GLUT8 is a class 3 sugar transport facilitator which is predominantly expressed in testis and also detected in brain, heart, skeletal muscle, adipose tissue, adrenal gland, and liver. Since its physiological function in these tissues is unknown, we generated a Slc2a8 null mouse and characterized its phenotype. Slc2a8 knockout mice appeared healthy and exhibited normal growth, body weight development and glycemic control, indicating that GLUT8 does not play a significant role for maintenance of whole body glucose homeostasis. However, analysis of the offspring distribution of heterozygous mating indicated a lower number of Slc2a8 knockout offspring (30.5:47.3:22.1%, Slc2a8(+/+), Slc2a8(+/-), and Slc2a8(-/-) mice, respectively) resulting in a deviation (p=0.0024) from the expected Mendelian distribution. This difference was associated with lower ATP levels, a reduced mitochondrial membrane potential and a significant reduction of sperm motility of the Slc2a8 knockout in comparison to wild-type spermatozoa. In contrast, number and survival rate of spermatozoa were not altered. These data indicate that GLUT8 plays an important role in the energy metabolism of sperm cells.

中文翻译：

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Slc2a8 (GLUT8) 的靶向破坏降低了精子的运动性和线粒体潜能。

GLUT8 是 3 类糖转运促进剂，主要在睾丸中表达，也在脑、心脏、骨骼肌、脂肪组织、肾上腺和肝脏中检测到。由于其在这些组织中的生理功能未知，我们生成了 Slc2a8 无效小鼠并表征了其表型。Slc2a8 基因敲除小鼠看起来很健康，并表现出正常的生长、体重发展和血糖控制，表明 GLUT8 对维持全身葡萄糖稳态没有发挥重要作用。然而，杂合交配的后代分布分析表明 Slc2a8 基因敲除后代的数量较少（分别为 30.5:47.3:22.1%、Slc2a8(+/+)、Slc2a8(+/-) 和 Slc2a8(-/-) 小鼠） ) 导致与预期孟德尔分布的偏差 (p=0.0024)。与野生型精子相比，这种差异与 ATP 水平较低、线粒体膜电位降低以及 Slc2a8 敲除的精子活力显着降低有关。相比之下，精子的数量和存活率没有改变。这些数据表明GLUT8在精子细胞的能量代谢中起重要作用。