نتایج جستجو برای: spermatogenesis
تعداد نتایج: 8138 فیلتر نتایج به سال:
Spermatogenesis- and oogenesis-specific helix-loop-helix transcription factor 2 (SOHLH2) is exclusively expressed in germ cells of the gonads. Previous studies show that SOHLH2 is critical for spermatogenesis in mouse. However, the regulatory mechanism of SOHLH2 during early spermatogenesis is poorly understood. In the present study, we analyzed the gene expression profile of the Sohlh2-deficie...
1. Male guinea-pigs were assigned to four different groups at birth. The heaviest group of animals was severely undernourished from 21 d of age (weight gain: 1.2 g/d v. 10 g/d for normally-fed animals). 2. At 35, 45, 55 and 65 d of age in normally-fed animals, and at 45 and 55 d of age in undernourished animals, blood testosterone levels were determined by radioimmunoassay, epididymidal tissue ...
Observations of the external morphology of wild-caught and captive male brown long-eared bats (Plecotus auritus) revealed a marked seasonal pattern of spermatogenesis, similar to that established by histological examination of other temperate-zone vespertilionids, with a peak in testes size in August and a lag between testicular growth and epididymal distension. This was followed by complete ce...
The Drosophila polypyrimidine tract-binding protein (dmPTB or hephaestus) plays an important role during spermatogenesis. The heph2 mutation in this gene results in a specific defect in spermatogenesis, causing aberrant spermatid individualization and male sterility. However, the array of molecular defects in the mutant remains uncharacterized. Using an unbiased high throughput sequencing appro...
BACKGROUND Spermatogenesis is the complex process by which diploid stem cells generate haploid germ cells in gamete production. Members of the Xlr (X-chromosome linked, lymphocyte regulated) superfamily play essential roles in spermatogenesis. The expression, localization and role in spermatogenesis of one such member, Xlr5c, has not been reported previously. METHODOLOGY/PRINCIPAL FINDINGS Xl...
The importance of gonadotropins and androgens for spermatogenesis is generally accepted in vertebrates, but the role played by specific hormones has not been clarified. Under cultivation conditions, male Japanese eels (Anguilla japonica) have immature testes containing only premitotic spermatogonia, type A and early-type B spermatogonia. In the present study, a recently developed organ-culture ...
The objective of research was to determine the sensitivity, specificity and positive predictive value of serum follicle stimulating hormone and testis size in predicting spermatogenesis in infertile men with azoospermia. In a prospective study, azoospermic men were studied. Serum follicle stimulating hormone measurement and scrotal sac ultrasonography were performed. Bilateral testis biopsy was...
Androgens are essential for normal spermatogenesis and male fertility, but how androgens exert this effect remains uncertain. Androgen receptors (ARs) are expressed in several testicular cell types, but continuing uncertainty exists over which cell type mediates androgen control of spermatogenesis. Androgen signaling via Sertoli cells (SCs) is essential for complete spermatogenesis, but the rol...
Y chromosome microdeletion is the most important genetic cause of impairment of spermatogenesis. Nevertheless, a significant proportion of patients with spermatogenic failure do not have this condition. This study investigated the expression level of AZF genes, DDX3Y (DBY), RBMY1, DAZ and TSPY in testicular tissues of 42 subjects with impaired spermatogenesis compared with 33 with normal sperma...
Feral raccoons (Procyon lotor) have been increasing in number since 1979 and are currently subject to pest control in Hokkaido. One of the reasons for the increase in numbers is thought to be the high reproductive potential of raccoons, but little is known about their reproduction. The main aim of this study was to clarify seasonal changes in spermatogenesis and peripheral testosterone concentr...
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