نتایج جستجو برای: testis sexual
تعداد نتایج: 137507 فیلتر نتایج به سال:
Bisphenol A (BPA) is a synthetic endocrine-disrupting chemical of high prevalence in the environment, which may affect the function of the hypothalamic-pituitary-testis (HPT) axis in adult rats. The aim of the present study was to evaluate whether exposure to BPA during hypothalamic sexual differentiation at doses below the reproductive no observable adverse effect level of the World Health Org...
The development of male sexual maturity varies among buffaloes. The Murrah buffalo is considered the most important and efficient milk and fat producer, but aspects of its reproductive biology are still unknown. The present study aimed to evaluate the daily sperm production (DSP) and spermatogenesis in developing Murrah buffalo bulls by evaluation of the seminiferous tubules, testicular morphom...
Most of the earlier investigations on the gonads of teleosts have been concerned with the lineage of germ-cells (Nussbaum, 1880; Eigenmann, 1891; Dodds, '10; Sink, '12; and Bachmann, '14). The structural development of the radialtype testis, as well as the history of the germ-cells in Cottus, was described by Hann ( '27). Essenberg ( '23) traced the development of the acinus-type testis in Xiph...
Genes involved in sex determination and differentiation have been identified in mice, humans, chickens, reptiles, amphibians and teleost fishes. However, little is known of their functional conservation, and it is unclear whether there is a common set of genes shared by all vertebrates. Coelacanths, basal Sarcopterygians and unique "living fossils", could help establish an inventory of the ance...
ناباروری( infertility) یکی از جدی ترین مشکلات اجتماعی در کشورهای پیشرفته است.تقریبا15% از زوج ها با موارد مختلف ناباروری مواجه میشوندو علت 50% از ناباروری این زوج ها مربوط به فاکتورهای وابسته به مردان است. بر اساس تحقیقات موجود علل ناباروری در مردان بیشتر در طی فرایند اسپرماتوژنز ( spermatogenesis) صورت می گیرد. تغییرات ژنتیکی در ژنهایی که در این فرایند درگیر هستند نقش مهمی در اختلالات روند اس...
The process of ageing is associated with negative effects of mutations acting late in life, which range from those affecting cells to those affecting the whole organism. In many animal taxa, the deterioration of the phenotype with age also affects traits such as males’ primary and secondary sexual characteristics. In three-spined sticklebacks (Gasterosteus aculeatus), males usually reproduce at...
Background. 47XYY syndrome is a rare sex chromosome variation characterized by an additional Y chromosome. Most patients with 47XYY karyotype have normal phenotype. This disorder seems associated with a higher risk of developing behavioral and cognitive problems, tall stature, and infertility in adulthood. Sexual development disorder is a rare finding. We report a first case with an abnormal le...
Genes previously implicated in mammalian sexual development have either a male- or female-specific role. The signaling molecule WNT4 has been shown to be important in female sexual development. Lack of Wnt4 gives rise to masculinization of the XX gonad and we showed previously that the role of WNT4 was to inhibit endothelial and steroidogenic cell migration into the developing ovary. Here we sh...
The process of ageing is associated with negative effects of mutations acting late in life, which range from those affecting cells to those affecting the whole organism. In many animal taxa, the deterioration of the phenotype with age also affects traits such as males' primary and secondary sexual characteristics. In three-spined sticklebacks (Gasterosteus aculeatus), males usually reproduce at...
The Sry locus on the mammalian Y chromosome is the developmental switch responsible for testis determination. Inconsistent with this important function, the Sry locus is transcribed in adult males at times and in tissues not involved with testis determination. Sry is expressed in multiple tissues of the peripheral and central nervous system. Sry is derived from Sox3 and is similar to other SOXB...
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