Variation In The Shape of the Human Birth Canal

The common understanding has been that the shape of a human mother's birth canal has been fashioned by the evolutionary forces that it needs to be wide enough to allow large brained babies to pass through but narrow enough for women to walk efficiently. This evolutionary compromise is known as the obstetrical dilemma. Research by biological anthropologist, Lia Betti, and evolutionary ecologist, Andrea Manica, challenge the obstetrical dilemma. The obstetrical dilemma would suggest that birth canal shape around the world would be relatively standardized but the findings of these researches did not support this. Betti and Manica measured the pelvises of 348 female human skeletons from 24 different parts of the world. They found women from sub-Saharan Africa and some Asian populations has pelvises that were narrow from side to side and deep from front to back. They found that Native American women had wider canals and that Native Americans and Europeans had the most oval-shaped upper canals. They saw that there was less variability in shape in populations farther from Africa.  Their analysis proposed that the variable shapes were due to neutral evolution through genetic drift and migration.  They hypothesized that climate could have contributed to different shapes however they found little evidence for it and suggest further research into other ecological factors.  Betti and Manica said their research could be important for modern obstetric practice in multi-ethnic societies as modern medical understanding is developed mainly on studies of European women.

https://www.sciencemag.org/news/2018/10/birth-canals-are-different-all-over-world-countering-long-held-evolutionary-theory
http://rspb.royalsocietypublishing.org/content/285/1889/20181807

Maeve Curran

Neanderthal and Modern Human Hybridization

Two researchers, one from the University of Arizona and one from Stanford University, recently published an article in which they analyzed segments of Neanderthal ancestry in the modern human genome related to virus resistance. They ultimately found 152 introgressed gene fragments. They then tested these fragments to try to address their “poison-antidote” hypothesis. Their hypothesis was that as the two species exposed each other to new viruses, they also exchanged virus-interaction proteins (VIPs), which allowed them to have some resistance to these viruses without developing these proteins through natural mutations. These VIPs interact with a variety of RNA viruses such as modern-day HIV, influenza A, and hepatitis C. The specific RNA virus-based VIPs are seen in higher proportions in European than East Asian populations. Most of these introgressed segments in modern humans originated from the second major interbreeding event. This type of analysis of introgressed segments can also be used to detect ancient epidemics. This study can have profound impacts on ancient genetic epidemiology and understanding how these introgressed segments impact the human genome as discussed in recent news articles such as this one.

Joshua Porter

Domestication of the Red Fox

This red fox experiment has been in the works for almost 60 years. The foxes are bred in captivity and then put into one of three groups for genotyping. These groups are the Tame, conventional, and aggressive populations. The foxes have the same window of DNA genotyped, while researchers look for the presence of a "friendliness" gene. Then once the fox's genes have been assessed, a physical test is made to back up the results. What is noted is that the domesticated fox isn't like a dog, they are anxious and curious and they are not like dogs at all. 

https://www.nature.com/articles/s41559-018-0611-6#MOESM4

https://www.theverge.com/2018/9/11/17842410/pet-tame-foxes-domestication-dogs-genetics

Mouse pups with same-sex parents born in China using stem cells and gene editing

Researchers from the Chinese Academy of Science were able to use haploid ESCs to create healthy viable mice that has DNA from two mothers; however, mice from male parents survived in utero but only lived for 48 hours outside the womb. The process of creating mice from same-sex parents had been done before, but when the mice from two females were born the first time it was tried with out the use of haploid ESCs they were stunted in growth and did not live very long. The mice created from two males did not even survive birth the over grew in utero and didn't survive birth. This discovery does not mean that haploid ESCs to create same sex offspring can be used in all species of mammals that cannot same sex reproduce because each species has different imprinting sites that have to be recognized and deleted to produce viable offspring, but it is a step in identifying all the possibilities of gene editing and stem cells.

original paper:
https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(18)30441-7
Science Daily report:
https://www.sciencedaily.com/releases/2018/10/181011143115.htm

Post by Sophia Sanchez

According to an article titled, "The Epigenetics of Being Black and Feeling Blue: Understanding African American Vulnerability to Disease", written by Dr. Darron Smith African American are suffering from various mental health serious due to racial discrimination, which remains a societal norm and a routine a part of their everyday lives. It influences human biology and physiology at the cellular level, leaving the poor, the impoverished, and the targeted more vulnerable to chronic disease. The result is epigenetic tags with harmful gene expressions. 

Nana Evison 

FDA Lifts Clinical Hold; Green-Lights Vertex and CRISPR’s Sickle Cell Gene Therapy Trial

According to this article published in BioSpace last week (as well as this article from Globe News Wire), in May of this year the FDA placed a clinical hold on an experimental trial for a treatment for sickle cell and other such diseases. The treatment was being co-developed by CRISPR Therapeutics and Vertex Pharmaceuticals, and was put on hold due to "concerns" from the FDA that needed to be reviewed before proceeding in experimental trials. The gene-editing treatment is known as CTX001, and is an ex vivo therapy for people who have inherited disorders involving hemoglobin, like sickle cell anemia or beta-thalassemia. CTX001 edits the genes through CRISPR technology to increase production of fetal hemoglobin in a patient's red blood cells. Fetal hemoglobin naturally exists in newborn babies, but sometimes carries over into adulthood, where it can provide protection for people with blood diseases. CTX001 appears to be safe because it affects only cells at the targeted site (via). The FDA did not say the specific "concerns" that they had, though it is speculated that they are being cautious about human trials because "it's a permanent alteration of a person's genetic code" (Brian Skorney). However, since CTX001 is CRISPR's "most advanced program," it seems that the FDA would rather be safe than sorry with regards to gene-editing treatments, considering potential dangers brought up regarding CRISPR technology in the past.

Ezra Lowe

Reproductive Revolution: how our skins cells might be turned into sperm and eggs

Scientists have recently discovered a way to make somatic cells into sperm and egg cells in vitro in mice (iPSC cells). They do this by injecting somatic cells with a cocktail of genes that generate transcription factors that then tricks the cell to into thinking it is a different type. To turn the cells into gametes, the iPSCs receive chemical signals from the tissues in the ovaries or sperm cells. Once the cells are induced they can then be planted back into the mouse to mature to their full development. This study has not been conducted on humans yet, however, this great of leap in science could lead to genetically modifying human offspring. It would also allow same sex partners to have a genetically related child, and even a single parent to create a child from 100% of their cells.

https://www.theguardian.com/science/2018/oct/14/scientists-create-sperm-eggs-using-skin-cells-fertility-ethical-questions?CMP=share_btn_link