NAME: ______________________
Figure 1. Cell biology of mammalian fertilization. (a) Diagram of the cell biology of mammalian sperm and egg during fertilization. (1) Sperm undergo the acrosome reaction and pass through the egg: cumulus cells and the zona pellucida. (2) The acrosome reaction triggers the re-localization of Izumo1 (red) from the acrosomal membrane to the sperm head plasma membrane. (3) Once within the perivitelline space, the now exposed Izumo1 ligand is able to interact with the egg receptor Juno (green) displayed on the oolema. (4) Finally the sperm and egg membranes fuse, fertilizing the egg.
Background: First read the article in this link: http://www.nature.com/news/scientists-find-protein-that-unites-sperm-and-egg-1.15058
Question1:
a. First define each of the words in Figure 1., that are underlined.
b. What is Juno and the Izumo1 ligand? How do they play a role in fertilization?
c. In 3 sentences, please summarize Figure 1 in your own words.
Figure 2. Amino acid sequence alignment of Juno with mouse and human orthologues. Juno (M. auratus) amino acid sequence (denoted by the upper case letters) is compared to amino acid sequences from human (Homo sapiens) and mouse (Mus musculus). The Juno proteon is ~243 amino acids long. Boxed amino acids indicate conserved sequences between these three species.
Question: Comparing amino acid sequences is important for determining evolutionary relationships. What purpose would comparing amino acid sequences of Juno between species help with fertilization research?
Figure 3.
Background Information: Scientists wanted to understand if (a) hamster Juno interacted with Izumo1 from human, mouse, and pig. In (b) The first column (human Juno (bait) & human Izumo1), column 2 (human Juno (bait) & mouse Izumo1), column 3 (mouse Juno (bait) and mouse Izumo1), and column 4 (negative control; no bait/no prey). . The y-axis shows the absorbance at A485nm was to detect interactions between Juno and Izumo1 proteins.
Question: Interpret the results of Figure 3. Once you have done this fill in Figure 3., as if you were the one filling in the information for this figure.
Get help from top-rated tutors in any subject.
Efficiently complete your homework and academic assignments by getting help from the experts at homeworkarchive.com