Fig. 5

zHTT-knockout, but not hemizygous, exhibit reduced size and survival. (A) Representative images of 30dpf wildtype, hemizygous, and knockout zHTT adults. Scale bar = 2mm. (B) Body length measurements of wildtype (N = 30), hemizygous (N = 48), and knockout (N = 4). Statistical significance calculated using one way ANOVA with multiple comparisons between groups analyzed by Dunnett’s test. Significant difference in body lengths was observed between wildtype and knockout groups. (p=0.0040). (C) Survival curves of zHTT knockout embryos when raised in competition with fish of other genotypes or out of competition starting at 5dpf. No significant difference in the lengths of survival observed in zHTT knockouts between the two treatments. Both conditions show reduced survival when compared to wildtype siblings (p <0.0001). (D) Growth curve of larval zebrafish at earlier timepoints measured from 8-12 embryos per genotype, n = 4 experiments starting at 6dpf up to 15dpf, when a large proportion of the knockout larval fish died. Significant difference in body length over time is observed between zhtttmp003/tmp003 and heterozygous or wildtype siblings (two-way ANOVA with Tukey’s multiple comparisons test, * ​= ​p-value ​< ​0.01, **** ​= ​p-value ​< ​0.0001, n.s. ​= ​p-value > 0.05). (E) Relative expression of zebrafish HTT mRNA normalized to ef1a expression over time in development. Data obtained by qPCR of a pool of 50 wildtype embryos per timepoint, with 2 different sets of primers to zHTT. hpf = hours postfertilization; dpf = days postfertilization. (F) Gene expression atlas data for zhtt expression in development obtained from https://www.ebi.ac.uk/gxa/home.