Grimes et al., 2019 - Left-right asymmetric heart jogging increases the robustness of dextral heart looping in zebrafish. Developmental Biology   459(2):79-86 Full text @ Dev. Biol.

Fig. 1 Abnormal organ asymmetry and loss of Spaw target genes in spawsa177 mutants. (A) Schematic of heart stages studied in this manuscript. The heart initially forms a symmetrical cone at 19 hpf; Spaw signaling activates lft2 expression in the left side of the cone (dark purple; dorsal view). Shortly after, by 23 hpf, the heart has formed a tube which is positioned to the left side (dorsal view). By 36 hpf, the heart has undergone looping morphogenesis to produce a dextrally looped heart (en face view). (B) The Spaw protein consists of a pro-domain and signaling ligand domain that are separated by proteolytic cleavage. The positions of the spawsa177 mutation (R275X) and spawt30973 mutation (C401F) are shown. (C) Jogging direction in control, spawsa177, spawt3097 and spawsa177/t30973 mutants, assessed by myl7 ISH at 23 hpf. All samples were statistically significantly different from each other (p ​< ​0.05; chi-square test) (D) Visceral organ situs in control, spawsa177, MOspaw and spawsa177;MOspaw embryos, assessed by ISH at 48 hpf for heart, liver and pancreas. All samples were statistically significantly different from each other (p ​< ​0.05) except spawsa177 and spawsa177;MOspaw (p ​> ​0.05; chi-square test). (E-G) Expression of lft2 (E), lft1 (F) and dand5 (G) in control and spawsa177 mutants at the indicated somite stages (ss). (H) Lateral plate mesoderm (LPM) spaw expression was scored by ISH across a range of ss for spawsa177 and ntlab160 mutants. hpf – hours post fertilization; ss – somite stage; SS – situs solitus; HTX – heterotaxy; SI – situs inversus.

Acknowledgments:
ZFIN wishes to thank the journal Developmental Biology for permission to reproduce figures from this article. Please note that this material may be protected by copyright.

Reprinted from Developmental Biology, 459(2), Grimes, D.T., Patterson, V.L., Luna-Arvizu, G., Schottenfeld-Roames, J., Irons, Z.H., Burdine, R.D., Left-right asymmetric heart jogging increases the robustness of dextral heart looping in zebrafish, 79-86, Copyright (2019) with permission from Elsevier. Full text @ Dev. Biol.