Lecture 21b Flashcards
What is the null allele for the Antp gene?
It is embryonic lethal, meaning that the fly cannot live.
A gain of function mutation that causes the Antp gene to be expressed further anteriorly results in what?
Results in legs growing where there should be antennas.
What does the Ubx gene specify?
Specifies the segment behind the one with the wings and is expressed all the way to the anterior tip.
Basically, it specifies what is behind the wings, not the actual wings themselves.
What does a mutation in Ubx result in?
A second segment with wings giving the fly an extra set of wings.
Is the Ubx gene an essential gene?
No cuz an extra set of wings can still allow the fly to live healthily.
What do Homeotic genes encode?
Encode for transcription factors that active sets of genes.
Where are DNA-binding sites found for the DNA-binding domain?
Within enhancers
Name the 4 vertebrate species that are studied for development.
Chicken, african clawed toad (Xenopus laevis), Zebrafish (Brachydanio rerio), and mouse.
What do chicken embryos resemble? How are they different?
Resemble mouse and human embryos, but they develop in an egg rather than inside the mother.
In chicken, where does the embryo lay?
On top of the yolk
How can chicken embryo development be observed?
Egg shell can be removed and development videotaped all the way to hatching.
How many days does it take for chicken to go from fertilization to hatching of the egg?
21 days
How could we manipulate chicken embryos to make regions untranslatable?
siRNA, antisense RNA, or morphilinos can be electroporated into the embryos at one side of the embryo.
What are Morphilinos?
They are like antisense RNA but chemically more stable (cannot be degraded because they aren’t RNA). They make an area untranslatable.
How could we manipulate chicken embryos to express a gene of interest?
Plasmids to express a gene of interest can be electroporated into the embryos.
