Siew S, Gill T J, Kunz H W
Am J Pathol. 1986 May;123(2):318-33.
The morphologic features of the testicular defect in the rat caused by the genes of the growth and reproduction complex (grc), which are linked to the major histocompatibility complex (MHC), were examined by transmission and scanning electron microscopy in animals homozygous for grc (grc/grc), heterozygous for grc (grc/+), and normal (+/+). The testes of the grc homozygotes were small, and their tubular epithelium showed a loss of the normal organization. There were no sperm because the spermatogonia developed only to the pachytene stage of the primary spermatocyte; there was cellular degeneration and necrosis; and the basal lamina showed reduplication and invagination into the tubule. The number of the Sertoli cells was increased, their nuclei were displaced into the adluminal layers of the tubular epithelium, and their cytoplasm extended into the lumens. There was an increase in interstitial fibrous tissue, and the blood vessels deep in the parenchyma had thickened walls. In the heterozygotes, there was some architectural disorganization of the tubular epithelium and a greater number of tubules with a low concentration of sperm tails. Some of the intermediate spermatogonia were not attached to the basal lamina, and there was an increase in developmental abnormalities and abnormal sperm. The number of Sertoli cells was increased, and their nuclei extended into the second and third layers of the tubular epithelium. The homozygous wild type animals showed normal testicular development and normal spermatogenesis. This is the first description of a developmental defect in the rat that is under the control of a well-defined genetic system. It also is the first evidence for the morphologic expression of a heterozygous recessive gene in an animal that is phenotypically normal.
通过透射电子显微镜和扫描电子显微镜，对与主要组织相容性复合体（MHC）相关的生长和生殖复合体（grc）基因导致的大鼠睾丸缺陷的形态学特征进行了检查，研究对象包括grc基因纯合子（grc/grc）、杂合子（grc/+）和正常（+/+）的动物。grc纯合子的睾丸较小，其管状上皮显示正常组织结构丧失。由于精原细胞仅发育到初级精母细胞的粗线期，所以没有精子；存在细胞变性和坏死；基膜显示重复并向小管内陷。支持细胞数量增加，其细胞核移位到管状上皮的近腔层，细胞质延伸到管腔。间质纤维组织增加，实质深处的血管壁增厚。在杂合子中，管状上皮存在一些结构紊乱，且有更多小管中精子尾部浓度较低。一些中间型精原细胞未附着于基膜，发育异常和异常精子数量增加。支持细胞数量增加，其细胞核延伸到管状上皮的第二层和第三层。纯合野生型动物显示睾丸发育正常和精子发生正常。这是首次描述受明确遗传系统控制的大鼠发育缺陷。这也是杂合隐性基因在表型正常动物中形态学表达的首个证据。
