Locating Of Ovum Mutant Modifier(Ommf) By QTLs 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 implemental strains have been developed. Therefore, mouse has become the key model animal for the research of development biology, functional genomics and disease mechanism.The inbred strain of DDK mice were breeded by Japanese from a kind of Germanic mice which attribute the M.m.domesticus subspecific, and it shows a unique property known as"DDK syndrome": the DDK males can normally fertilize the females of other strains like in the same strain,while the females of DDK strain are nearly infertile when crossed to males of other strains, owing to the F1 embryos failure of blastocyst formation between 3-5 days after pregnancy.Studies supported that the polar infertile characteristic is caused by an incompatibility between the cytoplamic materials in DDK oocyte and sperm factors in other strains,they were all controlled by an allele of Om locus which has been mapped om 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. After 3 years'hard working, we add the amount of samples at the basic of 164 data which professor Zhao collected and have obtained the phenotype data of all the 137 samples, and accomplished the genome scanning of 89 samples. Applying the software of winQTLcar, we analyzed the 89 samples with composite interval mapping. It is showed that there maybe existed the QTLs of implantation in the fourth chromosome with the LOD score of 3.0; In addition, there may be QTLs in the first,the ninth, the fourteenth and the seventeenth chromosome and their LOD scores are all above 1.5. The results were in accordance with professor Zhao's.Besides, the polygene regulation in the process of mouse's blastocyst formation is confirmed in this experiment, which can help to find out the effect and action law of mouse's Ovum Mutant, and make necessary preparations for the further study of Ommf's function expressing of Ovum Mutant.