SPO22/ZIP4 in yeast is a meiosis specific protein involved in sporulation [1]. It has been shown to regulate crossover distribution by promoting synaptonemal complex formation [3].

1: Bioinformatic analyses implicate the collaborating meiotic crossover/chiasma proteins Zip2, Zip3, and Spo22/Zip4 in ubiquitin labeling. Perry J, Kleckner N, Borner GV; Proc Natl Acad Sci U S A. 2005;102:17594-17599. PMID:16314568

2: ZIP4H (TEX11) Deficiency in the Mouse Impairs Meiotic Double Strand Break Repair and the Regulation of Crossing Over. Adelman CA, Petrini JH; PLoS Genet. 2008;4:e1000042. PMID:18369460

3: The meiosis-specific zip4 protein regulates crossover distribution by promoting synaptonemal complex formation together with zip2. Tsubouchi T, Zhao H, Roeder GS; Dev Cell. 2006;10:809-819. PMID:16740482