Page 246 - Veterinary Immunology, 10th Edition
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FIG. 8.13 Transcription factors bind to enhancer elements on DNA
located upstream of the genes they activate. Gene transcription is
turned on by a carefully regulated RNA polymerase. However, the
polymerase can only be turned on when transcription factors form a
basal transcription complex and activate the basic transcriptional
machinery.
Box 8.3
No Interleukin-26 in Horses
Interleukin-26 (IL-26) is a member of the IL-10 family. Its gene is
located in a cluster with the IFN-γ gene on one side and the IL-22
gene on the other. As a result of a one-base pair frame-shift
mutation, the IL-26 gene is inactivated in horses and related equids
such as zebras and donkeys. Since IL-26 is a stimulator of T cells
and may promote inflammation and autoimmunity, this
inactivation may explain, in part, why some aspects of acute
inflammation differ between horses and other mammals.
Data from Shakhsi-Niaei M, Drogemuller M, Jagannathan V, Gerber V, Leeb T: IL-26 gene
inactivation in Equidae, Anim Genet 44:770-772, 2013.
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