Molecular cloning of the Coch gene of guinea pig inner ear and its expression analysis in cultured fibrocytes of the spiral ligament.
CONCLUSIONS
We have cloned guinea pig Coch cDNA and the sequence information will be useful for future molecular study combined with physiological experiments. Proper Coch gene expression appears to be dependent on the unique extracellular micro-environment of the inner ear in vivo. These results provide insight into the Coch gene expression and its regulation.


OBJECTIVE
To characterize the guinea pig Coch gene, we performed molecular cloning and expression analysis in the inner ear and cultured fibrocytes of the spiral ligament.


METHODS
The Coch cDNA was isolated using RACE. Cochlin isofoms were studied by Western blot using three different types of mammalian inner ear. The cochlear fibrocytes were cultured and characterized by immunostaining. Coch gene expression in the fibrocytes was investigated and the influence of cytokine stimulation was evaluated.


RESULTS
The full-length 1991 bp Coch cDNA that encodes a 553 amino acid protein was isolated. The sequence had significant homology with other mammals, and the sizes of the Cochlin isoforms were identical. In the cultured fibrocytes, Coch mRNA was expressed in a very small amount and the isoform production was different, compared with the results in vivo. Cytokine stimulation did not alter the level of mRNA expression or isoform formation.
Li
Lishu
L
Department of Otorhinolaryngology, Nippon Medical School, Tokyo, Japan.
Ikezono
Tetsuo
T
Sekine
Kuwon
K
Shindo
Susumu
S
Matsumura
Tomohiro
T
Pawankar
Ruby
R
Ichimiya
Issei
I
Yagi
Toshiaki
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002417:Cattle; D002478:Cells, Cultured; D003001:Cloning, Molecular; D016207:Cytokines / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry; D004195:Disease Models, Animal; D016326:Extracellular Matrix Proteins; D005260:Female; D006168:Guinea Pigs / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000378:metabolism; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D055493:Spiral Ligament of Cochlea / Q000166:cytology / Q000378:metabolism*
C110668:COCH protein, human; D016207:Cytokines; D018076:DNA, Complementary; D016326:Extracellular Matrix Proteins; D020033:Protein Isoforms; D011506:Proteins; D012333:RNA, Messenger