Follicle microenvironment-associated alterations in gene expression in the mouse oocyte and its polar body

Fertil Steril. 2013 Apr;99(5):1453-1459.e1. doi: 10.1016/j.fertnstert.2012.12.009. Epub 2013 Jan 8.

Abstract

Objective: To determine whether the follicle environment modulates oocyte-specific gene transcript levels in cultured oocytes and polar bodies (PBs).

Design: Animal study.

Setting: Large academic research center.

Animal(s): CD1 mice.

Intervention(s): In vitro growth of secondary mouse follicles in 0.25% or 1.5% alginate (ALG) in a three-dimensional culture system.

Main outcome measure(s): Relative transcript levels of Gdf9, Bmp15, Nlrp5, Tcl1, and Zp3 were measured by real-time quantitative reverse transcriptase-polymerase chain reaction in oocytes during in vitro follicle development and oocyte maturation and in their first PBs after removal from metaphase II (MII) eggs.

Result(s): All transcripts decreased earlier in oocytes cultured in 1.5% ALG compared with 0.25% ALG. Transcript levels were lower in MII eggs cultured in 1.5% ALG compared with in 0.25% ALG. All genes were expressed in PBs, and transcript levels were lower in PBs cultured in 1.5% ALG compared with in 0.25% ALG. Abundance of all transcripts was lower in PBs than in their sibling oocytes.

Conclusion(s): Local follicle environment modulates oocyte-specific gene expression in the oocyte and first PB. There is a significant difference in the transcript levels of oocyte-specific genes in PBs of 1.5% versus 0.25% ALG that correlates with ovarian environment-related decreases in oocyte competence.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antigens / genetics
  • Bone Morphogenetic Protein 15 / genetics
  • Cellular Microenvironment / physiology*
  • Egg Proteins / genetics
  • Female
  • Gene Expression / physiology
  • Growth Differentiation Factor 9 / genetics
  • Infertility, Female / genetics
  • Infertility, Female / physiopathology
  • Meiosis / physiology
  • Membrane Glycoproteins / genetics
  • Mice
  • Mice, Inbred Strains
  • Oocytes / cytology*
  • Oocytes / physiology*
  • Organ Culture Techniques
  • Ovarian Follicle / cytology*
  • Ovarian Follicle / growth & development
  • Ovarian Follicle / physiology*
  • Polar Bodies / physiology*
  • Proto-Oncogene Proteins / genetics
  • RNA, Messenger / metabolism
  • Receptors, Cell Surface / genetics
  • Zona Pellucida Glycoproteins

Substances

  • Antigens
  • Bmp15 protein, mouse
  • Bone Morphogenetic Protein 15
  • Egg Proteins
  • Gdf9 protein, mouse
  • Growth Differentiation Factor 9
  • Membrane Glycoproteins
  • Nalp5 protein, mouse
  • Proto-Oncogene Proteins
  • RNA, Messenger
  • Receptors, Cell Surface
  • Tcl1 protein, mouse
  • Zona Pellucida Glycoproteins
  • Zp3 protein, mouse