Identification of cytoplasmic factor inhibiting the Y-sperm maturation and cytogenetical analysis of spermatogenesis.

抑制 Y 精子成熟的细胞质因子的鉴定和精子发生的细胞遗传学分析。

• 批准号: 02640496
• 负责人: YAMAMOTO Masatoshi
• 金额: $ 1.09万
• 依托单位: Miyazaki Medical College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640496/
• 关键词: Sex ratio; Spermatogenesis; Y chromosome; Sperms; Meiosis; Drosophila simulans; sex ratio(性比); cytoplasm(細胞質); 精子; 細胞質遺伝

A strain which exhibits an extreme sex ratio has been isolated from a wild population. The strain was originally reported to carry an cytoplasmic factor which is transmitted materhally and causes sex ratio distortion through in the males bearing the cytoplasm. We therefore examined the effect of an antibiotic, aging, mitochondrial DNA, cytoplasmic RNA and transplantation of the cytoplasm on the sex ratio distortion in order to identify the cytoplasmic factor, but could not support the original description. However we have found a sex ratio mutation on the X chromosome of the Drosophila simulans strain. The gene named paternal sonless (psl) is located at about 30 in map distance and has not been known in any species belonging to the Drosophila melanogaster species complex. Cytogenetical studies revealed as follows; The psl males show a high frequency of chromosome bridges at meiosis, especially at the second division, which resulting in multi-nuclear spermatocytes and spermatids. Almost every abnormal spermatid has a mass of fluorescent positive chromatin at the site of cytokinesis. The abnormal spermatids are mostly discarded from sperm cysts in the maturation process. Only normal sperms, which are consisted of largely X-sperms, get matured.

从一个野生种群中分离出一种表现出极端性别比例的菌株。该菌株最初被报道携带一种细胞质因子，这种因子通过物质传播，在携带细胞质的雄性中导致性别比例扭曲。因此，我们研究了抗生素、衰老、线粒体DNA、细胞质RNA和细胞质移植对性别比例扭曲的影响，以确定细胞质因素，但无法支持原始描述。然而，我们在拟果蝇菌株的X染色体上发现了一个性别比例突变。这个名为“父系无子”（psl）的基因位于30个位点上，在黑腹果蝇物种复合体的任何物种中都没有发现。细胞遗传学研究结果如下；psl雄性在减数分裂时，特别是在第二次分裂时，染色体桥接频率高，导致多核精母细胞和精母细胞。几乎每一个异常精子在细胞质分裂的位置都有大量的荧光阳性染色质。在精子成熟过程中，异常精子大多被从精子囊中丢弃。只有主要由x精子组成的正常精子才能成熟。

项目成果

Yamamoto, M-T: "Inviability of hybrids between D. melanogaster and D. simulans results from the absence of simulans X not the presence of simulans Y chromosome." Genetica.

Yamamoto, M-T：“黑腹果蝇和拟果蝇之间杂交的不存活性是由于拟果蝇 X 的缺失而不是由于拟果蝇 Y 染色体的存在。”

Sawamura, K., M-T. Yamamoto, and T. K. Watanabe: "Hybrid lethal systems in the Drosophila melanogaster species complex. II. The Zygotic hybrid rescue (Zhr) gene of D.melanogaster." Genetics. 133. 307-313 (1993)

泽村，K.，M-T。

Sawamura, K., M-T. Yamamoto: "Cytogenetical localization of Zygotic hybrid rescue (Zhr) of Drosophila melanogaster that rescues interspecific hybrids from embryonic lethality." Mol. Gen. Genet.(1993)

泽村，K.，M-T。

Sawamura,K.: "Cytological localization of a speciation gene Zygotic hybrid rescue(Zhr) of Drosophila melanogaster that rescues interspecific hybrids from embryonic lethality." Genetics.

Sawamura,K.：“黑腹果蝇物种形成基因合子杂种拯救（Zhr）的细胞学定位，该基因可拯救种间杂种免于胚胎致死。”

Yamamoto,M-T.: "Inviability of hybrids between D.melanogaster and D.simulans results from the absence of simulans X not the presence of simulans Y chromosome." Genetica.

Yamamoto,M-T.：“黑腹果蝇和模拟果蝇之间杂交的不存活性是由于模拟果蝇 X 的缺失而不是由于模拟果蝇 Y 染色体的存在。”