Currently, there have been several reports on methods for inducing differentiation into various endoderm cells (lung, liver, pancreas, stomach, intestine, etc.) using various inducing factors from the germ layer in the embryo.However, the differences in the properties and differentiation orientation of germ layer cells produced by different inducer treatments were unknown.

　This time, the research group elucidated that germ layers produced by different induction methods have different properties.We also showed that two types of anterior embryonic germ layers can be induced from the early anterior primitive streak (a groove-like structure that appears early in the development of mammals), respectively, without an inducing factor for the anterior foregut (middle ear, middle ear,). It also revealed that it has the ability to differentiate into the thoracic gland, thyroid gland, trachea, lungs, esophagus, etc.) and the posterior foregut (stomach, duodenum, pancreas, liver, etc.).Furthermore, it is said that a new method for inducing the late anterior primitive streak was established, from which the posterior embryonic germ layer having the ability to differentiate into the middle-hindgut (small intestine, large intestine, etc.) was induced without an inducing factor.

　In this study, we show that there are three subtypes in the germ layer cell population, which are currently defined by two markers, SOX17 and FOXA2, and developed the first method to separate them.In addition, it was found that the three types of germ layers induced this time have the ability to spontaneously differentiate into the posterior foregut, anterior foregut, and middle hindgut, respectively.It is expected that higher quality endoderm-based organ constituent cells can be produced by separately producing germ layers in the embryo by this method and then combining them with conventional induction methods.