Four twist genes in zebrafish, four expression patterns.
Twist genes code for regulatory bHLH proteins essential for embryonic development and conserved across the metazoa. There are four genes that constitute the zebrafish twist family: twist1a, twist1b, twist2--orthologs of the mammalian twist1 and twist2 genes; and twist3--a gene from a new clade that does not exist in mammals. Presented here are their embryonic mRNA expression profiles. The study extends the known conservation of twist developmental patterns in tetrapods to the fish, e.g., expression in cephalic neural crest, sclerotome and lateral plate mesoderm. Some other expression domains are unique, like hypochord and dorsal aorta; some, like the notochord, may be ancestral patterns retained from protochordates; and the expression in invaginating/migrating cells may have been retained from the jellyfish. Perhaps this is one of the more ancient functions of twist--conserved from diploblasts to humans--to facilitate cell movement.
Germanguz
Igal
I
Department of Virology and Developmental Genetics, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel.
Lev
Dmitri
D
Waisman
Tal
T
Kim
Cheol-Hee
CH
Gitelman
Inna
I
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning; D015509:Developmental Biology / Q000379:methods*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D018878:Limb Buds / Q000196:embryology; D008648:Mesoderm / Q000378:metabolism; D008969:Molecular Sequence Data; D009432:Neural Crest / Q000196:embryology; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D051879:Twist-Related Protein 1 / Q000096:biosynthesis* / Q000502:physiology; D015027:Zebrafish
D012333:RNA, Messenger; D051879:Twist-Related Protein 1