So, not your usual post here, but I thought I'd share this on the off chance anyone was interested. In the lab I work in we study plant chromosomes. The best way to look at plant chromosomes is to stop mitosis in the roots, then digest the root with some enzymes, squash the root on a slide, then put some fluorescent molecules on the chromosome spreads and look under the microscope.
A lab mate brought in some Cryptocoryne wendtii var. tropica and Hygrophila corymbosa to share earlier this week. Naturally, I decided to harvest some of the root tips and see what I could get. Unfortunately, the whole process is probably more art than science, and I did not have enough good root tips/time to figure out the best digest time for the roots to get good chromosome images. I stained chromatin (DNA) blue with a stain called DAPI.
H. corymbosa was a pain, and I didn't find a single chromosome spread. However, I applied a probe (in red) that hybridizes to telomeres (a sequence that's on the end of every chromosome....the short sequence is repeated and the same in virtually every plant species) and found that H. corymbosa probably has a LOT of small chromosomes. I'd guess over 40, but I can't find any papers detailing that, and I could be waaaaaay off.
C. wendtii was a bit easier to work with, as it had larger, healthier roots. Some papers I've found online suggest 2n=28, but that triploids (3n=42) are possible. I counted 33 chromosomes in the only spread I found, so that means I'm either missing some chromosomes, have extra chromosomes, or 2n does not equal 28 in this particular plant. I have some more roots, so I might play around a bit more when I have time.
The scale bar in each image is 10 µm.
A lab mate brought in some Cryptocoryne wendtii var. tropica and Hygrophila corymbosa to share earlier this week. Naturally, I decided to harvest some of the root tips and see what I could get. Unfortunately, the whole process is probably more art than science, and I did not have enough good root tips/time to figure out the best digest time for the roots to get good chromosome images. I stained chromatin (DNA) blue with a stain called DAPI.
H. corymbosa was a pain, and I didn't find a single chromosome spread. However, I applied a probe (in red) that hybridizes to telomeres (a sequence that's on the end of every chromosome....the short sequence is repeated and the same in virtually every plant species) and found that H. corymbosa probably has a LOT of small chromosomes. I'd guess over 40, but I can't find any papers detailing that, and I could be waaaaaay off.
C. wendtii was a bit easier to work with, as it had larger, healthier roots. Some papers I've found online suggest 2n=28, but that triploids (3n=42) are possible. I counted 33 chromosomes in the only spread I found, so that means I'm either missing some chromosomes, have extra chromosomes, or 2n does not equal 28 in this particular plant. I have some more roots, so I might play around a bit more when I have time.
The scale bar in each image is 10 µm.
Last edited:
