The active production and accumulation of VITELLINS (egg yolk proteins) in the non-mammalian OOCYTES from circulating precursors, VITELLOGENINS. Vitellogenesis usually begins after the first MEIOSIS and is regulated by estrogenic hormones.
Phospholipoglycoproteins produced in the fat body of egg-laying animals such as non-mammalian VERTEBRATES; ARTHROPODS; and others. Vitellogenins are secreted into the HEMOLYMPH, and taken into the OOCYTES by receptor-mediated ENDOCYTOSIS to form the major yolk proteins, VITELLINS. Vitellogenin production is under the regulation of steroid hormones, such as ESTRADIOL and JUVENILE HORMONES in insects.
Major egg yolk proteins from egg-laying animals such as non-mammalian VERTEBRATES; ARTHROPODS; and others. They are high-density lipoglycoproteins derived from circulating precursors, VITELLOGENINS. Vitellins serve as nutrients for the growing non-mammalian embryos (EMBRYO, NONMAMMALIAN).
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
A nutritional reservoir of fatty tissue found mainly in insects and amphibians.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
Proteins which are found in eggs (OVA) from any species.
Compounds, either natural or synthetic, which block development of the growing insect.
The plasma membrane of the egg.
Proteins found in eggs which are consumed as a food.
A phenomenon in which multiple and diverse phenotypic outcomes are influenced by a single gene (or single gene product.)
A large stout-bodied, sometimes anadromous, TROUT found in still and flowing waters of the Pacific coast from southern California to Alaska. It has a greenish back, a whitish belly, and pink, red, or lavender stripes on the sides, with usually a sprinkling of black dots. It is highly regarded as a sport and food fish. Its former name was Salmo gairdneri. The sea-run rainbow trouts are often called steelheads. Redband trouts refer to interior populations of rainbows.
Common name for an order (Anguilliformes) of voracious, elongate, snakelike teleost fishes.
Cytoplasm stored in an egg that contains nutritional reserves for the developing embryo. It is rich in polysaccharides, lipids, and proteins.
Steroids that bring about MOLTING or ecdysis in insects. Ecdysteroids include the endogenous insect hormones (ECDYSONE and ECDYSTERONE) and the insect-molting hormones found in plants, the phytoecdysteroids. Phytoecdysteroids are natural insecticides.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
Paired or fused ganglion-like bodies in the head of insects. The bodies secrete hormones important in the regulation of metamorphosis and the development of some adult tissues.
A primitive form of digestive gland found in marine ARTHROPODS, that contains cells similar to those found in the mammalian liver (HEPATOCYTES), and the PANCREAS.
Proteins found in any species of insect.
Insects of the order Dictyoptera comprising several families including Blaberidae, BLATTELLIDAE, Blattidae (containing the American cockroach PERIPLANETA americana), Cryptocercidae, and Polyphagidae.
The blood/lymphlike nutrient fluid of some invertebrates.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
The total process by which organisms produce offspring. (Stedman, 25th ed)
A genus of mosquitoes (CULICIDAE) frequently found in tropical and subtropical regions. YELLOW FEVER and DENGUE are two of the diseases that can be transmitted by species of this genus.
Common name for FISHES belonging to the order Perciformes and occurring in three different families.
Various fish of the family SALMONIDAE, usually smaller than salmon. They are mostly restricted to cool clear freshwater. Some are anadromous. They are highly regarded for their handsome colors, rich well-flavored flesh, and gameness as an angling fish. The genera Salvelinus, Salmo, and ONCORHYNCHUS have been introduced virtually throughout the world.
An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.

Glucocorticoid receptor immunoreactivity in neurons and pituitary cells implicated in reproductive functions in rainbow trout: a double immunohistochemical study. (1/135)

In order to identify the nature of the glucocorticoid receptor (GR)-expressing neurons and pituitary cells that potentially mediate the negative effects of stress on reproductive performance, double immunohistochemical stainings were performed in the brain and pituitary of the rainbow trout (Oncorhynchus mykiss). To avoid possible cross-reactions during the double staining studies, combinations of primary antibodies raised in different species were used, and we report here the generation of an antibody raised in guinea pig against the rainbow trout glucocorticoid receptor (rtGR). The results obtained in vitellogenic females showed that GnRH-positive neurons in the caudal telencephalon/anterior preoptic region consistently exhibited rtGR immunoreactivity. Similarly, in the anterior ventral preoptic region, a group of tyrosine hydroxylase-positive neurons, known for inhibiting gonadotropin (GTH)-2 secretion during vitellogenesis, was consistently shown to strongly express GR. Finally, we show that a large majority of the GTH-1 (FSH-like) and GTH-2 (LH-like) cells of the pituitary exhibit rtGR immunoreactivity. These results indicate that cortisol may affect the neuroendocrine control of the reproductive process of the rainbow trout at multiple sites.  (+info)

