Induction of the Vertebrate NS Flashcards
Which gene is found pan-neurally at the end of Xenopus gastrulation?
Sox2
Which gene is found in the forebrain at the end of Xenopus gastrulation?
Foxg1
Which gene is found posteriorly at the end of Xenopus gastrulation?
Hoxb9
Which gene is found at the neural crest at the end of Xenopus gastrulation?
Snai2
Which part of the gastrula is dark and which light?
Animal - dark
Vegetal - light
Describe Spemann’s experiment
Replaced ventral ectoderm (epidermis) with dorsal ectoderm (neural plate)
Transplant at start of gastrulation - dorsal ectoderm formed epidermis
Transplant at end of gastrulation - dorsal ectoderm formed neural plate - original neural plate forms primary axis - ectopic neural plate forms secondary axis
Describe Spemann and Mangold’s experiment
Transplanted dorsal blastopore into ventral side of host gastrula
Formed conjoined twin - secondary axis formed
Induced formation of neural tissue on ventral side - usually forms epidermis
Dorsal blastopore is organiser - induces neural tissue
Describe amphibian gastrulation
Mesoderm and endoderm involute at blastopore - migrate along inner surface of ectoderm
Organiser migrates under dorsal ectoderm
Which proteins are organiser-specific?
Chordin
Noggin
Follistatin
Describe an experiment showing the role of chordin, noggin, and follistatin
Animal cap from early gastrula incubated in salt solution - differentiates to epidermis
Add chordin/noggin/follistatin - differentiates to anterior neural tissue (forebrain)
What is the order of potency of noggin, chordin, and follistatin?
Noggin - most
Chordin
Follistatin - least
What is the key role of chordin?
Secondary axis induction
Name an epidermalising factor
BMP
What is the role of Frzb?
Head development
