A5059082385- Sperm and Testicular Function
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Reproductive Biology and Fertility
- Reproductive biology and impacts on aquatic species
- Sexual Differentiation and Disorders
- Animal Genetics and Reproduction
- Hormonal and reproductive studies
- Effects and risks of endocrine disrupting chemicals
- Testicular diseases and treatments
- Birth, Development, and Health
- RNA Interference and Gene Delivery
- CRISPR and Genetic Engineering
- Ovarian function and disorders
- Reproductive Physiology in Livestock
- Reproductive Health and Technologies
- Genetics, Aging, and Longevity in Model Organisms
- Veterinary Medicine and Surgery
- Fish Ecology and Management Studies
- Anesthesia and Neurotoxicity Research
- Regulation of Appetite and Obesity
- Animal Ecology and Behavior Studies
- Pluripotent Stem Cells Research
- Bat Biology and Ecology Studies
- Dietary Effects on Health
- Wildlife Ecology and Conservation
Universidade Federal de Minas Gerais
2013-2024
National Institute of Amazonian Research
2016-2020
Morpho (United States)
2007-2015
Universidade Estadual do Maranhão
2012
The University of Texas MD Anderson Cancer Center
2012
University of Calgary
2012
University of California, Davis
2012
Faculdades Guarulhos
2007
Southern Illinois University School of Medicine
1993-2007
Universidade Federal de Viçosa
1999
Spermatogenesis is one of the most productive self-renewing systems in body: on order 10(7) spermatozoa are produced daily per gram testis tissue. In each mammalian species, time required for completion process unique and unalterable. Because supported by somatic Sertoli cells, it has generally been thought that cell-cell interaction between germ cells controls duration cell cycles cellular organization. We have used newly developed technique spermatogonial transplantation to examine which...
Histometrical evaluation of the testis was performed in 36 Piau pigs from birth to 16 mo age investigate Sertoli cell, Leydig and germ cell proliferation. In addition, blood samples were taken seven animals 1 wk adulthood measure plasma levels FSH testosterone. proliferation shows two distinct phases. The first occurs between age, when number cells per increases approximately sixfold. second 3 4 or just before puberty, which 5 almost double their numbers testis. periods concomitant with high...
The zebrafish has become an important vertebrate model for basic and biomedical research, including the research field of biology reproduction. However, very few morphological stereological data are available regarding testis structure spermatogenesis. In this careful histomorphometric evaluation testis, we studied spermatogonial cells using molecular markers, determined combined duration meiotic spermiogenic phases, examined formation Sertoli cell barrier (tight junctions). We found at...
Background Germ cell transplantation results in fertile recipients and is the only available approach to functionally investigate spermatogonial stem biology mammals probably other vertebrates. In current study, we describe a novel non-surgical methodology for efficient into testes of adult tilapia (O. niloticus), which endogenous spermatogenesis had been depleted with cytostatic drug busulfan. Methodology/Principal Findings Using two different strains, production spermatozoa donor...
Background Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis, and reside within a specific microenvironment in testes called “niche” which regulates cell properties, such as, self-renewal, pluripotency, quiescence their ability to differentiate. Methodology/Principal Findings Here, we introduce zebrafish as new model for study SSCs vertebrates. Using 5′-bromo-2′-deoxyuridine (BrdU), identified long term BrdU-retaining germ cells, type A undifferentiated spermatogonia...
Fetal growth plays a role in programming of adult cardiometabolic disorders, which men, are associated with lowered testosterone levels. and fetal androgen exposure can also predetermine levels although how is unknown, because the Leydig cells (ALCs) that produce do not differentiate until puberty. To explain this conundrum, we hypothesized stem for ALCs must be present testis might susceptible to by during masculinization. address hypothesis, used ALC ablation/regeneration identify that,...
Germ cell survival and development critically depend on the cells' contact with Sertoli cells in vertebrate testis. Fish amphibians are different from mammals that they show a cystic type of spermatogenesis which single germ clone is enclosed by accompanied through stages an accompanying group cells. We maturing adult testes African catfish Nile tilapia, proliferation occurs primarily during spermatogonial proliferation, allowing cyst-forming to provide increasing space required growing...
