Axolotl Regeneration and Mapping Their DNA

Axolotl are small amphibians from Mexico who have extraordinary regenerative abilities. These creatures are able to regrow just about any body part, even up to half of the brain. Aside from cutting off the head, an exact replica of anything else will be regrown. Scientists around the world are attempting to completely map the DNA of this organism in hopes to provide advances in human regenerative medicine. Dr. Melissa Keinath describes that the axolotl genome is ten times larger than that of the human genome. The New York Times reports that "Dr. Keinath and her colleagues mapped more than 100,000 pieces of DNA onto chromosomes". Because DNA sequences that are physically close together on chromosomes are commonly inherited together, the researchers could use linkage mapping to organize the axolotl DNA. Additionally, the scientists were able to identify DNA exclusive to axolotl by crossing them with tiger salamanders. Knowing how DNA is positioned "allows you to start thinking about functions and how genes are related," scientist Dr. Voss explains. After understanding the relationships between the DNA position and gene function in the axolotl, scientists can observe whether the same relationships are seen in humans. 

The research on axolotl is interesting because if we can understand the genes and their functions behind axolotl regeneration, maybe a similar technique can be applied to human medicine. Studying the axolotl DNA may also reveal more about epigenetics and if deactivating certain genes results in excellent regenerative abilities. Furthermore, the physical location of where DNA is located and how it affects the genes can be analogous to humans. 

10 Times the Human With a Smile

           The axolotl, a smiling Mexican amphibian, is the largest genome ever sequenced. It has 32 billion base pairs, ten times the size of human genome. The axolotl has been bred and studied in laboratories for over 150 years and is endangered in the wild. The axolotl is an extremely interesting organism: it regenerates damaged organs, regrows amputated limbs with all bones, muscles, and nerves, and even heals wounds without scar tissue. The amazing thing about its ability to heal and regrow is that it will do so with the new organs or limbs functioning just like they did before. For example, a crushed spinal cord can function again normally like it was never crushed. This animal was the first salamander genome to ever be sequenced. It took so long to be done because it has many repetitive parts in its genome. This genome sequencing is just the beginning of their studies, but a huge advance in science because it has the potential to answer many questions. The genes involved in regeneration are being identified and studied. 

summarized article:

https://www.nytimes.com/2018/02/01/science/axolotl-genes-limbs.html

original scientific study:

https://www.nature.com/articles/nature25458

New Reasons why Crocs are a Better Birth Control

The Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin has noticed a peculiar trend. Male amphibians are being exposed to an extreme amount of synthetic hormones, skewing the ratio of males and females, and causing a decrease in population.

It turns out that the main ingredient of the pill is 17a-Ethinylestradiol (EE2), an aestrogenic endocrine disrupting chemicals (EEDCs). It is completely man made and because of such, waste plants cant completely remove the hormone from urine. Thus it returns back to natural water supplies. ln the three species accounted for in this study, sex reversal occurred in 15 to 100 percent in the males.
Also another study in small mouth bass, 85% displayed the synthetic hormone inducing "inter-sex" as cause for decreasing population. Ecologists are starting to become anti-pill for such reasons. It has been around for decades, yet presently"..more than 100 million women use the pill." With that huge magnitude it is understandable how water is being affected, and how ecological damage is surmounting.

This led me to wonder what they effects are for humans, since this synthetic hormone may also remain in our water. Even if it is in small amounts, could this be a reason that youth appear to be going through puberty earlier?

If I put a real picture of me the point would be proven more, but I didn't want to do that to you guys.
It would be interesting to have data regarding the presence of EEDC's in water sources, as well as what level promotes a reaction, and if synthetic hormones incite maturation. I believe more research should be invested into to ensuring better ingredients, to allow women to still have control over their bodies yet in a more sustainable, natural way.

Rapid Reproduction

This article is about the Batura toad, a Pakistani amphibian that has an extremely unique way of reproducing.  They do not have the common two copies of genes; they have three instead.  Their genes are carried on three sets of chromosomes.  The Batura toad parents carry two separate genomes.  These can be inherited in two distinct ways: one can get muddled up with the mate’s and the other makes a clone of itself.   This means that the offspring are partly a clone of the parent and partly a product of normal sexual reproduction.  These are called triploid animals and usually have genetic problems, such as mutations, making the survival of these frogs surprising.  The Batura toad had to pass on their three copies of their genes somehow; why not clone?