Discussion:
1. An investigator performed cytofluorimetric (FACS) analyses of a mouse strain called C.B20 and a spontaneously arising point mutant that arose in the same strain called "C.B20 scid." Splenocytes from each strain were stained with anti-IgM (green) and anti-CD3 (red), then analyzed. The proportion of cells falling into each phenotypic category defined by these markers were then assessed.
|
STRAIN
|
IgM-CD3-
|
IgM+CD3-
|
IgM-CD3+
|
|
C.B20
|
5
|
60
|
35
|
|
C.B20 scid
|
98
|
0
|
0
|
The table below shows the results from all possible donor-recipient combinations of skin grafts between C.B20, C.B20 scid and another, genetically disparate strain called C57BL. Each kind of graft was done on ten mice.
|
DONOR
|
RECIPIENT
|
|
|
C.B20
|
C.B20 scid
|
C57BL
|
|
C.B20
|
100%
|
100%
|
0%
|
|
C.B20 scid
|
100
|
100
|
0
|
|
C57BL
|
0
|
100
|
100
|
2. From the first table, what do you conclude about the scid mutation?
3. From the second table, what do you conclude about the mechanism of graft rejection?