نتایج جستجو برای: testis sexual
تعداد نتایج: 137507 فیلتر نتایج به سال:
We asked if essentiality for either fertility or viability differentially affects sequence evolution of human testis proteins. Based on murine knockout data, we classified a set of 965 proteins expressed in human seminiferous tubules into three categories: proteins essential for prepubertal survival ("lethality proteins"), associated with male sub- or infertility ("male sub-/infertility protein...
Over the past decade, studies on reproductive morphology in the Squamata (snakes and lizards) have expanded tremendously. With the accumulation of these studies and revisions of the terminology based on structural similarities and differences, it is imperative to review the work on tuataras to determine whether the structural organization fits the revised terminology of vertebrates. We investig...
Sperm morphology varies considerably across taxa, and postcopulatory sexual selection is thought to be one of the main forces responsible for this diversity. Several studies have investigated the effects of the variation in sperm design on sperm function, but the consequences of variation in sperm design on testis morphology have been overlooked. Testes size or architecture may determine the si...
46,XX disorders of sexual development (DSDs) occur rarely and result from disruptions of the genetic pathways underlying gonadal development and differentiation. We present a case of a young phenotypic male with 46,XX SRY-negative ovotesticular DSD resulting from a duplication upstream of SOX9 presenting with a painful testicular mass resulting from ovulation into an ovotestis. We present a lit...
Prenatal caffeine exposure adversely affects the development of the reproductive organs of male rat offspring. Thus, it is conceivable that peripubertal caffeine exposure would also influence physiologic gonadal changes and function during this critical period for sexual maturation. This study investigated the impact of high doses of caffeine on the testes of prepubertal male rats. A total of 4...
The emergence of a new coronavirus, officially referred to as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 ), has challenged all healthcare workers and clinicians worldwide. presence the virus in biological fluids including semen raised some concerns about infertility treatment. There is evidence that SARS-CoV-2, which causes disease 2019 (COVID-19), can damage male reproductive ...
The outcome of sperm competition is influenced by the relative quantity and quality of sperm among competing ejaculates. Whereas it is well established that individual ejaculate traits evolve rapidly under postcopulatory sexual selection, little is known about other factors that might influence the evolution of ejaculates. For example, the metabolic rate is likely to affect the sperm production...
Sperm competition is widely recognized as a potent force in evolution, influencing male behavior, morphology, and physiology. Recent game theory analyses have examined how sperm competition can influence the evolution of ejaculate expenditure by males and the morphology of sperm contained within ejaculates. Theoretical analyses rest on the assumption that there is sufficient genetic variance in...
background and aims: quantum dots (qds), as colloidal nanocrystalline semiconductors, present qd wavelengths in terms of biomedical assays and imaging, though the high toxicity of their core demands to be taken into consideration. investigating this subject is taken into account as an important concept concerning use of these nanoparticles in the medical applications. materials and methods: 1...
An interstitial cell tumour of the testis produces a characteristic clinical picture. Starting between the ages of 2 and 6 years, the boy develops macrogenitosomia praecox with a raised excretion of urinary 17-ketosteroids. The tumour, which is usually unilateral and non-malignant, may not be obvious initially. Occasionally there is gynaecomastia. Penile erections are frequent. The behaviour ra...
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