GFAP immunoreactivity reveals astrogliosis in females heterozygous for jimpy.
The jimpy gene is a sex-linked recessive mutation which produces severe hypomyelination throughout the central nervous system (CNS) in affected male mice. The female carrier also expresses the mutation, but the degree of hypomyelination varies considerably among the tracts. In the optic nerve, patches of unmyelinated tissue are interspersed with myelinated zones; in the brain, myelination is retarded during development but recovers in the adult. We have previously shown, in the male mutant, that an astroglial hypertrophy is associated with the white matter. The present study was undertaken to determine the existence and extent of astrogliosis in the female carriers. In this immunocytochemical investigation using antiserum to glial fibrillary acidic protein (GFAP), we show that the optic nerve of the female carriers exhibits patches of gliosis which are similar in appearance and intensity to those found in affected males. These patches are not present in the white matter of the carriers' brain and spinal cord, but GFAP-immunoreactivity is more intense than in control females. Throughout certain fiber tracts (e.g. optic tract and internal capsule), the number of immunostained astrocytes is increased in comparison to controls; they are larger, have more processes, and are more intensely immunoreactive. The results of the present study show that the retardation of myelin formation is accompanied by an astroglial response and that the intensity of the gliosis closely parallels the extent of the hypomyelination.
D000818:Animals; D001253:Astrocytes / Q000166:cytology*; D001921:Brain / Q000473:pathology*; D005260:Female; D005904:Glial Fibrillary Acidic Protein; D006579:Heterozygote; D008297:Male; D051379:Mice; D008816:Mice, Jimpy; D009030:Mosaicism; D009363:Neoplasm Proteins / Q000032:analysis*; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009900:Optic Nerve / Q000473:pathology*; D012737:Sex Factors
D005904:Glial Fibrillary Acidic Protein; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins