1. Sponsor Organization: USDA-CSREES

2. Project Title: Hormonal Control of Reproduction in Cattle, Sheep and Swine

3. Project Focus:

• Project Primary Focus: Ecological Effects
• Project Secondary Focus: Human Health Effects

4. Description:

OBJECTIVES: The objectives of this research program are to better identify the basic mechanisms of gametogenesis, ovulation, capacitation, fertilization, and implantation of the embryo utilizing both laboratory and domestic animals as models. Particular emphasis will be placed on the effect of gonadotropin induction of ovulation on the chromsomal normality of the oocytes produced and the chromosome normality of the embryos produced following in vitro fertilizaiton. This work will be carried out in cattle, rabbits, hamsters, and mice. Additional studies examine the effects of xenogenous steroid hormones on implantation in the pig and particularly on placental physiological functions. The current studies are to identify toxic effects of PCGs and their metabolites on the reproductive process. APPROACH: In vitro fertilization and in vivo fertilization procedures will be used. Traditionally, this work, in mice, involves study of two-cell frozen mouse embryos. Despite these observations, one cell embryos are more sensitive to environmental conditions. Thus, we developed testing procedures using one-cell mouse embryos. No damage was apparent immediately after thawing and a high degree of in vitro development was observed, verifying the usefulness of this method for one-cell embryos. Additionally, two PCG (Aroclor) mixes were tested using the mouse in vitro fertilization system.

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6. Inventory Category:

• Primary: Models
• Secondary: Measure

7. Inventory Subcategory:

• Primary: Basic Research
• Secondary:
  • Exposure And Risk Models

8. Keywords for Experimental System/Species:

• Species:
  • Rodents
• Study Type:
  • In Vitro
  • Laboratory Study
• Fate and Transport:

9. Keywords for Experimental Endpoints:

• Health Effect:
  • Reproductive
• Hormonal Measures:
• Level Of Study:
  • Physiology
• Chemistry Metabolism:
• Life Stage:
  • Embryo
• Risk Assessment:
  • Biologically Based-Dose Response

10. Chemical Agents:

• Pcbs

11. Performing Institution:

• Animal Science ;Michigan State University ;East Lansing, MI 48824 ;

12. Contact:

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