ABSTRACT
Objective To is ol ate novel thyroid hormone-response genes, to study the characterizations of the ir expressions and to predict their possible functions in neonatal rats. Methods A neonatal rat model with congenital hypothyr oidism was established and cDNA fragments of novel thyroid hormone-response gen es from cerebral cortex of neonatal rats were obtained by fluorescence-labeled DD-PCR analysis, subcloning and sequencing. Complete cDNAs of novel thyroid hor mone-response genes were cloned by the techniques of electronic clone, RT-PCR and sequencing, their expressions regulated by thyroid hormone were confirmed b y Northern blot analysis, their distributions, transcription levels in different tissues and different brain areas were further observed by semiquantitative RT -PCR analysis, and their possible functions were postulated through bioinformat ic techniques. Results A novel complete cDNA of thyroid hormone-response protein-1 (TRP-1) gene is cloned. It is 973 bp in f ull-length (Gene Bank accession no. AF348365), and its transcription was enhanc ed in cerebral cortex in neonatal hypothyroidism rats. The expression of its mRN A was very extensive, but more abundant in brain. Its transcriptional level in d ifferent brain areas was not uniform, much higher in olfactory bulb. Its encodin g protein had some significant domains and motifs. Conclusion TRP-1 gene is a new thyroid hormone-response gene and may play an important role during normal brain development. Its abnormal expression may b e partially responsible for neurological defects in brain arising from thyroid h ormone deficiency during critical period for perinatal rats.