Fig. 2.

Hormonal control of LHR mRNA expression in the ovary. A. Northern blot hybridization analysis of steady state LHR mRNA levels during hCG-induced downregulation. Autoradiogram of Northern blot hybridization analysis of total RNA isolated at the indicated times from the ovaries of saline-injected (control) (lanes 1-6) or hCG-injected (downregulated) (lanes 7-11) rats. Blots were probed using a labelled cDNA encoding the LHR carboxyl terminus and a portion of the 3’-UTR (nucleotides 1936-2682). B. LHR mRNA half-life determination in control and 12 h downregulated rat ovaries. Cell suspensions were incubated with 10 µg/ml actinomycin D for 2h. Duplicate aliquots of 20 × 10⁶ cells were removed at the indicated times. Total RNA was isolated and assayed for LHR mRNA by solution hybridization. Each data point represents the average of duplicate determinations. ▀ Contol, ▲ downregulated. (Source: Ref. 17, Reproduced with permission).