title: Feeding prepubescent gilts a high-fat diet induces molecular changes in the hypothalamus-pituitary-gonadal axis and predicts early timing of puberty.
abstract: OBJECTIVE
  The onset of puberty in females has been occurring earlier over the past decades, presumably as a result of improved nutrition in developed countries. However, the underlying molecular mechanisms responsible for the early attainment of puberty as a result of nutrition fortification remain largely unknown. The aim of this study was to evaluate the hormone and gene expression changes in prepubescent gilts fed a high-fat diet to investigate whether these changes could predict the early timing of puberty.
  
  
  METHODS
  Forty gilts were fed a daily basal diet (LE) or a basal diet with an additional 270 g/d or 340 g/d of fat (HE) during the prepubescent phase. Blood samples were collected during the prepubescent phase to detect hormone secretion changes in insulin-like growth factor-1, kisspeptin, estradiol, progesterone, and leptin. The gene expressions at the hypothalamus-pituitary-gonadal axis were examined on day 73 of the experiment (average age on day 177) during the prepubescent phase.
  
  
  RESULTS
  An HE diet resulted in accelerated body weight gain and back-fat thickness at the P2 point compared with LE gilts during the prepubescent phase. Gilts that were fed HE diets attained puberty 12 d earlier than LE gilts, and a larger proportion of HE gilts reached puberty at day 180 or 190 of age. A postmortem analysis revealed a promoted development of the uterus and ovary tissue that was characterized by a 53.7% and 29.5% increase in the uterine and ovary weight, respectively, and an increased length of the uterine horn and oviduct tissue in HE gilts. Real-time quantitative polymerase chain reaction revealed that HE gilts had higher Kiss-1, G protein-coupled receptor 54, gonadotropin-releasing hormone and estrogen receptor α mRNA expression levels in the hypothalamic anteroventral periventricular nucleus; the leptin receptor mRNA expression level was higher in the hypothalamic arcuate nucleus and ovary tissue; the insulin-like growth factor-1 receptor expression was higher in the pituitary and ovary tissues, and the follicle-stimulating hormone and luteinizing hormone mRNA expression levels were higher in the pituitary gland.
  
  
  CONCLUSIONS
  These data showed that the consumption of additional fat can facilitate early attainment of puberty, which can be predicted by the changes in secreted hormones and gene expression in the hypothalamus-pituitary-gonadal axis.
authors.affiliation: Institute of Animal Nutrition, and Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China, Sichuan Agricultural University, Ya'an, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhuo
authors.affiliation: Institute of Animal Nutrition, and Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China, Sichuan Agricultural University, Ya'an, PR China; Shenzhen Premix Inve Nutrition Co. Ltd, Shenzhen, PR China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Institute of Animal Nutrition, and Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China, Sichuan Agricultural University, Ya'an, PR China.
authors.forename: Lianqiang
authors.initials: L
authors.lastname: Che
authors.affiliation: Institute of Animal Nutrition, and Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China, Sichuan Agricultural University, Ya'an, PR China.
authors.forename: Zhengfeng
authors.initials: Z
authors.lastname: Fang
authors.affiliation: Institute of Animal Nutrition, and Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China, Sichuan Agricultural University, Ya'an, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Institute of Animal Nutrition, and Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China, Sichuan Agricultural University, Ya'an, PR China. Electronic address: Pig2pig@sina.com.cn.
authors.forename: De
authors.initials: D
authors.lastname: Wu
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D006728:Hormones / Q000235:genetics / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism; D011627:Puberty / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012741:Sexual Maturation / Q000187:drug effects* / Q000235:genetics; D013552:Swine; D014599:Uterus / Q000187:drug effects; D015430:Weight Gain / Q000187:drug effects
chemical_list: D004041:Dietary Fats; D006728:Hormones; D012333:RNA, Messenger
keywords: Gene expressions; Gilts; High-fat diet; Hormone; Puberty