title: Comparative analysis of follicle morphology and oocyte diameter in four mammalian species (mouse, hamster, pig, and human).
abstract: BACKGROUND
  Laboratory animals are commonly used for evaluating the physiological properties of the mammalian ovarian follicle and the enclosed oocyte. The use of different species to determine the morphological relationship between the follicle and oocyte has led to a recognizable pattern of follicular stages, but differences in follicle size, oocyte diameter and granulosa cell proliferation are not consistent across the different species. In an effort to better understand how these differences are expressed across multiple species, this investigation evaluates oocyte and follicle diameters and granulosa cell proliferation in the mouse, hamster, pig, and human.
  
  
  METHODS
  Histological sections of ovaries from the mouse, hamster, pig, and human were used to calculate the diameter of the oocyte and follicle and the number of granulosa cells present at pre-determined stages of follicular development. A statistical analysis of these data was performed to determine the relationship of follicular growth and development within and between the species tested.
  
  
  RESULTS
  These data have revealed that the relationships of the features listed are tightly regulated within each species, but they vary between the species studied.
  
  
  CONCLUSIONS
  This information may be useful for comparative studies conducted in different animal models and the human.
authors.affiliation: Andrology and IVF Laboratories, Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah 84108, USA.
authors.forename: Jeanine
authors.initials: J
authors.lastname: Griffin
authors.affiliation: Andrology and IVF Laboratories, Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah 84108, USA.|Department of Physiology, University of Utah School of Medicine, Salt Lake City, Utah 84108, USA.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Emery
authors.affiliation: Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA.
authors.forename: Ivan
authors.initials: I
authors.lastname: Huang
authors.affiliation: Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA.
authors.forename: C Matthew
authors.initials: CM
authors.lastname: Peterson
authors.affiliation: Andrology and IVF Laboratories, Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah 84108, USA.|Department of Physiology, University of Utah School of Medicine, Salt Lake City, Utah 84108, USA.|Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA.
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Carrell