Maize Genetics Cooperation Newsletter

maize gene review

Authors: Chung-Ju Rachel Wang, Inna Golubovskaya, Olivier Hamant, W. Zacheus Cande, University of California, Berkeley, CA 94720-3200 USA


Review: pending

Pub date: May 2009

Name: sgo1-shogoshin centromeric cohesion1

Synonyms: AY109536, CL5684_1, gnp_AW055587, gpm134, PZA02319

Chromosome 7 bin 7.02
Genome Browser via cDNA AY964185 | 63099688

Function: meiotic centromere cohesion and segregation of sister chromatids.

maize mutant

Summary: SGO1 protein protects the cohesin complex at centromeres from degradation at the onset of anaphase I, so that sister chromatid remain tethered until metaphase II. In the absence of SGO1, centromeric cohesion is lost precociously at anaphase I, leading to random segregation of sister chromatids at metaphase II. sgo1 mutant plants exhibit male and female sterility and have no vegetative defects. The distribution of SGO1 protein is restricted to meiotic cells and localizes to the centromeres from leptotene until anaphase I; it is not found on mitotic chromosomes and has no obvious mitotic function. (Hamant et al. 2005).

Images: Aceto-carmine stained (a)wild-type and (b) sgo1-1::Mu1 chromosomes at anaphase II stages, showing random segregation of sister chromatids in the mutant (b).

First reported: Hamant et al. 2005.

Key Alleles

sgo1-1::Mu1 , aka mtm99-31. Mu1 inserted in first exon. Null allele, exhibiting male and female sterility, but no vegetative defects.

sgo1-2::Mu1, Mu1 inserted in first intron. Phenotype similar to sgo1-1::Mu1.

Map Location

Recombination based mapping by two probes, a SNP or single nucleotide polymorphism, AY109536 and an RFLP or restriction fragment length polymorphism, gpm134 (gnp_AW055587, p-std614083G09). See MaizeGDB IBM2 Map 7; Falque et al. 2005.

Gene Product

SGO1 shogushin protein. A component of cohesin, localizes to meiotic centromeres from leptotene until anaphase I.


High in tissues with meiocytes; reduced in leaves and pollen containing tassels (Hamant et al 2005).

Related locus

afd1, whose REC8-like gene product is required for SGO1 recruitment to centromeres, unlike the situation for Shugoshins in yeast and Drosophila (Hamant et al 2005).


Falque M, Decousset L, Dervins D, Jacob AM, Joets J, Martinant JP, Raffoux X, Ribiere N, Ridel C, Samson D, Charcosset A, Murigneux A. (2005) Linkage Mapping of 1454 New Maize Candidate Gene Loci. Genetics 170:1957-1966. PUBMED

Hamant O, Golubovskaya I, Meeley R, Fiume E, Timofejeva L, Schleiffer A, Nasmyth K, Cande WZ (2005) A REC8-dependent plant Shugoshin is required for maintenance of centromeric cohesion during meiosis and has no mitotic functions. Curr Biol 15:948-954. PUBMED

Links: MGDB: sgo1 NCBI: sgo1 UniProt: Q4QSC8