与动物不同，植物的受精过程有两对精子和卵子参与。其中一对结合形成受精卵，而另一对则在子房中融合形成富有营养的胚乳。这个双受精过程中的一个迷团是单个花粉粒如何产生一对精子以同时满足受精和种子生产的需要。最近，英国莱斯特大学David Twell领导的一组科学家鉴定出一种在这个过程中发挥重要作用的基因，它使生殖细胞前体分裂形成两个精子细胞。他们的这项研究发表于最新一期的PloS Genetics。

这个名为Duo1的基因有两重作用：促进精子前体细胞分裂，同时还促使它们产生精子细胞。Twell强调说，这些发现“将有助于理解开花植物中配子发育的机制及演变，或许对控制作物间的基因流动及杂交行为有所帮助。”

推荐原始出处：

PLoS Genet 5(3): e1000430. doi:10.1371/journal.pgen.1000430

A Plant Germline-Specific Integrator of Sperm Specification and Cell Cycle Progression

Lynette Brownfield1, Said Hafidh1, Michael Borg1, Anna Sidorova1, Toshiyuki Mori2, David Twell1*

1 Department of Biology, University of Leicester, Leicester, United Kingdom, 2 Miyagishima Initiative Research Unit, Advance Science Institute, RIKEN, Wako, Saitama, Japan

The unique double fertilisation mechanism in flowering plants depends upon a pair of functional sperm cells. During male gametogenesis, each haploid microspore undergoes an asymmetric division to produce a large, non-germline vegetative cell and a single germ cell that divides once to produce the sperm cell pair. Despite the importance of sperm cells in plant reproduction, relatively little is known about the molecular mechanisms controlling germ cell proliferation and specification. Here, we investigate the role of the Arabidopsis male germline-specific Myb protein DUO POLLEN1, DUO1, as a positive regulator of male germline development. We show that DUO1 is required for correct male germ cell differentiation including the expression of key genes required for fertilisation. DUO1 is also necessary for male germ cell division, and we show that DUO1 is required for the germline expression of the G2/M regulator AtCycB1;1 and that AtCycB1:1 can partially rescue defective germ cell division in duo1. We further show that the male germline-restricted expression of DUO1 depends upon positive promoter elements and not upon a proposed repressor binding site. Thus, DUO1 is a key regulator in the production of functional sperm cells in flowering plants that has a novel integrative role linking gametic cell specification and cell cycle progression.