Impact of trisomy on fertility and meiosis in male mice
Impact of trisomy on fertility and meiosis in male mice
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DOI：
10.1093/humrep/del397
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发表时间：
2007-02-01
影响因子：
6.1
通讯作者：
Handel, M. A.
中科院分区：
文献类型：
--
作者：
Davisson, M.;Akeson, E.;Handel, M. A.
背景：染色体异常经常与哺乳动物精子发生的障碍或停止有关，但与相同异常的雌性携带者的生育能力相一致。在三体的情况下，小鼠有额外的基因组DNA和染色体异常，通常表现为额外的、未配对的染色体。因此，三体雄性精子发生的障碍可能是由于额外的基因组物质(即三倍体基因)的存在，或者由于减数分裂中染色体的异常和存在不成对的染色体。方法：本研究分析了雄性小鼠不同基因组片段三体在减数分裂前期的生育力和染色体配对构型。其中4个具有额外的节段性或三体染色体-ts(17(16))65Dn，ts(10(16))232Dn，ts(12(17))4Rk和ts(4(17))2Lws-还有一个具有与另一个染色体相连的三倍体片段-ts(16C-tel)1Cje。Ts(17(16))65Dn和ts(16C-tel)1Cje具有相似的基因含量三倍体，主要区别在于额外的DNA是否在额外的染色体上。结果：存在完整的额外染色体，而不是三体本身，与男性不育有关。此外，不孕不育与未配对的染色体与XY小体的高频率相关，XY小体包含大部分未配对的X和Y染色体。结论：完整的额外染色体干扰精子发生，未配对的染色体在减数分裂核中建立了独特的染色质区域。
BACKGROUND: Chromosomal abnormalities frequently are associated with impairment or arrest of spermatogenesis in mammals but are compatible with fertility in female carriers of the same anomaly. In the case of trisomy, mice have extra genomic DNA as well as the chromosomal abnormality, usually present as an extra, unpaired chromosome. Thus, impairment of spermatogenesis in trisomic males could be due to the presence of extra genomic material (i.e. triplicated genes) or due to the chromosomal abnormality and presence of an unpaired chromosome in meiosis. METHODS: In this study, fertility and chromosomal pairing configurations during meiotic prophase were analysed in male mice trisomic for different segments of the genome. Four have an extra segmental or tertiary trisomic chromosome-Ts(17(16))65Dn, Ts(10(16))232Dn, Ts(12(17))4Rk and Ts(4(17))2Lws-and one has the triplicated segment attached to another chromosome-Ts(16C-tel)1Cje. Ts(17(16))65Dn and Ts(16C-tel)1Cje have similar gene content triplication and differ primarily in whether the extra DNA is in an extra chromosome or not. RESULTS: The presence of an intact extra chromosome, rather than trisomy per se, is associated with male sterility. Additionally, sterility is correlated with a high frequency of association of the unpaired chromosome with the XY body, which contains the largely unpaired X and Y chromosomes. CONCLUSIONS: Intact extra chromosomes disrupt spermatogenesis, and unpaired chromosomes establish a unique chromatin territory within meiotic nuclei.