In the first half of the class we revealed what species of plant each of us brought in the previous class, based on the DNA sequencing. In order to check the lab results, the sequence for each plant was pasted into the Blast database for analyzation. When the sequence was run through the database a list of all the likely matches appeared, so by taking the most common beginning latin base phrase from each result, such as cucurbita pepo we could then enter this into a google search to narrow down the possible matches. The task was to check the score and barcode sequencing to see if it matches the database.
From the sequencing we were able to determine a number of samples brought in including lavender, artemisia argyi, mugwort, mint, and salix (willow species). Mugwort was an interesting find because it is an indigenous and invasive species known to be a “problem” for the environment, this specimen was found in Prospect Park by Katherine. The overall process from what I gathered consists of a guess and check method since there is no one single match that appears after running the score through the database, but you can tell from the sequencing when you have a likely match.
Mugwort Plant in Prospect Park Brooklyn
In the second part of the class we closely studied Zebrafish Embryology. Zebrafish are commonly used for research in embryonic development because of the elevated rate of development and the high frequency they emit egges. We discussed and viewed slides of the different early developmental stages which include:
- zygote - 1 cell
- cleavage period - 2 cells
- blastula period - 8th zygotic cell cycle
- gastrula period - different tissue types form
- segmentation period - tail lengthens and head straightens
- pharyngula period - brain is now sculptured into 5 lobes
Video showing time lapse of zebrafish embryo:
After this discussion we got to observe live embryonic samples in petri dishes of various developmental stages using a projection microscope. Since these embryos develop so rapidly, we were unable to observe any in the zygote stage, the samples were obtained the day before. It was really interesting to view the live samples, which provided a real life context to the slides.
Zebrafish Embryonic Development Slide
Live Embryo from Petri Dish
Live Embryonic Single-Cell Close-Up