Change in environmental condition is not necessary for natural selection.

TLS Online TPP Program

#Id: 10343

#Section 2: General Biology

The heavy chain is then expressed on the cell surface in combination with the surrogate light chain, which is made up of VpreB and λ5. 

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#Section 2: General Biology

B- cell maturation

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#Section 2: General Biology

T1 and T2 Transitional B Cells

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#Section 2: General Biology

T1 cells are mIgMhi, mIgD -/lo, CD21-, CD23-, CD24+, and CD93+. 

T2 cells differ from T1 cells in having higher levels of mIgD and in expressing CD21 and CD23. 

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#Section 2: General Biology

Transitional B cells bound for a follicular fate undergo positive and negative selection in the spleen.

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#Section 2: General Biology

BAFF-R expression is first detected in T1 B cells and increases steadily there after.

Signaling through the BAFF/BAFF-R axis promotes survival of transitional B cells by inducing the synthesis of anti-apoptotic factors such as Bcl-2, Bcl-xl, and Mcl-1