Reference "An insertional mutation in the rice PAIR2 gene, the ortholog of Arabidopsis ASY1, results in a defect in homologous chromosome pairing during meiosis"

Reference ID

11024

Title

An insertional mutation in the rice PAIR2 gene, the ortholog of Arabidopsis ASY1, results in a defect in homologous chromosome pairing during meiosis

Source

Mol Genet Genomics, 2004, vol. 271, pp. 121-129

Authors (8)

Nonomura-K-I	Nakano-M
Murata-K	Miyoshi-K
Eiguchi-M	Miyao-A
Hirochika-H	Kurata-N

Abstract

To elucidate the genetic system that establishes homologous chromosome pairing
in monocot plants, we have isolated an asynaptic mutant of rice, designated
pair2 (homologous pairing aberration in rice meiosis 2), in which 24 completely
unpaired univalents are observed at pachytene and diakinesis. The mutation was
caused by an insertion of the retrotransposon Tos17, as demonstrated by
complementation of the mutation by transformation with the corresponding wild-
type gene. The gene in which the element was inserted is orthologous to the ASY1
gene of Arabidopsis thaliana and the HOP1 gene of Saccharomyces cerevisiae.
Mature PAIR2 mRNA and several splicing variants were found to be highly
expressed in wild-type reproductive tissues, and lower expression was also
detected in vegetative tissues. In situ hybridization and BrdU incorporation
experiments revealed that PAIR2 expression is specifically enhanced in male and
female meiocytes, but not in those at pre-meiotic S phase or in the pollen
maturation stages. The results obtained in this study suggest that the PAIR2
gene is essential for homologous chromosome pairing in meiosis, as in the case
of the genes ASY1 and HOP1. The study also suggested the possibility that a
highly homologous copy of the PAIR2 gene located on a different chromosome is in
fact a pseudogene.