功能分析表明菱形藻 SPO11 具有有性生殖潜能。

Sexual reproduction potential implied by functional analysis of SPO11 in Phaeodactylum tricornutum.

机构信息

College of Marine Life, Ocean University of China, Qingdao 266003, China.

College of Marine Life, Ocean University of China, Qingdao 266003, China; Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences. Menglun, Mengla, Yunnan 666303, China.

出版信息

Gene. 2020 Oct 5;757:144929. doi: 10.1016/j.gene.2020.144929. Epub 2020 Jul 3.

DOI:10.1016/j.gene.2020.144929

PMID:32622990

Abstract

Phaeodactylum tricornutum is a model microalgae that is widely used to study diatom physiology and ecology. Since the meiotic process and sexual cycle have never been observed directly, P. tricornutum has been considered to be an asexual species. However, phylogenetic analysis of the P. tricornutum genome has revealed a series of meiosis-specific gene homologues in this species. We identified two copies of differently transcribed SPO11 homologs that contain the conserved motifs of Winged-helix and Toprim domains. The homolog PtSPO11-3 interacts with TopoVIB in yeast two-hybrid analysis, whereas the homolog PtSPO11-2 could rescue the sporulation defect of a Spo11 yeast mutant strain. PtSPO11-2 was also found to be significantly up-regulated at low temperatures in P. tricornutum and its key catalytic residue was important to the homolog's function in sporulation. The results herein provide positive clue that meiosis and sexual reproduction could exist in this diatom.

摘要

三角褐指藻是一种模式微藻，被广泛用于研究硅藻的生理和生态。由于减数分裂过程和有性周期从未被直接观察到，三角褐指藻被认为是一种无性物种。然而，三角褐指藻基因组的系统发育分析揭示了该物种中一系列减数分裂特异性基因同源物。我们鉴定了两个转录不同的 SPO11 同源物拷贝，它们含有翼状螺旋和 Toprim 结构域的保守基序。同源物 PtSPO11-3 在酵母双杂交分析中与 TopoVIB 相互作用，而同源物 PtSPO11-2 可以拯救 Spo11 酵母突变株的孢子形成缺陷。PtSPO11-2 在三角褐指藻中的低温下也被发现显著上调，其关键催化残基对同源物在孢子形成中的功能很重要。本文的结果提供了积极的线索，表明有丝分裂和有性生殖可能存在于这种硅藻中。