Thyroid hormone receptor beta is critical for intestinal remodeling during Xenopus tropicalis metamorphosis

摘要

Knocking out gene in does not affect early development. Genomic structure of gene and the CRISPR-short guide RNA (sgRNA) targeting . There are two known transcripts for , each with 7 exons (boxes). The specific sgRNA was designed to target exon 2 present in both transcripts. The sgRNA sequences are shown in red. Schematic diagram depicting the sequence of the sgRNA targeted region in the wild type and a mutant (5 base out-of-frame deletion) animal. Arrows represent primers used for genotyping: the forward primer F and the reverse primer R, respectively. Mendelian distribution of 4-day old (around stage 45/46) or stage 54 tadpoles obtained from mating two animals. Genotyping PCR was carried out by using tail tip genomic DNA of randomly selected 4-day old (stage 45/46) and stage 54 tadpoles, the onset of metamorphosis, and the results were close to the expected Mendelian distribution for the three expected genotypes. Knocking out does not affect the developmental rate up to the onset of metamorphosis (stage 54). The time in days for each animal obtained from mating two frogs to reach stage 54 was recorded and presented with the mean, marked as a line, and standard error (SE). No significant difference was observed for the 3 genotypes. Knocking out TRβ does not affect the animal size and morphology at stage 54. The total body length and snout-vent length were measured on randomly selected animals at stage 54 and presented with the mean, marked as a line, and standard error (SE). No significant difference was observed for the 3 genotypes