title: Cloning, characterization and expression of ferritin subunit from clam Meretrix meretrix in different larval stages.
abstract: Shell formation is one of the important events during larval development and metamorphosis in bivalves. However, the molecular mechanisms and environmental cues regulating shell initiation and growth are unclear. Here, we report that ferritin, a principal protein for biological iron storage and metabolism, might play a role in larval shell development of the bivalve mollusk Meretrix meretrix. A full-length ferritin subunit cDNA, named as MmeFer, was cloned and characterized. The MmeFer mRNA expression in different developmental stages, from trochophore to post larvae, was analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR). MmeFer mRNA expression in larvae of later developmental stages increased at least 8-fold following trochophores. Moreover, the temporal and spatial expressions of MmeFer mRNA were examined by whole mount in situ hybridization. In the trochophore stage, MmeFer was detectable where it was supposed to be for shell initiation. In the later developmental stages, MmeFer was found near digestive glands and mantle that secret larval shell. MmeFer expression was also detected in larvae cultured in artificial seawater with different iron concentrations ranging from 0 to 100 microM. These results suggest that ferritin may play a role in the shell formation of mollusks.
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Wang
authors.forename: Baozhong
authors.initials: B
authors.lastname: Liu
authors.forename: Jianhai
authors.initials: J
authors.lastname: Xiang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D032701:Biomimetics; D049872:Bivalvia / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D003001:Cloning, Molecular; D003470:Culture Media / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D004305:Dose-Response Relationship, Drug; D005293:Ferritins / Q000737:chemistry / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D006801:Humans; D017403:In Situ Hybridization; D007501:Iron / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012623:Seawater; D017422:Sequence Analysis, DNA; D013997:Time Factors
chemical_list: D003470:Culture Media; D018076:DNA, Complementary; D021122:Protein Subunits; D012333:RNA, Messenger; D005293:Ferritins; D007501:Iron