Caenorhabditis Elegan Case Study

The experiment was conducted using six worms, where three were used for one treatment and the other three for a different treatment level. Initially, the worm was transferred to a parafilm slide containing some water and placed under a dissecting microscope. Application sticks were used to place the worm on the mark and an additional light was placed to observe. The focus was on the posterior end of the worm to obtain the basal pulsation rate. A timer was used to record the basal pulsation rate for 15 seconds, then the result was multiplied by 4 to get the number of beats per minute and this was repeated for two more trials. Same methods were used to measure the pulsation rate of two additional worms and the data were recorded.

The next step of the project included preparing a Gram stain to discover the cell shape, arrangement, and if the bacteria is gram positive or

Caenorhabditis elegans, a type of free-living nematode that is found in soil, is the subject matter for this experiment (Marsh). C. elegans allow for an exceptional model organism because it is easily raised in the laboratory setting, it reproduces rapidly, has a short life cycle of 3 days where it develops from egg to adult worm, only 1.3mm in length, and although only having 959 somatic cells, it shares many characteristics with other multicellular organisms like having organs and a nervous system (Kaletta). These nematodes can either be a self-fertilizing hermaphrodite where each animal produces both sperm and egg, or they can be males that will mate with the hermaphrodites (Brenner). When a hermaphrodite self-fertilizes, the chance of having a male being produced is extremely low at just 0.1%, however, when a hermaphrodite is fertilized by a male, the ratio of males to hermaphrodites is generally equal making it 1:1 (Altun).

Keeping the experiment isolated on the focus of body size is as simple as not changing any other variables concerning the experiment. Therefore, predator number, predator size, habitat type, and any other possible variable in the experiment that is not body size will be kept as consistent and identical throughout the groups and replicable tests as

The C. elegans were washed several times once a week for several weeks. After the final wash for each week, a small amount of C. elegans was pipetted to the middle of each plate (3 experimental plates and 1 control plate). After all the passages for the C. elegans were completed, the three avoidance assay plates were set up. (A small amount of S. marcerens was pipetted on one side of each assay plate while a small

In part 2 of the experiment we are inducing RNAi through the process of feeding. To do so, a black pen is used to label the bottom of an OP50 seeded plate with the date and “wild type”. Another OP50 seeded plate is labeled with the date and “dpy-13”. A black pen is then used to label the bottom of the plate seeded with dpy-13 RNAi feeding strain with the date and “wild type”. Five L4-stage worms from the plate of wild type worms are then picked and moved to the OP50 seeded plate labeled “wild type”. Any eggs or young larvae that may have been accidentally transferred are to be picked off of the plate and then flamed in a Bunsen burner. The same method is used to move five L4 wild type worms to the plate seeded with the dpy-13 RNAi feeding strain, and once again to move five L4 dpy-13 worms to the OP50 seeded plate labeled “dpy-13”. These plates are then incubated upside down at 20˚C.

On Friday, March 31, a observation study was conducted at the L.A. Zoo. The time of arrival for the observation was at 11:48 am and the end of the observation was at 2:42 pm. The weather condition at the zoo was very sunny with a mild gust of wind every so often, which is a perfect weather condition to conduct a study. The main reason for conducting this observation study was to study and gather information about the many different types of primate that are located at the zoo. To see how different or similar each primate is to one anotherin different aspects.

This week in my clinic I learned about what to check for when looking at a fecal sample under the microscope. After being given the sample, I put together a fecal exam for a direct smear and a fecal floatation. My mentor then showed me how to work the microscope and what to look for in a sample through an example chart. She then made me look at the sample and tell her what I saw. With this particular patient I was able to see Roundworms/Hookworms eggs on the fecal exam. Roundworm eggs are in a round shape with a lighter outer membrane whereas Hookworm eggs are oval with cluster of round eggs in the middle. This was an exciting moment for me due to the fact that I have never had the chance to try and search for fecal worms on my own. Most of the time if one of the nurses saw something

The act of locomotion is highly dependent on the chemosensation of the worm, Caenorhabditis elegans (C. elegans). The use of chemotaxis enables the roundworm to distinguish various volatile and water-soluble chemicals that allow for growth and survival. We investigated the complex nervous system through the use of RNA interference (RNAi). By using RNAi, we were able to nullify certain protein expressions and test specific genes to observe their involvement in chemotaxis. The experiment made use of an attractive chemical signal, diacetyl, and how the two unknown genes and two control groups would respond. C. elegans without the ODR-10 gene were not able distinguish diacetyl, whereas the absence of protein sequence K08B12.1 and gene CEH-2 were still attracted to the chemical odorant. Based on the P values of our data, we can assume K08B12.1 and CEH-2 are not involved in chemosensation or genetic redundancy may be an alternative reason.

The Palaemonetes vulgaris were brought back to the lab in buckets. Then the Palaemonetes vulgaris were measured for their length. Calipers were used to measure from the tip of the rostrum to the end of the telson for the total body length to the nearest 0.1 mm. On that same specimen, for the carapace length, calipers were used to measure from the tip of the rostrum to the end of the carapace to the nearest 0.1 mm. Then the specimens were placed into a discard bucket so they weren’t measured twice. The Palaemonetes vulgaris are released back into their native home after all needed measurements were recorded. The recorded measurements of twenty-five Palaemonetes vulgaris were placed into a Excel spreadsheet, to calculate the average total length (mm) to be compared with a previously collected dataset from Fort DeSoto.

These methods are used to identify kinematic parameters without discomfort to the animal. Force plates, video/high speed cameras or 3D motion cameras cannot be used as there is no access to this software and technology, however the information that will be acquired in this study will use alternative software and methods that will support evidence obtained.

This experiment explored the effects of silencing ,through the use of RNAi ,the Srw-10 and Dyp-7 genes in C. Elegans, to determine if these genes were crucial in a nematodes’ ability to chemotax efficiently. To do this, worms were treated and placed in a chemotaxis assay. When the dpy-7 worms were silenced they outperformed the positive control, negative control, and Srw-10 silenced worms in the chemotaxis assay, producing the highest chemotaxis index . This suggests that silencing the dyp-7 gene will actually improve the nematodes’ ability to chemotax effectively but silencing the Srw-10 gene would have no effect on the worms’ chemotax ability. We attribute these results to the possibility that dpy-7 is important in reducing chemotaxis effectiveness whether by decreasing sensitivity to chemical signals or by affecting the worms muscle functions in a way that inhibits chemotaxis.

In the morning I got to observe Microsporum canis undern a microscope. One of the vet techs named Patty set up a wet mount, she first placed a few drops of lactophenol cotton blue onto her slide and then grabbed cellophane tape, with sticky side down she pressed the tape onto the center of a colony. She then placed the tape onto her slide and adjusted the microscope to high dry and examined the slide. I was able to see the macroconidia but they weren’t very well developed. An owners cat had been suffering with ring worm for a while and the owners been having trouble getting rid of it and wanted to see if there was still growth. The DTM had finished incubating and from what we saw under the microscope it was confirmed that there was growth.

Researchers define animal testing as an experiment where a living animal undergoes a procedure that causes them to go through pain, distress, suffering, or permanent and physical damage. In general, the experiments consist of radiation exposure, injections, inhalation of harmful gases, removal of any body parts, internal and external, and the exposure of terrifying situations that causes stress and depression for the animals (Scutti). Currently, a wide range of animals are being used for research, from farm to domestic animals. However, 90 percent of the studies use mice and rats (Quigley).

All of the procedures using research animals were approved by Institutional Animal ethical committee of Integral University, Lucknow, India.