scholarly journals Estrogen Receptor α Gene Promoter 0/B Usage in the Rat Sexually Dimorphic Nucleus of the Preoptic Area

Endocrinology ◽  
2010 ◽  
Vol 151 (4) ◽  
pp. 1923-1928 ◽  
Author(s):  
Tomohiro Hamada ◽  
Yasuo Sakuma

The volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) is two to four times larger in male rats than in females; however, the mechanism for the establishment of sexual dimorphism and the function of this nucleus is almost unknown. Perinatal estrogen can cause sexual dimorphism via the estrogen receptor α (ERα). Recently, transgenic rats were generated that express enhanced green fluorescent protein (EGFP) under the control of the ERα gene promoter 0/B to tag ERα-positive neurons in the brain. In the present study, we examined whether this EGFP expression could be a marker for the SDN-POA in adults. EGFP-labeled cells were distributed in the core of the SDN-POA (0/B-SDN) of male and female transgenic rats, in accordance with the Nissl staining and immunoreactivity for the SDN marker, calbindin. They were also immunoreactive for ERα. The core was bigger in volume and contained more 0/B-SDN neurons in males than in females. The EGFP-tagged cells were packed more densely in the female core than that in males. Subcutaneous injection of 100 μg 17β-estradiol to females on the day of birth, or orchidectomy of male neonates, reversed the sexually dimorphic phenotype of the volume of the 0/B-SDN, despite not affecting the cell number. We suggest that this EGFP expression in the SDN-POA could be a useful marker to clarify the sexual differentiation and function of the SDN-POA. Moreover, the ERα gene promoter 0/B plays a key role in the organization of the sexual differentiation of the SDN-POA.

Endocrinology ◽  
2010 ◽  
Vol 151 (5) ◽  
pp. 2297-2305 ◽  
Author(s):  
Joseph R. Kurian ◽  
Kristin M. Olesen ◽  
Anthony P. Auger

Sex differences in the brain are largely organized by a testicular hormone surge that occurs in males shortly after birth. Although this hormone surge is transient, sex differences in brain and behavior are lasting. Here we describe a sex difference in DNA methylation of the estrogen receptor-α (ERα) promoter region within the developing rat preoptic area, with males exhibiting more DNA methylation within the ERα promoter than females. More importantly, we report that simulating maternal grooming, a form of maternal interaction that is sexually dimorphic with males experiencing more than females during the neonatal period, effectively masculinizes female ERα promoter methylation and gene expression. This suggests natural variations in maternal care that are directed differentially at males vs. females can influence sex differences in the brain by creating sexually dimorphic DNA methylation patterns. We also find that the early estradiol exposure may contribute to sex differences in DNA methylation patterns. This suggests that early social interaction and estradiol exposure may converge at the genome to organize lasting sex differences in the brain via epigenetic differentiation.


2004 ◽  
Vol 26 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Shaw-Lang Yang ◽  
Yu-Yang Chen ◽  
Ya-Lun Hsieh ◽  
Su-Hwa Jin ◽  
Hseng-Kuang Hsu ◽  
...  

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