Question

The mouse thymus normally contains about 1-2 x 108 thymocytes, the vast maiority of which are CD4+CD8+ (double-positive) cells. When thymocytes from mice with a gene deficiency in the TCR-alpha locus are compared with those from TCR-beta deficient mice, a striking difference between the two different knockout lines is observed, as shown in Figure A in a simplified version of flow cytometry data. The numbers of thymocytes in each thymus is indicated in the yellow bar below the plots. Wild-type TCR-/- TCRB-7- CD4 CD4 CD4 CD8 CD8 CD8 2 x 108 cells 2 x 108 cells 1 x 106 cells

Answer 1

Annver: - option "A" is conut → Ceter:- The Thymus į made up of the outer costen and inner medulla. Immature they maytes. are presut in Caten while mature themocytes are present in medulla. Double negative cells politerate ne the Subcapsular region of the coltore. Double possitive cells are prenut in the deeper regions of the coster. The TCR alpha mice have DN and DP cells. Hence developing thy mocytes will present in the colten but absunt in the medulla of thymes. The TCR beta cells lack Dr, CD4 + sp and CD8+ sp cells. Hence, the medulla will lack the duroloping thymagtes, while in the caster will be dudoping the moutes in the Sun region. The deeper regions will back themocytes. - Wild-type CD4 CD4+5 blean Rote my Ansurs is in the Subscapsular developing bu + SP DN CDS tsp CD8 2XLos cells.