Fig 1.
CBPΔCH1/ΔCH1 mice display craniofacial anomalies.
(A) CBPΔCH1/ΔCH1 mice show shortened nasal bones with 100% penetrance. (B, C) MicroCT scans show that CBPΔCH1/ΔCH1 mice have loss of lateral symmetry (B) and hyperdontia (C, see extra tooth indicated by yellow arrow) with partial penetrance. (D, E) Alcian Blue/Alizarin Red S staining of e18.5 embryos demonstrates additional developmental defects in the occipital bone of the skull (D) and bifurcation of the xyphoid process (E) in CBPΔCH1/ΔCH1 embryos (both with 100% penetrance). Yellow arrows indicate occipital bone (D) and xyphoid process (E). CBPΔCH1/ΔCH1 embryos all displayed decreased staining of cartilage with Alcian blue dye (compare wild type with CBPΔCH1ΔCH1 embryos in D and E; different embryo pair represented in each panel).
Fig 2.
CBPΔCH1/ΔCH1 mice show repetitive behaviors, hyperactivity, and less anxiety.
(A,B) CBPΔCH1/ΔCH1 mice display repetitive forelimb movements. White dots (A) indicate position of paws. Scores assigned in (B) represent the frequency of the repetitive movements. 0 = no forelimb repetitive movements (FRM); 1 = occasional FRM; 2 = continuous FRM. Mean ± SEM. N = 8 wild type (WT), 9 CBP+/ΔCH1, 8 CBPΔCH1/ΔCH1. (C) CBPΔCH1/ΔCH1 mice show significantly increased self-grooming time. N = 14 WT, 21 CBP+/ΔCH1, 13 CBPΔCH1/ΔCH1. (D-F) CBPΔCH1/ΔCH1 mice show increased travel distance (D), speed (E), and rearing (F) in a 30-min open field test. (G) CBPΔCH1/ΔCH1 mice stay longer in the center of the open field arena. (H-I) CBPΔCH1/ΔCH1 mice stay shorter in the closed arm, and enter less frequently the closed arm of an elevated plus maze. For (D-I), N = 19 WT, 24 CBP+/ΔCH1, 16 CBPΔCH1/ΔCH1. For (B-I) Asterisks indicate the p value for either Dunnett’s (in the repetitive movement assay) or Tukey (in the other tests) post hoc analysis after one-way ANOVA (*: p<0.05; **: p<0.01; ***: p<0.001; ****: p< 0.0001). All the other pairings are not statistically different.
Fig 3.
CBPΔCH1/ΔCH1 mice show abnormal social behaviors.
(A) CBPΔCH1/ΔCH1 mice show reduced interest in an introduced animal in a three chamber-sociability assay. N = 15 wild type (WT), 21 CBP+/ΔCH1, 13 CBPΔCH1/ΔCH1. (B) CBPΔCH1/ΔCH1 mice display a decreased preference for the novel animal in a three chamber-social recognition assay. N = 15 wild type (WT), 21 CBP+/ΔCH1, 11 CBPΔCH1/ΔCH1. (C) CBPΔCH1/ΔCH1 mice are less aggressive. Open circles represent (unusual) attacks initiated by the intruder instead of the resident. (D) CBPΔCH1/ΔCH1 mice have impaired nest-building skills. Nest building evaluated as follows: 0 = Kimwipe not notably touched; 1 = Kimwipe touched but no identifiable nest; 2 = an identifiable but flat nest; 3 = a (near) perfect nest with walls higher than the mouse body. For (C-D), N = 15 wild type (WT), 21 CBP+/ΔCH1, 13 CBPΔCH1/ΔCH1. Asterisks indicate the p value for either Dunnett’s (in the nest building assay) or Tukey (in the other tests) post hoc analysis after ANOVA (*: p<0.05; **: p<0.01; ***: p<0.001; ****: p< 0.0001). All the other pairings are not statistically different.
Fig 4.
CBPΔCH1/ΔCH1 mice display motor dysfunction and abnormal recognition memory.
(A) CBPΔCH1/ΔCH1 mice fall faster in a wire hang assay. N = 15 wild type (WT), 21 CBP+/ΔCH1, 14 CBPΔCH1/ΔCH1. (B, C) CBPΔCH1/ΔCH1 mice show significantly less grip strength for forelimbs only (B) or all four limbs (C). N = 15 WT, 21 CBP+/ΔCH1, 14 CBPΔCH1/ΔCH1. (D) CBPΔCH1/ΔCH1 mice perform normally in a classic rotarod assay. N = 10 WT, 12 CBP+/ΔCH1, 10 CBPΔCH1/ΔCH1. (E,F) In a modified rotarod assay, in which the grips were eliminated from the rod surface, CBPΔCH1/ΔCH1 mice perform normally when walking against the rod rotation (backward, E), but are impaired when walking with the rotation (forward, F). N = 42 WT, 27 CBPΔCH1/ΔCH1. (G,H) In an object recognition test, CBPΔCH1/ΔCH1 mice have intact short-term recognition memory but impaired long-term memory. N = 17 WT, 12 CBPΔCH1/ΔCH1. Asterisks indicate the p value for the Student’s t-test (in the modified rotarod and the recognition memory test) or Tukey post hoc analysis after ANOVA in the other tests (*: p<0.05; **: p<0.01; ***: p<0.001; ****: p< 0.0001). All the other pairings are not statistically different.
Fig 5.
CBPΔCH1/ΔCH1 mice showed increased hippocampal long-term potentiation (LTP).
(A-C) Mean field excitatory postsynaptic potentials (fEPSPs) as a function of stimulation intensity (A), paired-pulse ratios as a function of interstimulus interval (B), and mean fEPSPs as a function of time before and after 200-Hz tetanus (applied at time 0) (C) measured at CA3-CA1 synapses in 2–3 slices per animal from WT (N = 4) and CBPΔCH1/ΔCH1 (N = 5) mice. * p<0.05.