A Ph1-like Kinase from Arabidopsis is Required for Meiotic Chromosome Pairing

Plant Breeding depends on the ability to generate a wide range of genetic diversity from which to select desirable phenotypic variants and, in many breeding programs, this can be a rate limiting step.  It is therefore impertative to understand the molecular mechanisms that regulate processes such as meiotic chromosome pairing and recombination at a level that might allow us to manipulate and optimize them.  From previous investigations, it appears that pairing and recombination are regulated in order to promote  genome stability and this is especially evident in recent polyploid species such as hexaploid bread wheat.  Therefore, genetic tools (such as the ph1 locus) that are useful for introgressing foreign germplasm can also lead to genome instability. Here we report the identification of a Ph1-like gene from Arabidopsis and, using molecular and cellular approaches, compare its role in chromosomal dynamics with that of Ph1.  We conclude that these proteins are highly likely to operate in the same pathway, and we speculate that the Ph1 kinases have arisen by gene duplication and diversification early in the basal monocots.