Week 3: Mouse Dissections, Imaging, and Presentations!

Hi everyone! Welcome back to another fun week of science in the lab. This week, I did less coding and focused more on honing some key developmental biology research techniques!

Last Friday, I attended the lab meeting for my advisor’s second lab since they are getting a joint M.D-Ph.D. degree from 2 labs. During the meeting, I learned about retinoic acid (RA) signaling and the rebirth of the yolk syncytial layer (YSL) in zebrafish embryos. The YSL contains yolk syncytial nuclei (YSN) that are the focus of the lab member’s project. They are trying to investigate heterogeneity in YSN to determine whether there are distinct nuclei populations (anterior, posterior, dorsal, or ventral). Their positioning may be indicative of later developments that happen in the embryo. I also got to learn about all the different ways in which RA affects nervous system development — yay neuro! Too much or too little RA can affect hindgut development in the zebrafish as well as cause neural crest defects.

Throughout the week, we checked in on the mice that we would eventually dissect for Friday’s experiment. We checked for pregnancies in another litter of mice (to be used for a future project). We had also hoped to perform more FACS of oogonia and somatic cells — however, to do that, we needed to collect oogonia and somatic cells. For those to be collected, recall from Week 1’s post that we would need to dissect female embryos at the E13.5 time point. For the embryo dissection to take place though, the female mouse carrying these embryos would have to be pregnant! While visual cues (such as size) may make it very clear when a mouse is pregnant, it is difficult to say when it is not, since it is possible for the female mouse to carry a small litter. Unfortunately, when we checked for mouse pregnancies (via dissection) on both Monday and Wednesday, none of them were pregnant, which meant we couldn’t gather cells for our FACS. However, I will be doing a FACS sort on Friday (using cells from a mouse we definitely know is pregnant), so join me for that in next week’s blog! For the mice that weren’t pregnant, I got to dissect them further to identify the different organs in the body and get a better understanding of mouse anatomy!

I also helped my advisor genotype a mouse litter using PCR, to determine the right pups to breed for their future experiments. Finally, I was able to see other grad students’ amazing images of mouse blastocysts and whole-mount stained mouse ovaries under the NSPARC microscope (a faster, higher resolution microscope that offers a larger field-of-view than traditional confocal microscopy)!