Irxl1 mutant mice show reduced tendon differentiation and no patterning defects in musculoskeletal system development.
Irxl1 (Iroquois-related homeobox like-1) is a newly identified three amino-acid loop extension (TALE) homeobox gene, which is expressed in various mesoderm-derived tissues, particularly in the progenitors of the musculoskeletal system. To analyze the roles of Irxl1 during embryonic development, we generated mice carrying a null allele of Irxl1. Mice homozygous for the targeted allele were viable, fertile, and showed reduced tendon differentiation. Skeletal morphology and skeletal muscle weight in Irxl1-knockout mice appeared normal. Expression patterns of several marker genes for cartilage, tendon, and muscle progenitors in homozygous mutant embryos were unchanged. These results suggest that Irxl1 is required for the tendon differentiation but dispensable for the patterning of the musculoskeletal system in development.
Wataru
W
Kimura
Masashi
M
Machii
XiaoDong
X
Xue
Nishat
N
Sultana
Keisuke
K
Hikosaka
Mohammad T K
MT
Sharkar
Tadayoshi
T
Uezato
Masashi
M
Matsuda
Haruhiko
H
Koseki
Naoyuki
N
Miura
D000818:Animals; D019521:Body Patterning / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D041641:Musculoskeletal Development / Q000235:genetics; D009141:Musculoskeletal System / Q000033:anatomy & histology / Q000196:embryology; D011995:Recombination, Genetic; D012097:Repressor Proteins / Q000235:genetics; D013710:Tendons / Q000196:embryology*
D018398:Homeodomain Proteins; D012097:Repressor Proteins; C490797:Tgif1 protein, mouse; C510657:mohawk protein, mouse