Document from the year 2020 in the subject Biology - Genetics / Gene Technology, grade: PhD student, Southwest University, language: English, abstract: This book systematically introduces the basic knowledge of the Hypothalamic Pituitary Gonads (HPG) axis and provides information on the location and regulation, gene mutations, function, reproduction, life cycle, sexual behaviour, disorders and the role of the environmental factors on GnRH gene. Also, we focused on gene and receptor structures, and the signalling pathways of GnRH, and its related genes and hormones such as Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH), Progesterone (P4) and Oestradiol (E2). Also, it was pointed to Gonadotropin Inhibiting Hormone (GnIH) and its related peptides, such as RFamide peptides which were found to decrease hormones secretion by working on HPG in an inhibiting biosynthesis process of gonadotropin (a-ß) subunits. In addition, the roles of hormones on fertility and reproduction, also, disruption resulted from mutations. Special characteristics of many hormones and pulsatile secretions of GnRH were summarized. This information is necessary for an understanding way of work some necessary hormones also, elucidating reasons infertility. Although, several studies have presented a lot of kinds of regulators of expression for many genes related by fertility in many species, however, the knowledge of the relationship between molecular relating and infertility still has many gaps and problematic, also, many remains to be discovered, and a lot of significant questions (such as sexual behaviour, the regulation of gonadotropin secretion, and growth of tumour cell, in addition to; whether GnRHs are expressed as a full-length or not?), need to be solved, and mechanisms of pulsatile secretions and potential functions of many reproductive hormones need to be elucidated. So, this investigation very important for those researchers and readers to start solve and answer these questions and understanding many things related to (HPG) axis, and (GnRH).

Auteur

*Ahmed A. Saleh, MSc; Genetic Studies on small ruminant at Alexandria University. *MBA; Business Economics at Cairo University. *MSc; Human Resource Management at EL-Arish University*Assistant lecturer at Faculty of Agriculture, Alexandria University, Egypt. *PhD student at Southwest University, Chongqing, China.