EMBRYO BONUS MARKS MATERIAL
1. Listening to mother versus listening to neighbors
A. Pluripotency is given but future is determined by interaction with others
(conditional specification – neighbours) and origin (autonomous specification –
2. Make a difference while you are still young.
A. You don’t have to be fully differentiated to influence others
i. Optic cup influences outer ectoderm to be lens before it becomes the retina
ii. Myotome cell tells dorsal sclerotome to become tendon before it becomes
3. One has to be “mature enough” to recognize signaling.
A. Competency is just as important as signaling
i. To be able to respond is a specialized state that is attained through
previous induction or maternal specification
1. Chick epiblast cannot respond to bone morphogenetic protein
(BMP) antagonists until it is exposed to fibroblast growth factors
4. Relationship as a smallest unit of analysis.
A. What an entity becomes is a property of its relationships
i. Cell-cell interaction, enhancer-transcription factor interaction, organism-
5. Whether an action is helpful depends on where and when it is done (context is important).
A. Determines outcome of relationships
B. Bone morphogenic protein cause
i. bone formation at certain locations and places
ii. apoptosis at other places and times
iii. specifies epidermis at other times and places
6. The three fundamental rules of development:
A. Timing is everything
B. Location – determine value
C. Both of the above-mentioned statements are very important, true
7. Use small units to build a big thing.
A. Embryo use cassette/module for functions
i. If one doesn’t work entire system in trouble
8. Scaffolding might be temporary (but sometimes stays).
A. Units of construction not necessarily units of adult
i. Rhombomeres, heart fields, medial rib do not exist in adult but are
important in construction OF adult
9. See the whole picture (in your head) but use local builders (they are cheaper)
A. Drosophila embryo use different transcription factors to form second even skipped
transcription stripe and first and third odd skipped transcription stripe EMBRYO BONUS MARKS MATERIAL