减数分裂由两次产生单倍体生殖细胞的核分裂组成。实现减数分裂，姐妹染色体必须在第一次分裂联会，这过程姐妹染色体在着丝粒结合。保护这种结合的因子还不是很清楚。这里我们确定Sgo1（shugoshin）是裂殖酵母中着丝粒结合的保护因子。我们同时确定了在芽殖酵母中存在Sgo1的同源基因。我们也能证明shugoshin在真核生物中广泛的保守存在。而且，我们证实Sgo2，裂殖酵母的shugoshin的paralogue，是有丝分裂染色体聚集所必需的。Sgo1和Sgo2在着丝粒上的定位需要激酶Bub1，shugoshin是Bub1的关键目标。这些发现为研究减数分裂以及有丝分裂和减数分裂中动粒调节的演变提供了基础。

Meiosis comprises a pair of specialized nuclear divisions that produce haploid germ cells.  To accomplish this, sister chromatids must segregate together during the first meiotic division (meiosis I) , which requires that sister chromatid cohesion persists at centromeres.  The factors that protect centromeric cohesion during meiosis I have remained elusive.  Here we identify Sgo1 (shugoshin), a protector of the centromeric cohesin Rec8 in fission yeast.  We also identify a homologue of Sgo1 in budding yeast.  We provide evidence that shugoshin is widely conserved among eukaryotes.  Moreover, we identify Sgo2, a paralogue of shugoshin in fission yeast, which is required for faithful mitotic chromosome segregation.  Localization of Sgo2 and Sgo2 at centromeres requires the kinase Bub1, identifying shugoshin as a crucial target for the kinetochore function of Bub1.  These findings provide insights into the evolution of meiosis and kinetochore regulation during mitosis and meiosis.