The Arabidopsis anaphase‐promoting complex/cyclosome subunit 8 is required for male meiosis

Abstract

Summary Faithful chromosome segregation is required for both mitotic and meiotic cell divisions and is regulated by multiple mechanisms including the anaphase‐promoting complex/cyclosome (APC/C), which is the largest known E3 ubiquitin‐ligase complex and has been implicated in regulating chromosome segregation in both mitosis and meiosis in animals. However, the role of the APC/C during plant meiosis remains largely unknown. Here, we show that Arabidopsis APC8 is required for male meiosis. We used a combination of genetic analyses, cytology and immunolocalisation to define the function of AtAPC8 in male meiosis. Meiocytes from apc8‐1 plants exhibit several meiotic defects including improper alignment of bivalents at metaphase I, unequal chromosome segregation during anaphase II, and subsequent formation of polyads. Immunolocalisation using an antitubulin antibody showed that APC8 is required for normal spindle morphology. We also observed mitotic defects in apc8‐1, including abnormal sister chromatid segregation and microtubule morphology. Our results demonstrate that Arabidopsis APC/C is required for meiotic chromosome segregation and that APC/C‐mediated regulation of meiotic chromosome segregation is a conserved mechanism among eukaryotes.

The Role of Anaphase-Promoting Complex/Cyclosome (APC/C) in Plant Reproduction

“…Showing that APC8 plays a role in meiotic chromosome segregation at metaphase I. Moreover, at metaphase II, apc8-1 chromosomes are misaligned providing an unequal chromosome segregation of sister chromatids at anaphase II, giving additional evidence that APC8 is required for chromosome segregation in meiosis II (Xu et al, 2019).…”

The potential of resilient carbon dynamics for stabilizing crop reproductive development and productivity during heat stress

“…The down‐regulated gene ANAPHASE‐PROMOTING COMPLEX SUBUNIT 8 ( APC8 ) (Figure 2a) is required for correct mitotic progression in the cell cycle. APC8 mutants have no or just single sperm‐like cells reducing both pollen viability and the ability to produce a pollen tube (Xu et al, 2019; Zheng, Chen, & McCormick, 2011). Genes involved in tapetum development are also affected as reflected by our querying of differential expression in rice panicles during heat stress (Figure 2b).…”

Ubiquitination in Plant Meiosis: Recent Advances and High Throughput Methods

“…CDC20.1—which interacts with APC/C subunits APC3, APC8, and APC10 ( Kevei et al, 2011 ; Qiao et al, 2016 )—is essential to proper chromosomal segregation ( Niu et al, 2015 ). Similarly, AtAPC8 has been shown to be involved in chromosome alignment, chromosomal segregation, and microtubule organization ( Xu et al, 2019 ). In recent years, considerable progress has been made in understanding the precise role and substrate specificity of APC/C in chromosomal segregation at anaphase I and II in Arabidopsis .…”