Abstract：
OBJECTIVE: This study aimed to analyze the possible role of rDNA copy number variation in the association between hexavalent chromium [Cr (VI)] exposure and semen quality in semen donors and further confirm this association in mice.
METHODS: In this cross-sectional study, whole blood and semen samples were collected from 155 semen donors in the Zhejiang Human Sperm Bank from January 1st to April 31st, 2021. Adult C57BL/6 J male mice were treated with different doses of Cr (VI) (0, 10, or 15 mg/kg b.w./day). Semen quality, including semen volume, total spermatozoa count, sperm concentration, progressive motility, and total motility, were analyzed according to the WHO laboratory manual. Cr concentration was detected using inductively coupled plasma mass spectrometry. The rDNA copy number was measured using qPCR.
RESULTS: In semen donors, whole blood Cr concentration was negatively associated with semen concentration and total sperm counts. Semen 5 S and 45 S rDNA copy numbers were negatively associated with whole blood Cr concentration and whole blood 5.8 S rDNA copy number was negatively associated with semen Cr concentration. In mice, Cr (VI) damaged testicular tissue, decreased semen quality, and caused rDNA copy number variation. Semen quality was related to the rDNA copy number in whole blood, testicular tissue, and semen samples in mice.
CONCLUSIONS: Cr (VI) was associated with decreased semen quality in semen donors and mice. Our findings suggest an in-depth analysis of the role of the rDNA copy number variation in the Cr (VI)-induced impairment of semen quality.
METHODS: In this cross-sectional study, whole blood and semen samples were collected from 155 semen donors in the Zhejiang Human Sperm Bank from January 1st to April 31st, 2021. Adult C57BL/6 J male mice were treated with different doses of Cr (VI) (0, 10, or 15 mg/kg b.w./day). Semen quality, including semen volume, total spermatozoa count, sperm concentration, progressive motility, and total motility, were analyzed according to the WHO laboratory manual. Cr concentration was detected using inductively coupled plasma mass spectrometry. The rDNA copy number was measured using qPCR.
RESULTS: In semen donors, whole blood Cr concentration was negatively associated with semen concentration and total sperm counts. Semen 5 S and 45 S rDNA copy numbers were negatively associated with whole blood Cr concentration and whole blood 5.8 S rDNA copy number was negatively associated with semen Cr concentration. In mice, Cr (VI) damaged testicular tissue, decreased semen quality, and caused rDNA copy number variation. Semen quality was related to the rDNA copy number in whole blood, testicular tissue, and semen samples in mice.
CONCLUSIONS: Cr (VI) was associated with decreased semen quality in semen donors and mice. Our findings suggest an in-depth analysis of the role of the rDNA copy number variation in the Cr (VI)-induced impairment of semen quality.
摘要：
目的：本研究旨在分析rDNA拷贝数变异在六价铬[Cr(VI)]暴露与精液供者精液质量之间的相关性中的可能作用，并进一步证实这种相关性。
方法：在这项横断面研究中，1月1日至4月31日在浙江人类精子银行采集155名精液捐献者的全血和精液样本,2021年。用不同剂量的Cr(VI)(0、10或15mg/kgb.w./天)处理成年C57BL/6J雄性小鼠。精液质量,包括精液体积,精子总数,精子浓度,渐进运动，和总运动性，根据WHO实验室手册进行分析。使用电感耦合等离子体质谱法检测Cr浓度。使用qPCR测量rDNA拷贝数。
结果：在精液捐献者中，全血Cr浓度与精液浓度和精子总数呈负相关。精液5S和45SrDNA拷贝数与全血Cr浓度呈负相关，全血5.8SrDNA拷贝数与精液Cr浓度呈负相关。在老鼠身上,Cr(VI)损伤睾丸组织,精液质量下降，并导致rDNA拷贝数变异。精液质量与全血中rDNA拷贝数有关,睾丸组织,和小鼠的精液样本。
结论：Cr（VI）与精液供体和小鼠的精液质量下降有关。我们的发现表明，对rDNA拷贝数变异在Cr（VI）诱导的精液质量受损中的作用进行了深入分析。
方法：在这项横断面研究中，1月1日至4月31日在浙江人类精子银行采集155名精液捐献者的全血和精液样本,2021年。用不同剂量的Cr(VI)(0、10或15mg/kgb.w./天)处理成年C57BL/6J雄性小鼠。精液质量,包括精液体积,精子总数,精子浓度,渐进运动，和总运动性，根据WHO实验室手册进行分析。使用电感耦合等离子体质谱法检测Cr浓度。使用qPCR测量rDNA拷贝数。
结果：在精液捐献者中，全血Cr浓度与精液浓度和精子总数呈负相关。精液5S和45SrDNA拷贝数与全血Cr浓度呈负相关，全血5.8SrDNA拷贝数与精液Cr浓度呈负相关。在老鼠身上,Cr(VI)损伤睾丸组织,精液质量下降，并导致rDNA拷贝数变异。精液质量与全血中rDNA拷贝数有关,睾丸组织,和小鼠的精液样本。
结论：Cr（VI）与精液供体和小鼠的精液质量下降有关。我们的发现表明，对rDNA拷贝数变异在Cr（VI）诱导的精液质量受损中的作用进行了深入分析。
