Still Learning

Today was focused on cleaning plates after breaking down the crosses we set up yesterday. To 
clean 
the 
dish, 
I had to place the 
embryos under 
a 
dissecting
 microscope
 and
 removed 
unfertilized
 or 
damaged
 eggs.

 The most challenging part of cleaning is knowing when the embryo is fertilized or unfertilized - unfertilized
 eggs 
will 
not 
undergo
 the 
first 
mitotic
 division.



The first embryo from the left shows an embryo that is activated at the one-cell stage and ready to be fertilized, but many cells become stuck at this stage and are therefore infertile. The second embryo is fertilized and the cell has multiplied into thousands of tiny cells. The third embryo is at 50% epiboly in the gastrula period, meaning it has formed an epiblast and hypoblast after about 5.5 hours. The second to last embryo is at the bud stage where it has formed an embryonic axis. Finally, the last embryo is characteristic of an 18-somite, where neuromeres develop and a tail appears.