Thirdly, the Tex19.1 mouse mutant phenocopies the Ubr2 null mutant, underscoring the physiological relevance of the Tex19.1-Ubr2 Tex19.1-Ubr2
The Tex19.1-null mouse mutant phenocopies the Ubr2-deficient mutant in three aspects: heterogeneity of spermatogenic defects, meiotic chromosomal asynapsis, and embryonic lethality preferentially affecting females.
FRAS and FREM mutations found in individuals with FS (or in the blebs family of mouse mutants that phenocopy the disorder) lead to defects in epidermal adhesion and the formation of large skin blisters in utero.
Thus, consistent with the interaction between Tex19.1 and Ubr2, these two mouse null mutants phenocopy each other.
Curiously, Prickle1 mutants recapitulate the characteristic features of human Robinow syndrome and phenocopy mouse mutants with Wnt5a or Ror2 gene defects, prompting us to explore an association of Prickle1 with the Wnt pathway.
Interestingly, mice heterozygous for Twist-1 or Twist-2 mutant alleles are viable, and double heterozygous mutants phenocopy the severe cachexia seen in twist-2 null mice, suggesting that Twist-1 and Twist-2 may act redundantly to control an essential post-natal process (Sosic et al, 2003).
The FS-spectrum diseases are phenocopied by the 'blebs' family of mouse mutants, whose causative mutations lie in the mouse homologues of these FRAS/FREM genes (McGregor et al., 2003; Vrontou et al., 2003; Smyth et al., 2004; Jadeja et al., 2005).
10.7554/eLife.08201.017 Figure 4. amotl2a mutants phenocopy the morphant phenotype.
We have previously shown that Tyro3 mouse mutants, Gas6 mouse mutants, and retina-specific Pros1 mouse mutants all have a normal number of PRs at this time (Prasad et al., 2006; Burstyn-Cohen et al., 2012); but that Gas6/Pros1 double mutants display PR death and retinal degeneration that fully phenocopies the degeneration of the Mertk mutants (Burstyn-Cohen et al., 2012).
We find that FbxL7 mutants phenocopy the RNAi lines, exhibiting enlarged and rounded wings (Fig. 1E).
