title: Follicular size and stage and gonadotropin concentration affect alginate-encapsulated in vitro growth and survival of pre- and early antral dog follicles.
abstract: Understanding stage-specific requirements of mammalian folliculogenesis is limited in the domestic dog. The present study examined the effects of two potential regulators of dog follicle growth and survival in vitro, namely the original stage of the follicle (i.e. preantral (≤230µm diameter) vs early antral (diameter from >230 to ≤330µm) and FSH and/or LH concentrations. After isolation and alginate encapsulation, follicles were cultured in 0, 1, 10 or 100µgmL-1FSH and 0, 1 or 10ngmL-1LH for 20 days. Regardless of stage, FSH promoted growth, but LH did the same only in the absence of FSH. Production of 17β-oestradiol and progesterone was detectable, indicating theca cell activity. The greatest growth occurred in preantral (mean (± s.d.) 61.4±25.9%) versus antral (42.6±20.3%) follicles, but neither developmental stage nor gonadotropin affected survival. Antrum detection was minimal due, in part, to antral collapse, and oocytes exhibited an increasingly pale appearance and chromatin degeneration over time. The results demonstrate that pre- and early antral stage dog follicles encapsulated in alginate grow significantly in vitro. However, because FSH and LH alone or in combination fail to promote antrum development, the next step is identifying factors that enhance antral expansion.
authors.affiliation: Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA 22630, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Nagashima
authors.affiliation: Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA 22630, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Wildt
authors.affiliation: Baker Institute for Animal Health, Cornell University, Ithaca, NY 14583, USA.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Travis
authors.affiliation: Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA 22630, USA.
authors.forename: Nucharin
authors.initials: N
authors.lastname: Songsasen
mesh_terms: D000464:Alginates; D000818:Animals; D002470:Cell Survival / Q000187:drug effects* / Q000502:physiology; D003470:Culture Media / Q000737:chemistry; D004285:Dogs; D004958:Estradiol / Q000032:analysis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D007986:Luteinizing Hormone / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000187:drug effects* / Q000502:physiology; D011374:Progesterone / Q000032:analysis
chemical_list: D000464:Alginates; D003470:Culture Media; D006603:Hexuronic Acids; D011374:Progesterone; D004958:Estradiol; D020723:Glucuronic Acid; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone