Parity rules by Erwin Chargaff

Rule of complementarity (First parity rule)

Rule of Equal amount applies more closely to introns than to exons (Second parity rule)

Cluster rule – Purines in nontemplate strand applies more closely to Exons (Third parity rule)

GC Rule- GC content tends to be greater in exons than in introns (Fourth parity rule

TLS Online TPP Program

#Id: 10342

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 10343

#Unit 4. Cell Communication and Cell Signaling

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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#Id: 10344

#Unit 4. Cell Communication and Cell Signaling

B- cell maturation

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#Unit 4. Cell Communication and Cell Signaling

T1 and T2 Transitional B Cells

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#Unit 4. Cell Communication and Cell Signaling

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. 

TLS Online TPP Program

#Id: 10347

#Unit 4. Cell Communication and Cell Signaling

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