High impact information on TSHB

• Methionine 32 in TSH-beta can be modified with retention of full activity under conditions where methionines 8, 9, and 58 are not modified [1].
• As thyroid hormone levels were preceded by maximal TSHbeta mRNA levels on e-19, we next determined whether TSHbeta gene expression on e-19 was under TRH and T3 regulation [2].
• The objective of this study was to characterize expression of chicken TSHbeta messenger RNA (mRNA) compared with that of thyroid hormones and GH in embryonic and neonatal chickens [2].
• We have concluded that the sensitivity of the pituitary thyrotropes to hypothalamic stimulation decreases throughout the last week of embryonic development, so that the higher expression of TSH-beta mRNA around E16-E19, and hence the increasing plasma thyroxine level, is unlikely to be the result of an increased stimulation by either TRH or CRH [3].
• Development of thyroid-stimulating hormone beta subunit-producing cells in the chicken embryonic pituitary gland [4].

Biological context of TSHB

• The amino acid sequence of chicken TSH beta subunit is highly conserved (98.5%) between chicken and Japanese quail, whereas it has a low homology between chicken and mammals (67-69%), an amphibian (58%) and fish (40-49%) [5].

Anatomical context of TSHB

• The cells that synthesize thyroid-stimulating hormone (TSH) in the pars distalis of the chick embryo were identified immunocytochemically (immunoperoxidase and immunofluorescence) using anti-bovine TSH-beta and anti-human TSH-beta sera [6].

Associations of TSHB with chemical compounds

• In experiment 2, our objective was to determine if thyroid inhibition would result in a detectable change in TSHbeta mRNA and alterations in the pituitary luteinizing hormone (LH) or indices of gonadal function [7].

Regulatory relationships of TSHB

• RT-PCR also showed that TSHbeta mRNA was expressed from E9 and that Pit-1 mRNA was expressed from E5 [4].

Other interactions of TSHB

• Therefore, a semiquantitative RT-PCR method was used to detect possible changes in GH and TSHbeta mRNA levels [8].
• TRH affected both the GH and TSHbeta mRNA levels [8].
• Consistent with cellular ontogeny, TSHbeta mRNA increased steadily between e10 and e17, GH mRNA increased between e12 and e17, and PRL mRNA did not increase until e17 [9].

Analytical, diagnostic and therapeutic context of TSHB

• In situ hybridization analysis revealed that TSHbeta mRNA-expressing cells were expressed from E9 in the cephalic lobe and that the extent of TSHbeta mRNA-expressing cells coincided with that of TSHbeta-ip cells [4].
• In this study, we examined the distribution of thyroid-stimulating hormone beta subunit-immunopositive (TSHbeta-ip) cells and the expression of TSHbeta mRNA in the pituitary glands of chicken embryos by immunohistochemistry using a specific antiserum to the chicken TSHbeta, in situ hybridization and RT-PCR [4].
• The transcribed riboprobe was shown to be pituitary gland specific, and differences in TSHbeta mRNA levels were detectable with 2.5 microg of total RNA in Northern blot analysis [7].

References