Rough draft.This research track is under review with Dr. Atit's lab. Content and sequence may still change.
The Baby Mateo Case
Developmental domainPrinciples of Biomedical Science (PBS)Lesson 3 of 20Your seat: Neural crest cell biologist
Where Do the Cells That Build the Face Come From?
Discovery question
Where in the early are the face-building cells born, and how do they get free to start their journey?
💡 Most of the face is built by cranial that form at the crest of the neural folds and break free by an -to-mesenchymal transition.
The plan
Prerequisite check
Before this page, you should know
- Five prominences surround the early mouth (the ): one , a paired , and a paired .
- Nasal pits split the into the inner medial nasal processes and the outer lateral nasal processes.
Today's new idea is only
Most of the face is built by cranial that form at the crest of the neural folds and break free by an -to-mesenchymal transition.
Learn first
What you will learn
Goal: Describe the origin of cranial at the edges of the neural folds, explain by -to-mesenchymal transition, and state why these cells are called .
Know by the end
- The cells that build most of the face are cranial , which form at the crest of the neural folds where the folding meets.
- To leave home, undergo by an , switching from a stuck-together sheet cell to a free, crawling cell.
- are : one cell can become bone, , , dermis, and more.
- Because they supply the prominences, anything that reduces their number, survival, or release can leave a too small to fuse.
Learn first
Model: Birth at the neural folds, then break free (delamination)
Early in development the back of the folds up to form the (the future brain and spinal cord). Picture a flat sheet of cells rolling up like a taco; the two rising top edges are the neural folds, and right at their crest sits a special strip, the . The neural crest in the head (the cranial neural crest) is the population that builds the face, and it starts out as part of a tightly packed sheet (an ).
A short time after the folds meet, these cells loosen their grip on their neighbors, change shape from boxy sheet-cells into loose crawling cells, and break free from the top of the . That break-free step is , and the shape change behind it is an . Once free, a single cranial can become many different things: bone, , , dermis, tooth-forming cells, nerve-supporting cells, and pigment cells. A cell that can become many types is called .
Do the work
Explore (work the model before reading on)
- Where exactly are located when they first form (which part of the neural folds)?
- What are the three things a cranial does during ?
- List three different cell types a cranial can become.
- Why does a cell have to undergo EMT (stop being a tight sheet) before it can migrate? Connect the shape change to the ability to move.
- The prominences are filled mostly with neural-crest-derived . Using that fact, explain why a problem in making or releasing these cells could lead to a too small to fuse.
The plan
Guided notes
1
Where the face cells are born
Model start: The cells that build most of the face are the cranial , and they form at the crest of the neural folds where the edges of the folding meet.
- To leave home they undergo ____: they loosen from the sheet and break free.
- The underlying change is an -to-mesenchymal transition, switching from a stuck-together ____ cell to a free, crawling ____ cell.
2
Multipotent raw material
- These cells are ____, meaning one cell can become many cell types such as bone, , , and dermis.
- Anything that reduces their number, survival, or release can leave a too small to reach across and ____.
3
An honesty note
- This lesson explains the cell source for ____ development; we are not claiming Mateo had a defect.
- We are learning the toolkit so the team can later weigh each possible ____ point.
Explore
Reading the Research
What to read
Read the title and the abstract only, not the whole paper. Lan & Jiang 2015, Cellular and Molecular Mechanisms of Palatogenesis (Curr Top Dev Biol)
Why this source matters
This is the published evidence behind today's idea: Most of the face is built by cranial that form at the crest of the neural folds and break free by an -to-mesenchymal transition.
Words to unlock first
Reading moves
- Skim the title and abstract first to get the gist.
- Circle the one sentence that states the main claim.
- Box the evidence the authors give for that claim.
- Mark one sentence that confuses you, and move on.
Stop point
You do not need the methods or statistics yet. If a sentence is about lab technique or math you have not learned, mark it and skip it.
Your output
Write one claim-evidence sentence: what this source claims, and the one piece of evidence that backs it up.
