Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th St AHC4-233, Miami, FL, 33199, USA.
National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA.
Sci Rep. 2021 May 5;11(1):9636. doi: 10.1038/s41598-021-89025-6.
Understanding the molecular and biochemical basis of egg development is a central topic in mosquito reproductive biology. Lipids are a major source of energy and building blocks for the developing ovarian follicles. Ultra-High Resolution Mass Spectrometry (UHRMS) combined with in vivo metabolic labeling of follicle lipids with deuterated water (HO) can provide unequivocal identification of de novo lipid species during ovarian development. In the present study, we followed de novo triglyceride (TG) dynamics during the ovarian previtellogenic (PVG) stage (2-7 days post-eclosion) of female adult Aedes aegypti. The incorporation of stable isotopes from the diet was evaluated using liquid chromatography (LC) in tandem with the high accuracy (< 0.3 ppm) and high mass resolution (over 1 M) of a 14.5 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (14.5 T FT-ICR MS) equipped with hexapolar detection. LC-UHRMS provides effective lipid class separation and chemical formula identification based on the isotopic fine structure. The monitoring of stable isotope incorporation into de novo incorporated TGs suggests that ovarian lipids are consumed or recycled during the PVG stage, with variable time dynamics. These results provide further evidence of the complexity of the molecular mechanism of follicular lipid dynamics during oogenesis in mosquitoes.
了解卵子发育的分子和生化基础是蚊媒生殖生物学的核心课题。脂质是卵巢滤泡发育的主要能量来源和构建模块。超高分辨率质谱（UHRMS）结合氘水（HO）对滤泡脂质的体内代谢标记，可以在卵巢发育过程中提供明确的新合成脂质种类的鉴定。在本研究中，我们跟踪了雌性埃及伊蚊成虫卵巢前发生（PVG）阶段（蜕皮后 2-7 天）新合成三酰甘油（TG）的动态变化。采用液相色谱（LC）结合配备六极检测的 14.5T 傅里叶变换离子回旋共振质谱仪（14.5T FT-ICR MS）的高精度（<0.3ppm）和高质量分辨率（超过 1M），评估了来自饮食的稳定同位素的掺入情况。LC-UHRMS 可根据同位素精细结构对有效脂质类别的分离和化学公式进行鉴定。监测稳定同位素掺入新合成 TG 的情况表明，在 PVG 阶段，卵巢脂质被消耗或回收，其时间动态具有可变性。这些结果进一步证明了在蚊子卵子发生过程中滤泡脂质动态的分子机制的复杂性。
