Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604.
Annu Rev Plant Biol. 2011;62:461-84. doi: 10.1146/annurev-arplant-042110-103824.
The flowering plant germline is produced during the haploid gametophytic stage. Defining the germline is complicated by the extreme reduction of the male and female gametophytes, also referred to as pollen and embryo sac, respectively. Both male and female gamete progenitors are segregated by an asymmetric cell division, as is the case for the germline in animals. Genetic studies and access to the transcriptome of isolated gametes have provided a regulatory framework for the mechanisms that define the male germline. What specifies female germline identity remains unknown. Recent evidence indicates that an auxin gradient provides positional information and plays a role in defining the identity of the female gamete lineage. The animal germline is also marked by production of small RNAs, and recent evidence indicates that this trait might be shared with the plant gamete lineage.
开花植物的生殖细胞系是在单倍体配子体阶段产生的。生殖细胞系的定义很复杂，因为雄性和雌性配子体（分别称为花粉和胚囊）极度退化。雄性和雌性配子体的前体细胞都通过不对称细胞分裂进行分离，就像动物的生殖细胞系一样。遗传研究和对分离配子的转录组的研究为确定雄性生殖细胞系的机制提供了一个调控框架。而决定雌性生殖细胞系身份的因素尚不清楚。最近的证据表明，生长素梯度提供了位置信息，并在确定雌性配子系的身份方面发挥了作用。动物的生殖细胞系也以产生小 RNA 为特征，最近的证据表明，这一特征可能与植物配子系共享。