Control of oocyte maturation in sexually mature Drosophila females. (2/135)

In many sexually mature insects egg production and oviposition are tightly coupled to copulation. Sex-Peptide is a 36-amino-acid peptide synthesized in the accessory glands of Drosophila melanogaster males and transferred to the female during copulation. Sex-Peptide stimulates vitellogenic oocyte progression through a putative control point at about stage 9 of oogenesis. Here we show that application of the juvenile hormone analogue methoprene mimics the Sex-Peptide-mediated stimulation of vitellogenic oocyte progression in sexually mature virgin females. Apoptosis is induced by 20-hydroxyecdysone in nurse cells of stage 9 egg chambers at physiological concentrations (10(-7) M). 20-Hydroxyecdysone thus acts as an antagonist of early vitellogenic oocyte development. Simultaneous application of juvenile hormone analogue, however, protects early vitellogenic oocytes from 20-hydroxyecdysone-induced resorption. These results suggest that the balance of these hormones in the hemolymph regulates whether oocytes will progress through the control point at stage 9 or undergo apoptosis. These data are further supported by a molecular analysis of the regulation of yolk protein synthesis and uptake into the ovary by the two hormones. We conclude that juvenile hormone is a downstream component in the Sex-Peptide response cascade and acts by stimulating vitellogenic oocyte progression and inhibiting apoptosis. Since juvenile hormone analogue does not elicit increased oviposition and reduced receptivity, Sex-Peptide must have an additional, separate effect on these two postmating responses.  (+info)

AHR38, a homolog of NGFI-B, inhibits formation of the functional ecdysteroid receptor in the mosquito Aedes aegypti. (3/135)

In anautogenous mosquitoes, vitellogenesis, the key event in egg maturation, requires a blood meal. Consequently, mosquitoes are vectors of numerous devastating human diseases. After ingestion of blood, 20-hydroxyecdysone activates yolk protein precursor (YPP) genes in the metabolic tissue, the fat body. An important adaptation for anautogenicity is the previtellogenic developmental arrest (the state-of-arrest) preventing the activation of YPP genes in previtellogenic females prior to blood feeding. Here, we show that a retinoid X receptor homolog, Ultraspiracle (AaUSP), which is an obligatory partner in the functional ecdysteroid receptor, exists at the state-of-arrest as a heterodimer with the orphan nuclear receptor AHR38, a homolog of Drosophila DHR38 and nerve growth factor-induced protein B. Yeast two-hybrid and glutathione S-transferase pull-down assays demonstrate that AHR38 can interact strongly with AaUSP. AHR38 also disrupts binding of ecdysteroid receptor to ecdysone response elements. Cell co-transfection of AHR38 with AaEcR and AaUSP inhibits ecdysone-dependent activation of a reporter gene by the ecdysteroid receptor. Co-immunoprecipitation experiments indicate that AaUSP protein associates with AHR38 instead of AaEcR in fat body nuclei at the state-of-arrest.  (+info)

Differential expression and regulation by 20-hydroxyecdysone of mosquito ultraspiracle isoforms. (4/135)

Ultraspiracle (USP), the insect homologue of the vertebrate retinoid X receptor, is an obligatory dimerization partner for the ecdysteroid receptor (EcR). Two USP isoforms, USP-A and USP-B, with distinct N-termini, occur in the mosquito Aedes aegypti. In the fat body and ovary, USP-A mRNA is highly expressed during the pre- and late vitellogenic stages, corresponding to a period of low ecdysteroid titer, while USP-B mRNA exhibits its highest levels during the vitellogenic period, correlating with a high ecdysteroid titer. Remarkably, 20-hydroxyecdysone (20E) has opposite effects on USP isoform transcripts in in vitro fat body culture. This steroid hormone upregulates USP-B transcription and its presence is required to sustain a high level of USP-B expression. In contrast, 20E inhibits activation of USP-A transcription. Although EcR.USP-A recognizes the same ecdysteroid-responsive elements, EcR.USP-B binds them with an affinity twofold higher than that of EcR.USP-A. Likewise, EcR.USP-B transactivates a reporter gene in CV-1 cells twofold more strongly than EcR.USP-A. These results suggest that USP-B functions as a major heterodimerization partner for EcR during the vitellogenic response to 20E in the mosquito.  (+info)