The observation that mice with a selective ablation of the androgen receptor (AR) in Sertoli cells (SC) (SCARKO mice) display complete block meiosis supports contention SC play pivotal role control germ cell development by androgens. To delineate physiological and molecular mechanism responsible for this control, we compared tubular pubertal SCARKO littermate controls. Particular attention was paid to differences maturation, barrier formation cytoskeletal organization mediators potentially...
Growth factors modulate germ line stem cell self-renewal and differentiation behavior. We investigate the effects of Igf3, a fish-specific member igf family. Fsh increased in steroid-independent manner number mitotic index single type A undifferentiated spermatogonia clones differentiating adult zebrafish testis. All 4 gene family members are expressed testis but tissue culture only igf3 transcript levels response to recombinant Fsh. This occurred cAMP/protein kinase A-dependent manner, with...
Abstract Background : The testes of rats treated neonatally with propylthiouracil (PTU) grow to almost twice their normal size. cause testicular enlargement has been suggested be the result delayed maturation Sertoli cells, allowing cell division occur beyond 15th postnatal day, commonly recognized cutoff date for divisions. It shown that an increased population cells in development supports numbers germ adult animals. After examining developing PTU, we hypothesized approximate 10‐day delay...
Background information . Efferent ductules reabsorb more than 90% of the rete testis fluid, a process that involves ion transporters and AQP (aquaporin) water channels. Oestrogen has been shown to modulate expression involved in this activity, but reports regulation male tract have confounding. To understand better AQP1 AQP9, we investigated their rat efferent initial segment epididymis after treatment with pure antioestrogen ICI 182,780 or bilateral duct ligation, castration, followed by...
The wild boar is a natural inhabitant of Europe, Asia, and North Africa phylogenetically the ancestor domestic pig. Because its phylogenetic economic importance, this species an interesting model for studying testis function in boars. Therefore, present study was performed to investigate structure, spermatogenic cycle length, Sertoli cell (SC) efficiencies eight adult Each lasted 9.05 days, total duration spermatogenesis estimated as lasting approximately 41 days. percentages volume occupied...
Thyroid hormones participate in regulating growth and homeostatic processes vertebrates, including development adult functioning of the reproductive system. Here we report a new stimulatory role thyroid hormone on proliferation Sertoli cells (SCs) single, type A undifferentiated spermatogonia (A(und)) zebrafish testes. for T3 testis is suggested by situ hybridization studies, which localized receptor α (thrα) SCs β (thrβ) mRNA Leydig cells. Using primary tissue culture system, effect steroid...
Development of spermatogonial transplants was studied by using 5- to 6-wk-old histocompatible mice as cell donors and sterile (W-locus) recipients. Groups animals transplanted with germ suspensions were killed at 10 min, 9 h, 24 1 wk, mo, 2 3 mo along age-matched “start” “end” W-locus controls. Weight testes increased significantly h through after transplantation, suggesting that the infused cells quickly stimulated organ function. Small clones young spermatocytes evident sperm mo. The...
Abstract It is established that androgens and unidentified Sertoli cell (SC)-derived factors can influence the development of adult Leydig cells (LC) in rodents, but mechanisms are unclear. We evaluated LC function SC-selective androgen receptor (AR) knockout (SCARKO) complete AR (ARKO) mice. In controls, number increased 26-fold size by approximately 2-fold between 12 140 d age. SCARKOs was normal on 12, reduced more than 40% at later ages, although were larger contained lipid droplets...
ABSTRACT: Xenografting of immature mammalian testis tissue into mice can accelerate sperm production. To determine whether this shortened time to production is because reduced length the spermatogenic cycle, we applied bromodeoxyuridine (BrdU) incorporation analyze cycle in porcine and ovine xenografts. Small fragments from newborn pigs sheep were ectopically grafted mice. Once complete spermatogenesis was present tissue, injected with BrdU grafts recovered at different points thereafter. In...