Gonads

A stronger backbone: DHEA hormone replacement increases bone density in older women

... more favorable effects on bone density." DHEA (dehydroepiandrosterone), a naturally occurring steroid hormone produced in the adrenal gland, gonads and brain, decreases with age. According to Weiss, low DHEA concentration has been associated with low bone density, which lead researchers to ...

American Chemical Society's Weekly PressPac -- Jan. 30, 2008

... distinctive, gender-related plumage. Since birds lack external genital organs, sexing a bird typically involves endoscopic examination of the animals gonads under general anesthesia or specific molecular biological methods. Since these methods are expensive, time-consuming, and stressful for the bird, ...

'Gender-Benders': Sports and Sex Determination

... tests to be gender- biased and unfair to women born with rare genetic abnormalities and who have sexual developmental deficiencies involving the gonads and the external genitalia. Several others opine that these tests are inaccurate, besides being insensitive and humiliating. The sex determination ...

Long-life genes - A new way to combat cancer…

... sensory neurons in the brain. In the study, the team mutated a tumor suppressor gene called gld-1 in the worms, causing cells in the animals' gonads to divide rapidly and form germ-line tumors. These tumor cells, when left undisturbed, break out of the gonad and fill the body, killing the worm at ...

Aggression And Fatherly Behavior: Men Have It In Their Genes

... determines if a growing embryo should develop into a male or female formed the main focus of the study. The presence of SRY gene causes the primitive gonads to develop into testis (the male gland that produces sperms and male sex hormones). The gene is believed to be partially responsible for aggressive ...

Gonads in Medical Products

DHEA RIA Test

Description:... Dehydroepiandrosterone (DHEA) is produced in the adrenal cortex and, to a lesser extent, the gonads [1,2,3]. DHEA serves as a precursor in testosterone and estrogen synthesis, and has relatively weak androgenic activity, estimated at ~10% that of ...
Company:Diagnostic Systems Laboratories, Inc.

DHEA EIA Test

Description:... Dehydroepiandrosterone (DHEA) is produced in the adrenal cortex and, to a lesser extent, the gonads [1,2,3]. DHEA serves as a precursor in testosterone and estrogen synthesis, and has relatively weak androgenic activity, estimated at ~10% that of ...
Company:Diagnostic Systems Laboratories, Inc.

17a-OH Progesterone RIA Test

Description:... 17alpha-OH-Progesterone (17alpha-OH-P) is a steroid produced in the adrenal gland and gonads and has no defined physiological role except as a precursor molecule. In the adrenal glands, 17alpha-OH-P can be converted to cortisol by the ...
Company:Diagnostic Systems Laboratories, Inc.

17a-OH Progesterone EIA Test

Description:... 17alpha-OH-Progesterone (17alpha-OH-P) is a steroid produced in the adrenal gland and gonads and has no defined physiological role except as a precursor molecule. In the adrenal glands, 17alpha-OH-P can be converted to cortisol by the ...
Company:Diagnostic Systems Laboratories, Inc.

Estrone RIA Test

Description:... natural estrogens include estradiol and estriol. Estrone is produced primarily from androstenedione originating from either the adrenal cortex or gonads [1,2]. In premenopausal adult women, more than 50% of estrone is secreted by the ovary. In prepubertal children, men and postmenopausal women, the ...
Company:Diagnostic Systems Laboratories, Inc.

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Gonads in Medical Definition

Pathology

... ) - Hyperaldosteronism ( Conn syndrome , Bartter syndrome ) - Adrenal insufficiency ( Addison's disease ) - Hypoaldosteronism gonads Polycystic ovary syndrome - 5-alpha-reductase deficiency - Hypogonadism - Delayed puberty - Precocious puberty Other Autoimmune ...

