Nucleolar extrusion in germinal cells of the human male gonad

1966 ◽  
Vol 53 (18) ◽  
pp. 486-486 ◽  
Author(s):  
D. Y. Tjioe ◽  
E. Steinberger
Keyword(s):  
Male Gonad ◽  
Human Male ◽  
Germinal Cells ◽  
Nucleolar Extrusion

Are sperm counts really falling?

1998 ◽  
Vol 10 (1) ◽  
pp. 93 ◽  
Author(s):  
D. M. de Kretser
Keyword(s):  
Semen Quality ◽  
Biological Significance ◽  
Point Of View ◽  
Male Gonad ◽  
The Past ◽  
Human Male ◽  
Sperm Counts ◽  
Short Period ◽  
Environmental Agents ◽  
Male Genital

Semen quality is said to have been declining over the past 50 years. The biological significance of these changes is emphasized by a concomitant increase in the incidence of genitourinary abnormalities such as testicular cancer and cryptorchidism. The increase in regional frequency of testicular abnormalities over a relatively short period of time may be due to local environmental factors, including the comparatively recent fashion for wearing tight-fitting underwear. Data also indicates that prenatal exposure to environmental agents can affect the development of the male genital tract. From the reproductive point of view, an increased environmental impact on the human male gonad is of concern and merits the development of sensitive techniques that can detect deleterious agents.

scholarly journals Differential Segregation Patterns of Sperm Mitochondria in Embryos of the Blue Mussel (Mytilus edulis)

Genetics ◽  
2004 ◽  
Vol 166 (2) ◽  
pp. 883-894
Author(s):  
Liqin Cao ◽  
Ellen Kenchington ◽  
Eleftherios Zouros
Keyword(s):  
Mitochondrial Dna ◽  
Mytilus Edulis ◽  
Blue Mussel ◽  
Uniparental Inheritance ◽  
Male Gonad ◽  
Doubly Uniparental Inheritance ◽  
Organelle Genomes ◽  
Somatic Tissues ◽  
Tight Linkage ◽  
Mitotracker Green

Abstract In Mytilus, females carry predominantly maternal mitochondrial DNA (mtDNA) but males carry maternal mtDNA in their somatic tissues and paternal mtDNA in their gonads. This phenomenon, known as doubly uniparental inheritance (DUI) of mtDNA, presents a major departure from the uniparental transmission of organelle genomes. Eggs of Mytilus edulis from females that produce exclusively daughters and from females that produce mostly sons were fertilized with sperm stained with MitoTracker Green FM, allowing observation of sperm mitochondria in the embryo by epifluorescent and confocal microscopy. In embryos from females that produce only daughters, sperm mitochondria are randomly dispersed among blastomeres. In embryos from females that produce mostly sons, sperm mitochondria tend to aggregate and end up in one blastomere in the two- and four-cell stages. We postulate that the aggregate eventually ends up in the first germ cells, thus accounting for the presence of paternal mtDNA in the male gonad. This is the first evidence for different behaviors of sperm mitochondria in developing embryos that may explain the tight linkage between gender and inheritance of paternal mitochondrial DNA in species with DUI.

THE INFLUENCE OF SERUM ON THE UPTAKE, CONVERSION AND ACTION OF DIHYDROTESTOSTERONE IN RAT PROSTATE GLANDS IN ORGAN CULTURE

1975 ◽  
Vol 64 (2) ◽  
pp. 289-297 ◽  
Author(s):  
ILSE LASNITZKI ◽  
HILARY R. FRANKLIN
Keyword(s):  
Organ Culture ◽  
Horse Serum ◽  
Target Tissue ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Human Pregnancy ◽  
Human Male ◽  
Columnar Cells

SUMMARY The influence of serum on the uptake, conversion and action of dihydrotestosterone in relation to the sex steroid binding protein, TeBG, has been investigated in rat ventral prostates in organ culture. The organs were incubated with [1,2-3H]dihydrotestosterone in: (1) serum-free medium, (2) horse serum, foetal and newborn bovine serum or (3) human male and human pregnancy serum. With all sera the uptake of dihydrotestosterone fell with rising serum concentration, at first steeply and then more gradually. At the same concentration, the uptake was significantly lower in explants incubated with human pregnancy serum than in those kept with human male serum. The conversion of dihydrotestosterone to androstanediol followed the same pattern and less androstanediol was formed in the presence of pregnancy serum. Since pregnancy serum contains higher amounts of TeBG than male serum, the lowered uptake suggests that only the free hormone was available to the target organ. Addition of unlabelled dihydrotestosterone resulted in a higher uptake than that measured in explants incubated with the labelled steroid only. The effect of the human sera on uptake and conversion was correlated with the androgenic activity of dihydrotestosterone applied at physiological concentrations and expressed as the percentage of secretory columnar cells present. The degree of maintenance closely corresponded to the uptake of the hormone. In serum-free medium, the number of columnar cells approached the values found in vivo, with male serum their number, though reduced, was still substantial, with pregnancy serum it was extremely low. It is concluded that the amounts of TeBG present in serum regulate the supply of the hormone to the target tissue and thus control its biological action.

A review of human male field studies of hormones and behavioral reproductive effort

2017 ◽  
Vol 91 ◽  
pp. 52-67 ◽  
Author(s):  
Peter B. Gray ◽  
Timothy S. McHale ◽  
Justin M. Carré
Keyword(s):  
Reproductive Effort ◽  
Field Studies ◽  
Human Male

scholarly journals Lead Acetate Induced Cytotoxicity in Male Germinal Cells of Swiss Mice.

2003 ◽  
Vol 41 (3) ◽  
pp. 291-294 ◽  
Author(s):  
U.R. ACHARYA ◽  
S. ACHARYA ◽  
M. MISHRA
Keyword(s):  
Lead Acetate ◽  
Swiss Mice ◽  
Germinal Cells

Fertility Studies in the Human Male with Traumatic Injuries of the Spinal Cord and Cauda Equina

1948 ◽  
Vol 239 (25) ◽  
pp. 959-961 ◽  
Author(s):  
Herbert W. Horne ◽  
David P. Paull ◽  
Donald Munro
Keyword(s):  
Spinal Cord ◽  
Cauda Equina ◽  
Traumatic Injuries ◽  
Human Male
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