Ablation of the anchor cell in wild-type C. elegans results in...

Question

Ablation of the anchor cell in wild-type C. elegans results in a vulva-less phenotype.

What about if the anchor cell is ablated in a let-23 gain-of-function mutant?

Accepted Answer

Welcome back, everyone. Let's look at our next question. Which of the following genes contributes to the differentiation of somatic cells during C elegans development. Choice. A lin four choice B. Lin 14 choice C lin or choice D par one. So we're looking at sea elegance, a little tiny worm development very commonly looked at for development because it's tiny, it's transparent, it has just a little over 200 somatic cells. So a great model for being a simple model, easy to study for development. And we're looking for which gene contributes to differentiation. So the cells going down different paths to be different organs in the body and the gene we're looking for here is choice C linn 41. This is a really tricky one because we have these three very similar sounding genes. Lin four lin 14 lin 41 but lin is key to differentiation. It is part of the process. Mhm That determines the proliferation versus differentiation decisions. So in very early development, we have stem cells proliferating, just dividing over and over again and then they begin to differentiate into different cell types. And lin 41 is key to this differentiation process. It codes for an E three ubiquitin ligase protein. Let's put that there. E three ubiquitin which causes the suppression or degradation of different R N A targets. It's an R N A binding protein and these different R N A s that help kind of control this proliferation versus differentiation and directs the fate of different cell types. It targets these R N E S for suppression or degradation when they've done accomplish their role in early development and aren't going to be used anymore. So let's look at our other answer choices. Just to be thorough. The easiest one to eliminate is choice D par one. This is, is, is involved in the earliest stage of development in establishing the anterior posterior axis of the worm. So long before differentiation, very, very early in development, not what we're looking for. And then choices A and B. Lin four and 14 are both crucial to embryonic development, but they're not key to the differentiation process. The way Lin 41 is uh lin four is actually a short or micro R N A. Interesting little note, it was the first micro R N A discovered and that led to the understanding of how important micro R N A s were in gene regulation. And it actually targets Lin for degradation as part of the timing of developmental processes. But it's not what we're looking for because it's not involved in differentiation and then finally, Lin 14, the gene codes for a transcription factor, a protein that controls the timing of cell division in early development. So that is expressed early on in development. And then lin four comes in, binds to a region on the Lin 14 gene and that then targets the specific protein for degradation. So that's why that's not our answer choice. Again, all involved in cell division early on in development but not differentiation. So again, our question asks us which of the following genes contribute to the differentiation of somatic cells and c elegans development. And the answer is choice C lin 41. See you in the next video.

Ablation of the anchor cell in wild-type C. elegans results in a vulva-less phenotype.
What about if the anchor cell is ablated in a let-23 gain-of-function mutant?

Key Concepts

Anchor Cell Function

LET-23 Receptor

Gain-of-Function Mutations

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