Where this fits
Tested on (Ohio WebXam)
Genetics of Disease · 072130
PLTW lesson
MI · Developmental domain · Cell differentiation and multipotent populations that build the face
WebXam domain
Bio-Molecular Technology
Evidence to produce
Sketch a 3-panel comic of one cranial neural crest cell: panel 1 sitting in the neural fold as part of a sheet, panel 2 undergoing EMT and delaminating, panel 3 free and ready to travel. Under panel 3 write one sentence naming a real fate it can become inside a facial prominence.
Lab / skill
Principles of Biomedical Science (PBS) · Medical Interventions (MI)
Explore
Vetted readings for this lesson
- Lan & Jiang 2015, Cellular and Molecular Mechanisms of Palatogenesis (Curr Top Dev Biol)
- Mishina & Snider 2014, Neural crest cell signaling pathways critical to cranial bone development (Exp Cell Res)
- Liao et al. 2022, Gene regulatory network from cranial neural crest cells to osteoblast differentiation (Cell Mol Life Sci)
The plan
Track your progress today
Check these off as you work through the lesson, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
Check off as you finish
- Read the Model and answered the Explore questions.
- Filled in the guided notes in my own words.
- Defined the new vocabulary with an example.
- Built the producible: Sketch a 3-panel comic of one cranial neural crest cell: panel 1 sitting in the neural fold as part of a sheet, panel 2 undergoing EMT and delaminating, panel 3 free and ready to travel. Under panel 3 write one sentence naming a real fate it can become inside a facial prominence.
- Wrote my Claim, Evidence, and Reasoning exit ticket.
Pick your period and code first.
Check yourself
Exit ticket (Claim, Evidence, Reasoning)
- Claim: The cells that fill the facial prominences come from the cranial .
- Evidence: form at the ____ of the neural folds and undergo ____ (EMT) to break free and migrate.
- Reasoning: Because these cells supply the prominences, the face cannot be built normally unless they are made and released in adequate numbers.
How this is graded (rubric)
For: Sketch a 3-panel comic of one cranial neural crest cell: panel 1 sitting in the neural fold as part of a sheet, panel 2 undergoing EMT and delaminating, panel 3 free and ready to travel. Under panel 3 write one sentence naming a real fate it can become inside a facial prominence.
| Criterion | Proficient | Developing | Beginning |
|---|---|---|---|
| Complete | Every required part of the artifact is present and filled in. | Most parts are present, but one is missing or left blank. | Several parts are missing. |
| Accurate | The science and data are correct and match the evidence. | Mostly correct, with a small factual slip. | Key science or data is wrong. |
| Scientific reasoning (CER) | States a claim, backs it with specific evidence, and explains the reasoning. | Has a claim and evidence, but the reasoning is thin or missing. | Gives an answer with no evidence or reasoning. |
| Professional communication | Clear, organized, and labeled the way a clinician or scientist would write it. | Readable but disorganized or missing labels. | Hard to follow. |
| Submitted | Turned in the right way (Schoology for routine work) and confirmed. | Turned in, but in the wrong place or unconfirmed. | Not turned in. |
How the model answer scores against this rubric
- CompleteProficient: Nothing is left blank: the model fills every part of "Sketch a 3-panel comic of one cranial neural crest cell: panel 1 sitting in the neural fold as part of a sheet, panel 2 undergoing EMT and delaminating, panel 3 free and ready to travel. Under panel 3 write one sentence naming a real fate it can become inside a facial prominence.".
- AccurateProficient: Every number and claim matches the case evidence.
- Scientific reasoning (CER)Proficient: It names a claim, cites the specific evidence, and explains the reasoning, not just the answer.
- Professional communicationProficient: It is organized and labeled like a real chart note.
- SubmittedProficient: It would be turned in on Schoology and confirmed.
Explore
Where this leads: careers
Cell biologist Stem cell researcher Developmental biologist
What's next: The face-building cells are born at the top of the , near the brain, and break free by . But the prominences they need to fill sit far away around the mouth and jaw. So the next question is: how do these cells travel from the neural folds to the right facial blocks? We chase that next time.
Which Building Blocks Must Fuse to Make a Lip and Palate?How Do the Face-Building Cells Get to the Right Place?