rharrison's blog

In class, we learned about different types of cytoskeletal filaments. We covered intermediate, actin, and microtubules. Intermediate filaments are only found in some animals, have a high tension capacity, and are made up of 8 tetramers stacked on top of each other. They have no directional polarity. Since they do not have polarity, they do not have any motor proteins. They also have no DNA triphosphate on them, so they are not dynamic filaments.

Actin filaments are highly dynamic and easily reorganized. They are 9 nanometers in diameter. Their subunits are called G actin and when in a polymer it is called F actin. A free actin subunit is bound to ATP while in the polymer it is bound to ADP instead. It also goes under a conformational change when incorporated into a filament. Actin has directional polarity where new subunits can be added or taken from each side. The plus end grows and shrinks faster than the minus end in that respect. 

Microtubules themselves have a negative charge and are 25-30 nanometers in diameter, forming hollow tubes, The subunit is a heterodimer of alpha tubulin and beta tubulin. It has directional polarity where the beta tubulin faces the plus end and alpha tubulin faces the minus end. Microtubules are dynamic and rearrange into mitotic spindle during mitosis or can form cilia for cell movement. With its polarity, it also has motor proteins going along it. Dyenin is a minus end motor protein and kinesis is a plus end motor protein. 

For proteins to get into the nucleus, it requires a Nuclear Localization Sequence (NLS). This NLS has a chain of positive amino acids in the sequence that the nuclear pore complex can recognize and let the protein through to the inside of the nucleus. To let it in, the protein with the NLS, importin Alpha and Beta bind to it. Once in the nucleus, RAN GTP binds to importin and importin Beta leaves the protein with the NLS. Some proteins that are less than 50kDa to pass through the nuclear membrane through diffusion. Also, in the nuclear import, the signal sequence is not removed and the protein does not need to be unfolded. 

For the transport into the ER, a long sequence of hydrophobic amino acids are required. When the protein travels to the ER for import, the signal sequence is cleaved off and the protein unfolds. Once in the ER lumen, it refolds but the protein is shorter since the signal was clipped off.

In class, we learned about different types of cytoskeletal filaments. We covered intermediate, actin, and microtubules. Intermediate filaments are only found in some animals, have a high tension capacity, and are made up of 8 tetramers stacked on top of each other, They have no directional polarity so they do not have any motor proteins. They also have no DNA triphosphate on them so they are not dynamic filaments.

This week I babysat my friends hamster, Cayenne. She is a Syrian Hamster. Cayenne is a large hamster so we nicknamed her Chubby. Everyday, I had to make sure she had enough food. Cayenne needs about 1/3 cup of hamster food everyday and every other day she can have fresh vegetables and fruits. To get her use to me, I wore gloves in case she would bite and gave her a sunflower seed as treats. I filled her water bottle and when I was down to about 1/4 full, I refilled it for her. Hamsters are nocturnal, so when I was in class I would cover her tank with a blanket and closed the blinds so she could sleep. Around 7 or 8pm she would start moving and then when she was fully awake by 9 or 10pm, I would take her out so she could run around in her hamster ball for about 45 minutes. After then, I would put her back in the tank so she could get some food and water. After that she spends all nigh on her wheel, which can get quite loud sometimes. Cayenne is asleep by the time I get up for class in the morning. 

My friend got a hamster yesterday. Her hamster is a female Syrian Hamster, also known as a Teddy Bear Hamster or Golden Hamster. Her nickname is Chubby until she decides what to actually name her.  She is very fluffy. The scientific name of this hamster is Mesocricetus auratus. As a member of the rodent family, she has sharp ever growing incisors. She nipped my finger after she smelt me and it hurt more than I thought it would. She has cheek pouches that expands when she eats or tries to bring food back to her little house. She fur is soft and is a light brown color. Syrian hamsters are usually between 5-7 inches in length and weigh about 120 grams. As pets, they can live up to 3-4 years, and in the wild up to 2 years.  

My friend got a hamster yesterday. She lives off campus and let me come over to see it. She is a Syrian Hamster, also known as a Teddy Bear Hamster or Golden Hamster. Her nickname is Chubby until she decides what to actually name her.  The scientific name of this hamster is Mesocricetus auratus. As a member of the rodent family, she has sharp ever growing incisors. She nipped my finger after she smelt me. She has cheek pouches that expands when she eats or tries to bring food back to her little house. She fur is soft and a light brown color. Syrian hamsters are usually between 5-7 inches in length and weigh about 120 grams. As pets, they can live up to 3-4 years, and in the wild up to 2 years.  

https://f1000research.com/posters/5-1984

The poster design does seem basic with 4 columns with a straight forward flow going down each column. Each column has a specific header and the information flows nicely. Figures are also placed in the right columns based on what they show. The poster only uses the colors blue and green. The writing is in bullet points so it is easy to follow but if presented, it might distract from the presenters speech. Graphs were legible and easy to get too. 

    The cheetah (Acinonyx jubatus) is a wild cat found scattered around in small parts of Africa and Iran. It is famous for being the fastest land animal on the planet, able to reach speeds up to 75 miles per hour. There are five subspecies; four that are African and one that is Asian. According to a research paper titled The global decline of cheetah and what it means for conservation by Sarah M. Durant and her team, the cheetah’s historic range was most of Africa (excluding parts of central Africa, Egypt, and Madagascar) and the Middle East into India. Today, cheetahs have lost 98% of their range in Asia, and the Asian Cheetah (Acinonyx jubatus venaticus) is critically endangered with an estimated 50 individuals. In Africa, the remaining four subspecies live only on 13% of the land they once inhabited, causing the Northwest African Cheetah subspecies (Acinonyx jubatus hecki) to also become critically endangered. As of 2014, the known cheetah population is about 6700 individuals over 29 subpopulations (Durant).

With this new retrovirus killing domestic dogs, I believe that in order to save the species, the breed that should receive the vaccine should be the basenji. The basenji is an African domestic dog breed. It is considered to be a basal breed, meaning it is genetically very similar to wild dogs like dingos and wolves. Its lineage is thought to have begun in Ancient Egypt, based on illustrations and dog mummies in tombs. Being a basal breed, it has not been modified to the extremes like many modern breeds today. Modifications ranging from the smushed face of the pug (which makes it hard for them to breath) to the dachshund whose legs are so short that sometimes they cannot support their own bodies. Those extreme modification also often include inbreeding or puppy mills which harms all the dogs involved. 

If the basenji were to be saved, dog breeding could essentially and eventually be re-done with better methods to insure that future breeds could face little to no health disorders. According to the cladogram on the Science Magazine website, the basenji eventually gave rise to the husky, malamute, shiba inu, chow chow, and more which then gave rise to others. The basenji, once numerous, could act as a template for new breeds. Overtime, based on environment (climate, human interaction, etc.) new breeds could begin to develop. 

    To help combat the sharply declining cheetah populations, countries in Africa have placed them under protection under the law in areas where they still exist and some areas of its historic range. These laws do still allow for farmers to kill cheetahs in order to protect their farm animals (Durant). The government sometimes offer incentives to farmers to promote coexistence with the animal. These countries also have monitored, protected land and parks, as well as educate the community. In Iran, the Asian Cheetah is protected within 5 national parks and wildlife refuges, and in 2009 the Afghan government made all hunting and trading illegal even though it may be extinct in the country.