Huntingtin confers fitness but is not embryonically essential in zebrafish development

Dev Biol. 2020 Feb 1;458(1):98-105. doi: 10.1016/j.ydbio.2019.10.037. Epub 2019 Nov 2.

Abstract

Attempts to constitutively knockout HTT in rodents resulted in embryonic lethality, curtailing efforts to study HTT function later in development. Here we show that HTT is dispensable for early zebrafish development, contrasting published zebrafish morpholino experiment results. Homozygous HTT knockouts were embryonically viable and appeared developmentally normal through juvenile stages. Comparison of adult fish revealed significant reduction in body size and fitness in knockouts compared to hemizygotes and wildtype fish, indicating an important role for wildtype HTT in postnatal development. Our zebrafish model provides an opportunity to understand the function of wildtype HTT later in development.

Keywords: Huntingtin; Loss-of-function; Zebrafish.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Body Size
  • CRISPR-Cas Systems
  • Conserved Sequence
  • Embryo, Nonmammalian / drug effects
  • Embryo, Nonmammalian / embryology
  • Gene Editing
  • Gene Knockout Techniques
  • Genetic Association Studies
  • Genetic Fitness
  • Humans
  • Huntingtin Protein / chemistry
  • Models, Animal*
  • Morpholinos / pharmacology
  • Nerve Tissue Proteins / deficiency
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology*
  • Neurulation / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Zebrafish / embryology
  • Zebrafish / genetics*
  • Zebrafish / growth & development
  • Zebrafish Proteins / deficiency
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / physiology*

Substances

  • HTT protein, human
  • Htt protein, mouse
  • Huntingtin Protein
  • Morpholinos
  • Nerve Tissue Proteins
  • Zebrafish Proteins
  • htt protein, zebrafish