AP Biology class blog for discussing current research in Biology

Author: jackuole

Crispr 9, A Dangerous New Field


Crispr 9 Editing

With the new developments in gene altering, scientists have begun to use technology to alter the gene sequence of embryos. According to an article by Tia Ghost, Chinese scientists have modified the genes of human embryos with mixed results. The idea behind the research was that they would cut out a faulty gene in the DNA sequence and replace it with a correct one, therefore improving the embryo. This is done through a stretch of RNA called CRISPR targets places on the genome that are then cut by Cas9, an enzyme that cuts out specific strands of DNA leaving a spot to be filled within the genome. Scientists then provide a new strand of DNA as replacement. This method is effective in all different kinds of animals as well as humans.

However, the technology is not yet accurate enough to become common practice. According to a leading scientist in the field “the CRISPR technology is simply too risky to use in embryos” at this point. The issue arises in the fact that the RNA sometimes goes to a different site then the one desired, slicing out a necessary part of the genome and replacing it with useless information. This could lead to harmful mutations in the embryo, the opposite of what the scientists want. Even if the technology was at a higher level, editing embryos is still a large ethical dilemma. Some scientists feel that they should not alter life, but simply let it play out the same way it has for billions of years. Other’s argue that each child deserves the best possible chance they can get. Both have strong arguments, and only time will tell which side will win out.




Original Article:

A Star Gives Birth… To Twins?


Black Hole 

According to a recent study published by astrophysicist Avi Loeb, scientists now believe that collapsing stars can now lead to the creation of two individual black holes. Avi Leob had been debating whether or not the existence of this phenomenon  was a reality but the recent detection of gravitational waves convinced Leob that this does exist. Gravitational Waves are the ripples through time caused by extreme gravity altering the matter the waves interact with. Einstein first theorized that two black holes spinning around each other would alter the fabric of space time. The Laser Interferometer Gravitational Wave Observatory used detectors in Louisiana and Washington in order to register the waves and the detections confirmed the existence and collision of two rotating blackholes.

Leob’s theory is that if a star is spinning fast enough when it collapses, the matter in the star could be distributed into a dumbbell shape and form two black holes. The detection of gravitational waves confirmed that it was indeed two individual black holes but it was unclear if these black holes where the byproduct of a star collapsing in the area or if the holes massive gravity had just pulled them together from different regions of space. When a star collapses inward, the influx of matter can cause the star to release a burst of gamma radiation, the most high energy form of light. A telescope trained on the area where the equipment recorded the gravitational waves also picked up a burst of gamma light. This provides validity to the theory that one star collapsed in the region and created these two black holes rather than the black holes moving from a different location in space.


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Original Article:

Trust Your Gut and Exercise


File:Wild garden of the gut bacteria 5.jpg

According to an article on GEN news, the level of Microbiomes contained within the Gut is influenced by exercise as a young child. Microbiota are the organisms that share our body space, and the gut has a particularly concentrated region of these organisms. Scientists estimate that gut microbiomes make up anywhere from 1-3% of total body mass. As it turns out the saying, “trust your gut” has some scientific merit. Microbiomes promote healthy brain function and promote anti-depressant effects, as well as adding up to 5 million genes to the human genome. Having a healthy gut is a key to overall biological health.

A recent study by Colorado University claims a connection between early life exercise and healthy microbiome activity. This study was conducted with rats, with one group young of rats exercising daily contrasted against a control of rats who behaved normally. The younger exercising rats experienced a growth of probiotic bacteria in their guts, more so then the stationary rats or even older rats who exercised. Researchers “emphasize the ability of exercise” to promote a healthy brain and metabolic function. In the future, Colorado University will look for ways to promote healthy microbiome activity in adults who have a much more stagnant microbiome structure.







The Immaculate Conceptions: Smalltooth Sawfish Experiencing Virgin Births


From Flickr

Chances are you have never heard of the Smalltooth Sawfish, an endangered species most commonly found off the western cost of Florida. These creatures grow to be as long as 25 feet, but their is more that is impressive about these fish than their shockingly large size. Recent studies have shown that around 3% of Smalltooth reproduce asexually, a virgin birth. This is the first hard evidence that birth of parthenogens, offspring born of asexual reproduction, happens in nature. This speaks to the adaptability of life, scientist Demian Chapman, says that it makes sense that endangered species would be the ones most commonly reproducing asexually, “that life finds a way”. This discovery was made when researchers tagged and sampled DNA from around 190 Sawfish, which lead to the discovery of 7 parthenogens.

Scientist hypothesize that during meiosis, sex cells fused together to form offspring. Incredibly, all seven of the parthenogens are fully healthy and functioning, and seem to be viable sexual partners. This “suggests that parthenogens are not a dead end” that this “extreme form of inbreeding” does not lead to any serious defects. Unfortunately, Smalltooth Sawfish are on the verge of extinction due to human interference in their natural habitat. Although the Sawfish are able to reproduce asexually, the occurrence rate is too small to sustain a viable number of Sawfish to save them from extinction, but raising awareness of the issue could be the key to saving these magnificent creatures.


Original Article

Sawfish Extinction

More Examples of Parthenogens in Nature

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