Meichroacidin (MCA)

RSPH1 has an acidic N terminus, followed by 6 repeat sequences, a 7-glutamic acid sequence, a short hydrophobic region, and an acidic C terminus. It also contains several potential phosphorylation sites. Northern blot analysis of several mouse tissues detected highest expression in testis, with much lower expression in ovary, and no expression in any other tissue examined. Tsa2 was expressed in neonatal mouse testis beginning at day 12, and high expression was detected in testis from day 14 to adult.  Immunohistochemical analysis indicated that Tsa2 was expressed in the cytoplasm of pachytene spermatocytes through to round spermatids. However, during the disappearance of the nuclear envelope at both the first and second meiotic divisions, Tsa2 localized around metaphase chromosomes and spindles.