Pleiotropic functions of Hox genes revealed by mutants for genes in Hox seventh and ninth paralogous groups

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Publication Type thesis
School or College School of Medicine
Department Human Genetics
Author Chen, Feng
Title Pleiotropic functions of Hox genes revealed by mutants for genes in Hox seventh and ninth paralogous groups
Date 1998-08
Description The mammalian Hox complex consists of 39 genes that are believed to control the regionalization of the embryo along its major body axes. To investigate the in vivo functions of Hox genes, mice individually mutant for a subset of Hox genes were generated by gene-targeting. Mice with mutations in genes on separate chromosomes were mated to generate multiple mutants to reveal redundant functions not apparent in individual mutants. The analysis of Hoxb9 mutants and Hoxa9/Hoxb9 double mutants demonstrates a role of Hoxb9 in the patterning of the thoracic region and a synergistic and quantitative interaction between Hoxa9 and Hoxb9. Although Hoxa7 mutants do not have any detectable phenotype, the functions of Hoxa7 in the patterning of the upper thoracic region became apparent in Hoxa7/Hoxb7 mutants, in which the effects of the disruption of Hoxb7 on the first two ribs were greatly exaggerated by the addition of the Hoxa7 mutant allele(s). The similarity of the defects found in the Hoxa7/Hoxb7 and Hoxa9/Hoxb9 mutants evokes a modification of the current hypothesis explaining the defects in the axial column in Hox mutants. Limb defects were observed when a Hoxd9 mutation was introduced into the Hoxa9/Hoxb9 mutants. Many triple mutant genotypes have overt forelimb defects caused mainly by a series of skeletal defects in the limb. In particular, the humerus was greatly reduced in length and altered in shape. Hox genes appear to confer positional cues to different portions of the vertebrate limb, as well as to regulate the growth of cells forming different structures of the limbs. Of particular interest, hypoplasia of the mammary gland has been observed in pregnant and lactating females with multiple mutations in Hoxa9, Hoxb9 and Hoxd9. This broadens our concept of Hox gene function from patterning of the developing embryo to include indispensable roles in adults.
Type Text
Publisher University of Utah
Subject Developmental; Analysis
Subject MESH Gene Expression Regulation; Mice; Amino Acids
Dissertation Institution University of Utah
Dissertation Name PhD
Language eng
Relation is Version of Digital reproduction of "Pleiotropic functions of Hox genes revealed by mutants for genes in Hox seventh and ninth paralogous groups". Spencer S. Eccles Health Sciences Library. Print version of "Pleiotropic functions of Hox genes revealed by mutants for genes in Hox seventh and ninth paralogous groups". available at J. Willard Marriott Library Special Collection, QH9.7 1998 .C44.
Rights Management © Feng Chen.
Format Medium application/pdf
Format Extent 2,099,254 bytes
Identifier undthes,4539
Source Original: University of Utah Spencer S. Eccles Health Sciences Library (no longer available).
Master File Extent 2,099,300 bytes
ARK ark:/87278/s6ns0wrz
Setname ir_etd
ID 191221
Reference URL https://collections.lib.utah.edu/ark:/87278/s6ns0wrz
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