Identification And Location Of Ovum Mutant Modifier (Ommf) In Mice

The history of mouse genetics started when mice strains were imported from pet farm to Castle'S laboratory in Harvard University about one hundred years ago. Mouse genome is highly homologous to human and can be modified by various approaches. Moreover, thousands of inbred strains, mutant strains and tool strains had been developed. Therefore, mouse had become the key model animal for the research of development biology, functional genomics and disease mechanism.Inbred strain of mice DDK showed a unique property of reproduction (DDK syndrome). This property was caused by an incompatibility between the cytoplasmic substance of DDK eggs and the sperm factor of other strains, both of which were controlled by the alleles at the ovum mutant (Om) locus on mouse Chromosome 11. Recently years, professor Zhao found there were the ovum mutant modifiers (Ommf) in B6 background, which made the mortality of embryo advanced with the alteration of the genetic background. Meanwhile, there were some scholars found the modifiers through different ways and methods, but different conclusions were existed about the number of the modifier and the way it expressed.In the present study, we mainly to find out the number of the ovum mutant modifiers (Ommf), it would be the foundation of launching the ways of modifiers study. We would add the amount of samples at the basic of 164 data which professor Zhao collected, and screened the microsatellites during the district where there probable were modifiers, which were used to the refined location, and it would be convenience to cloning the genes and studied the ways their done, the results as follow;1. The screen of the microsatellite markers: we randomly selected 50 and 30 pairs of markers from chromosome 9 and 14, respectively, and obtained 3 pairs of polymorphous markers (D9Mit128,D9Mit140,D9Mit318) on chromosome 9 and 5 pairs of polymorphous markers (D14Mit14,D14Mit129,D14Mit59,D14Mit35,D14Mit50) on chromosome14. 2. Linkage-analysis; we analyzed the 48 samples through the WinQTLcart software, and found the QTLs of Implantation and Live-Fetus on chromosome 10, the LOD values were 0.8 and 3.2 respectively. Meanwhile, there probable exist QTLs on chromosome 5, 6, 9 and 14, their LOD values reached above 1.5. The results were in accordance with professor Zhao obtained. In addition, we located the Ommf9 between D9Mit27 and D9Mit318, it was about 16cM spaces.