(343) Folliculogenesis in the Domestic Cat

Anija Woods, Ramirrah Reid, Jaime Harris, Devineshia Walkins and Rajeev Chandra¹

Department of Biological Sciences, Hampton University, Hampton, VA

¹Associate Professor, Department of Biological Sciences, Hampton University, Hampton, VA, USA

Abstract Text:

The mammalian ovary is a unique organ comprised of many differentiated cell types all working in concert to promote normal function. Within the ovary, isolated follicular units composed of specialized cells surround each oocyte. The follicle aids in the development of a healthy oocyte, which upon appropriate endocrine signaling, will be ovulated and, perhaps, fertilized. The follicle plays a fundamental role in the female reproductive process as well as producing steroids necessary for normal function of the brain and skeletal and cardiovascular systems. Follicles mature through the highly orchestrated, yet complicated, process known as folliculogenesis, which is dependent on classic endocrine signaling within the hypothalamic–pituitary–gonadal axis. In addition, the ovary produces factors that proximally control follicle growth and development.

Folliculogenesis is the cycle of maturation of a follicle within the ovary of the adult human female. A follicle is a membranous sac of cells that contains an immature egg cell, called an oocyte. The primary investigation of this research includes a study identifying various stages of follicle development with particular reference to antral follicle development and their respective sizes during the estrous cycle and to describe follicular dynamics via Estradiol assay of the domestic cat, Felis catus. Follicular growth in the feline ovary is usually detected indirectly, through behavior observation, vaginal smears, or more invasively, by estradiol assay in blood.  This understanding will help enhance the ability to assess risk and develop preventative strategies of ovarian dysfunction such as Polycystic Ovarian Syndrome, as highlighted. Ovaries from adult female domestic cats were obtained from routine spaying procedures conducted at a local veterinary clinic. The primary methods utilized in the study include histology of the ovarian tissue and assaying plasma Estradiol via Enzyme Immunoassay. Briefly, ovaries were surgically removed during a spaying procedure at a veterinary clinic and washed in PBS. Ovarian tissue was fixed in formalin solution, followed by rinsing in a graded ethanol series (70%, 95%, 100%). Tissues were then embedded in paraffin, serially sectioned (5μm), mounted onto microscope slides, and stained with hematoxylin and eosin by a standard histological procedure. Gross follicular morphology, including their respective sizes, was evaluated for various developmental stages of the ovarian follicles.  Blood plasma samples were extracted for Estradiol assay.