HORMONE CONTROL OF SPERMATOGONIAL ARREST IN MUTANT MICE

突变小鼠精原细胞停滞的激素控制

• 批准号: 6707997
• 负责人: Marvin L. Meistrich
• 金额: $ 27万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6707997
• 关键词: Leydig cells; Sertoli cells; androgen inhibitor; androgen receptor; cell differentiation; developmental genetics; estradiol; estrogen receptors; follicle stimulating hormone; gene expression; gene mutation; gonadotropin releasing factor; hormone regulation /control mechanism; laboratory mouse; messenger RNA; microarray technology; mutant; recombinase; sperm; spermatogenesis; testis; testosterone; tissue /cell culture; vascular smooth muscle

Juvenile spermatogonial depletion (jsd) mice initiate a wave of spermatogenesis at puberty, but then sperm differentiation ceases despite the continued presence of A spermatogonia. Although the mechanism is not known, we showed that testosterone (T) inhibits spermatogonial differentiation, which can be restored with GnRH antagonist or estradiol (E2). We hypothesize that inhibition of spermatogonial differentiation in jsd mice is due to the action of T on gene expression in a specific somatic cell (Sertoli, Leydig, peritubular myoid, or arteriolar smooth muscle). We utilize the power of mouse genetics to elucidate the mechanism by which T mediates spermatogonial "arrest" in jsd mice and begin identifying the cell type and hormonally regulated gene(s) involved in the following Aims: (I) To establish the specific role of androgen and not FSH, we will complete studies using jsd mice also carrying mutations in the androgen receptor (AR) and FSHbeta genes. To determine the mode and the site of action of E2, the restoration of spermatogenesis with GnRH-antagonist and E2 treatment will be compared in jsd mice with that in jsd mice carrying mutations for estrogen receptor (ER)-alpha or for ERbeta. (II) To establish that the hormones affect spermatogonial differentiation by direct action on the testis and/or seminiferous tubules, we will examine their effects on spermatogonia in in vitro cultures of testicular tissue and tubules from jsd mice. (III) To identify the cell that is the target for hormonal inhibition of spermatogonial differentiation, we will transplant tubules between jsd mice and AR-deficient jsd mice and use cell-type specific elimination of an AR gene with loxP sites using Cre-recombinase driven by promoters specific for the different somatic cells. (IV) To identify the responsible gene, we will differentially screen for candidate hormone-regulated genes in the target cell of jsd mice using microarrays. A good candidate gene must have its level changed by GnRH antagonist in one direction and by T in the opposite direction. Elucidation of the mechanism of this spermatogonial "arrest" and its reversal in the jsd mouse could apply to cases of genetically determined male infertility. Because of its remarkable similarity to the failure of spermatogonial differentiation in toxicant-treated and aging rats, these results could also apply to azoospermia induced by reproductive toxicants and the decline in spermatogenesis with aging.

少年精子耗竭（JSD）小鼠在青春期引发了精子发生的一波，但尽管持续存在精子症，但随后精子分化停止了。 尽管该机制尚不清楚，但我们表明睾丸激素（T）抑制了精子分化，可以用GNRH拮抗剂或雌二醇（E2）恢复。 我们假设JSD小鼠对精子分化的抑制是由于T对特定体细胞（Sertoli，Leydig，Peritubular Myoid或小动脉平滑肌）的基因表达作用所致。 我们利用小鼠遗传学的力量来阐明T介导JSD小鼠中的精子“停止”的机制，并开始识别以下目的所涉及的细胞类型和荷尔蒙调节基因：（i）我们将使用JSD小鼠的特定研究来建立和不同意的基因，也可以携带和fsh cot and carta和FSH。 为了确定E2的模式和作用部位，将在JSD小鼠中比较用GnRH抗抗酸剂和E2处理的精子发生，而在携带雌激素受体（ER）-Alpha或ERBETA突变的JSD小鼠中，将在JSD小鼠中进行比较。 （ii）为了确定激素通过直接作用对睾丸和/或生精小管的直接作用影响精子分化，我们将研究它们对睾丸组织的体外培养物和JSD小鼠的小管的影响。 （iii）为了识别是激素抑制精子分化的靶标，我们将在JSD小鼠和缺乏AR的JSD小鼠之间移植小管，并使用loxP位点使用Cre-Recombinase驱动器驱动器驱动者对不同的sompys细胞进行特定于不同的sompys细胞的细胞型特异性消除AR基因的特异性消除。 （iv）为了识别负责任的基因，我们将使用微阵列在JSD小鼠的靶细胞中差异筛选候选激素调节的基因。 一个好的候选基因必须在一个方向上和t朝相反的方向改变其水平。阐明这种精子“停滞”机制及其在JSD小鼠中的逆转可能适用于遗传确定的男性不育症的病例。 由于其与毒物治疗和衰老大鼠精子分化的失败的显着相似性，这些结果也可能适用于生殖有毒物质引起的植物植物，以及随着衰老而导致精子发生的下降。