During development, the @entity2135 ( @entity2135 ) gene is expressed in a tissue specific manner; however, the molecular mechanisms governing its developmental regulation remain poorly defined. To examine the hypothesis that expression of the @entity14023 accounts, in part, for the tissue specific expression of the @entity2135 gene during development, the developmental regulation of @entity2135 and @entity14023 gene expression in @entity35 tissues was examined. The level of @entity2135 and @entity14023 mRNA was quantified in RNA prepared from @entity35 between day 17 of gestation (E17) and 17 months of age (17M) using an RNase protection assay. Developmental regulation of @entity2135 gene expression was tissue specific with four different patterns of expression seen. In liver, @entity2135 mRNA levels increased markedly between E17 and postnatal day 45 (P45) and declined thereafter. In contrast, in brain, skeletal muscle and testis, @entity2135 mRNA levels decreased between P5 and 4M but were relatively unchanged thereafter. In heart and kidney, a small increase in @entity2135 mRNA levels was observed between the early postnatal period and 4 months, whereas in lung, minimal changes were observed during development. The changes in @entity14023 mRNA levels were, in general, coordinate with the changes in @entity2135 mRNA levels, except in skeletal muscle. Interestingly, quantification of @entity14023 levels by Western blot analysis in skeletal muscle demonstrated changes coordinate with @entity2135 mRNA levels. The levels of the proteins which mediate @entity14023 signaling ( @entity69860 , and @entity13720 ) were quantified by Western blot analysis. These proteins also are expressed in a tissue specific manner during development. In some cases, the pattern of expression was coordinate with @entity2135 gene expression, whereas in others it was discordant. To further define molecular mechanisms for the developmental regulation of @entity2135 gene expression, protein binding to IGFI-FP1, a protein binding site that is in the major promoter of the @entity35 @entity2135 gene and is important for basal promoter activity in vitro, was examined. Gel shift analyses using a 34-base pair oligonucleotide that contained IGFI-FP1 did not demonstrate changes in protein binding that paralleled those in @entity2135 gene expression, suggesting that protein binding to IGFI-FP1 does not contribute to the developmental regulation of @entity2135 gene expression, at least in brain and liver. In summary, the present studies demonstrate coordinate expression of the @entity2135 gene and @entity14023 during development and suggest that @entity14023 expression contributes to the tissue specific expression of the @entity2135 gene during development.

Developmental regulation of insulin-like growth factor-I and XXXX gene expression.

@entity69860 :: ('25124;25125;24918', 'Gene') :: ['STAT1, -3, and -5'] @entity2135 :: ('24482(Tax:10116)', 'Gene') :: ['insulin-like growth factor I', 'IGF-I'] @entity13720 :: ('24514(Tax:10116)', 'Gene') :: ['JAK2'] @entity35 :: ('10116', 'Species') :: ['rat', 'rats'] @entity14023 :: ('25235(Tax:10116)', 'Gene') :: ['GH receptor', 'growth hormone (GH) receptor']
@entity14023 :: (25235(Tax:10116),Gene) :: ['growth hormone receptor']
