By Elaine Zhu
Selfishness is the act of not caring about others, only thinking about getting ahead, and profiting at the expense of others. While most people think of selfishness as an acquired human trait, research has shown that some human genes can also act in a selfish or even parasitic manner in order to increase the gene’s chances of passing on its genetic material to its offspring. These parasitic genes don’t benefit the body’s overall fitness but instead methodically increase their own chances of transmission. Recent studies have investigated the mechanisms used by these selfish and parasitic genes and their potential applications.
In a study conducted by Nicole Nuckolls, María Angélica Bravo Núñez, and Sarah Zanders, a gene called wtf4 in Schizosaccharomyces kambucha fission yeast was identified as one of these selfish genes. The researchers discovered that the wtf4 gene in yeast actually acts simultaneously as a poison and an antidote. During fission, the wtf4 gene cleverly produces a specifically timed molecular poison during meiosis that is spread to all growing gametes, both the gametes that inherited the wtf4 gene and the ones that didn’t. Before the walls of the spores have formed, the molecular poison spreads to every offspring of the cell.
However, the cells with the wtf4 gene also carry the antidote to the poison it created. The antidote for the poison is made in the later stages of cell development and division after the spore walls have completely formed. Therefore, the gametes that did inherit the gene are guarded against the effects of the poison, but the cells that do not have the gene are left to suffer with the poison and eventually die off. Thus, the gametes that did not inherit wtf4 are left with no protection from the poison and are vulnerable, thereby selecting for the wtf4 gene. By coloring the proteins, Dr. Zanders and her colleagues found the two specific RNA message molecules that the wtf4 gene uses to encode for the poison and antidote. After imaging the cells while they underwent meiosis, the scientists were able to clearly confirm that the wtf4 poison was spread in every cell, but the antidote was only in the spores with the wtf4 gene.
Further research is currently being conducted to identify more selfish genes with the hope that the mechanisms for these genes can be applied in other scientific disciplines. These selfish genes can also provide insight into human infertility, since the “cheating” methods that such genes use can bias natural selection and even directly cause infertility. That is, a selfish gene could produce spores with an incorrect number of chromosomes, which can actually be detrimental to the survival of the daughter cells. Research has shown that chromosomal abnormalities are one of the leading explanations for why miscarriages happen in humans. In an interview conducted by the National Institute of General Medical Sciences, Dr. Zanders stated that “learning general principles about selfish genes in simple models will guide future searches for selfish genes that could be contributing to human infertility.”
Another exciting potential application of these selfish genes is to gene drives. Gene drives are a type of genetic engineering technology that can spread a desired set of genes to a population by increasing their probability of being inherited. These selfish gene mechanisms can potentially lead to the creation of a type of gene drive that may curb or even eradicate problematic insect populations, such as malaria or dengue fever transmitting mosquitoes. These selfish genes use a variety of methods to overpower other genes, and scientists may one day be able to utilize these mechanisms to ultimately improve the quality of human life.
By Vicky Communale
Rapidly melting glaciers, a loss of species diversity, and rising sea levels—the delicate balance of our planet is in chaos. While many deny these and other effects of global warming, or think that the consequences are distant and intangible, these ramifications are much more connected to our personal health than one would think. In that regard, a new study has found a very pressing concern—the effects of global warming will become directly intertwined with our neurological health in the near future.
Through research conducted by a group at Dalhousie University in Canada, it is predicted that in less than 80 years, over 96 percent of the world’s population will not have access to an essential component to brain health—docosahexaenoic acid. This lack of access is tied directly to the increasing water temperatures brought on by global warming.
