BioQuakes

AP Biology class blog for discussing current research in Biology

Author: punnetstephens

Not All Giraffes Are Just Giraffes

Up until now Giraffes have been considered a singular species with nine subspecies.  Recently scientist from Senckenberg and the Giraffe Conservation Center have studied the genetic makeup of giraffes throughout the continent. The samples were taken through skin biopsies of the Giraffes. The analysis of these samples have proved that there is not “only one, but at least four genetically highly distinct groups of giraffes.” These giraffes also seem to not mate in the wild. This discovery of four genetically different groups of giraffes means that the traditional way of classifying giraffes is in need of an upgrade. The traditional  way of determining species of giraffes was based on coat patterns, horn structures, and geographical distribution. The new way of classifying species is based on their genetic structure. The four species based on genetics would be “southern giraffe (Giraffa giraffa), comprising two distinct subspecies, Angolan (G. g. angolensis) and South African giraffe (G. g. giraffa), (2) Masai giraffe (G. tippelskirchi), (3) reticulated giraffe (G. reticulata), and (4) northern giraffe (G. camelopardalis), which includes Nubian giraffe (G. c. camelopardalis), West African giraffe (G. c. peralta) and Kordofan giraffe (G. c. antiquorum) as distinct subspecies.” Not only did this study differentiate species but brought some older species of giraffes. This new discovery not only changes the way we refer to giraffes but how species conservation is carried out. Now not only is the giraffe under threat but their biodiversity is also under severe attack.

By LucaGaluzzi
https://commons.wikimedia.org/wiki/User:Lucag

If you want to read more on giraffe conservation you can click here.

CRISPR The End of ALS?

ALS, amyotrophic lateral sclerosis, is a nervous system disease that weakens muscles and impacts physical functions. ALS is diagnosed in less than 20,000 people a year but there is currently no cure. Amyotrophic lateral sclerosis is caused by protein clumps in the brain which make voluntary movements progressively harder. The protein clumps destroy neurons in the brain through toxins. Scientist are yet to figure out how the toxins do this. A group of researches then decided to use CRISPR-Cas9 to get a better understanding of what is actually happening. During their research they realized that when a gene was affected it protected the neurons. It was already known that a gene called C9orf72 caused for unnatural repeating in certain parts of DNA and is the cause for the build up of proteins in ALS. The research group isolated certain genes by knocking out others. During this process they realized that when the gene Tmx2 is inactive it hindered cell deaths in mouse neurons. “If you have a small molecule that could somehow impede the function of Tmx2, there might be a therapeutic window there” said co-author Micheal Haney. Michael Bassik, Ph.D., assistant professor of genetics at Stanford and other reaserchers plan to do more studies on Tmx2 to get more detailed and accurate information. They also plan on doing CRISPR screens to find other possible causes for ALS and work on cures for other neurodegenerative disorders.

Other researchers are trying to use CRISPR-Cas9 to find a cure to ALS. Researchers are beginning to focus on editing RNA in hopes to cure a form ALS and other neurodegenerative diseases.This technique has produced mixed results. Research at the University of California, Riverside, has made progress in developing a molecule which can target EphA, this is a “gene that’s known to govern the onset and progression of neurodegenerative diseases”.

You can read more here.

The 450 Million Year Old Superbug

The first superbug may have occurred 450 million years ago when animals decided to leave the water and begin to live on land.  The scientists at the Broad Institute found evidence displaying a group of antibiotic-resistant bacteria which are as old as the first land animals. Like us humans, the animals possessed these superbugs in their guts. Since the bacteria has been around for so long it has given it time to adapt and develop necessary traits to make it resistant to antibiotics like penicillin. The specific superbug which has lasted since the first land animal is Enterococci.

Photo by Eric Erbe

They can be considered the “godfather” of superbugs. Enterococci were found during the 80’s and were one of the first pathogens to be known to resist antibiotics. Enterococci bacteria today is a major cause of hospital infections in the United States and infects up to 70,000 Americans and kills up to 1,000 each year. Enterococci is so special because it possesses a number of genes which are focused on “hardening and fortifying” the cell wall. The reinforced cell wall allows for the bacteria to fight off disinfectants and not dry out. Research also shows that the fortification was added around the same time that animals began to come ashore. Since the two events happened around the same time it is assumed that the new fortification was to assist the survival of the bacteria in the new environment.

Enterococci had to create new fortification against new elements on land which was not present in the water. Since Enterococci is located in the gut some are excreted through feces. In water, the excreted Enterococci would end up at the bottom of the ocean floor which was moist and filled with nutrients, similar to the guts of a marine animal. When the Enterococci was released on land it would meet a harsher environment where they were exposed to Ultra-violent light from the sun. This caused the bacteria to dry up and die. Eventually, the bacteria developed and picked up the fortification needed which now helps them to thrive in hospitals. Their shell from 450 million years ago allows them to be resistant to the typical effects of cleaning measures in hospitals. The protection the bacteria has is what causes it to be considered a superbug. Even though superbugs are becoming more prominent the understanding of the so-called “godfather” of superbugs may help us to find ways to defeat Enterococci and hopefully other superbugs.

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