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. Author manuscript; available in PMC: 2021 Mar 1.
Published in final edited form as: Biochim Biophys Acta Gen Subj. 2019 Nov 15;1864(3):129482. doi: 10.1016/j.bbagen.2019.129482

Figure 4. PRMT1 knockout tadpoles are stalled in development after feeding begins.

Figure 4.

(A) Representative photos of tadpoles at stages 47–50, depicting the criteria used to determine the stages. Arrowhead indicates limb bud at stage 47. At stage 48, the vertical length (b) of limb bud is longer than the horizontal length (a) (a<b). At stage 49, both lengths are the same (a=b). At stage 50, the horizontal length is longer than the vertical length (a>b). Bars: 1 mm.

(B) PRMT1 homozygous knockout tadpoles stop development shortly after tadpole feeding begins around stage 44/45 (day 4). The tadpoles as genotyped in Figure 3B were allowed to develop for up to 2 weeks and their developmental stages were determined at indicated ages based on intestinal morphology (stage 44-stage 46) or limb morphology (stage 47-stage 50, see A). The average developmental stage for each of the three genotypes, wild type, PRMT1 heterozygous, and PRMT1 homozygous, was determined and plotted. Note that PRMT1 knockout tadpoles were stalled at stage 46 and eventually died by day 14 (see Fig. 3) The asterisks indicate a significant difference among the 3 genotypes (P < 0.01).

(C) PRMT1 homozygous tadpoles have a severe growth inhibition. The tadpoles as genotyped in Figure 3B were allowed to develop for up to 2 weeks and their total body lengths were measured at indicated ages. The average body length for each of the three genotypes was determined and plotted. The asterisks indicate a significant difference among the 3 genotypes (P < 0.01).

(D) Representative photos of 12-day-old tadpoles. The wild-type tadpole (right) is much bigger than the PRMT1 homozygous knockout tadpole (left) (dorsal view). Bar: 5 mm.

(E) No significant difference in the expression of two growth hormone genes between 10-day-old wild type and PRMT1(+/−) tadpoles. Total RNA was isolated from the intestine of wild type and PRMT1 homozygous knockout tadpoles at 10 days of age and used for real-time RT-PCR analysis of the expression of growth hormone genes: gh1 and gh2. The mRNA levels were normalized against that of rpl8. The groups included 4 wild and 5 PRMT1 homozygous animals. These results were plotted with the mean, marked as a line, and SE. ns: No significant difference between knockout and wild-type animals as determined by student-t test. The experiments were done with two or more batches of tadpoles with similar results.