PCB 3063 Lecture Notes - Lecture 19: Sirenomelia, Arthrogryposis, Amnion
18 Dec 2018
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These three types are known as pluripotent cells, as they can become many cell types but not all cell types. Many of them came from studies with drosophila: maternal effect genes are the mother"s proteins that are expressed and placed into the oocyte before fertilization. Zygotic segmentation genes are transcribed and translated from dna in nuclei of embryonic cells due to the maternal effect proteins. There are gap genes, pair rule genes, and segment polarity genes, as previously mentioned, that cause a hierarchical cascade: gap genes in fruit flies: first expressed and divide the embryo into broad regions. They have binding sites in the promoter that have different affinities for maternal effect genes. Once turned on, they code for more transcription factors, which activate pair rule genes in drosophila. These establish boundaries of segments in the thorax (seven bands specifically).
