Prince Henry's Institute of Medical Research, Clayton, Victoria, Australia.
Biol Reprod. 2010 Jan;82(1):153-62. doi: 10.1095/biolreprod.109.078766. Epub 2009 Aug 19.
Betaglycan (Tgfbr3) is a coreceptor for transforming growth factor-beta (TGFB) superfamily ligands. In the current study, a defect in seminiferous cord formation was detected in 12.5-13.5 days postcoitum (dpc) beta glycan null murine testis. Immunohistochemistry with antibodies against cell-specific markers revealed defects in somatic cell populations. To confirm these data, quantitative real-time PCR was performed to determine changes in the expression levels of genes involved in fetal testis cell differentiation and function. The expression levels of the Leydig cell markers Insl3, Cyp17a1, Cyp11a1, Star, and Hsd3b1 were reduced in knockout testis compared to wild-type testis, beginning at 12.5 dpc. Whole mount in situ hybridization confirmed that Cyp11a1 expression was reduced in the null testis, but its distribution pattern was unchanged. Apoptosis was not affected by the loss of beta glycan, but proliferation within the interstitium was reduced at 14.5 dpc. However, morphometric analysis showed no changes in Leydig cell counts between the wild-type and the knockout testes at 14.5 dpc, indicating that fetal Leydig function, rather than number, was affected by the loss of beta glycan. The expression levels of Sertoli cell markers Dhh, Sox9, and Amh were also reduced in the knockout testis at 14.5 dpc. However, the expression of fetal germ cell markers Pou5f1 and DDX4 were not changed across the genotypes at any age examined. Our data show that the presence of beta glycan is required for normal cord formation, normal fetal Leydig cell development, and the establishment of fetal testis endocrine function, thus implicating TGFB superfamily members as regulators of early fetal testis structure and function.
β糖蛋白（Tgfbr3）是转化生长因子-β（TGFB）超家族配体的核心受体。在本研究中，在 12.5-13.5 天的受精后（dpc）β糖蛋白缺失的雄性小鼠睾丸中检测到精曲小管形成缺陷。用针对细胞特异性标志物的抗体进行免疫组织化学染色显示体细胞群存在缺陷。为了证实这些数据，进行了定量实时 PCR 以确定参与胎儿睾丸细胞分化和功能的基因的表达水平变化。与野生型睾丸相比，Leydig 细胞标志物 Insl3、Cyp17a1、Cyp11a1、Star 和 Hsd3b1 的表达水平在 knockout 睾丸中降低，从 12.5 dpc 开始。全胚胎原位杂交证实，Cyp11a1 在缺失睾丸中的表达降低，但分布模式不变。β糖蛋白的缺失并不影响细胞凋亡，但间质中的增殖在 14.5 dpc 时减少。然而，形态计量学分析显示，在 14.5 dpc 时，野生型和 knockout 睾丸之间的 Leydig 细胞计数没有变化，这表明胎儿 Leydig 功能而不是数量受到β糖蛋白缺失的影响。Sertoli 细胞标志物 Dhh、Sox9 和 Amh 的表达水平在 knockout 睾丸中也在 14.5 dpc 时降低。然而，在任何检查的年龄，Pou5f1 和 DDX4 的胎儿生殖细胞标志物的表达在各基因型之间均未改变。我们的数据表明，β糖蛋白的存在对于正常的索形成、正常的胎儿 Leydig 细胞发育以及胎儿睾丸内分泌功能的建立是必需的，因此表明 TGFB 超家族成员是早期胎儿睾丸结构和功能的调节剂。
