Recombination single gene

TCDD causes bone marrow hypocellularity, with specific decreases in the total number of hematopoietic stem cells (HSC) and lymphocyte precursors.42 16 Exposure to TCDD also diminishes mRNA levels of recombination activating gene-1 and terminal deoxy-nucleotidyl transferase in bone marrow cells.47 The best characterized effect of TCDD on bone marrow is the impaired maturation of B cells. A single dose of TCDD causes a transient, time- and dose-dependent, and developmental stage-specific impairment in B cell maturation, with mature B cells affected first, followed by depletion of B cell progenitors.45-46... 

Recombinant DNA technology shows that a single gene directs development of chromosomally female mice into males. 

Fig. 1.3. Four possible orientations of products of intermolecular recombination. When one vector carries the entire transgene and the other an enhancer, all four will be active. When the two vectors carry the two halves of a single gene coding region with an intervening intron, only the first of these will be active.

Fig. 31.5. Gene shuffling using a single gene (1) or a family of genes (2) (A) errorprone PCR generating diversity (B) DNAse treatment (C) homologous recombination of fragments and generation of diversity.

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