Gonads in Biological News

Playing it safe

... them to form over 200 of the body's cell types. In fact, a number of researchers have recently stumbled on the multiple talents in the male gonads of humans and mice. It all began with the work of Takashi Shinohara's team in 2004. The Japanese scientists discovered that, like embryonic stem ...

Changing sexes on the sea floor

... out the storm," so to speak, says Prof. Loya. "Males are less expensive in the evolutionary sense to maintain. They are cheaper in terms of their gonads and the energy needed to maintain their bodies," he adds. He also notes that this theory probably doesn't apply to humans, even those who have ...

Female embryonic sexual development driven by universal factor

... the ovaries, the researchers developed a mouse embryo in which the beta-catenin gene could be shut off at the earliest stage of development of the gonads while remaining functional in other organs. "To our surprise, the ovaries still formed," Yao said. But male sexual structures also appeared, ...

Eliminating germline lengthens fly lifespan, Brown study shows

... Tatar said the team found a possible explanation for the paradox. In reaction to the flies brains boosting insulin production, the insects gonads their ovaries or testes produce a protein that acts like a sponge, binding to the insulin and blocking its signals throughout the body. So the ...

Scientists alter sexual orientation in worms

... they crawled toward the pheromones of other hermaphrodites. "People debate whether the brain is influenced by sexual hormones from the gonads or whether the behavior is derived from the brain alone, Jorgensen says. In this case, its clear the brain is sexualized. The surprise was that ...

Sudden change in social status triggers genetic response in male fish, study finds

... hormones--chemical signals from the brain to the gonads that regulate sexual development in all ... his appearance changes dramatically and his gonads mature. When the male descends in status, the ... yet it's reading from his brain right down to his gonads in a way that has to have a cellular and ...

Genetic tug of war determines sexual differentiation

... or an ovary. During the earliest stages of development, both XX and XY gonads are characterized by similar patterns of Sox9, Fgf9 and Wnt4 expression. ... "Based on our findings, we believe that the ultimate fate of the early gonads is controlled by mutually antagonistic signals between Fgf9 and Wnt4." ...

The influence of the menstrual cycle on the female brain

... menstrual cycle that begins after ovulation and ends on the last day of the period. 6. Gonadal neurosteroids: steroidal hormones produced by the gonads (ovaries and testicles), which interact with estrogen receptors, progesterone or androgens. 7. Luteinizing hormone (LH) is a hormone produced ...

Gonads in Biological Definition

Gamete

... a spermatozoon (or sperm). The equivalent "male" structure in higher plants is called a pollen grain . Organs that produce gametes are called gonads in animals , and archegonia or antheridia in plants . Gametes are haploid cells; that is, they contain one complete set of chromosomes ...

Hormone

... Examples of protein hormones include insulin and growth hormone. Steroid hormones are derived from cholesterol . The adrenal cortex and the gonads are primary sources. Examples of steroid hormones are testosterone and cortisol . Sterol hormones such as calcitriol are a homologous system. ...

Spermatogenesis

... Spermatogenesis refers to the creation, or genesis, of sperm cells, which occurs in the male gonads or testes . Sperm cells develop initially from germ stem cells known as spermatogonia . As these differentiate they become spermatocytes , ...

Gonads in Biological Dictionary

Gonads

... The gonad is the organ that makes gametes. The gonads in males are the testes and the gonads in females are the ovaries. The product, ... the gonad term can refer to either male gonads (testicles) or female ...

Oogonia

... the ovary ... Oogonia develop by mitosis. ... Development of the gonads The prenatal development of the gonads is a part of the ... Once they have reached the gonadal ridge they are ...

Sex cells

... Germ cells are progenitors of the gametes. These singled-out cells move through the gut to the developing gonads and undergo mitotic proliferation followed by meiosis and differentiation into either eggs or sperm . Plants do not have a germ line set ...

Ovary

... found in pairs as part of the vertebrate female reproductive system. Ovaries in females are homologous to testes in males, in that they are both gonads and ... In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. Specifically, it ...

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