Docosahexaenoic acid, also known as DHA, is an omega-3 fatty acid that has numerous benefits, including reducing heart disease risk and reducing inflammation. A healthy, functioning brain requires a high level of DHA: studies conducted in the 1990’s found that DHA is vital to the brain development of infants. For formula-fed infants, adding DHA to the formula was shown to improve cognitive and visual development. On the other hand, a lack of DHA has been implicated in numerous neurological disorders. One study, conducted by a group from the New England Medical Center in 2006, found that the brain tissue of people afflicted with Alzheimer’s Disease had significantly lower levels of DHA when compared to healthy human brain tissue. Furthermore, the scientists conducting this study also found that people with high blood levels of this fatty acid were half as likely to develop dementia as those with lower levels.
Given that DHA has been established as a vital component of healthy brain development and function, the depletion of this compound would be massively detrimental to all of us. Additionally, our bodies do not produce much DHA, so we must obtain it through our diet. The most abundant source of DHA is fish, and fish acquire DHA through their consumption of algae. Algae change the proportion of different fatty acids in their cellular membranes in accordance with the surrounding temperature. When water temperatures are cold, algae need to ensure that their cell membranes remain flexible. They do so by increasing their membranes’ proportion of polyunsaturated fatty acids, a group which includes DHA. On the molecular level, this occurs because the multiple double bonds in the fatty acid tails prevent them from packing tightly with each other, thus preventing freezing. With rising temperatures, however, the algae replace the polyunsaturated fatty acids with saturated fatty acids to promote more packing of the fatty acids, countering the heat but consequently reducing the presence of DHA. Therefore, the Dalhousie University group’s study predicted that due to warming environments, from region to region, algal production of DHA will decrease by anywhere from 10 to 58 percent. Because of this, the DHA found in fish will be significantly reduced, and consequently, our access to the compound will likewise be depleted.
While the study predicts that countries with small populations and prominent fishing industries, such as Norway and Chile, will still be able to maintain adequate access to DHA, the same cannot be said for other countries around the world. Countries with rapid population growth, such as China and Indonesia, are predicted to face severe shortages. Landlocked countries will also suffer greatly from the shortage, and the intake of DHA by their populations will fall below recommended levels.
There is some hope that future scientific endeavors may help alleviate the effects of the shortage. Several initiatives are trying to directly farm algae as a source of DHA and others are trying to genetically engineer plants that produce high amounts of DHA, all with the goal of compensating for the damaging effects of a DHA shortage on our neurological health. At this time, however, it is unclear if these endeavors will become a permanent solution to solving this issue. Even if they do, it will only be a band-aid solution to the myriad other problems that arise from global warming.
By Ellen Alt
Warning: This content contains a discussion of consent and sexual abuse.
Late 2017 proved crucial for the newest wave of consent in America. The Harvey Weinstein case broke, and his firing had ripple effects on society and survivors of sexual harassment, encouraging them to come forward and share their stories as the #MeToo movement grew. Although it is unclear if coming forward will result in justice, as seen with the confirmation of Justice Brett Kavanaugh in October 2018, the country’s understanding of consent has shifted: sexual abusers such as Kevin Spacey, Matt Lauer, Bill Cosby, Jeffrey Epstein, and Olympic gymnastics doctor Larry Nassar have begun to be held accountable. Although the gymnastics doctor was convicted, all of medicine should apply standards of accountability and consent with the same vigor as the media industry. Medical procedures that lack consent exhibit this need for accountability in medicine.
Imagine going through childbirth only to have your husband betray and abuse you—yes, that’s right, betray and abuse you—by asking your doctor to do something to you without your knowledge, presumably for his own sexual satisfaction: the doctor adds an extra stitch or two when they reach the vaginal laceration point of their 12-point inspection of the new mother. This is called the husband stitch. The typical inspection involves surgical restoration of urination and stool disposal, while the deeper suture of the husband stitch joins the perineal muscles, which are “most important for sexual function.” Although it is commonly perceived that the effects of childbirth decrease heterosexual sexual pleasure for men due to women’s loosened tissue after giving birth, long-term studies have found otherwise: “Delivery method has no long-term effect on female sexual function,” which includes pleasure for both partners as well as the woman’s ability to conceive. Even if this misconception that loosened vaginal tissue decreases sexual pleasure was true, it is not the best method to address the issue; if women find that their vaginal tissue is not as toned as it was before childbirth, pelvic floor physical therapy exercises are the best method of restoration. Doctors, husbands, and spouses should not execute power and authority over their partner’s body, not only since adding the extra stitch only causes pain to the recipient woman and does not improve sexual pleasure, but also because the lack of consent is abhorrent. According OB-GYN’s and long-term studies, vaginal tissue is sure to be stretched after giving birth, but will return to normal without an extra stitch—so why not ask for consent and avoid taking advantage of a woman’s body?
