Zhou J, Adesanya O O, Vatzias G, Hammond J M, Bondy C A
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
Endocrinology. 1996 Nov;137(11):4893-901. doi: 10.1210/endo.137.11.8895362.
In situ hybridization was used to map anatomical patterns of insulin-like growth factor (IGF) system gene expression in the gilt ovary through the estrous cycle. IGF-I, IGF-II< and IGF-I receptor messenger RNAs (mRNAs) were coexpressed in granulosa cells of developing and dominant follicles through the follicular phase. IGF-I and IGF-I receptor mRNAs were selectively concentrated in healthy follicles, whereas IGF-II mRNA was found in all follicles regardless of incipient or overt atresia. IGF-binding protein-1 (IGFBP-1) was not detected in the gilt ovary at any stage. IGFBP-2 mRNA was most abundant in granulosa cells of small follicles and in the ovarian vasculature regardless of cycle stage. IGFBP-2 mRNA persisted in granulosa cells of preovulatory follicles and corpora lutea. IGFBP-3 mRNA was not detected in developing follicles, but was detected in all luteal phase corpora lutea, apparently expressed by theca lutein cells. IGFBP-4 demonstrated a highly dynamic pattern of gene expression, closely tracking LH receptor gene expression throughout the follicular and luteal phases of the estrous cycle. IGFBP-4 mRNA was concentrated in the theca of medium to large growing follicles, but was not detected in granulosa cells until the emergence of dominant follicles in the late follicular stage, when the granulosa cells showed morphological evidence of luteinization as well as LH receptor gene expression. IGFBP-4 mRNA expression continued in granulosa cells of corpora lutea during the luteal phase and was not detected in atretic follicles. IGFBP-5 mRNA was concentrated in the surface or germinal epithelium and in capillary endothelium, particularly in capillaries of corpora lutea. In summary, there is selective expression of IGF-I, IGF-I receptor, and IGFBP-2 and -4 mRNAs during the process of follicular selection in the gilt ovary, with IGFBP-4 expression being closely associated with follicular selection and luteinization. These observations support an important role for autocrine/paracrine IGF action modulated by IGFBP-2 and -4 in both follicular growth and differentiation in the porcine ovary.
采用原位杂交技术，通过发情周期绘制了后备母猪卵巢中胰岛素样生长因子（IGF）系统基因表达的解剖学模式。在卵泡期，IGF-I、IGF-II和IGF-I受体信使核糖核酸（mRNA）在发育中的卵泡和优势卵泡的颗粒细胞中共同表达。IGF-I和IGF-I受体mRNA选择性地集中在健康卵泡中，而IGF-II mRNA在所有卵泡中均有发现，无论卵泡是初期闭锁还是明显闭锁。在任何阶段的后备母猪卵巢中均未检测到IGF结合蛋白-1（IGFBP-1）。无论处于何种周期阶段，IGFBP-2 mRNA在小卵泡的颗粒细胞和卵巢脉管系统中最为丰富。IGFBP-2 mRNA在排卵前卵泡和黄体的颗粒细胞中持续存在。在发育中的卵泡中未检测到IGFBP-3 mRNA，但在所有黄体期的黄体中均检测到，显然是由黄体膜细胞表达的。IGFBP-4表现出高度动态的基因表达模式，在发情周期的卵泡期和黄体期，其表达与促黄体生成素（LH）受体基因表达密切相关。IGFBP-4 mRNA集中在中到大的生长卵泡的卵泡膜中，但在卵泡晚期优势卵泡出现之前，颗粒细胞中未检测到，此时颗粒细胞显示出黄体化的形态学证据以及LH受体基因表达。在黄体期，黄体颗粒细胞中持续存在IGFBP-4 mRNA表达，而在闭锁卵泡中未检测到。IGFBP-5 mRNA集中在表面或生发上皮以及毛细血管内皮中，尤其是在黄体的毛细血管中。总之，在后备母猪卵巢卵泡选择过程中，IGF-I、IGF-I受体以及IGFBP-2和-4 mRNA存在选择性表达，其中IGFBP-4表达与卵泡选择和黄体化密切相关。这些观察结果支持了由IGFBP-2和-4调节的自分泌/旁分泌IGF作用在猪卵巢卵泡生长和分化中起重要作用。