Regulation of the vitellogenin receptor during Drosophila melanogaster oogenesis. (5/135)

In many insects, development of the oocyte arrests temporarily just before vitellogenesis, the period when vitellogenins (yolk proteins) accumulate in the oocyte. Following hormonal and environmental cues, development of the oocyte resumes, and endocytosis of vitellogenins begins. An essential component of yolk uptake is the vitellogenin receptor. In this report, we describe the ovarian expression pattern and subcellular localization of the mRNA and protein encoded by the Drosophila melanogaster vitellogenin receptor gene yolkless (yl). yl RNA and protein are both expressed very early during the development of the oocyte, long before vitellogenesis begins. RNA in situ hybridization and lacZ reporter analyses show that yl RNA is synthesized by the germ line nurse cells and then transported to the oocyte. Yl protein is evenly distributed throughout the oocyte during the previtellogenic stages of oogenesis, demonstrating that the failure to take up yolk in these early stage oocyte is not due to the absence of the receptor. The transition to the vitellogenic stages is marked by the accumulation of yolk via clathrin-coated vesicles. After this transition, yolk protein receptor levels increase markedly at the cortex of the egg. Consistent with its role in yolk uptake, immunogold labeling of the receptor reveals Yl in endocytic structures at the cortex of wild-type vitellogenic oocytes. In addition, shortly after the inception of yolk uptake, we find multivesicular bodies where the yolk and receptor are distinctly partitioned. By the end of vitellogenesis, the receptor localizes predominantly to the cortex of the oocyte. However, during oogenesis in yl mutants that express full-length protein yet fail to incorporate yolk proteins, the receptor remains evenly distributed throughout the oocyte.  (+info)

The Drosophila ecdysone receptor (EcR) gene is required maternally for normal oogenesis. (6/135)

Oogenesis in Drosophila is regulated by the steroid hormone ecdysone and the sesquiterpenoid juvenile hormone. Response to ecdysone is mediated by a heteromeric receptor composed of the EcR and USP proteins. We have identified a temperature-sensitive EcR mutation, EcR(A483T), from a previously isolated collection of EcR mutations. EcR(A483T) is predicted to affect all EcR protein products (EcR-A, EcR-B1, and EcR-B2) since it maps to a common exon encoding the ligand-binding domain. In wild-type females, we find that both EcR-A and EcR-B1 are expressed in nurse cells and follicle cells throughout oogenesis. EcR mutant females raised at permissive temperature and then shifted to restrictive temperature exhibit severe reductions in fecundity. Oogenesis in EcR mutant females is defective, and the spectrum of oogenic defects includes the presence of abnormal egg chambers and loss of vitellogenic egg stages. Our results demonstrate a requirement for EcR during female reproduction and suggest that EcR is required for normal oogenesis.  (+info)

Transcriptional interference between glucocorticoid receptor and estradiol receptor mediates the inhibitory effect of cortisol on fish vitellogenesis. (7/135)

In oviparous species, the synthesis of vitellogenin (Vg) takes place in the liver according to a strictly estrogen-dependent mechanism that first involves an up-regulation of the estrogen receptor (ER) by its own ligand. However, reports from the literature indicate that in trout stress or cortisol may cause a reduction of cytosolic E2-binding sites in the liver and a decrease in plasma Vg levels. To investigate the mechanisms underlying these effects, in vivo and in vitro experiments were designed in rainbow trout (Oncorhynchus mykiss). The results demonstrate that cortisol implanted into maturing females caused a marked decrease of rainbow trout ER (rtER) and rainbow trout Vg (rtVg) mRNA levels in the liver. In vitro experiments on hepatocyte aggregates also showed that dexamethasone (Dex) caused a strong decrease in the basal and E2-stimulated rtER mRNA and to a lesser extent rtVg mRNA. These effects were specific as no other hormones were able to mimic the inhibitory action of Dex. A study of rtER mRNA stability indicated that the effects of glucocorticoids are likely to take place at the transcriptional level. This was further indicated by transfection experiments in CHO-K(1) cells, which showed that rainbow trout glucocorticoid receptor (rtGR) strongly inhibited the E2-stimulated transcriptional activity of the rtER promoter. Taken together, these results indicate that the rtGR exerts a transcriptional interference on the expression of the rtER that may explain some of the negative effects of stress or cortisol on vitellogenesis.  (+info)

