Modeling Congenital Adrenal Hyperplasia and Testing Interventions for Adrenal Insufficiency Using Donor-Specific Reprogrammed Cells

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性腺母细胞瘤的分子遗传机制研究进展

性腺母细胞瘤(Gonadoblastoma, GB)是一种由性索和生殖细胞演化而来的罕见原位性腺肿瘤,与性腺遗传物质异常有密切联系。80%的GB患者表现为46,XY女性表型,其余为45,XY 和46,XX性别发育异常患者等。35%的GB会进一步演化为无性细胞瘤和精原细胞瘤等恶性肿瘤。由于表型与遗传的异质性,GB的分子遗传机制还未完全揭示。越来越多的研究显示GB的发生与性别分化和决定调控基因(如SRY、WT1、SOX9、Foxl2和TSPY等)之间存在密切关联,且表现出遗传与表观遗传调控相互作用。本文综述了GB的临床表现、病理特征、诊断与治疗措施,总结了性腺遗传异常导致GB的分子遗传与表观遗传调控机制,分析并归纳参与GB形成相关基因的共同表达调控网络,指出了当前研究中的障碍与不足,为进一步研究GB致病分子机制提供新思路。     

Sex-chromosome differentiation and ‘sex races’ in the common frog (Rana temporaria)

Sex-chromosome differentiation was recently shown to vary among common frog populations in Fennoscandia, suggesting a trend of increased differentiation with latitude. By rearing families from two contrasted populations (respectively, from northern and southern Sweden), we show this disparity to stem from differences in sex-determination mechanisms rather than in XY-recombination patterns. Offspring from the northern population display equal sex ratios at metamorphosis, with phenotypic sexes that correlate strongly with paternal LG₂ haplotypes (the sex chromosome); accordingly, Y haplotypes are markedly differentiated, with male-specific alleles and depressed diversity testifying to their smaller effective population size. In the southern population, by contrast, a majority of juveniles present ovaries at metamorphosis; only later in development do sex ratios return to equilibrium. Even at these later stages, phenotypic sexes correlate only mildly with paternal LG₂ haplotypes; accordingly, there are no recognizable Y haplotypes. These distinct patterns of gonadal development fit the concept of ‘sex races’ proposed in the 1930s, with our two populations assigned to the ‘differentiated’ and ‘semi-differentiated’ races, respectively. Our results support the suggestion that ‘sex races’ differ in the genetic versus epigenetic components of sex determination. Analysing populations from the ‘undifferentiated race’ with high-density genetic maps should help to further test this hypothesis.     

A histological description of gonadal development and sex differentiation in the coho salmon (Oncorhynchus kisutch) for both untreated and oestradiol immersed fry

Gonadal development is described in detail for coho salmon ( Oncorhynchus kisutch ) between hatching and 1000 degree-days, post-hatch, to aid sex reversal research. Germ cell morphology and sequence, vascular and reproductive duct development, and gross characteristics of the gonads are presented. Sex differentiation occurs by 380 degree-days, post-hatch (800 degree-days, post-fertilization) and is direct to male and female. Oocytes proliferate rapidly after differentiation while the testes enter a period of quiescence. Fry immersed for short durations in oestradiol (200 μg ⁻¹) are also examined. Hormone immersion advanced sex differentiation by 70 degree-days. The immersions were applied early, at 20 and 90 degree-days, post-hatch, yet still altered the sex ratio and timing of differentiation. Definitive germ cells, which are abundant during this period, may be the type most receptive to steroid treatment.     

Expression of steroidogenic factors 1 and 2 in normal human pancreas

Orphan nuclear receptor steroidogenic factor-1 (SF-1) is crucial for development and function of steroidogenic organs. The steroidogenic factor-2 (SF-2) is an essential factor involved in cholesterol transfer and activation of promoters of steroidogenic enzymes CYP11A1, CYP17 and Steroidogenic Acute Regulatory Protein (StAR). We have previously demonstrated steroidogenic activity in pancreatic tissue. The aim of this study was to investigate the presence of SF-1 and SF-2 in human pancreas. Total RNA was extracted from normal male (five) and female (five) samples, obtained from the organs donor program. RT-PCR approach was used to analyze the expression of SF-1 and SF-2. Immunohistochemical analysis was performed for SF-1. The bands of expression were present in both male and female samples, although differential expression was observed. For both factors, the signal detected was more evident in males than in females. A similar pattern was present in the immunohistochemical study. Normal human pancreas expresses SF-1 and SF-2 factors similarly to ovary and adrenals. A distinctive characteristic is the sexually dimorphic expression of these factors. Our data provide evidence suggesting that the pancreas achieves steroidogenic activity supporting the presence of gender- and location-related differences in the expression of these steroidogenic factors.     

哺乳动物性别决定的研究进展

近年来,人们对与哺乳动物性别决定相关的SRY、SOX9、SF-1、WT1和DAX-1基因的结构、功能和产物之间的相互作用进行了一系列的研究,使人们对哺乳动物的性别决定分子机制的探索又向前推进了一步,这将对发育生物学和性别决定的进化研究起到推动作用。     

利用cut&tag技术探究LHX9基因在颗粒细胞的调控机制

摘要 目的：在人卵巢颗粒细胞癌细胞株KGN中探索转录因子LHX9下游主要的靶基因及其调控。方法：首先我们采用实时荧光定量PCR观察KGN细胞在卵泡刺激素（FSH）干预前后性腺分化和性激素合成过程中重要基因的表达情况,同时我们利用cut&tag测序技术在两组细胞中识别LHX9下游靶基因,并采用双荧光素酶报告实验对重要靶基因NR5A1的调控进行了验证。结果：实时荧光定量PCR结果显示,通过加FSH处理12小时后,LHX9和NR5A1基因的mRNA水平表达降低,相反的,StAR和CYP19A1基因的mRNA水平表达增高;通过cut&tag测序技术和生物信息学分析,我们发现LHX9下游基因主要分布在内吞作用、细胞衰老、肿瘤相关通路、细胞周期、凋亡、卵母细胞减数分裂、雌激素信号转导等通路上。LHX9可以转录调控性腺分化以及类固醇激素合成的一些重要基因,其中包括NR5A1和SOX9等,荧光素酶报告基因证实了LHX9可以直接结合NR5A1基因的启动子区。结论：本研究利用cut&tag测序技术,发现转录因子LHX9对性腺分化和性激素合成的关键基因有转录调控作用,对深入理解LHX9基因对生殖系统的作用具有重要意义。