Phenotype Image Detail

Image

Caption

A: Ultrastructure of rod nuclei in Tg(RHO-SCA7)R7EJman/0 (R7E) mice. Electron microscopy micrographs from 2 year old Tg(RHO-SCA7)R7NJman/0 (R7N) (panel a) and two distinct Tg(RHO-SCA7)R7EJman/0 (panels b and c) mice are shown. In Tg(RHO-SCA7)R7NJman/0 mice, rod nuclei are characterized by a large territory of centrally located heterochromatin. In Tg(RHO-SCA7)R7EJman/0 mice, rod nuclei were bigger and rounder, and displayed much more euchromatin, which appears lightly stained by electrons. Arrows indicate pale grey structures likely resulting from aggregation of mutant ATXN7 in rods from Tg(RHO-SCA7)R7EJman/0 mice. Scale bars: 1um. B: Ultrastructure of photoreceptor nuclei during disease progression in Tg(RHO-SCA7)R7EJman/0 mice. Electron microscopy micrographs from 2 year old Tg(RHO-SCA7)R7NJman/0 (panel a), 2 month old and 2 year old Tg(RHO-SCA7)R7EJman/0 (panels b and c, respectively) mice are shown. This time-course analysis revealed that alterations of rod nuclear architecture progressively worsened as retinopathy progressed in Tg(RHO-SCA7)R7EJman/0 mice. Cone photoreceptor nuclei (c), which are found in the outermost part of the outer nuclear layer (ONL) adjacent to inner segments (is), present a different architecture with several heterochromatin clumps surrounded by more euchromatin. As evidenced in panel c, rod nuclei in Tg(RHO-SCA7)R7EJman/0 mice look highly similar to cone nuclei. Scale bar: 5um. C: Ultrastructure of photoreceptor nuclei in Atxn7^tm1Hzo/Atxn7⁺ (SCA7^266Q/5Q) mice. Electron microscopy micrographs from 3 month old wild type (panels a and d) and two distinct age-matched Atxn7^tm1Hzo/Atxn7⁺ (panels b,c,e and f) mice are shown. Morphological appearance of the central densely stained heterochromatin territory is altered in mutant mice. At higher magnification (lower panels [e-f]), rod nuclei from heterozygous mice are slightly larger and contain more euchromatin than nuclei from wild type mice. Cone nuclei (c) and photoreceptor inner segments (is) are depicted. Scale bar: a-c, 2um; e-f, 0.5um.

Copyright

This image is from Helmlinger D, PLoS Biol 2006 Mar;4(3):e67, and is displayed under the terms of the Creative Commons Attribution 4.0 International License. J:107098

Associated Alleles

Symbol	Name
Atxn7^tm1Hzo	ataxin 7; targeted mutation 1, Huda Y Zoghbi
Tg(RHO-SCA7)R7EJman	transgene insertion R7E, Jean-Louis Mandel
Tg(RHO-SCA7)R7NJman	transgene insertion R7N, Jean-Louis Mandel

Associated Genotypes

Allelic Composition	Genetic Background
Atxn7^tm1Hzo/Atxn7^+	involves: 129S7/SvEvBrd * C57BL/6J
Tg(RHO-SCA7)R7EJman/0	involves: C57BL/6 * SJL
Tg(RHO-SCA7)R7NJman/0	involves: C57BL/6 * SJL