Absence of oculomotor and trochlear motoneurons leads to altered extraocular muscle development in the Wnt-1 null mutant mouse.
Wnt-1 null mutant mice lack midbrain somatic motor nuclei. Primordial migration and spatial patterning of the extraocular muscles, however, was preserved, but myogenesis was disrupted in aneural muscles. Some muscles normally innervated by oculomotor and trochlear nuclei received aberrant innervation, which proved sufficient to maintain prenatal stages of myogenesis. The absence of motoneurons followed by innervation from inappropriate motoneuron pools is a viable candidate mechanism in ocular motility disorders, including Duane retraction syndrome and congenital fibrosis of extraocular muscle.
Porter
J D
JD
Department of Anatomy, University of Kentucky Medical Center, Lexington 40536-0084, USA. anajohnp@pop.uky.edu
Baker
R S
RS
D000483:Alleles; D000818:Animals; D005314:Embryonic and Fetal Development; D006580:Genetic Carrier Screening; D006720:Homozygote; D008636:Mesencephalon / Q000002:abnormalities* / Q000196:embryology; D051379:Mice; D018345:Mice, Knockout; D009046:Motor Neurons / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000648:ultrastructure; D009801:Oculomotor Muscles / Q000002:abnormalities / Q000196:embryology / Q000648:ultrastructure; D009802:Oculomotor Nerve / Q000002:abnormalities* / Q000196:embryology; D010641:Phenotype; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics*; D011519:Proto-Oncogenes; D014321:Trochlear Nerve / Q000002:abnormalities* / Q000196:embryology; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins
D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D051155:Wnt1 Protein; C495246:Wnt1 protein, mouse; D029961:Zebrafish Proteins