Sample information

Our group found this large spider nearby a medical biology classroom walkway in the spring on a sunny day near school, near a large flower garden. We collected the spider at around 2PM, at around 70-73 degrees F outside when we obtained the sample. We attached a picture of the area we collected the pillbug from above, and there did not appear to be additional spiders of its kind in the area.

Methods

DNA Extraction

We made sure to dissect the large spider with precision, splitting it in half and isolating the abdominal section for crushing for our sample DNA extraction.

Gel Electrophoresis

The following lane order for our gel:

1. N/A
2. N/A
3. Steatoda triangulosa (3-1; small spider)
4. N/A
5. N/A
6. Steatoda grossa (3-2; big spider)
7. N/A
8. Armadillidum vulgare (3-2; isopod)
9. N/A
10. Wolbachia positive sample (3-4)
11. Wolbachia negative sample (3-5)
12. DNA positive sample (3-6)
13. Ladder
14. DI Water

Data Analysis

We had problems with our positive and negative Wolbachia controls, namely we had to rush part of the process for running our samples due to time constraints. The large spider sample well displayed two visible bands, the same quantity and close position as the two visible bands from the positive Wolbachia DNA control. The putative identification for this large spider specimen was revealed to be Marinarozelotes mutabilis, not Steatoda grossa. The assumption for the latter considered frequently-appearing native spider species to Southern California, but the specimen we assessed turned out to be nonnative to North America entirely, instead being native to Romania and the Mediterranean. This species is not specifically confirmed to have Wolbachia, but the overarching Marinarozelotes genus does have several species members with confirmed Wolbachia infection. As taxonomic classification often labels these spiders by their genus category rather than by individual species, data is limited on these individual species.

Results

While the DNA positive sample and ladder went well, the Wolbachia positive and negative samples showed no bands. This is likely a mishap during Wolbachia sample extraction, and keeps us from fully confirming the precision of our samples. Despite this, at least one band should have appeared on both Wolbachia samples, and the presence of bands in our large spider (Marinarozelotes mutabilis) sample as predicted that aligns closely with our DNA-positive sample during gel electrophoresis indicates that the sample does, in fact, contain Wolbachia DNA. Furthermore, we did not run into problems with the large spider DNA extraction in the process, and so we can be confident that the large spider (Marinarozelotes mutabilis) was infected with Wolbachia.