An endogenous nuclease in hamster, mouse, and human spermatozoa cleaves DNA into loop-sized fragments.
An endogenous nuclease in hamster, mouse, and human spermatozoa cleaves DNA into loop-sized fragments.
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DOI：
10.1002/j.1939-4640.2005.tb01095.x
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发表时间：
2005-03
影响因子：
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通讯作者：
Barbara Sotolongo;Thomas T F Huang;Elisabete Isenberger;W. Ward
中科院分区：
文献类型：
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作者：
Barbara Sotolongo;Thomas T F Huang;Elisabete Isenberger;W. Ward
我们实验室最近的工作为仓鼠精子中存在核酸酶提供了证据。这种内源性核酸酶在DNA环结构域的碱基处将精子染色质切割成平均大小约为50 kb的大片段。在这里，我们证明了这种精子核酸酶存在于精子核中，并且它被钙和镁的存在激活的效率比单独使用任何一种离子都要高得多，导致DNA在30分钟内降解。我们还表明，类似的核酸酶存在于小鼠和人类精子。人核酸酶可被非冷冻保护介质中冻融精子激活。所有3个物种中精子核酸酶的活性类似于一组体细胞DNA酶的活性，所述体细胞DNA酶也需要钙和镁，并且在细胞凋亡期间将染色质消化成环大小的片段。
Recent work from our laboratory provided evidence for the existence of a nuclease in hamster spermatozoa. This endogenous nuclease cleaves sperm chromatin at the bases of DNA loop domains into large fragments with an average size of roughly 50 kb. Here, we demonstrate that this sperm nuclease is present in the sperm nucleus and that it is activated by the presence of both calcium and magnesium much more efficiently than with either ion alone, resulting in DNA degradation in 30 minutes. We also show that similar nucleases are present in mouse and human spermatozoa. The human nuclease can be activated by freeze-thawing spermatozoa in noncryoprotective media. The activity of the sperm nuclease in all 3 species resembles that of a group of somatic cell DNAses that also require both calcium and magnesium and that digest the chromatin into loop-sized fragments during apoptosis.