NEUROGENESIS Flashcards
WHAT HAPPENS IF YOU MAKE A SHH-/-
NO VENTRALISATION OF THE NEURAL TUBE CYCLOPIA HOLOPROSENCEPHALY LACK OF PITUITARY/ABNORMAL GROWTH ABNORMAL LIMBS OFTEN BORN WITH A PROBOSCIS
SHH IS EXPRESSED WHERE
THROUGHOUT THE NOTOCHORD
AT THE TIME THAT SHH IS BEING SECRETED WHAT HAS ALREADY HAPPENED
UNDER THE INFLUENCE OF RA, THE AP AXIS HAS BEEN REGIONALISED
WHAT IMPACT DOES REGIONALISATION OF THE AP AXIS HAVE ON THE SECRETED SHH
THE TISSUES IT IS TARGETING ARE ALL EXPRESSING DIFFERENT TFS
WHAT IS THE IMPACT OF SHH ON SETS OF CELLS EXPRESSING DIFFERENT TFS
DEPENDING ON THE COMBINATION YOU WILL INDUCE TF THAT WILL GIVE RISE TO DIFFERENT PROGENITOR CELLS ALONG THE ROSTROCAUDAL AXIS
DESCRIBE THE HH PATHWAY
PATCHED (PTC) USUALLY INHIBITS SMOOTHENED
THIS INHIBITION MEANS THAT GLI TRANSCRIPTION FACTORS ARE REPRESSED
IF HH BINDS TO PTC, THIS INHIBITION STOPS AND THE GLI TRANSCRIPTION FACTORS ARE ACTIVATED TO TRANSCRIBE HH TARGET GENES
NOT ALL DAUGHTER CELLS DIFFERENTIATE, WHAT DO THEY DO INSTEAD
THEY REMAIN AS PROGENITORS AND ARE RETAINED CLOSE TO THE LUMEN IN THE VENTRICULAR ZONE
THESE ARE CALLED RADIAL GLIA
WHAT IS THE FUNCTION OF RADIAL GLIA
PROVIDE A POOL OF UNDIFFERENTIATED CELLS THAT ARE NEEDED TO BUILD UP THE NS OVER EMBRYOGENESIS
THE EARLY NEURAL TUBE IS ONLY ONE CELL THICK. THIS IS CALLED
NEUROEPITHELIUM
AS THE NEUROEPITHELIUM PROLIFERATE, THEY CHANGE SHAPE TO BECOME
RADIAL GLIA
NEUROEPITHELIUM DIVIDE IN WHAT MANNER
SYMMETRICALLY
RADIAL GLIA CAN DIVIDE IN WHAT MANNERS
SYMMETRICALLY AND ASYMMETRICALLY
WHAT CAN RADIAL GLIA DIVIDE TO BECOME
SYMMETRICAL - RADIAL GLIA
ASYMMETRICAL - A CELL THAT WILL MIGRATE TO BECOME A NEURON
WHAT CONCEPTS EXPLAIN WHAT DETERMINES WHETHER DAUGHTERS WILL BOTH BE GLIA OR ONE GLIA AND ONE NEURONAL
- PLANE OF DIVISION
2. NOTCH SIGNALLING
WHAT IS THE PLANE OF DIVISION CONCEPT
DIVISION ALONG THE MERIDIAN OR THE EQUATOR LINES RESULT IN SYMMETRICAL DUAGHTERS AND ASYMMETRICAL DAUGHTERS DEPENDING ON WHICH LINE THEY ARE DIVIDED BY
