BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: monkeys

Monkeys Cloned with CRISPR Technology

Chinese researchers used CRISPR technology to genetically edit macaque monkey embryos in order to create five monkeys with severe sleeping disorders by removing BMAL1, a gene important for circadian regulation. They then chose the monkey of the five with the most severe symptoms to clone as a model to use for future tests on monkeys with these disorders. The idea behind this research was to create a template to create clone monkeys with the disease to run tests on rather than the real monkeys themselves.

A large issue with this experiment was the ethics behind it. While the end result is to reduce the number of monkeys used in research experiments. According to the study, the disorder in the monkeys resulted in not only lack of sleep but also changes in blood hormones, increased anxiety and depression, and even “schizophrenia-like” behavior. Bioethicist Carolyn Neuhaus thinks the study is morally wrong because the monkeys are used as tools, and the research’s success is based on their suffering.

Image result for crispr

Genes

Planet of the (CRISPR-Edited, Cloned) Apes

Several months ago, scientists in China cloned five gene-edited macaque monkeys. The clones were made through the somatic cell nuclear transfer method (SCNT)—a process in which a viable embryo is created from a body cell and an egg cell—that was used to produce the first primate clones around a year ago. In this instance, however, the monkeys’ genomes were first edited using CRISPR-Cas9—a unique genome editing tool that enables geneticists to edit parts of the genome by removing, adding, or altering sections of the DNA sequence—to show symptoms of sleep disorders by eliminating BMAL1, one of the positive elements in the mammalian auto-regulatory TTFL, which is responsible for generating molecular circadian rhythms. The result? The monkeys exhibited a wide range of circadian disorder phenotypes, including elevated night-time locomotive activities, reduced sleep time, reduced circadian cycling of blood hormones, increased anxiety and depression, and other schizophrenia-like behaviors. 

File:Macaque Monkey (16787053847).jpg

Macaque Monkey

Naturally, the results of the investigation triggered much backlash. According to Carolyn Neuhaus of The Hastings Center, the researchers viewed the suffering of the monkeys as a triumph, and failed to consider the moral implications of their investigation. “It’s very clear that these monkeys are seen as tools,” she told Gizmodo, the latter publication writing in a similar sentiment, “Their experiment is a minefield of ethical quandaries—and makes you wonder whether the potential benefits to science are enough to warrant all of the harm to these monkeys”. 

Nevertheless, the researchers involved in the experiment remain firm in their support of the experiment—the goal of which was to produce genetically identical monkey models of disease for biomedical research—on both moral and scientific grounds. “We believe that this approach of cloning gene-edited monkeys could be used to generate a variety of monkey models for gene-based diseases, including many brain diseases, as well as immune and metabolic disorders and cancer,” stated Qiang Sun, one of the research paper’s authors and director of the Nonhuman Primate Research Facility at the Chinese Academy of Science’s Institute of Neuroscience in Shanghai. Moreover, Reuters reported, “Xinhua [the state news agency] said the program, supervised by the institute’s ethics panel, was in line with international ethical standards for animal research”. Time will tell, ultimately, if the results of their experiment prove consequential on a larger scale. 

The Genetic Secrets in Monkey Poop!

 

We’ve learned that two distinct species cannot produce viable hybrid offspring, BUT…

A researcher from Florida Atlantic University has documented that two genetically distinct species of guenon monkeys in Gombe National Park in Tanzania, Africa, have been successfully mating and producing hybrid offspring for hundreds or thousands of years! How did she learn this? From their poop!

Earlier Knowledge: Previous studies showed that guenon monkeys’ widely varying physical traits keep them from interbreeding because of mate choice. In other words, a male monkey won’t be attracted  to/mate with a female unless her face matches his. Therefore, blue monkeys and red-tailed monkeys (two different species) wouldn’t be expected to mate. The two species currently live in close proximity to each other in narrow riverine forests along Lake Tanganyika in Gombe National Park, and Kate Detwiler has been studying them for years.

 

Red-Tailed Monkey https://www.flickr.com/photos/derekbruff/13353495075

Blue Monkey https://commons.wikimedia.org/wiki/File:Blue_monkey_(Cercopithecus_mitis_stuhlmanni)_pair.jpg

 

 

 

 

 

 

The Breakthrough: Kate Detwiler, author and an assistant professor in the Department of Anthropology in FAU’s Dorothy F. Schmidt College of Arts and Letters, challenges this claim that red-tailed and blue monkeys don’t mate. She studies the extent and pattern of gene flow from “red tailed” (Cercopithecus ascanius) monkeys to “blue” monkeys (Cercopithecus mitis) due to hybridization. Detwiler observes and studies the two monkey species in Gombe National Park, and recognizes hybrids by combined markings of the two parent species. She estimates 15% of the population are hybrids!

The Evidence: Detwiler uses mitochondrion DNA extracted from the monkey species to show movement of genetic material from one guenon species to another. More specifically, she examined fecal samples and found that all of the monkeys (hybrids, blues, and red-tails) have red-tailed mitochondrial DNA traced back to female red-tailed monkeys. Using mitochondrial DNA was the best option because it is more abundant than nuclear DNA and only comes from the mother. In her study, her control group was a group of blue monkeys outside the park; when she extracted DNA from these monkeys, she found that they only had blue monkey DNA. Upon studying the hybrid monkeys, Detwiler found no consequences of cross breeding.

Detwiler’s Theory: The key finding made from Kate Detwiler’s study is that blue monkeys in Gombe National Park emerged out of the hybrid population. She speculates that red-tailed monkeys got to Gombe Natoinal Park first and thrived. Male blue monkeys had to leave their original homes outside the park and then mated with red-tailed females. How was the hybrid population sustained? Detwiler believes that the monkeys have learned socially that if you grow up in a hybrid group it is okay to mate with any other monkey.

So What? “The Gombe hybrid population is extremely valuable because it can be used as a model system to better understand what hybridization looks like and how genetic material moves between species,” said Detwiler. This is especially important because hybridization often occurs in response to environmental changes, and climate change is happening now! Who knows what hybrids we will see in the future? Check out the full article here to read more about this fascinating study!

 

 

 

 

Powered by WordPress & Theme by Anders Norén

Skip to toolbar