title: Effect of RFRP-3 on reproduction is sex- and developmental status-dependent in the striped hamster (Cricetulus barabensis).
abstract: RFamide-related peptides (RFRPs) are orthologous to gonadotropin-inhibitory hormone (GnIH) inhibiting gonadotropin release. There are only two RFRP sequences (RFRP-1 and RFRP-3) encoded in rodents. RFRP-3, which was considered as a hypothetical inhibitor on GnRH, shows a stimulatory effect on the male Syrian and male Siberian hamster in short days. As a dominant rodent pest in northern China farmland, the striped hamster (Cricetulus barabensis) has higher reproductive activities and could act as a model to study the mechanism of reproduction. However, the effect of RFRP-3 on the reproductive activity for the striped hamster is less understood. In the study, we cloned 643 bp RFRP cDNA from the striped hamster hypothalamus, which contained an ORF of 570 bp encoding two RFamide-related peptide (RFRP) sequences: SPAPANKVPHSAANLPLRF-NH2 (C. barabensis RFRP-1) and TLSRVPSLPQRF-NH2 (C. barabensis RFRP-3). We also investigated the expression variation of RFRP mRNA and GnRH mRNA in the hypothalamus from hamsters with different developmental statuses (7-week-, 13-week- and 1.5-year-olds) using FQ-PCR, in which the 13-week-old female individuals were in estrous. The striped hamsters that are 7 weeks and 1.5 years old are non-breeding individuals, and those that are 13-week hamsters have breeding phenomena. The highest hypothalamus RFRP mRNA level was found in breeding males as compared to non-breeding males. Conversely, the lowest RFRP mRNA level in the hypothalamus was observed in breeding females, with no significant level when the breeding females were compared to the 7-week-old individuals. Additionally, the investigation of GnRH expression level showed a declining expression trend across the developmental stages (7-week-, 13-week- and 1.5-year-olds) in both sexes. Significant negative and positive relationships were detected in the 13-week estrous female (r=-0.997, P=0.035) and the 13-week male (r=0.998, P=0.029) striped hamsters respectively, which suggest that RFRP-3 has inhibitory and stimulatory effects on female and male adults respectively. Our results suggest that the effects of RFRP-3 on reproduction are sex- and developmental status-dependent in the striped hamster.
authors: College of Life Science, Qufu Normal University, 273165, China.
authors: Lei
authors: L
authors: Zhao
authors: College of Life Science, Qufu Normal University, 273165, China; Department of Biological Sciences, Auburn University, AL 36849, USA.
authors: Min
authors: M
authors: Zhong
authors: College of Life Science, Qufu Normal University, 273165, China.
authors: Hui-Liang
authors: HL
authors: Xue
authors: College of Life Science, Qufu Normal University, 273165, China.
authors: Ji-Shun
authors: JS
authors: Ding
authors: College of Life Science, Qufu Normal University, 273165, China.
authors: Shuo
authors: S
authors: Wang
authors: College of Life Science, Qufu Normal University, 273165, China.
authors: Jin-Hui
authors: JH
authors: Xu
authors: College of Life Science, Qufu Normal University, 273165, China.
authors: Lei
authors: L
authors: Chen
authors: College of Life Science, Qufu Normal University, 273165, China. Electronic address: xulx@mail.qfnu.edu.cn.
authors: Lai-Xiang
authors: LX
authors: Xu
mesh_terms: D000367:Age Factors; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D006224:Cricetinae; D003412:Cricetulus / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism; D007031:Hypothalamus / Q000254:growth & development / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012098:Reproduction; D012737:Sex Factors
chemical_list: D009479:Neuropeptides; C416987:RFamide peptide; D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone
keywords: Developmental status; GnRH; RFRP-3; Sex; The striped hamster