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Hen-feathered
Hen feathering in cocks is the occurrence of a genetically conditioned character in domestic fowl (''Gallus gallus domesticus''). Males with this condition develop a female-type plumage, although otherwise look and respond as virile males. Hen-feathering in cocks is one of the typical characteristics of the Sebright Bantam, a breed established circa 1810, in accordance with the intentions of its creator, Sir John Saunders Sebright. Sexual dimorphism in plumage is very common in birds, particularly within Phasianidae where males are bigger and have brighter and more colorful plumage than females among other morphological differences. Cocks with hen-feathering Males of most chicken breeds distinguish from their females in having longer, sharp and more scalloped feathers in neck, hackle, saddle and wing bows. But in some breeds, like the fancy breeds Sebright and Campine and some game breeds like Pettai Madhirione can see males that have a plumage completely similar in all asp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebright (chicken)
The Sebright (IPA: ) is a British breed of bantam chicken. It is a true bantam – a miniature bird with no corresponding large version – and is one of the oldest recorded British bantam breeds. It is named after Sir John Saunders Sebright, who created it as an ornamental breed by selective breeding in the early nineteenth century.Hobson, Jeremy and Lewis, Cecilia. ''Choosing & Raising Chickens: The complete guide to breeds and welfare''. David and Charles publishing. London. 2009. p 85. The first poultry breed to have its own specialist club for enthusiasts, Sebrights were admitted to poultry exhibition standards not long after their establishment. Today, they are among the most popular of bantam breeds. Despite their popularity, Sebrights are often difficult to breed, and the inheritance of certain unique characteristics the breed carries has been studied scientifically. As a largely ornamental chicken, they lay tiny, white eggs and are not kept for meat production. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Sebright Cockerel
Golden means made of, or relating to gold. Golden may also refer to: Places United Kingdom *Golden, in the parish of Probus, Cornwall *Golden Cap, Dorset *Golden Square, Soho, London *Golden Valley, a valley on the River Frome, Stroud#Golden Valley, River Frome in Gloucestershire *Golden Valley, Herefordshire United States *Golden, Colorado, a town West of Denver, county seat of Jefferson County *Golden, Idaho, an unincorporated community *Golden, Illinois, a village *Golden Township, Michigan *Golden, Mississippi, a village *Golden City, Missouri, a city *Golden, Missouri, an unincorporated community *Golden, Nebraska, ghost town in Burt County *Golden Township, Holt County, Nebraska *Golden, New Mexico, a sparsely populated ghost town *Golden, Oregon, an abandoned mining town *Golden, Texas, an unincorporated community *Golden, Utah, a ghost town *Golden, Marshall County, West Virginia, an unincorporated community Elsewhere *Golden, County Tipperary, Ireland, a village on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromatase
Aromatase (), also called estrogen synthetase or estrogen synthase, is an enzyme responsible for a key step in the biosynthesis of estrogens. It is CYP19A1, a member of the cytochrome P450 superfamily, which are monooxygenases that catalyze many reactions involved in steroidogenesis. In particular, aromatase is responsible for the aromatization of androgens into estrogens. The enzyme aromatase can be found in many tissues including gonads (granulosa cells), brain, adipose tissue, placenta, blood vessels, skin, and bone, as well as in tissue of endometriosis, uterine fibroids, breast cancer, and endometrial cancer. It is an important factor in sexual development. Function Aromatase is localized in the endoplasmic reticulum where it is regulated by tissue-specific promoters that are in turn controlled by hormones, cytokines, and other factors. It catalyzes the last steps of estrogen biosynthesis from androgens (specifically, it transforms androstenedione to estrone and testoster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aviculture
Aviculture is the practice of keeping and breeding birds, especially of wild birds in captivity. Types There are various reasons that people get involved in aviculture. Some people breed birds to preserve a species. Some people breed parrots as companion birds, and some people breed birds to make a profit. Aviculture Aviculture is the practice of keeping birds (class ''Aves'') in captivity using controlled conditions, normally within the confines of an aviary, for hobby, business, research and conservation purposes. Some reasons for aviculture are: breeding birds to preserve the species because many avian species are at risk due to habitat destruction and natural disaster. Aviculture encourages conservation, provides education about avian species, provides companion birds for the public, and includes research on avian behaviour. Publications and avicultural societies Publications on aviculture include books on species which include pets, books on breeding and introductory b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromatase Excess Syndrome
Aromatase excess syndrome (AES or AEXS) is a rare genetic and endocrine syndrome which is characterized by an overexpression of aromatase, the enzyme responsible for the biosynthesis of the estrogen sex hormones from the androgens, in turn resulting in excessive levels of circulating estrogens and, accordingly, symptoms of hyperestrogenism. It affects both sexes, manifesting itself in males as marked or complete phenotypical feminization (with the exception of the genitalia; i.e., no pseudohermaphroditism) and in females as hyperfeminization. To date, 30 males and 8 females with AEXS among 15 and 7 families, respectively, have been described in the medical literature. Signs and symptoms Observed physiological abnormalities of the condition include a dramatic overexpression of aromatase and, accordingly, excessive levels of estrogens including estrone and estradiol and a very high rate of peripheral conversion of androgens to estrogens. In one study, cellular aromatase mRNA expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromatase
