Tag: "testis" at biology news
Stem cells toward sperm cells and back again
...lies, we literally can count each stem cell in the testis
because we can detect proteins that distinguish them, and we know exactly where the stem cells are supposed to be," says Matunis. "In fruit flies, we also know the signal that keeps the stem cells in their primitive state, and we can turn it off and ...
Hormone linked to obesity plays positive role in fertility & possibly male arousal
...eptors for orexins in a number of areas within the testis
and penis. These areas include the: Testicular cells responsible for making testosterone, the primary male sex hormone, and in tubules that are responsible for producing sperm. They are also present in an area called the epididymis, implicating ...
U. Chicago study overturns conclusion of historic human genome data
...n of X-derived autosomal genes that express in the testis
using the fruit fly, work published in Genome Rese...percent of the genes leaving the X chromosome have testis
expression, compared to 44 percent of genes that jump from autosome to autosome. The researchers not...
UT Southwestern researchers learn importance of insulin family signaling in male sex determination
...nd the exact pathway required for the formation of testis
in different species," she said. "Sry, for example...omes potentially interesting for playing a role in testis
formation in other species as well." Other UT Southwestern contributors to the Nature study were Dr....
Finished Y-chromosome sequence reveals a genomic 'crystal palace'
...he ampliconic sequences are very restricted to the testis
in their expression. And to the extent that we've studied them in detail, it looks like they're actually expressed in only in the spermatogenic cells themselves." Thus, said Page, these genes are likely to play an extremely important role in generati...
US researchers find first conclusive evidence that lead is linked to male infertility
... suggest that lead is acting at multiple levels in testis
and sperm to decrease human male fertility. "Our data also confirm that increased seminal plasma lead levels can occur without any detectable effects on male reproductive hormone function and also that they are associated with decreased sperm concent...
Sertoli cell transfer restores sperm production in infertile mice
...nt takes place." Much of the volume of a mammalian testis
consists of tightly coiled seminiferous tubules that hold mature sperm. Sperm development also occurs within these tubules, which are home to spermatogenic stem cells, the seeds from which spermatogenesis arises. Seminiferous tubules are lined with...
New study promises safer hormone replacement therapy
...female mice. Some of the mice had their ovaries or testis
removed, to halt the production of their natural sex hormones. These mice showed a 6-percent loss in bone density, a 23-percent loss in bone strength, and, in the female mice, a 71-percent loss in the weight of the uterus. The researchers then gave...
Rad50 and the maintenance of genome stability
...haracterized by a ~50% decrease in size and severe testis
and bone marrow cell attrition, causing a large number of the mice to die early on (by age 3 months) due to the severe anemia that results from progressive bone marrow depletion. Longer-lived Rad50-mutant mice exhibited a predisposition to lymphoma d...
Mice become first animals to produce other species' sperm
... sperm from three different mammals indicates that testis
tissue grafting may be applicable to a wide variet...urity. Unlike cryonic approaches to preservation, testis
tissue grafting offers a potentially inexhaustible supply of male gametes. Mice with the testis
Making embryos male
...mbryo. Fetal Leydig cells are the cells within the testis
that produce testosterone during development, and thereby impart secondary male sex characteristics to the embryo, including the internal and external male genitalia. This discovery posits DHH as the only known factor to induce fetal Leydig cell dif...
Newly found estrogen role in males might lead to contraceptive for men
...ion during the transfer of sperm in fluid from the testis
through the efferent ductules to the epididymis, where sperm matures and is stored. The PNAS paper provides a molecular picture of what estrogen does. Efferent ductules are small tubes that produce concentrated semen. In a series of experiments usi...
A parvovirus may be linked to infertility in men say German scientists
...n with normal semen. The researchers also analysed testis
samples from 38 men participating in an ICSI** programme, whose semen contained no sperm. They wanted to see whether it was possible for sperm to be infected during maturation. Ten of the samples carried AAV DNA. The research team said that further v...
Male infertility: Scientists discover candidate gene for impaired spermatogenesis
...hat the ZNF214 gene mainly expresses itself in the testis
and is located on chromosome 11p15. This part of the chromosome is linked to the Beckwith Wiedemann Syndrome (BWS) a complex overgrowth disorder, which often involves boys being born with undescended testicles (cryptorchidism) who suffer from infer...
TDS - a new syndrome hitting men's reproductive health says Danish fertility expert
...ubfertility. In Finland, for example the rates of testis
cancer, undescended testis
and hypospadias are lower than among Danish men. But Danish men have poorer semen quality." ...
Tissue proteolysis and male infertility
...the activity of multiple serine proteinases in the testis
is greatly increased in the mutant males. Presumab...pe females. Because of the multiple defects in the testis
that could account for the abnormalities in the sperm, the present findings do not address whether t...
Scientists discover gene required for testis development
Dmrt1 is required for mammalian testis
differentiation In the October issue of Genes ...the gene, Dmrt1, is essential for normal mammalian testis
development. This work provides the first functional evidence that Dmrt1 is required for male sexua...
Disposable nappies may explain the increase in male infertility
... Leading article: How vulnerable is the developing testis
to the external environment? 2000;83:281-2 The use of disposable nappies may explain the increase in male infertility over the past 25 years, suggests a study in the Archives of Disease in Childhood. Nappies lined with plastic si...
Northwestern researchers map gene mutation that makes mice deaf and causes them to dance
...years ago, first in intercellular junctions in the testis
and later in the kidney and intestine. "Because espins were originally discovered in these organs, we never would have guessed that these proteins would be so important for the functioning of hair cells in the inner ear," Bartles said. Bartles and co...
UCSF researchers find evidence of faulty DNA repair in some infertile men
...ive DNA repair," Reijo Pera said. "We asked if the testis
tissue of these infertile men showed certain "fingerprints" characteristic of a problem repairing DNA." The current UCSF study included five men with normally functioning testes and five whose testes made little or no sperm, also called testes fail...