Sexual dimorphism in the neonatal gonad
| Autor: | N Coleman, A Cheng, Han N. Lim, J.R. Hawkins, K L Ng, S Faisal Ahmed, Ieuan A. Hughes |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Gonad Ovary Endocrine System Embryonic and Fetal Development Internal medicine Y Chromosome Testis medicine Humans Aromatase Testosterone Sex Characteristics biology Gonadal ridge luteinizing hormone/choriogonadotropin receptor Infant Newborn General Medicine Sex Determination Processes medicine.anatomical_structure Endocrinology Pediatrics Perinatology and Child Health biology.protein Female Luteinizing hormone Germ cell |
| Zdroj: | Acta paediatrica (Oslo, Norway : 1992). Supplement. 88(428) |
| ISSN: | 0803-5326 |
| Popis: | The neonatal gonad has two distinct forms (i.e., is sexually dimorphic), as judged by morphological and endocrine characteristics. The dimorphic process begins early in embryogenesis. It is well established by the time of birth, by which time the genital ridge has developed into either a testis or an ovary. The mechanisms involved in sex determination involve the Y chromosome, autosomal genes, transcription factors and possibly other unidentified control networks. This review paper describes the morphological changes that occur and the endocrine functions in the developing gonads. It highlights a number of important differences in fetal and neonatal gonadal function. The testis has early histological definition, several determining genes, delayed germ cell maturation, early autonomous steroid secretion, luteinizing hormone (LH) receptor and steroid enzyme expression, high fetal testicular testosterone content, prominent postnatal Leydig and Sertoli cells and high postnatal serum testosterone levels. The ovary has a prolonged monomorphic state, probably one determining gene, germ cells in early meiotic arrest, delayed expression of LH receptor and aromatase, low ovarian oestradiol content, prominent postnatal follicles and low postnatal serum oestradiol levels. |
| Databáze: | OpenAIRE |
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