Identification of new netrin family members in zebrafish: developmental expression of netrin 2 and netrin 4.
Netrin 1 is a diffusible factor that attracts commissural axons to the floor plate of the spinal cord. Recent evidence indicates that Netrin 1 is widely expressed and functions in the development of multiple organ systems. In mammals, there are three genes encoding Netrins, whereas in zebrafish, only the Netrin 1 orthologs netrin 1a and netrin 1b have been identified. Here, we have cloned two new zebrafish Netrins, netrin 2 and netrin 4, and present a comparative sequence and expression analysis. Despite significant sequence similarity with netrin 1a/netrin 1b, netrin 2 displays a unique expression pattern. Netrin 2 transcript is first detected in the notochord and in developing somites at early somitogenesis. By late somitogenesis, netrin 2 is expressed in the fourth rhombomere and is subsequently expressed in the hindbrain and otic vesicles. In contrast, netrin 4 is detected only at very low levels during early development. The nonoverlapping expression patterns of these four Netrins suggest that they may play unique roles in zebrafish development.
Department of Oncological Sciences, University of Utah, Salt Lake City, Utah.
Kye Won
KW
Park
Lisa D
LD
Urness
Megan M
MM
Senchuk
Carrie J
CJ
Colvin
Joshua D
JD
Wythe
Chi-Bin
CB
Chien
Dean Y
DY
Li
D000595:Amino Acid Sequence; D000818:Animals; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D000075385:Netrins; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000145:classification / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
D009414:Nerve Growth Factors; D000075385:Netrins; D012333:RNA, Messenger; D029961:Zebrafish Proteins; C506551:ntn4 protein, zebrafish; C088894:netrin-2