Hello Everyone! After months of research into the West African lungfish (Protopterus annectens), I have finally decided to end my blog on this fascinating creature. Up until now, we’ve learned some amazing facts about this creature such as how the W.A. lungfish walks on land, breathes air, and how it is related to other species. To finish off this blog, I’ve decided to look into what other researchers are studying regarding this fish that seems to defy all logic! While reading through some articles, I was fortunate enough to stumble upon one that covered an amazing ability of the West African lungfish, its ability to regenerate its tails.

This article was written by Verissimo, Kellen, et al., and discusses a major problem regarding tail regeneration. Although salamanders, tadpoles, and many other lizards have the ability to regenerate their tail, the development and genetic architecture of tail regeneration is very poorly understood. Therefore, this article experiments with and shows the “morphological and molecular hallmarks of tetrapod tail regeneration in the West African lungfish Protopterus annectens, a living representative of the sister group of tetrapods (Verissimo et al, 2020).” Of course, with a paper taking on a heavy topic such as this, there popped up many words that I didn’t understand. To save all of you the painstaking effort of combing through the dictionary, I’ve directly written down the keywords I wasn’t able to understand within the research paper, as well as some crucial keywords to understand the subject.

KEYWORDS:

Tetrapod: Four-footed animals, which include vertebrates

Plesiomorphic: The ancestral character in a particular clade

Blastema: Mass of cells that are capable of growth

Shh Gene: Instructions to make the Sonic Hedgehog protein, which is a chemical signal essential for embryonic development

Transposon: sequences of repetitive DNA that can move locations within a genome

After understanding some of the keywords above, we get a clear look into what this research is about. The authors believed that if lungfish regeneration was proven, then lungfish could be established as valuable research material into regenerative biology and could help form a link to the ancestors of the sarcopterygian clade. The researchers went about with this experiment by acquiring 30 juvenile West African lungfish and amputating the tails of each lungfish at a calculated distance from its snout. Afterward, they spent each day recording the changes in the amputated lungfish. After 56 days since amputation, the general results were that lungfish are able to regenerate their tails similar to salamanders. This can be seen in Figure 1 below which shows the progress of growth of the West African lungfish’s tail after amputation.

Salamander-like regeneration refers to the similar way in which lungfish regenerate their tails. First, a wound epithelium will be established, which will then thicken and form an AEC. After this, a mass of proliferating blastemal cells will form, which will finally lead to the restoration of the original tail tissue organization. Since salamander-like regeneration was proved in lungfish, this means that tail regeneration was present in the common ancestor of tetrapods and lungfish. Also, the origin of this amazing ability may even be from a time even earlier to the common ancestor since this form of tail regeneration is parallel to that seen in vertebrates. This gives us a clue to better understand the evolutionary history of tail regeneration. This trait also helps to highlight the lungfish as a new model system to better understand the evolution of tetrapod traits and a new model system to understand the mechanics of regeneration.

After having read this article, I was able to think of a couple of different ideas which I believe will be worth trying. In order to further our understanding of tail regeneration, I think we will need to further our array of research species and look for more evidence in past creatures, which can be done by researching fish fossils. These further experiments will hopefully help us understand our remaining questions and expand our knowledge of this subject. This research is one I put high emphasis on since it directly ties to a field that I am interested in, which is human regeneration. As children, we humans are able to regenerate lost fingertips. When we grow up, we are able to “regenerate” our hair, intestinal linings, and skin. Therefore, the more we understand how creatures are able to regenerate their bodies, the more advancements we are able to make into how humans can regenerate themselves. 

If anyone wishes to further study the findings of this article, I will paste the hyperlink below. It has been a pleasure getting to share my findings about the West African lungfish with you all, and thanks for keeping up with my blog!

Link: https://royalsocietypublishing.org/doi/full/10.1098/rspb.2019.2939#d1e1236

 

Citations:

Verissimo, Kellen et al(2020). Salamander-like tail regeneration in the West African lungfish.The Royal Society, 287(1935),

        261-271.https://doi.org/10.1098/rspb.2019.293