User:Mouarick/sandbox

Major Focus: Parasite Article

Currently I'm working on the page in Wikipedia titled, "Parasite". This page need its section on Host Defense expanded. I've found three article so far diving into different species and their defense against parasites. I haven't engaged on any Talk forums, but I am planning to after I established my background knowledge.

File:Parasite.png

Parasite infecting a fish

General Host Defense Mechanism: Animal

Skin

Our first line of defense against invading parasite is our skin. Our skin is made up layers of dead cells and acts as a physical barrier to invading organisms. These dead cells contain the protein keratin, which makes our skin tough and waterproof. Most microorganism needs a moist environment to survive. By keeping the skin dry, it prevents invading organisms from colonizing. Furthermore, our skin also secretes sebum, which is toxic to most microorganisms.

Mouth

The mouth contains saliva, which prevents foreign organism from getting into the body orally. Furthermore, the mouth also contains lysozyme, an enzyme found in tears and the saliva. This enzyme breaks down cell walls of invading microorganisms.

Stomach

If the organism gets pass the mouth, our stomach is the next line of defense. The stomach contains hydrochloric acid and gastric acids, which makes it ph level around 2. In this environment, the acidity of the stomach helps kills most microorganisms that tries to invade the body through the gastric intestinal tract.

Eyes

Parasites can also invade the body through the eyes. The lashes on the eyelid prevents invading microorganism from entering the eye in the first place. Even if the microorganism do get into the eye, tears contain the enzyme lysozyme, which will kill most invading microorganisms.

Immune System

If the parasite makes it into the body, the immune system is a vertebrate’s major defense against parasitic invasion. The immune system is made up of different families of molecules. These include serum proteins and pattern recognition receptors (PRRs). PRRs are intracellular and cellular receptors that activates dendritic cells, which in turn activates the adaptive immune system’s lymphocytes. Lymphocytes such as the T cells and antibody producing B cells with variable receptors that recognizes parasites.

General Host Defense Mechanism: Plants

In response to parasitic attack, plants undergo a series of metabolic and biochemical reaction pathways that will enact defensive responses. For example, parasitic invasion causes an increase in the jasmonic acid-insensitivel (JA) and NahG (SA) pathway . These pathways produces chemicals that will induce defensive responses, such as the production of chemicals or defensive molecules to fight off the attack. Different biochemical pathways are activated by different parasites . In general, there are two types of responses that can be activated by the pathways. Plants can either initiate a specific or non-specific response . Specific responses involve gene-gene recognition of the plant and parasite. This can be mediated by the ability of the plant’s cell receptors recognizing and binding molecules that are located on the cell surface of parasites. Once the plant’s receptors recognizes the parasite, the plant localizes the defensive compounds to that area creating a hypersensitive response. This form of defense mechanism localizes the area of attack and keeps the parasite from spreading. Furthermore, a specific response against parasitic attack prevents the plants from wasting its energy by increasing defenses where it’s not need. However, specific defensive responses only target specific parasites. If the plant lacks the ability to recognize a parasite, specific defense responses won’t be activated. Nonspecific defensive responses work against all parasites. These responses are active over time and are systematic, meaning that the responses are not confined to an area of the plant, but rather spread throughout the entirety of the organism. However, nonspecific responses are energy costly, since the plant has to ensure that the genes producing the nonspecific responses are always expressed. .

Reference

Hatcher, J. M. & Dunn, M. A. (2011). Parasites in Ecological Communities. Cambridge, UK: Cambridge University Press.

Maizels, M. R. (2009). Parasite immunomodulation and polymorphisms of the immune system. Journal of Biology, (8)62, 1-4. doi: 10.1186/jbiol166.

Frank, A. S. (2000). Specific and non-specific defense against parasitic attack. Journal of Theoretical Biology, (202), 283-304. doi: 10.1006/jtbi.1999.1054

Runyon, B. J., Mescher, C. M., & De Moraes, M. C. (2010). Plant defenses against parasitic plants show similarities to those induced by herbivores and pathogens. Plant Signaling and Behavior. (5)8, 929-931.

Host-Parasite Interactions Innate Defenses of the Host. Retrieved from University of Colorado website: http://www.colorado.edu/outreach/BSI/k12activities/interactive/innatedefenses.pdf

Parasite:Talk Page

The talk page for the Parasite on Wikipedia, isn't that active. The last talk was engaged in 2011. Neither of the Talks addressed expanding on the Host Defense section of the page. I will write a draft first and submit it to a new talk to see if anybody else have an opinion on the matter.

Research

I've currently have three articles about host defenses against parasite. However, I feel like I need more to improve upon my knowledge before starting a draft for the section.

Minor Things

1)Wikipedia page title Hunting Wasp is to generic. Articles already exists for specific species of hunting wasps. For example, the species of spider hunting wasps called Pompilidae . I started a talk page, and suggested deleting the first article, since it's irrelevant and "Hunting Wasp" is not technically a species, family, or genus, but a generic term for the diverse group of insect.