نتایج جستجو برای: spermatogonia

تعداد نتایج: 1841  

Journal: :iranian journal of basic medical sciences 0
mohammad-reza esmaili-nejad graduated student of veterinary medicine, shahid bahonar university of kerman, kerman, iran homayoon babaei department of clinical sciences, faculty of veterinary medicine, shahid bahonar university of kerman, kerman, iran reza kheirandish department of pathobiology, faculty of veterinary medicine, shahid bahonar university of kerman, kerman, iran

objective(s):leptin is a novel and interesting hormone for anyone trying to lose weight, but its effects on male gonad structure in longitudinal study is unknown. the present study was designed to explore morphometrical changes of mouse testicular tissue after long-term administration of leptin. materials and methods:thirty healthy mature male mice were randomly assigned to either control (n=15...

2011
L. WEI K. M. PENG H. LIU H. SONG Y. WANG L. TANG Lan WEI Ke-Mei PENG Huazhen LIU Hui SONG Yan WANG Lia TANG

Th e aim of this study was to observe the microstructure and ultrastructure of the testis, demonstrate testicular cell development and apoptosis, and elucidate regularity of development and apoptosis in ostrich chick testes. By employing light microscopy 3 obvious development characteristics were detected with ostrich age increasing: fi rst, many primordial germ cells and a few spermatogonia we...

Journal: :Andrology 2014
Z Sahin A Szczepny E A McLaughlin M L Meistrich W Zhou I Ustunel K L Loveland

Although the contribution of Hedgehog (Hh) signalling to stem cell development and oncogenesis is well recognised, its importance for spermatogonial stem cells (SSCs) has not been established. Here we interrogate adult rat SSCs using an established model in which only undifferentiated spermatogonial cells remain in the testis at 15 weeks following irradiation, and spermatogonial differentiation...

2015
H. Zhang Y. Wang J. Zhan L. Wang Q. Li X. Sheng Y. Han Z. Yuan Q. Weng

The nerve growth factor (NGF) not only has an essential effect on the nervous system, but also plays an important role in a variety of non-neuronal systems, such as the reproductive system. The aim of this study was to investigate the seasonal changes in expression of NGF and its receptors (TrkA and p75) in testes of the wild ground squirrel during the breeding and nonbreeding seasons. Immunolo...

Journal: :Reproduction, nutrition, development 1997
M T Hochereau-de-Reviers C Perreau

This work was designed to elucidate, in foetal ovine testis, whether the reason why gonocytes do not differentiate into spermatogonia and do not initiate spermatogenesis is due to inadequate foetal environment (temperature and/or hormonal balance) or if somatic testicular cell proliferation is a prerequisite for initiation of male meiosis. The development and differentiation of gonocytes were a...

2013
Jennifer C. Perry Crystal T. Tse

Male costs of mating are now thought to be widespread. The two-spot ladybird beetle (Adalia bipunctata) has been the focus of many studies of mating and sexual selection, yet the costs of mating for males are unknown. The mating system of A. bipunctata involves a spermatophore nuptial gift ingested by females after copulation. In this study, we investigate the cost to males of mating and of tra...

Journal: :Stem cells 2014
Pawan Puri Bart T Phillips Hitomi Suzuki Kyle E Orwig Aleksandar Rajkovic Philip E Lapinski Philip D King Gen-Sheng Feng William H Walker

SHP2 is a widely expressed protein tyrosine phosphatase required for signal transduction from multiple cell surface receptors. Gain and loss of function SHP2 mutations in humans are known to cause Noonan and LEOPARD syndromes, respectively, that are characterized by numerous pathological conditions including male infertility. Using conditional gene targeting in the mouse, we found that SHP2 is ...

2013
Lisa Dovere Stefania Fera Margherita Grasso Dante Lamberti Cesare Gargioli Barbara Muciaccia Anna Maria Lustri Mario Stefanini Elena Vicini

In mammals, the biological activity of the stem/progenitor compartment sustains production of mature gametes through spermatogenesis. Spermatogonial stem cells and their progeny belong to the class of undifferentiated spermatogonia, a germ cell population found on the basal membrane of the seminiferous tubules. A large body of evidence has demonstrated that glial cell line-derived neurotrophic ...

2012
Skye C. McIver Simone J. Stanger Danielle M. Santarelli Shaun D. Roman Brett Nixon Eileen A. McLaughlin

The last 100 years have seen a concerning decline in male reproductive health associated with decreased sperm production, sperm function and male fertility. Concomitantly, the incidence of defects in reproductive development, such as undescended testes, hypospadias and testicular cancer has increased. Indeed testicular cancer is now recognised as the most common malignancy in young men. Such ca...

Journal: :The Journal of Cell Biology 1977
CF Millete AR Bellve

The temporal expression of cell surface antigens during mammalian spermatogenesis has been investigated using isolated populations of mouse germ cells. Spermatogenic cells at advanced stages of differentiation, including pachytene primary spermatocytes, round spermatids, and residual bodies of Regaud and mature spermatozoa, contain common antigenic membrane components which are not detected bef...

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