Back to the roots: segregation of univalent sex chromosomes in meiosis
- 731 Downloads
In males of many taxa, univalent sex chromosomes normally segregate during the first meiotic division, and analysis of sex chromosome segregation was foundational for the chromosome theory of inheritance. Correct segregation of single or multiple univalent sex chromosomes occurs in a cellular environment where every other chromosome is a bivalent that is being partitioned into homologous chromosomes at anaphase I. The mechanics of univalent chromosome segregation vary among animal taxa. In some, univalents establish syntelic attachment of sister kinetochores to the spindle. In others, amphitelic attachment is established. Here, we review how this problem of segregation of unpaired chromosomes is solved in different animal systems. In addition, we give a short outlook of how mechanistic insights into this process could be gained by explicitly studying model organisms, such as Caenorhabditis elegans.
KeywordsMale meiosis Univalent chromosomes Sex chromosomes Nematodes C. elegans Chromosome segregation
The authors thank Drs. Mary Howe and Andre Pires da Silva for critically reading the manuscript, as well as Dr. Kai Johnsson (EPFL, Switzerland) for sharing unpublished reagents. C. remanei, C. brenneri, and Pristionchus pacificus were obtained from the Caenorhabditis Genetics Center (CGC), which is funded by an NIH Research Infrastructure Program (P40 OD010440). The authors would also like to thank Franziska Friedrich (MPI-CBG, Dresden, Germany) for help in scientific drawing. Research on meiosis in the Müller-Reichert lab is funded by the Deutsche Forschungsgemeinschaft (DFG SPP1384 “Mechansims of Genome Haploidization,” grant MU1423/3-1 and 3-2 to TMR).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest. This article does not contain any studies with human participants performed by any of the authors. All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.
- Boring AM (1909) A small chromosome in Ascaris megalocephala. Arch f Zellf 4:120–131Google Scholar
- Boveri T (1899) Die Entwicklung von Ascaris megalocephala mit besonderer Rücksicht auf die Kernverhältnisse. In: Festschrift zum siebzigsten Geburtstag von Carl v. Kupffer, Jena., pp 383–429Google Scholar
- Boveri T (1909) Über Geschlechtschromosomen bei Nematoden. Arch f Zellf 4:132–141Google Scholar
- Geinitz B (1915) Über Abweichungen bei der Eireifung von Ascaris. Arch f Zellf 18:588–633Google Scholar
- Hughes SE, Gililand WD, Cotitta JL, Takeo S, Collins KA, Hawley RS (2009) Heterochromatic threads connect oscillating chromosomes during prometaphase I in Drosophila oocytes. PLoS Genet. E1000348Google Scholar
- Lukinavičius G, Umezawa K, Olivier N, Honigmann A, Yang G, Plass T, Mueller V, Reymond L, Corrêa IR Jr, Luo ZG, Schultz C, Lemke EA, Heppenstall P, Eggeling C, Manley S, Johnsson K (2013) A near-infrared fluorophore for live-cell super-resolution microscopy of cellular proteins. Nat Chem 5:132–139CrossRefPubMedGoogle Scholar
- Theurkauf WE, Hawley RS (1992) Meiotic spindle assembly in Drosophila females—behavior of nonexchange chromosomes and the effects of mutations in the Nod kinesin-like protein. J Cell Sci 115:1541–1549Google Scholar
- White MJD (1977), Animal Cytology and Evolution. Cambridge University PressGoogle Scholar