Sample information

I found this cellar spider below a mirror on the wall in a household bathroom. I collected it at about 8 am.

Methods

Gel electrophoresis lanes
1. PCR molecular weight ruler (1000, 700, 500, 200, 100 bp)
2. DNA sample of pholcus phalangioides
3. DNA sample of sphaerophoria scripta
4. Wolbachia-positive (16S) arthropod control
5. Wolbachia-negative (16S) arthropod control
7. Arthropod-positive (CO1) DNA control
8. Arthropod-negative (CO1) DNA control

Analysis

The pholcus phalangioides sample had a band matching the Wolbachia-positive control’s band (16S), but not a band matching the arthropod-positive control’s upper band (CO1; like how the arthropod-negative control had no bands), so pholcus phalangioides seems to be a non-arthropod and Wolbachia-positive.

Results

The Wolbachia-positive and Wolbachia-negative controls might not have completely worked because they’re arthropods, but didn’t have bands matching the arthropod-positive control’s upper band (CO1 or the arthropod gene, which has a larger molecular weight) out of its two bands (the lower band with a smaller molecular weight in common with the Wolbachia-positive control should be 16S or the Wolbachia gene). This is similar to our results where pholcus phalangioides tested arthropod-negative, which can’t be trusted because all spiders are arthropods. Pholcus phalangioides could’ve tested arthropod-negative because the CO1 primers failed to get the CO1 gene on the pholcus phalangioides DNA amplified during PCR. So, a band matching the arthropod-positive control’s CO1 band wasn’t visible on the gel for pholcus phalangioides.