Many mothers will agree that parenthood is not a bed of roses. Yet bench scientists may argue that we do in fact spawn from something akin to a field of rosettes. When embryonic stem cells are cultured in vitro, those developing along the neural [brain] pathway form the characteristic rosette structures pictured. Columnar ‘whorls’ of cells (nuclei stained blue) arrange themselves radially in ‘floral’ bundles. More developed neurons are forming around the outside (green). In vivo, stem cells in the embryo are guided to different developmental fates through molecular gradients that are generated along the body axis, from tip to toe. The neural rosette is the developmental signature of immature neurons in culture, but whether these structures actually form in the womb is not known. Similar structures are characteristic of certain brain tumours, including medulloblastoma. Understanding how stem cells differentiate is critical to the success of regenerative medicine.
Written by Brona McVittie
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