Fig. 4.
CNS myelin is reduced in znf16l mutants. (A-C) Expression of mature oligodendrocyte markers claudin k (A,B) and mbp (C) was reduced in znf16lst78 mutants between 3 and 9 dpf. Expression of cldnk was reduced but detectable at 5 dpf (B), and expression of mbp was reduced but detectable at 9 dpf (C). (D,E) Transverse transmission electron microscopy images of ventral spinal cord showed that many wild-type axons were already myelinated in wild type (D) but not mutants (E). (F,G) At 9 dpf, more axons were myelinated in the mutants (G) than at 5 dpf, but the number was still much less than in wild-type siblings at 9 dpf (F). (H) Quantification of the number of myelinated axons in ventral spinal cord at 5 and 9 dpf. Error bars show s.d.; significance was determined with two-tailed Student's t-test. ***P<0.001 in H. (I) Adult znf16l homozygous mutants are viable and fertile, with no gross morphological defects compared with their wild-type siblings for both of the alleles. Genotypes of all fish analyzed were determined by PCR assay.