Fig. 4

Phenotypic analysis of homozygous embryos carrying mutant mab21l2 alleles encoding p.(Gln48Serfs*5) truncation (mab21l2^Q48Sfs*5) and p.(Arg51_Phe52del) in-frame deletion (mab21l2^R51_F52del) proteins.

A-R. Embryonic phenotypes. Images of wild-type larvae at 96-hpf (A-E) and 120-hpf (F), as well as embryos carrying the p.(Gln48Serfs*5) frameshift (G-L) or p.(Arg51_Phe52del) in-frame deletion (M-R) alleles are shown. Whole mount images (A-C, G-I, and M-O), as well as frontal (E, J, K, Q) and sagittal (D, P) ocular sections are presented. Please notice reduced eye size (G-K), coloboma (white arrows in H), degenerative (H-J) or absent (K) lens, disorganized retina and irregular cornea (J, K) in embryos with frameshift mutations, as well as severe coloboma (white arrows in N) with disorganized retina, discontinuous RPE (white arrows in P, Q), and corneal defects (O) but overall comparable to wild-type eye size and lenses (M-Q) in embryos that are homozygous for the in-frame deletion. Alcian blue stain of wild-type (F) and mutant embryos (L, R) identified defects in craniofacial development with primary defects in the development of the ceratohyal cartilage of the hyoid arch (or the second pharyngeal arch). S-W. Adult phenotype. Images of adult wild-type (S, T) and Arg51_Phe52del mutant (U-W) fish: please notice microphthalmic highly disorganized eye with pigmented cornea (V) and anophthalmic contralateral eye with residual abnormal pigmented tissue (W). Please also note normal appearance of pectoral fins in the mutant fish (U). ch, ceratohyal; ep, ethmoid plate; m, Meckel′s cartilage; pq, palatoquadrate; e, eye; c, cornea; le, lens; ipl, inner plexiform layer; on, optic nerve; pf, pectoral fins; r, retina.