Aromatase (), also called estrogen synthetase or estrogen synthase, is an enzyme responsible for a key step in the biosynthesis of estrogens. It is CYP19A1, a member of the cytochrome P450 superfamily, which are monooxygenases that catalyze many reactions involved in steroidogenesis. In particular, aromatase is responsible for the aromatization of androgens into estrogens. The enzyme aromatase can be found in many tissues including gonads (granulosa cells), brain, adipose tissue, placenta, blood vessels, skin, and bone, as well as in tissue of endometriosis, uterine fibroids, breast cancer, and endometrial cancer. It is an important factor in sexual development. Function Aromatase is localized in the endoplasmic reticulum where it is regulated by tissue-specific promoters that are in turn controlled by hormones, cytokines, and other factors. It catalyzes the last steps of estrogen biosynthesis from androgens (specifically, it transforms androstenedione to estrone and testoster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gigantomastia
Breast hypertrophy is a rare medical condition of the breast connective tissues in which the breasts become excessively large. The condition is often divided based on the severity into two types, macromastia and gigantomastia. Hypertrophy of the breast tissues may be caused by increased histologic sensitivity to certain hormones such as female sex hormones, prolactin, and growth factors. Breast hypertrophy is a benign ''progressive'' enlargement, which can occur in both breasts (bilateral) or only in one breast (unilateral). It was first scientifically described in 1648. Description and types The indication is an excess breast weight that exceeds approximately 3% of the total body weight. There are varying definitions of what is considered to be excessive breast tissue, that is the expected breast tissue plus extraordinary breast tissue, ranging from as little as up to with most physicians defining macromastia as excessive tissue of over . Some resources distinguish between ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precocious Puberty
In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. In a minority of children with precocious puberty, the early development is triggered by a disease such as a tumor or injury of the brain. Even when there is no disease, unusually early puberty can have adverse effects on social behavior and psychological development, can reduce adult height potential, and may shift some lifelong health risks. Central precocious puberty can be treated by suppressing the pituitary hormones that induce sex steroid production. The opposite condition is delayed puberty. The term is used with several slightly different meanings that are usually apparent from the context. In its broadest sense, and often simplified as early puberty, "precocious puberty" sometimes refers to any physical sex hormone effect, due to any cause, occurring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gynecomastia
Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse (10 November 2018) Gynecomastia can cause significant psychological distress or unease. Gynecomastia can be normal in newborn babies due to exposure to estrogen from the mother, in adolescents going through puberty, in older men over age 50, and/or in obese men. Most occurrences of gynecomastia do not require diagnostic tests. Gynecomastia may be caused by abnormal hormone changes, any condition that leads to an increase in the ratio of estrogens/androgens such as liver disease, kidney failure, thyroid disease and some non-breast tumors. Alcohol and some drugs can also cause breast enlargement. Other causes may include Klinefelter syndrome, metabolic dysfunction, or a natural decline in testosterone production. This may occur even if the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromatase Excess Syndrome
Aromatase excess syndrome (AES or AEXS) is a rare genetic and endocrine syndrome which is characterized by an overexpression of aromatase, the enzyme responsible for the biosynthesis of the estrogen sex hormones from the androgens, in turn resulting in excessive levels of circulating estrogens and, accordingly, symptoms of hyperestrogenism. It affects both sexes, manifesting itself in males as marked or complete phenotypical feminization (with the exception of the genitalia; i.e., no pseudohermaphroditism) and in females as hyperfeminization. To date, 30 males and 8 females with AEXS among 15 and 7 families, respectively, have been described in the medical literature. Signs and symptoms Observed physiological abnormalities of the condition include a dramatic overexpression of aromatase and, accordingly, excessive levels of estrogens including estrone and estradiol and a very high rate of peripheral conversion of androgens to estrogens. In one study, cellular aromatase mRNA expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expressiveness Of Hen-feathering In Cocks
Expressivity, expressiveness, and expressive power may refer to: *Expressivity (genetics), variations in a phenotype among individuals carrying a particular genotype *Expressive loa, a type of loanword in phono-semantic matching *Expressive power (computer science) of a programming language *Expressive suppression, an aspect of emotion regulation *Expressive therapies, the use of creative arts as therapy *Expressive timing Expressive timing refers to the musical phenomenon whereby a performer introduces subtle temporal nuances to an otherwise metronomic ("perfectly" timed) interpretation. This is also referred to as ''microtiming'' or ''microrhythm''. For instance, ..., musical phenomenon See also * Expression (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testosterone Estradiol Conversion
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. In addition, testosterone in both sexes is involved in health and well-being, including moods, behaviour, and in the prevention of osteoporosis. Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss. Testosterone is a steroid from the androstane class containing a ketone and a hydroxyl group at positions three and seventeen respectively. It is biosynthesized in several steps from cholesterol and is converted in the liver to inactive metabolites. It exerts its action through binding to and activation of the androgen receptor. In humans and most other vertebrates, testosterone is secreted primarily by the testicles of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
