Analysis Tools
mortality/aging
|
• the few homozygotes that survived to adulthood appeared quite unhealthy
|
|
• homozygous null mice developed to term, and appeared normal, representing 23% of the offspring
• approximately 97% of mutant mice died within 3 weeks after birth
|
cellular
| N |
• FACS analysis of Hoechst-stained skeletal muscle-derived cells revealed approximately equal numbers of verapamil-sensitive pluripotent stem cells (also called side-population [SP] cells) in both wild-type and mutant mice
• mutant muscle cells displayed an increased hematopoietic potential and generated granulocyte and monocyte colonies as shown by Ly-6G immunoreactivity
• colony-forming assay of muscle cells cultured in stem-cell medium/methylcellulose over a period of 2 weeks showed almost a 10-fold increase in hematopoietic potential of mutant stem cells
• importantly, muscle-derived pluripotent stem cells primarily gave rise to myoblasts when cultured in stem-cell medium; by contrast, mutant muscle stem cells displayed almost a 10-fold increase in propensity toward hematopoietic differentiation and were incapable of forming adult myoblasts
|
craniofacial
short maxilla
(
J:32018
)
|
• alizarin red and alcian blue staining revealed that all homozygous null mice had a reduced maxilla: the maxilla was shortened in the anterior/posterior direction; this phenotype was more prominent in a lateral view
|
|
• the inferior lateral part of the nasal capsule was not formed; in wild-type, this structure is normally associated with the cartilage that lines the anterior nasal cavity
• analysis of embryos at 14.5 d.p.c. revealed that the anterior part of the nasal capsule was absent
|
pointed snout
(
J:32018
)
|
• homozygous animals appeared to have a pointed snout which distinguished them phenotypically from the wild-type and heterozygous animals
|
digestive/alimentary system
| N |
• many of the surviving mutant mice exhibited dilatations in the small intestine and appendix; however, eosin-hematoxylin stained sagittal and transverse sections of whole embryos revealed no obvious defect
|
embryo
| N |
• analysis of 9-11.5 dpc homozygous null embryos by whole-mount in situ hybridization using myogenic markers revealed no obvious changes in the dermomyotome or myotome, indicating that these somitic structures were morphologically normal
|
growth/size/body
|
• the inferior lateral part of the nasal capsule was not formed; in wild-type, this structure is normally associated with the cartilage that lines the anterior nasal cavity
• analysis of embryos at 14.5 d.p.c. revealed that the anterior part of the nasal capsule was absent
|
pointed snout
(
J:32018
)
|
• homozygous animals appeared to have a pointed snout which distinguished them phenotypically from the wild-type and heterozygous animals
|
|
• a few days after birth, homozygous null mice became readily identifiable by their growth retardation and frequent lethality
(J:32018)
• at 7 days of age, the body weight of mutant mice was 50% reduced compared with wild-type littermates; at 2 weeks of age, mutant animals were approximately 33% the weight of wild-type mice
(J:64793)
|
muscle
| N |
• after 11.5 dpc, and in newborn mutant mice, histological analysis revealed no obvious changes in the intercostal muscles
|
|
• H&E-stained lower hindlimb skeletal muscle of 1-week-old mutant mice revealed a 1.5-fold reduction in the diameter of mutant fibers; notably, the overall organization of muscle fibers was not affected
|
|
• the diaphragms of 7-day-old homozygous null mice were significantly thinner than those of wild-type littermates
|
|
• TEM analysis of gastrocnemius muscle from 7- to 10-day-old wild-type mice revealed that satellite cells were readily identifiable in wild-type muscle and comprised 25% of peripheral sublaminar nuclei; in contrast, satellite cells could not be identified in >300 sublaminar nuclei examined from mutant muscles
• in addition, satellite cells were undetectable in mutant muscle from E18 embryos, indicating complete failure of muscle satellite cells to form
|
|
• homozygous null mice displayed muscle weakness characterized by an abnormal gait and splayed hindlimbs
|
respiratory system
|
• the inferior lateral part of the nasal capsule was not formed; in wild-type, this structure is normally associated with the cartilage that lines the anterior nasal cavity
• analysis of embryos at 14.5 d.p.c. revealed that the anterior part of the nasal capsule was absent
|
skeleton
short maxilla
(
J:32018
)
|
• alizarin red and alcian blue staining revealed that all homozygous null mice had a reduced maxilla: the maxilla was shortened in the anterior/posterior direction; this phenotype was more prominent in a lateral view
|
|
• the inferior lateral part of the nasal capsule was not formed; in wild-type, this structure is normally associated with the cartilage that lines the anterior nasal cavity
• analysis of embryos at 14.5 d.p.c. revealed that the anterior part of the nasal capsule was absent
|
nervous system
| N |
• the mesencephalon, hindbrain, neural tube and adult mutant brain appeared morphologically normal
• in addition, no obvious abnormalities were detected in neuronal derivatives of the cephalic neural crest
|
endocrine/exocrine glands
|
• in homozygous null mice, the tubules of serous glands, which are associated with the lateral wall of the middle meatus and those associated with the nasal septum were severely reduced in number relative to wild-type mice
|
