Insight Into the Evolutionary History and Phylogenetic Relationships of Deep Sea Asteroidea Using Mitogenomics

 

        Mitogenomics is the the the sequencing and analysis of mitochondrial DNA. The majority of mitochondrial DNA comes from maternal descent, is relatively small, and has a high nucleotide substitution mutation rate. allowing researchers to better understand the evolutionary history and phylogenetic relationships of a particular organism.
        Sun et al. use this technique to study the geographic origin and relationships between shallow water and deep-sea Asteroidea. For their experiment, they selected five deep-sea genomes. It showed that deep-sea Asteroidea had a much higher A+T nucleotide content compared to those in shallow water, providing insight into the divergence of base composition. Studying the genome also allowed researchers to identify the sequences responsible for the deep-sea adaptations against cold temperatures and hydrostatic pressure.
        By comparing sequences of different Asteroidea with each other and seeing when new mutations arose and for how long they were passed on, the origin of each mutation could be speculated. The more matches in DNA, the closer the relationship. Using this information, it was speculated that during the Triassic-Jurassic transition marked by a mass extinction event, the rapid divergence between the deep and shallow water varieties occurred to fill in the newly opened niches. Although it was inconclusive, the results also pointed towards a deep-sea ancestral origin.
        It is important to understand the evolutionary history and evolutionary mechanisms of organisms since it helps us understand why a species may exist in a certain environment and how the world as we know it today came to be. It is also important to compare the survival mechanisms of different organisms because it can help with cultivation for commercial purposes or conservation efforts.


What to read next: Global Diversity and Phylogeny of the Asteroidea (Echinodermata)

Sea Anemones Aren't So Simple After All

In a recent article from Science Daily, it states that tube-dwelling anemones have the largest mitochondrial genome on record.  They contain about 81,000 base pairs where, according to a journal entitled Scientific Reports, human mitochondrial DNA has less than 17,000 base pairs.  Meg Daly was saying that since they have simple behavior and movements that scientists always believed them to be simple creatures.  The article states that the mitochondrial DNA of a tube-dwelling anemone defies the typical circular shape and is arranged in fragmented pieces.  Daly and other scientists are trying to find an evolutionary explanation for this.

A Baby Boy born with three Biological Parents

Through a new in vitro fertilization (IVF) technique a boy was born with DNA from three parents. Researchers have questioned if the number of mitochondrial DNA will help with a successful pregnancy. This trial was done on a woman will taking her egg a mans sperm and also introducing a female donors mitochondrial DNA. The woman had tried IVF four times and was unsuccessful each time until the experiment. There not the only ones trying this method of in vitro fertilization currently there are already eight other implanted eggs and 24 other women signed up for the trial.

Although, this may seem like the perfect solution for women that want to get pregnant it's only been approve for families that have rare mitochondrial diseases. I think that the mitochondrial DNA could've been helpful in the IVF treatment but this is the first of this kind of study and not enough information to justify using mitochondrial DNA. This seems very interesting and would definitely be helpful to some but I think could mislead or give false hope to others. However, I think that this sort of thinking would be correct based on how mitochondrial DNA is important to cell function and because everyone obtain mitochondrial DNA from their mother.