Question

Read the Haas and Whited (2017) review paper on limb regeneration and answer one of the three following questions. A good answer to this question might require you to look up papers cited in this review. You can search for articles on scholar.google.com, and a great number can be downloaded on campus. If you do use another paper, please provide a citation.

   1. Describe what you feel is the critical step in the morphological development of the regenerated limb. Why is it the critical one?
   2. Choose one of the genes mentioned and explain what it does to aid in limb regeneration.
   3. Choose one of the techniques used to determine candidate genes and describe how it works and why it is useful. Choices are RNASeq, Transcriptomics, Expressed Sequence Tags/Microarray.

Answer each part in 3-5 sentences.

Answer 1

Answer 1

The review paper by Haas and Whited (2017) on limb regeneration is based on the studies conducted on salamanders and their comparison with humans as both the salamanders and humans are considered anatomically similar. The study is based on the limb regenerative capacity of Axolotls and the genome editing which could be done on humans to achieve the same regenerative results.

From my point of view, the critical step in the morphological development of the regenerated limb is the process of transcription that takes place on mRNA i.e. the strand specific RNA sequencing.

This step is critical because of the fact that epigenetics play an important role during regeneration through modulating cell state changes and cellular memories. This study has shown that if RNA sequencing is done sufficiently deep, then the fundamental aspects of limb development could be predictably controlled and even very lowly expressed transcripts may be recovered. An accurate representation of the relative expression values for very highly-expressed genes can be determined as it was seen with mRNA sequencing, that the saturation effect that occurs with microarrays for very highly-expressed transcripts does not exist.