scholarly journals Expression and Characterization of the Extracellular Ca2+-Sensing Receptor in Melanotrope Cells of Xenopus laevis

Endocrinology ◽  
2003 ◽  
Vol 144 (6) ◽  
pp. 2524-2533 ◽  
Author(s):  
M. J. J. van den Hurk ◽  
D. T. W. M. Ouwens ◽  
W. J. J. M. Scheenen ◽  
V. Limburg ◽  
H. Gellekink ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Pituitary Gland ◽  
South African ◽  
Intermediate Lobe ◽  
Rt Pcr ◽  
G Protein Coupled ◽  
Ca2 Channels ◽  
Intermediate Pituitary Lobe

Abstract The extracellular Ca2+-sensing receptor (CaR) is expressed in many different organs in various species, ranging from mammals to fish. In some of these organs, this G protein-coupled receptor is involved in the control of systemic Ca2+ homeostasis, whereas in other organs its role is unclear (e.g. in the pituitary gland). We have characterized the CaR in the neuroendocrine melanotrope cell of the intermediate pituitary lobe of the South African clawed toad Xenopus laevis. First, the presence of CaR mRNA was demonstrated by RT-PCR and in situ hybridization. Then it was shown that activation of the CaR by an elevated extracellular Ca2+ concentration and different CaR-activators, including l-phenylalanine and spermine, stimulates both Ca2+ oscillations and secretion from the melanotrope. Furthermore, it was revealed that activation of the receptor stimulates Ca2+ oscillations through opening of voltage-operated Ca2+ channels in the plasma membrane of the melanotropes. Finally, it was shown that the CaR activator l-phenylalanine could induce the biosynthesis of proopiomelanocortin in the intermediate lobe. Thus, in this study it is demonstrated that the CaR is present and functional in a defined cell type of the pituitary gland, the amphibian melanotrope cell.

scholarly journals The identification and characterization of a testis-specific cDNA during spermatogenesis

2006 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Chen ◽  
Jiarui Hu ◽  
Ping Song ◽  
Wuming Gong
Keyword(s):  
Experimental Validation ◽  
Rna Binding ◽  
Pcr Analysis ◽  
Splicing Factors ◽  
Rt Pcr ◽  
Rich Domain ◽  
Pachytene Spermatocytes ◽  
Identification And Characterization

AbstractUsing bioinformatics and experimental validation, we obtained a cDNA (named srsf) which was exclusively expressed in the mouse testes. RT-PCR analysis showed that srsf mRNA was not expressed in the gonad during the sex determination period or during embryogenesis. In developing mouse tests, srsf expression was first detected on post-natal day 10, reached its highest level on day 23, and then reduced to and remained at a moderate level throughout adulthood. In situ hybridization analysis demonstrated that srsf mRNA was expressed in pachytene spermatocytes and round spermatids in the testes. The predicted protein contains one RNA-binding domain (RBD) and a serine-arginine rich domain (RS), which are characterized by some splicing factors of SR family members. These findings indicate that srsf may play a role during spermatogenesis.

296. Characterization of E74 like factor 3 in the murine pre-implantation embryo

2005 ◽  
Vol 17 (9) ◽  
pp. 125
Author(s):  
E. B. Little ◽  
J. L. Stanton ◽  
D. P. L. Green
Keyword(s):  
In Situ Hybridisation ◽  
Specific Gene ◽  
Hydrophobic Core ◽  
Rt Pcr ◽  
Core Motif ◽  
Cell Embryo ◽  
Ets Family ◽  
Ets Factors

The E26 transformation specific (ETS) family of transcription factors is defined by a highly conserved DNA binding domain containing a hydrophobic core motif 5′-GGA[A/T]-3′. A subfamily of ETS factors, epithelium-specific ETS factor (ESE), includes E74-like factor 3 (Elf3). Elf3 is expressed in many organs including the eye, skin and gastrointestinal tract. By upregulating specific gene transcription, Elf3 is instrumental in causing these organs to become fully differentiated. The presence of Elf3 in the pre-implantation embryo was first reported in 2002.1 Data mining has suggested that the expression of Elf3 increases at the 16-cell embryo and blastocyst stages of pre-implantation development compared to the preceding stages. Reverse transcriptase–polymerase chain reaction (RT-PCR) was used to amplify the 3′ untranslated region (3′UTR) of Elf3. These results suggest that there are two isoforms of Elf3 present in the pre-implantation embryo, which differ by an 88 bp deletion/insertion. The expression and location of these isoforms was investigated using RT-PCR and in-situ hybridisation. (1)Stanton and Green (2002) Mol. Hum. Rep. 8, 149–166.

Effects of TRH, prolactin and TSH on cell proliferation in the intermediate lobe of the rat pituitary gland

1996 ◽  
Vol 148 (2) ◽  
pp. 193-196 ◽  
Author(s):  
T Pawełczyk ◽  
M Pawlikowski ◽  
J Kunert-Radek
Keyword(s):  
Cell Proliferation ◽  
Body Weight ◽  
Pituitary Gland ◽  
Anterior Lobe ◽  
Intermediate Lobe ◽  
Proliferating Cells ◽  
Rat Pituitary ◽  
Trh Analogues ◽  
Intermediate Pituitary Lobe ◽  
Significant Stimulatory Effect

Abstract The effect of TRH on cell proliferation in the anterior lobe of the pituitary is well known and documented. On the other hand, there are no data on the effects of TRH on the intermediate lobe of the pituitary gland. The aim of this study was to investigate the effect of TRH and its analogues (pGlu-His-Gly, pGlu-His-Gly-NH2) on cell proliferation in the intermediate pituitary lobe. The bromodeoxyuridine technique was used to detect the proliferating cells. It was found that TRH stimulated cell proliferation 24 h after a single injection at a dose of 100 μg/kg body weight. The TRH analogues did not exert any significant stimulatory effect either 12 h or 24 h after the injection. The second experiment was carried out to distinguish the probable mechanism of the action of TRH. The effects of TSH and prolactin (PRL) on intermediate lobe cell proliferation were examined. It was found that both PRL and TSH exerted a significant stimulatory effect 24 h after a single s.c. injection of PRL at a dose of 150 IU/kg body weight or TSH at a dose 20 IU/kg body weight. It therefore appears that the stimulatory effect of TRH on intermediate pituitary lobe cell proliferation is mediated by PRL and TSH. Journal of Endocrinology (1996) 148, 193–196

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