Expression of metallothionein gene during embryonic and early larval development in zebrafish.
Metallothionein (Mt) has been considered as a molecular marker of metal pollution in aquatic ecosystems. Less is known about the expression of mt gene during embryogenesis. Here, we report the cloning, sequencing, and the expression pattern of mt gene during developmental stages in zebrafish. The zebrafish embryogenesis when takes place in a medium containing a dosage of 1000 microM zinc resulted in high mortality, indicating the deleterious effect of zinc on development. The zebrafish mt gene consists of three exons encoding 60 amino acids with 20 conserved cysteine residues. RT-PCR result indicates the maternal contribution of Mt transcripts. Using digoxigenin (DIG)-labeled anti-sense RNA probe, whole-mount in situ hybridization was performed to observe the expression pattern of zebrafish mt gene during embryonic and early larval stages. Stronger as well as ubiquitous expression of mt gene during early embryonic stages narrowed to specific expression after hatching. The mt promoter region contains seven copies of putative metal-responsive elements (MREs), which are shown to be important for the high level activity by deletion analysis. The expression of mt gene during embryogenesis implies its significant role on development.
Chen
Wen-Ya
WY
Department of Aquaculture, National Taiwan Ocean University, Keelung, Taiwan.
John
Joseph Abraham Christopher
JA
Lin
Chih-Hung
CH
Lin
Hui-Fen
HF
Wu
Shao-Chun
SC
Lin
Cheng-Hui
CH
Chang
Chi-Yao
CY
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018507:Gene Expression Regulation, Developmental; D015698:Genomic Library; D017403:In Situ Hybridization; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015027:Zebrafish / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D015032:Zinc
D017931:DNA Primers; D008668:Metallothionein; D015032:Zinc