Aside from the crudely named husband stitch, another major yet under-discussed abuse of consent in medicine is non-consensual pelvic exams. In training hospitals where fresh-out-of-medical-school doctors fulfil their residency, doctors who are their superiors sometimes ask these students to go against bioethics: women under anesthesia act as cadavers on which students practice pelvic exams. Pelvic exams provide an understanding of the vulva and internal gynecological organs via the external, speculum, bimanual, and rectovaginal sections of the exam. The nature of a medical exam includes “a blend of communication, respect, and technical skill,” whereas “the act of putting fingers into an orifice for the sake of education can actually do harm.” Through a survey of five Philadelphia medical schools, 90% of students reported the practice of non-consensual pelvic exams. Some of these women under anesthesia are undergoing a gynecological procedure, but non-consensual pelvic exams are conducted in unrelated surgeries as well, such as stomach surgery. Regardless, these women have not consented to this procedure conducted on their bodies. In medical ethics, autonomy is understood as “one’s ability to self-govern, to act in accord with one’s values, goals, and desires,” which includes self-governance over one’s own body. Should a patient choose to undergo a specific procedure, they are consenting to the procedure within their autonomy; but in this case, a pelvic exam is not within the understanding of a the agreed-upon procedure, and the patient’s autonomy is violated. Although the technical skill of performing a pelvic exam may be necessary for students in the future, Friesen and other medical professionals argue that the practice does more harm than good. Non-consensual pelvic exams directly counter medical ethics and consent, especially with the new wave of consent awareness in America.
Considering medical ethics, the case for consent in medicine should be an obvious one. However, legislation fails us: there is no law regulating the husband stitch, and non-consensual pelvic exams are legal in all but six states. In a field that revolves around the health of bodies, we should treat these bodies with respect, and should have been doing so even before the #MeToo movement normalized speaking out about sexual abuse. Medicine should adopt the same stringency as does the media with large figures in entertainment and business. Individuals who have influence over women’s bodies, such as OB-GYN’s post-birth, residents, and doctors instructing residents should be held accountable. Even in the absence of legislation, these individuals should contribute to the cultural shift of increased respect, respecting medical ethics and the autonomy of women and female bodies.
Friesen, Phoebe. “Educational pelvic exams on anesthetized women: Why consent matters.” Wiley Bioethics. vol.32. pp. 298–307. 2018.
Ghorat, F.; Esfehani, R. J.; Sharifzadeh, M.; Tabarraei, Y.; Aghahosseini, S. S.“Long term effect of vaginal delivery and cesarean section on female sexual function in primipara mothers.” Electron Physician. vol. 9, iss. 3. pp. 3991-3996. Mar. 2017.
Herman, Christine. “#MeToo? Some Hospitals Allow Pelvic Exams Without Explicit Consent.” Side Effects: Public Media. Jan. 8, 2019.
Planned Parenthood. “What is a pelvic exam?” Planned Parenthood: Health & Wellness. n. d.
Rupe, Heather, DO. “An OB Weighs in on the ‘Husband Stitch’.” WebMD: WebMD Blogs. Mar. 16, 2018.
The Daily. “When #MeToo Went on Trial.” The New York Times. Oct. 4. 2019.