title: Graded response to short photoperiod during development and early adulthood in Siberian hamsters and the effects on reproduction as females age.
abstract: Short day (SD) lengths delay puberty, suppress ovulation, inhibit sexual behavior, and decelerate reproductive aging in female Siberian hamsters (Phodopus sungorus). To date, the modulation of the age-associated decline in reproductive outcomes has only been demonstrated in female hamsters experiencing different day lengths during development. To determine if developmental delay is necessary for photo-inhibition to decelerate reproductive aging, hamsters raised in LD were transferred to SD as young adults and remained there for 6 months. Females that demonstrated the most immediate and sustained photo-inhibition were found to have greater numbers of ovarian primordial follicles at advanced ages (9 and 12 months) than did females held in LD, nonresponders to SD, and females with a marginal SD-response. Similarly, for females raised in SD from conception to 6 months of age, prolonged developmental delay was associated with greater numbers of primordial follicles at later ages as compared to hamsters that became refractory to SD. A robust response to SD in juvenile and adult hamsters is associated with decelerated reproductive aging, which may result in greater reproductive success in older females as compared to age-matched individuals demonstrating a more modest response to SD.
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA. njp27@cornell.edu
authors.forename: Ned J
authors.initials: NJ
authors.lastname: Place
authors.forename: Jenifer
authors.initials: J
authors.lastname: Cruickshank
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D054304:Anti-Mullerian Hormone / Q000097:blood; D000906:Antibodies / Q000032:analysis; D015415:Biomarkers; D006224:Cricetinae; D005260:Female; D006433:Hemocyanins / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000032:analysis / Q000096:biosynthesis; D008297:Male; D009929:Organ Size; D006080:Ovarian Follicle / Q000502:physiology; D017111:Phodopus; D017440:Photoperiod; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D014599:Uterus / Q000254:growth & development
chemical_list: D000906:Antibodies; D015415:Biomarkers; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D054304:Anti-Mullerian Hormone; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin