, no research shoed the whole picture of MMc cell population, in other words, we still do not know which cell types are included as MMc cells in our bodies and how much of certain cell types consists of the major proportion of MMc cell population. In this project, we adopted single cell RNA-seq and combined it with our developed MMc cell isolation method to estimate MMc cell type more comprehensively from the gene expression pattern of each cell.