Department of Animal Science, Center for Reproductive Biology and Health (CRBH), College of Agricultural Sciences, The Pennsylvania State University, University Park, PA, USA.
PLoS One. 2013;8(4):e60611. doi: 10.1371/journal.pone.0060611. Epub 2013 Apr 2.
PRAME belongs to a group of cancer/testis antigens (CTAs) that are characterized by their restricted expression in normal gametogenic tissues and a variety of tumors. The PRAME family is one of the most amplified gene families in the mouse and other mammalian genomes. Members of the PRAME gene family encode leucine-rich repeat (LRR) proteins functioning as transcription regulators in cancer cells. However, the role of PRAME in normal gonads is unknown. The objective of this study is to characterize the temporal and spatial expression of the mouse Pramel1 gene, and to determine the cellular localization of the PRAMEL1 protein during the mouse spermatogenesis. Our results indicated that the mouse Pramel1 was expressed in testis only. The mRNA and protein expression level was low in the newborn testes, and gradually increased from 1- to 3-week-old testes, and then remained constant after three weeks of age. Immunofluorescent staining on testis sections with the mouse PRAMEL1 antibody revealed that PRAMEL1 was localized in the cytoplasm of spermatocytes and the acrosomal region of round, elongating and elongated spermatids. Further analyses on the testis squash preparation and spermatozoa at a subcellular level indicated that the protein localization patterns of PRAMEL1 were coordinated with morphological alterations during acrosome formation in spermatids, and were significantly different in connecting piece, middle piece and principal piece of the flagellum between testicular and epididymal spermatozoa. Collectively, our results suggest that PRAMEL1 may play a role in acrosome biogenesis and sperm motility.
PRAME 属于一组癌症/睾丸抗原 (CTA)，其特征是在正常配子组织和多种肿瘤中表达受限。PRAME 家族是小鼠和其他哺乳动物基因组中扩增最多的基因家族之一。PRAME 基因家族的成员编码富含亮氨酸重复 (LRR) 蛋白，在癌细胞中作为转录调节剂发挥作用。然而，PRAME 在正常性腺中的作用尚不清楚。本研究的目的是表征小鼠 Pramel1 基因的时空表达，并确定 PRAMEL1 蛋白在小鼠精子发生过程中的细胞定位。我们的结果表明，小鼠 Pramel1 仅在睾丸中表达。新生睾丸中的 mRNA 和蛋白表达水平较低，从 1 至 3 周龄睾丸逐渐增加，3 周龄后保持不变。用小鼠 PRAMEL1 抗体对睾丸切片进行免疫荧光染色显示，PRAMEL1 定位于精母细胞的细胞质和圆形、伸长和伸长精子的顶体区域。在睾丸压片和精子亚细胞水平上的进一步分析表明，PRAMEL1 的蛋白定位模式与精子中顶体形成过程中的形态变化相协调，在睾丸和附睾精子的连接段、中段和主段之间存在显著差异。总之，我们的结果表明 PRAMEL1 可能在顶体生物发生和精子运动中发挥作用。
