Sororin is enriched at the central region of synapsed meiotic chromosomes

Abstract

During meiotic prophase cohesin complexes mediate cohesion between sister chromatids and promote pairing and synapsis of homologous chromosomes. Precisely how the activity of cohesin is controlled to promote these events is not fully understood. In metazoans, cohesion establishment between sister chromatids during mitotic divisions is accompanied by recruitment of the cohesion-stabilizing protein Sororin. During somatic cell division cycles, Sororin is recruited in response to DNA replication-dependent modification of the cohesin complex by Esco acetyltransferases. How Sororin is recruited and acts in meiosis is less clear. Here we have surveyed the chromosomal localization of Sororin and its relationship to the meiotic cohesins and other chromatin modifiers with the objective of determining how Sororin contributes to meiotic chromosome dynamics. We show that Sororin localizes to the cores of meiotic chromosomes in a manner that is dependent on synapsis and the synaptonemal complex protein SYCP1. In contrast, cohesin, with which Sororin interacts in mitotic cells, shows axial enrichment on meiotic chromosomes even in the absence of synapsis between homologs. Using high-resolution microscopy, we show that Sororin is localized to the central region of the synaptonemal complex. These results indicate that Sororin regulation during meiosis is distinct from its regulation in mitotic cells, and may suggest that it interacts with a distinctly different partner to ensure proper chromosome dynamics in meiosis.

PDS 5 proteins regulate the length of axial elements and telomere integrity during male mouse meiosis

“…Likewise, similar distribution patterns have been previously reported in mouse meiosis for the cohesin cofactors WAPL , and NIPBL and MAU2 . The exception is Sororin, which localizes at the central region of the SC .…”

PDS5 proteins regulate the length of axial elements and telomere integrity during male mouse meiosis

“…6J-L) and AEs/LEs ( Fig. 6M-O), respectively, as previously reported in wild-type spermatocytes (Brieño-Enríquez et al, 2016;Gómez et al, 2016;Jordan et al, 2017). Centromeric cohesion defects were not evident in deficient Pds5AB zygotene and early pachytene spermatocytes, as kinetochore signals appeared unaltered at the ends of AEs/LEs or SCs, respectively, as in Pds5AB proficient mid pachytene spermatocytes ( Fig.…”

“…Likewise, similar distribution patterns have been previously reported in mouse meiosis for the cohesin cofactors WAPL (Zhang et al, 2008;Brieño-Enríquez et al, 2016), and NIPBL and MAU2 (Visnes et al, 2014). The exception is Sororin, which localizes at the central region of the SC (Gómez at al., 2016;Jordan et al, 2017).…”

“…WAPL decorates the AEs/LEs of chromosomes in mouse oocytes (Zhang et al, 2008) and spermatocytes, where it is involved in the removal of arm cohesion by the end of prophase I (Brieño-Enríquez et al, 2016). Unexpectedly, Sororin has been detected at the SC central region, unlike the cohesin subunits and WAPL (Gómez et al, 2016;Jordan et al, 2017).…”

The cohesin complex in mammalian meiosis

“…Since genetic disruption of either one of the meiosis‐specific cohesin subunits leads to infertility with different phenotypes of chromosome structure, each of them plays an essential role in chromosome dynamics during meiosis (Bannister, Reinholdt, Munroe, & Schimenti, ; Fukuda, Fukuda, Agostinho, Hernandez‐Hernandez, & Kouznetsova, ; Herran, Gutierrez‐Caballero, Sanchez‐Martin, Hernandez, & Viera, ; Hodges, Revenkova, Jessberger, Hassold, & Hunt, ; Hopkins, Hwang, Jacob, Sapp, & Bedigian, ; Ishiguro, Kim, Shibuya, Hernandez‐Hernandez, & Suzuki, ; Llano, Gomez, Garcia‐Tunon, Sanchez‐Martin, & Caburet, ; Revenkova et al., ; Winters, McNicoll, & Jessberger, ; Xu, Beasley, Warren, Horst, & McKay, ). The accessory proteins, PDS5B (Fukuda & Hoog, ), WAPL (Adelfalk, Janschek, Revenkova, Blei, & Liebe, ; Brieno‐Enriquez, Moak, Toledo, Filter, & Gray, ; Zhang, Hakansson, Kuroda, & Yuan, ) and SORORIN (Gomez, Felipe‐Medina, Ruiz‐Torres, Berenguer, & Viera, ; Jordan, Eyster, Chen, Pezza, & Rankin, ), also appear on chromosomes during meiotic prophase I and regulate the stability of the binding of cohesin on the chromatin. Thus, in addition to a canonical somatic cell‐type cohesin complex, different combinations of subunits generate distinct cohesin complexes during meiosis, which provide specialized functions for generating meiotic chromosomes.…”