Shake It Off: The Elimination of Erroneous Kinetochore-Microtubule Attachments and Chromosome Oscillation.

Ayumu Yamamoto

doi:10.3390/ijms22063174

Abstract

Cell proliferation and sexual reproduction require the faithful segregation of chromosomes. Chromosome segregation is driven by the interaction of chromosomes with the spindle, and the attachment of chromosomes to the proper spindle poles is essential. Initial attachments are frequently erroneous due to the random nature of the attachment process; however, erroneous attachments are selectively eliminated. Proper attachment generates greater tension at the kinetochore than erroneous attachments, and it is thought that attachment selection is dependent on this tension. However, studies of meiotic chromosome segregation suggest that attachment elimination cannot be solely attributed to tension, and the precise mechanism of selective elimination of erroneous attachments remains unclear. During attachment elimination, chromosomes oscillate between the spindle poles. A recent study on meiotic chromosome segregation in fission yeast has suggested that attachment elimination is coupled to chromosome oscillation. In this review, the possible contribution of chromosome oscillation in the elimination of erroneous attachment is discussed in light of the recent finding.

Highlights

During mitotic cell division, replicated chromosomes termed sister chromatids become attached to opposite spindle poles and separate from each other, leading to the formation of two genetically identical daughter cells (Figure 1a, mitosis) [1]
The relationship between of improper attachments and tension at thechromosomes kinetochromosomes linkedI).by(b)chiasmata are attached to elimination opposite poles, resulting in segregation of thegenerated homologous chores. When both sister chromatids in mitosis or homologous chromosomes in meiosis I are attached to the same pole,. (b) The relationship between elimination of improper attachments and tension generated at the kinetochores
In the fission yeast Schizosaccharomyces pombe, sister centromeres split upon bi-oriented attachment [99,100], enabling the sister kinetochores to readily face in opposite directions during meiosis I (Figure 4a)

Summary

Introduction

During mitotic cell division, replicated chromosomes termed sister chromatids become attached to opposite spindle poles (referred to as bi-oriented attachment) and separate from each other (equational segregation), leading to the formation of two genetically identical daughter cells (Figure 1a, mitosis) [1]. Sister chromatids undergo equational segregation (meiosis II), resulting in the formation of haploid gametes In both equational and reductional segregations, chromosomes interact with the spindle in a random manner initially, resulting in the frequent attachment of chromosomes to improper poles (Figure 1b) (reviewed in References [2,3]). The relationship between of improper attachments and tension at thechromosomes kinetochromosomes linkedI).by(b)chiasmata are attached to elimination opposite poles, resulting in segregation of thegenerated homologous chores When both sister chromatids in mitosis or homologous chromosomes in meiosis I are attached to the same pole,. (b) The relationship between elimination of improper attachments and tension generated at the kinetochores When both sister chromatids in mitosis or homologous chromosomes in meiosis I are attached to the same pole, insufficient tension is generated and attachment is unstable (mono-oriented attachment). Their mechanisms have been reviewed in greater detail elsewhere [3,6,10,11,13,14,15,16,17,18,19]

The Current Model for the Tension-Dependent Attachment Establishment

Chromosome

Problems with the Tension-Dependent Spatial Separation Model during Meiosis

The Possible Contribution of Centromere Oscillation to Attachment Elimination

Future Direction