Concept explainers
To review:
Based upon the mechanism of opposing concentration gradients of Bicoid and Caudal determine specification of the anterior-to-posterior axis in Drosophila melanogaster, and whether same mechanism work in a fly embryo that is larger or has different proportions per body segment. Also, determine precision of actual gradient and precision to set a nucleus/cell upon a lineage-specific path of maturation.
Introduction:
Research studies revealed that the cytoplasm of egg is not uniform as compared to other eggs. It comprises of ascents of positional information determining the cell density along the egg's anterior-posterior axis. In the syncytial blastoderm, nuclei in the frontal part of the cell are open to cytoplasmic determination factors usually not found in the posterior segment of the cell. These determination factors in differing amount with the nuclei specify cell fate.
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Developmental Biology
- Practice Question 8 - Below are two cell signalling pathways that work together to regulate cell growth, proliferation and ultimately the size of organs in O.Extremus. In other closely related organisms, dysfunction of these pathways has been associated with tumor growth. MTOR pathway: 1. Growth factors bind and stimulate the receptors. crosstalk Hippo Pathway 2. Receptors can activate the phosphatidylinositol 3 kinase (PI3K) – Akt signaling pathway. MTOR Pathway 3. The activated Akt, a serine threonine kinase, inhibits theTSC1-TSC2 complex, allowing Rheb to activate mTORC1. Mst РІЗК PTEN T Lats АКТ 4. In parallel, amino acids activate the mTORC1 pathway through a mechanism requiring the Rag- Ragulator complex. (miR-29 YAP TSC2-TSC1 amino acids Rag-Ragulator Hippo pathway: 1. The binding of the ligand activates the receptors which activate Mst and Lats. Rheb cell division MTORC1 organ size 2. YAP activity is modulated by phosphorylation of Mst and Lats. YAP upregulates miR-29, which in…arrow_forwardPractice Question 8 - Below are two cell signalling pathways that work together to regulate cell growth, proliferation and ultimately the size of organs in O.Extremus. In other closely related organisms, dysfunction of these pathways has been associated with tumor growth. MTOR pathway: 1. Growth factors bind and stimulate the receptors. crosstalk Hippo Pathway 2. Receptors can activate the phosphatidylinositol 3 kinase (PI3K) – Akt signaling pathway. MTOR Pathway 3. The activated Akt, a serine threonine kinase, inhibits theTSC1-TSC2 complex, allowing Rheb to activate mTORC1. Mst РІЗК PTEN Lats АКТ 4. In parallel, amino acids activate the mTORC1 pathway through a mechanism requiring the Rag- Ragulator complex. miR-29 YAP TSC2-TSC1 amino acids Hippo pathway: 1. The binding of the ligand activates the receptors which activate Mst and Lats. Rheb Rag-Ragulator cell division MTORC1 organ size 2. YAP activity is modulated by phosphorylation of Mst and Lats. YAP upregulates miR-29, which in…arrow_forwardTask #3 Impact of allelic difference: The receptor protein encoded by the recessive m allele sequence cannot bind its hormone partner, and as a result the fur pigment eumelanin is not effectively produced. Briefly explain how one amino acid change might impact the function of the receptor protein. Task # 4 Genotypes and Phenotypes: The Mc1r gene is located on chromosome #16 in mice. Mice are diploid so every somatic cell has two copies of the Mc1r gene. Since there are two Mc1r alleles there are three possible genotypes: MM, Mm and mm. M=dark pigment m=less pigmentParental generation: an inland mouse (MM) mates with a beach mouse (mm) A. What is the genotype of the F1 offspring? ________B. If this trait exhibits simple (Mendelian) dominance, circle the phenotype expected for the F1 fur color: dark pigment / medium pigment / less pigment Observed phenotype: F1 actually have medium pigment. Initially this looks like blending, but it is not. M and m are discrete units. This observation…arrow_forward
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- Need help with parts a,b and c, please and thank you!arrow_forwardQuestion for assignment: Using a transgenic technique, propose an experiment to determine whether Cdx2 is sufficient for trophoblast development in the mouse embryo. Describe two results that you would expect to observe at the blastocyst stage if Cdx2 is indeed sufficient for trophoblast development. Be as specific as possible regarding the transgene that you propose for this experiment (including what gene's enhancer you would use in the transgene). Note: you do not need to explain the details of how a transgenic mouse is made. Describe the experiment in steps (Step 1: ..., Step 2: ... etc) and please keep your answer to under 150 words. TIPS FOR ANSWERING: DONT talk about stop cassetes/memory cassetes, focus on transgenes Paper (below) gave lots of results that you might see,, 6 diff ways that cdx2 is required for trophoblasts need specific gene enhancer (dont just say "expressed enhancer in genital ridge")arrow_forwardQuestion for assignment: Using a transgenic technique, propose an experiment to determine whether Cdx2 is sufficient for trophoblast development in the mouse embryo. Describe two results that you would expect to observe at the blastocyst stage if Cdx2 is indeed sufficient for trophoblast development. Be as specific as possible regarding the transgene that you propose for this experiment (including what gene's enhancer you would use in the transgene). Note: you do not need to explain the details of how a transgenic mouse is made. Describe the experiment in steps (Step 1: ..., Step 2: ... etc) and please keep your answer to under 150 words. TIPS FOR ANSWERING: DONT talk about stop cassetes/memory cassetes, focus on transgenes Paper (Cdx2 is required for correct cell fate specification and differentiation of trophectoderm in the mouse blastocust) gave lots of results that you might see,, 6 diff ways that cdx2 is required for trophoblasts need specific gene enhancer (dont just say…arrow_forward
- Questions 10-13, true or false about the following statements on gigas (gig, fly TSC2) mutant clones and the corresponding WT twin spots were generated during Drosophila eye development. gig mutant clones will be larger than twin spots with larger cells gig mutant clones will be larger than twin spots with more cells gig mutant clones will be larger than twin spots with high levels of phosphorylated Akt gig mutant clones will be larger than twin spots with high levels of phosphorylated S6Karrow_forwardBioarrow_forward13arrow_forward
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