Generative Cell Specification Requires Transcription Factors Evolutionarily Conserved in Land Plants
Generative Cell Specification Requires Transcription Factors Evolutionarily Conserved in Land Plants
复制标题
DOI：
10.1016/j.cub.2017.12.053
复制
发表时间：
2018-02
期刊：
影响因子：
9.2
通讯作者：
Shohei Yamaoka;R. Nishihama;Yoshihiro Yoshitake;Sakiko Ishida;Keisuke Inoue;M. Saito;Keitaro Okahashi;Haonan Bao;Hiroyuki Nishida;K. Yamaguchi;S. Shigenobu;K. Ishizaki;K. Yamato;T. Kohchi
中科院分区：
文献类型：
--
作者：
Shohei Yamaoka;R. Nishihama;Yoshihiro Yoshitake;Sakiko Ishida;Keisuke Inoue;M. Saito;Keitaro Okahashi;Haonan Bao;Hiroyuki Nishida;K. Yamaguchi;S. Shigenobu;K. Ishizaki;K. Yamato;T. Kohchi
陆生植物在单倍体配子体中分化生殖细胞。在开花植物中，生殖细胞被指定为一个前体，随后在发育中的雄配子体（花粉）中分裂成两个精细胞。生殖细胞特化需要细胞周期控制和微管依赖性核移位（综述见[1-3]）。然而，生殖细胞命运决定因子及其进化起源仍然未知。配子体在多细胞生殖器官中产生卵子和精子，分别称为颈卵器和精子器，或统称为配子囊。鉴于陆地植物的单系起源[4-6]，进化上保守的机制可能在这些不同的生殖过程中发挥关键作用。在这里，我们发现，一个单一的成员的亚家族VIIIa的基本螺旋-环-螺旋（bHLH）转录因子在地钱多形地钱积累在初始细胞，并控制其发展成配子囊。然后，我们证明，anArabidopsis thalianaVIIIa bHLH短暂积累在较小的子细胞减数分裂衍生的小孢子的不对称分裂后，生殖细胞规范冗余与其paradigm所需的。此外，这些拟南芥VIIla bHLH在功能上可以被多形分枝杆菌VIIla bHLH取代。这些研究结果表明，VIIIa BHLH蛋白作为核心调节生殖发育，包括生殖细胞分化，因为陆地植物进化的早期阶段。
Land plants differentiate germ cells in the haploid gametophyte. In flowering plants, a generative cell is specified as a precursor that subsequently divides into two sperm cells in the developing male gametophyte, pollen. Generative cell specification requires cell-cycle control and microtubule-dependent nuclear relocation (reviewed in [1–3]). However, the generative cell fate determinant and its evolutionary origin are still unknown. In bryophytes, gametophytes produce eggs and sperm in multicellular reproductive organs called archegonia and antheridia, respectively, or collectively called gametangia. Given the monophyletic origin of land plants [4–6], evolutionarily conserved mechanisms may play key roles in these diverse reproductive processes. Here, we showed that a single member of the subfamily VIIIa of basic helix-loop-helix (bHLH) transcription factors in the liverwortMarchantia polymorphaprimarily accumulated in the initial cells and controlled their development into gametangia. We then demonstrated that anArabidopsis thalianaVIIIa bHLH transiently accumulated in the smaller daughter cell after an asymmetric division of the meiosis-derived microspore and was required for generative cell specification redundantly with its paralog. Furthermore, theseA. thalianaVIIIa bHLHs were functionally replaceable by theM. polymorphaVIIIa bHLH. These findings suggest the VIIIa bHLH proteins as core regulators for reproductive development, including germ cell differentiation, since an early stage of land plant evolution.