Heres How Researchers Made Mice With 2 Dads Article Review Riley Morgan

Riley Morgan

Biology Mr. Ippolito

Current Event 5

10/21/18

https://www.livescience.com/63877-two-dad-mice.html

The article written by Stephanie Pappas discusses the discovery made by senior study author Wei Li, a stem-cell researcher at the Chinese Academy of Sciences. For the first time, researchers have created mice from 2 male mice and no female. According to the article, the mice were not able to survive for more than one day but the process of creating these mice by  coaxing an embryo made out of the DNA from two male mice all the way through the fetal development stage was extremely challenging. It was way harder then creating mice using too female mice which the article says has been done in 2004. According to Wei, the barrier to single sex reproduction is something called genomic imprinting which is a very important feature for embryonic development. During Sexual reproduction, the offspring inherits half of its DNA from its father and half from its mother.  The DNA from each parent has molecular tags that are added during the formation of the original sperm and egg. These tags are very important to early embryonic development. According to Mellissa Mann, a researcher in reproductive science at the University of Pittsburgh School of Medicine and the Magee-Womens Research Institute, studies have shown that when genetical engineers try to create an offspring based off of 2 sperm and no eggs, the embryo is unable to develop while the Placenta flourishes. Other studies have shown that when genetical engineers have tried to create offspring based on two eggs and no sperm, the Embryo thrives and the Placenta fails to develop. While undergoing this study, Wei claims that researches also wondered why mammals cannot reproduce on their own. In order to figure this out, scientists experimented to see what it takes to create parthenogenesis in mammals. Parthenogenesis is the process where a female produces without a male. The researchers used genetically engineered mice stem cells which only had 1 set of maternal chromosomes and injected them into another normal egg. This created an embryo with 2 sets of maternal DNA. The scientists then transferred this embryo of 2 maternal sets and no sperm into a surrogate mouse. The mice appeared normal but were not extensively tested for a long period of time so it is unsure how healthy they would of been as time progressed. Mice with 2 mothers had already been experimented with before in 2004 so scientists focused on a more new and relevant topic: creating mice with 2 dads.  This has only been done once before by researchers at M.D. Anderson Cancer Center in Texas. Researched create male stem cells with x but no y chromosomes. They then injected them into female blastocysts. They let the females develop into adults and then mated the female mice who only carried male X-DNA with other males. When paired, they created offspring that carried genes from two dads. This time, the scientists wanted to take a slightly different approach of seeing if they could make with two dads without the step of genetically engineered females. To tackle this problem scientists injected a sperm cell and stem cell with only paternal DNA into an egg cell which had its nucleus removed. When the nucleus was removed the cell was stripped of all maternal DNA. They then extracted stem cells which developed in the resulting embryo. The extracted stem cells were put into a separate blastocyst.  This was necessary to develop a placenta. After this, the stem cell injected blastocyst was placed into a surrogate mouse mother According to the article, this is “The first time that bi-paternal mice with two direct fathers has been produced.” Although born, the mice did not thrive well. Out of 1023 tries, only 12 mice babies were born. The 12 mice that survived were “swollen with fluids and were more than twice as big as regular mice pups.” The mice had problems breathing and being fed and died one day after birth.

This article is very relevant and has a big effect on society because  according to senior author Qi Zhou, also of the Chinese Academy of Sciences this method can be used again to target the effects of imprinting on various developmental disorders. These findings also are a big help when explaining why mammals cannot produce alone like most amphibians. Although the article says this is very far away, it is possible that these discoveries could also be part of a foundation for same sex human reproduction

This article was extremely well written, detailed, and interesting. Its strengths consisted of being extremely detailed. Every term that was used in the article was defined if not obvious. The experiments also were described in a detailed way. Pappas also did an excellent job explaining the background and events that led up to the main experiment the article was meant to focus on. Although very detailed and clear in some parts, The article was extremely lengthy which caused me to lose interest at some points. The background information of events that led up to the article took up a majority of the writing. The event I wanted to read about was not talked about until the very end. At some points the article was confusing as well. The lengthy descriptions in some cases were helpful but in others just made it even more confusing. To improve this article I would advice Stephanie Pappas to get to the point quicker and not wait till the last paragraph to talk about the topic listed in the Title. I would also work on cutting down and taking out unnecessary words to make the article not only less lengthy but more interesting and less confusing. In conclusion, This article was very innovative in many different ways and was extremely interesting to read but did get confusing and lengthy at times.