The Distribution Of Lipids In Mouse Ovary Revealed By MALDI Mass Spectrometry Imaging

The development of oocytes is particularly sensitive to changes in the environment.Balanced metabolism is essential for oocyte maturation.The development of primary follicles to mature follicles and the expulsion of mature oocytes are accompanied by energy changes.Lipid metabolism is an important source of energy.Matrix assisted laser desorption/ionization mass music like(MALDI-MSI)is a direct implementation in the tissue section unmarked mapping technology,molecular species currently used in a variety of disciplines to study all kinds of small molecules and macromolecules such as proteins,lipids,sugars and other functions,in order to achieve the purpose of better understanding of the metabolic process of these molecules,in clinical,biological,pharmaceutical,and other fields have been applied.ObjectiveUse MALDI-MSI technology to obtain the expression profile of lipids in the mouse ovary in the range of m/z100-900,analyze the lipid distribution of oocytes in the mouse ovary,in order to improve the development and lipid metabolism of mouse oocytes.The distribution relationship has a more intuitive understanding.Materials and methods1.Take out the ovary from the mouse to make 10?m frozen tissue section,spray the matrix evenly on the surface of the tissue and use the MALDI-FT-ICR mass spectrometer for ionization,and collect the ionized molecules to obtain the expression profile of the ovarian surface lipid.2.The H&E stained sections were analyzed under the microscope to analyze the structure of the ovary,and compared with the mass spectrometer object to analyze the difference in the distribution of lipids on the ovary.3.use SCILS Lab software to perform cluster analysis,composition analysis,ROC analysis and box plot analysis on the acquired mass spectrometry data To analyze the difference in lipids on the ovary.Results1.Studies had found that the most abundant lipids on mouse ovaries are mainly glycerophospholipids,including phosphatidic acid(PA),phosphatidylcholine(PC),phosphatidylglycerol(PG),and phosphatidylethanolamine(PE),Phosphatidylglycerophosphate(PGP).2.Some lipids such as m/z 770.5639(PE 38:3)and m/z 797.5407(PG 38:5)m/z798.5908(PE 40:3)are more abundant in mouse oocytes than particles cells,lipid m/z767.4835(PG 36:6)has stronger signal at cumulus cells than oocytes.3.Lipid m/z 761.4364(PGP 29:0)and m/z 789.5151(PGP 31:0)are abundant in the oocytes of mouse primary follicles,but the content of oocytes in mature follicles is significantly decreased.It could not be detected even in cumulus cells.Conclusion1.The study found that various lipids are distributed on the mouse ovary.Their distribution and content are different on the mouse ovary.The mouse ovary undergoes abundant lipid metabolism to maintain the maturity of the oocyte.2.Significant differences in lipid distribution and content were found in mouse oocytes and granular cells.3.There are differences in the distribution and content of different lipids in oocytes at different developmental stages.