The developmental basis of fingerprint pattern formation and variation

Fingerprints are complex and individually unique patterns in the skin. Established prenatally, the molecular and cellular mechanisms that guide fingerprint ridge formation and their intricate arrangements are unknown. Here we show that fingerprint ridges are epithelial structures that undergo a truncated hair follicle developmental program and fail to recruit a mesenchymal condensate. Their spatial pattern is established by a Turing reaction-diffusion system, based on signaling between EDAR, WNT, and antagonistic BMP pathways. These signals resolve epithelial growth into bands of focalized proliferation under a precociously differentiated suprabasal layer. Ridge formation occurs as a set of waves spreading from variable initiation sites defined by the local signaling environments and anatomical intricacies of the digit, with the propagation and meeting of these waves determining the type of pattern that forms. Relying on a dynamic patterning system triggered at spatially distinct sites generates the characteristic types and unending variation of human fingerprint patterns

Ms. Apple is Missing!

Ms. Apple is Missing: The Case of the Chocolate Pudding Catastrophe! When your and the res of the students arrive to school, you find out that your teacher is missing! You, along with the rest of the students, need to try to figure out where Ms. Apple is. Make sure to make the right choices or your teacher will never be found!https://digitalcommons.snc.edu/snc_kids_books/1004/thumbnail.jp