Spatiotemporal and cell-type dependent phasiRNA biogenesis in maize male reproduction (RNA-seq2)

Maize anthers, the male reproductive floral organs, express two classes of phased, small interfering RNAs (phasiRNAs). RNA profiling from ten sequential cohorts of staged maize anthers plus mature pollen revealed that 21-nt phased siRNAs (21-phasiRNAs) from 463 loci appear abruptly after germinal and initial somatic cell fate specification and then diminish, while 24-nt phased siRNAs (24-phasiRNAs) from 176 loci coordinately accumulate during meiosis and persist as haploid gametophytes differentiate into pollen. RNA sequencing of anther developmental mutants, together with in situ RNA hybridization detection of phasiRNA biogenesis factors, demonstrated that 21-phasiRNAs and 24-phasiRNAs are independently regulated. Furthermore, 21-phasiRNAs require epidermal cells while 24-phasiRNAs require functional tapetal cells. Maize phasiRNAs and mammalian PIWI-interacting RNAs (piRNAs) illustrate convergent evolution of small RNAs to support male reproduction. Examination of maize phasiRNAs by high throughput sequencing for RNA-seq. This series is an extension of the data previously submitted in GSE52290.

玉米花药作为雄性生殖花器官，可表达两类阶段性小干扰RNA（phased small interfering RNAs，phasiRNAs）。对10个连续分期的玉米花药队列及成熟花粉开展RNA谱分析后发现，来自463个基因座的21核苷酸阶段性小干扰RNA（21-phasiRNAs）会在生殖细胞与初始体细胞命运特化完成后突然出现，随后表达量逐渐降低；而来自176个基因座的24核苷酸阶段性小干扰RNA（24-phasiRNAs）则在减数分裂阶段协同积累，并在单倍体配子体分化为花粉的过程中持续存在。对花药发育突变体进行RNA测序，结合phasiRNA生物合成因子的原位RNA杂交检测，证实21-phasiRNAs与24-phasiRNAs的调控机制相互独立。此外，21-phasiRNAs的生成依赖表皮细胞，而24-phasiRNAs的生成则依赖功能完整的绒毡层细胞。玉米phasiRNAs与哺乳动物PIWI相互作用RNA（PIWI-interacting RNAs，piRNAs）共同印证了小RNA在支撑雄性生殖功能层面的趋同进化规律。本数据集通过高通量测序技术完成玉米phasiRNAs的RNA-seq分析，其数据为此前提交的GSE52290数据集的扩展版本。