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.

中文翻译：

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植物中的种系规格和功能

开花植物种系是在单倍体配子体阶段产生的。由于雄性和雌性配子体（也分别称为花粉和胚囊）的极度减少，生殖系的定义变得复杂。雄性和雌性配子祖细胞都通过不对称的细胞分裂进行分离，就像动物生殖系的情况一样。遗传研究和获得分离配子的转录组为定义雄性生殖系的机制提供了监管框架。什么指定女性生殖系身份仍然未知。最近的证据表明，生长素梯度提供了位置信息，并在确定雌配子谱系的身份中发挥作用。动物种系的特征还在于产生小 RNA，