Transcription factor pit-1 expression is modulated upon seasonal acclimatization of eurythermal ectotherms: identification of two pit-1 genes in the carp.
A second Pit-1 gene in carp (Cyprinus carpio), including the complete structural gene and 1.1 kb of promoter region, was identified and completely sequenced. The exon-intron structure was determined, and reverse transcription-polymerase chain reaction (RT-PCR) experiments suggest that only one Pit-1 splice variant is present in carp pituitary. The effect of seasonal acclimatization on the extent of Pit-1 gene expression was studied in summer- and winter-acclimatized carp. Quantitative RT-PCR analysis revealed a clear increase of Pit-1 mRNA in the pituitaries from summer-acclimatized carp compared with the winter-adapted fish. In situ hybridization of pituitary gland sections with riboprobes representing the complete 5'-transactivating region of carp Pit-1 depicted a significantly higher Pit-1 mRNA level in the rostral pars distalis of the summer-acclimatized fish where prolactin is expressed in a manner that resembles the seasonal increase observed in the proximal pars distalis and the pars intermedia. The cell- and temporal-specific transcription of Pit-1 supports its role in the molecular mechanisms that underly the acclimatization process undergone by eurythermal fish as a result of the physical effects of seasonal changes on their habitat.
Kausel
G
G
Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
Vera
M I
MI
San Martin
R
R
Figueroa
J
J
Molina
A
A
Muller
M
M
Martial
J
J
Krauskopf
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002347:Carps / Q000235:genetics* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics*; D020440:Gene Duplication; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics; D017403:In Situ Hybridization; D008297:Male; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012621:Seasons; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D050817:Transcription Factor Pit-1; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D050817:Transcription Factor Pit-1; D014157:Transcription Factors