Graduate School of Life Sciences, Ritsumeikan University, Shiga, 525-8577, Japan.
Department of Life Sciences, Ritsumeikan University, Shiga, 525-8577, Japan.
Sci Rep. 2021 May 12;11(1):10054. doi: 10.1038/s41598-021-89539-z.
We recently isolated a novel adenylyl cyclase/cAMP phosphodiesterase gene from the liverwort, Marchantia polymorpha. The protein encoded by this gene has a class III adenylyl cyclase (AC) in the C-terminal domain and class I phosphodiesterase (PDE) in the N-terminal domain; therefore, we named it CAPE (COMBINED AC with PDE). CAPE protein is likely involved in spermatogenesis and sperm motility due to its tissue-specific expression pattern in M. polymorpha and the distribution of CAPE genes in streptophytes. However, little is known about the distribution of CAPE in gymnosperms that use motile sperm for fertilization, such as cycads and ginkgo. The present study aimed to isolate CAPE genes from the cycad, Cycas revoluta, the ginkgo, Ginkgo biloba, and the hornwort, Anthoceros agerestis. Sequences with high homology to CAPE were obtained from these species. Our analyses revealed that all plant taxonomic groups reproducing via motile sperm possessed CAPE, whereas those that do not produce motile sperm did not possess CAPE, with one exception in gymnosperm Cupressales. The phylogenic distribution of CAPE almost corresponds to the evolutionary history of motile sperm production and further suggests that CAPE may be involved in sexual reproduction process using motile sperm in streptophytes.
我们最近从地钱属植物中分离出一种新型的腺苷酸环化酶/cAMP 磷酸二酯酶基因。该基因编码的蛋白在 C 端具有一个 III 类腺苷酸环化酶 (AC) 和在 N 端具有一个 I 类磷酸二酯酶 (PDE)，因此我们将其命名为 CAPE（具有 PDE 的组合 AC）。由于 CAPE 蛋白在地钱属植物中的组织特异性表达模式以及 CAPE 基因在石松类植物中的分布，它可能参与了精子发生和精子活力。然而，对于使用游动精子进行受精的裸子植物，如苏铁和银杏，关于 CAPE 的分布知之甚少。本研究旨在从苏铁、银杏和角苔属植物中分离 CAPE 基因。从这些物种中获得了与 CAPE 具有高度同源性的序列。我们的分析表明，所有通过游动精子繁殖的植物分类群都具有 CAPE，而那些不产生游动精子的植物则没有 CAPE，但裸子植物 Cupressales 中有一个例外。CAPE 的系统发育分布几乎与游动精子产生的进化历史相对应，进一步表明 CAPE 可能参与了石松类植物中使用游动精子的有性生殖过程。
