Table 1.
Summary of R6/2×TG2 cohorts.
Table 2.
Summary of zQ175×TG2 cohorts.
Table 3.
Quantitative Polymerase Chain Reaction (qPCR) information.
Table 4.
Quantitative Western Blots Antibody information.
Figure 1.
Transglutaminase 2 protein levels in R6/2×TG2 KO line.
A. TG2 expression levels in the striatum of 12 week old animals from the R6/2×TG2 KO line (n = 11–12 per genotype). *p<0.05,***p<0.0001. See materials and methods' section for details regarding the calculation of TG2 protein expression levels. B. Westen blotting examples of striatal lysates of animals from the R6/2×TG2 KO line probed with antibodies that recognize TG2 and the housekeeping proteins.
Figure 2.
A–B. Mean body weights of mice from the R6/2×TG2 KO line. A. Male mice (n = 14–16 per genotype). B. Female mice (n = 13–16 per genotype). C–D Mean body weights of mice from the zQ175×TG2 KO line. A. Male mice (n = 5–6 per genotype). B. Female mice (n = 6–7 per genotype). *Significant differences R6/2 vs WT,*1significant differences HOM vs WT, *2significant differences HET vs. WT, #significant TG2 genotype differences. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET HOM: zQ175 HOM.
Figure 3.
Behavioral data captured in the PhenoCube system as a function of genotype, age and light cycle phase in animals from the R6/2×TG2 KO line.
A. Overall visit frequency. B. Mean path length. C. Percent alternations (Data for this measure were not collected at 16 weeks of age since R6/2 mice were not tested in this protocol due to reduced licking). *Significant HD genotype differences within each light phase, at each age; #: significant differences due to light phase in the diurnal cycle in the WT mice; ##significant differences due to light phase in the cycle for each age independently of genotype; ###significant differences due to light phase in the diurnal cycle in the R6/2 mice; ∧significant TG2 genotype differences. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout.
Figure 4.
Overall visit frequency detected in the PhenoCube system as a function of genotype, age and light cycle phase in animals from the zQ175×TG2 KO line.
*Significant HD genotype differences regardless of the light phase (in the mean path length the differences were detected between HET and WT animals); ##significant differences due to light phase in the cycle independently of genotype; ∧significant TG2 genotype differences (see results method for details). WT: wild-type, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET, HOM: zQ175 HOM.
Figure 5.
Acquisition of the procedural T-maze task (n = 20–24 per genotype).
A. Proportion of mice acquiring the task on each test day. B. Average (±SEM) number of days to acquire the task (only animals that fulfill the acquisition criterion within 10 training days were included). *Significant HD genotype effect. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout.
Figure 6.
Reversal phase of the procedural T–maze task (platform location switched; n = 19–24 per genotype).
The graph shows the mean (±SEM) percent correct for each group, on each test day. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout.
Figure 7.
Acquisition of the procedural T-maze task in the zQ175×TG2 KO animals (n = 11–12, per genotype).
A. Proportion of mice acquiring the task on each test day. B. Average (±SEM) number of days to acquire the task. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET, HOM: zQ175 HOM.
Figure 8.
Reversal phase of the procedural T–maze task (platform location switched; n = 11–12 per genotype).
WT: wild-type, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET, HOM: zQ175 HOM.
Figure 9.
Mean number of days required to obtain 40 reinforcers across two consecutive sessions during the training phase (n = 6–12 per genotype).
*Significant HD genotype effect. WT: wild-type, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET.
Figure 10.
Discrimination performance (n = 6–12 per genotype).
A. Discrimination ratio across the training period. B. Response rate for the reinforced (S+ RPM) and unreinforced (S- RPM) conditions averaged across the final four sessions for the zQ175×TG2 KO line. *Significant HD genotype effect. WT: wild-type, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET.
Figure 11.
The relative striatal (left panels) and cortical (right panels) mRNA expression level of mice examined from the R6/2×TG2 KO line at 12 weeks of age (n = 12 per genotype).
Relative mRNA levels are normalized to WT controls. For normalization, the geometric means of Ubc, Eif4a2 an Atp5b were used. *Significant HD Genotype effect; #significant TG2 Genotype effect. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout.
Figure 12.
The relative striatal mRNA expression level of mice examined from the zQ175×TG2 KO line at 12 months of age (n = 7–12 per genotype).
Relative mRNA levels are normalized to zQ175_WT TG2_WT controls. For normalization, the geometric means of Ubc, Eif4a2 an Atp5b were used. *Significant HD Genotype effect. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET.
Figure 13.
Seprion ligand quantification of aggregate load.
A. Aggregate load in cortical tissues from 12-week-old R6/2×TG2 KO mice. The background readings obtained from the WT animals (n = 3 per group) were averaged and subtracted from the readings obtained from the R6/2 animals in order to remove the baseline reading. B. Aggregate load in striatal tissues from 52-week-old zQ175×TG2 KO mice. The readings obtained from the zQ175_WT animals (n = 5–7 per group) were averaged and subtracted from the readings obtained from the zQ175_HET animals in order to remove the baseline reading. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET.
Figure 14.
Whole brain, striatal and cortical volumes of 16-week-old R6/2×TG2 KO mice (top panels, n = 6 per genotype per sex) and of 52-weeks-old zQ175×TG2 KO mice (bottom panels, n = 6 per genotype per sex).
*Significant differences compared to WT animals, #significant differences compared to HET mice. WT: wild-type, TG2+/−: heterozygous TG2 knockout, TG2−/−: homozygous TG2 knockout, HET: zQ175 HET, HOM; zQ175HOM.