Conserved molecular mechanism for the stage specificity of the mosquito vitellogenic response to ecdysone. (8/135)

In the mosquito Aedes aegypti, the adult female becomes competent for a vitellogenic response to ecdysone after previtellogenic development. Here, we show that betaFTZ-F1, the nuclear receptor implicated as a competence factor for stage-specific responses to ecdysone during Drosophila metamorphosis, serves a similar function during mosquito vitellogenesis. AaFTZ-F1 is expressed highly in the mosquito fat body during pre- and postvitellogenic periods when ecdysteroid titers are low. The mosquito AaFTZ-F1 transcript nearly disappears in mid-vitellogenesis when ecdysteroid titers are high. An expression peak of HR3, a nuclear receptor implicated in the activation of betaFTZ-F1 in Drosophila, precedes each rise in mosquito FTZ-F1 expression. In in vitro fat body culture, AaFTZ-F1 expression is inhibited by 20-hydroxyecdysone (20E) and superactivated by its withdrawal. Following in vitro AaFTZ-F1 superactivation, a secondary 20E challenge results in superinduction of the early AaE75 gene and the late target VCP gene. Electrophoretic mobility-shift assays show that the onset of ecdysone-response competence in the mosquito fat body is correlated with the appearance of the functional AaFTZ-F1 protein at the end of the previtellogenic development. These findings suggest that a conserved molecular mechanism for controlling stage specificity is reiteratively used during metamorphic and reproductive responses to ecdysone.  (+info)

Vitellogenesis is the process of producing and accumulating yolk proteins in the oocytes (immature ovum or egg cell) of females in preparation for fertilization and embryonic development. This process is primarily seen in oviparous animals, such as birds, fish, and insects, where the yolk serves as a source of nutrients for the developing embryo.

The yolk proteins are synthesized mainly in the liver under the control of estrogen hormones and are then transported to the oocytes through the bloodstream. Once inside the oocytes, these proteins are taken up by a process called pinocytosis, where they are enclosed in vesicles and fuse with lysosomes to form yolk granules. The accumulation of these yolk granules provides the developing embryo with essential nutrients such as lipids, carbohydrates, and proteins.

In addition to its role in reproduction, vitellogenesis has been used as a biomarker for environmental estrogen exposure in non-target organisms, as the production of yolk proteins can be induced by estrogenic compounds found in pollutants such as pesticides and industrial chemicals.

Vitellogenins are a group of precursor proteins that are synthesized in the liver and subsequently transported to the ovaries, where they are taken up by developing oocytes. Once inside the oocyte, vitellogenins are cleaved into smaller proteins called lipovitellins and phosvitins, which play a crucial role in providing nutrients and energy to the developing embryo.

Vitellogenins are found in many oviparous species, including birds, reptiles, amphibians, fish, and some invertebrates. They are typically composed of several domains, including a large N-terminal domain that is rich in acidic amino acids, a central von Willebrand factor type D domain, and a C-terminal domain that contains multiple repeat units.

In addition to their role in egg development, vitellogenins have also been implicated in various physiological processes, such as immune function, stress response, and metal homeostasis. Moreover, the levels of vitellogenin in the blood can serve as a biomarker for environmental exposure to estrogenic compounds, as these chemicals can induce the synthesis of vitellogenins in male and juvenile animals.

Vitellins are a group of precursor proteins found in the yolk of eggs of many animals, including birds and reptiles. They play a crucial role in the development of the embryo by providing it with essential nutrients, such as amino acids, lipids, and carbohydrates. Vitellins are synthesized in the liver of the female animal and then transported to the ovaries, where they are stored in the yolk granules of developing eggs. During embryonic development, vitellins are broken down into smaller peptides and free amino acids, which can be easily absorbed and utilized by the growing embryo.

In a medical context, vitellins may be studied in relation to reproductive biology, nutrition, and developmental biology. However, they do not have direct clinical relevance to human health or disease, as humans do not produce eggs with yolks containing vitellins.

Oogenesis is the biological process of formation and maturation of female gametes, or ova or egg cells, in the ovary. It begins during fetal development and continues throughout a woman's reproductive years. The process involves the division and differentiation of a germ cell (oogonium) into an immature ovum (oocyte), which then undergoes meiotic division to form a mature ovum capable of being fertilized by sperm.

The main steps in oogenesis include:

1. Multiplication phase: The oogonia divide mitotically to increase their number.
2. Growth phase: One of the oogonia becomes primary oocyte and starts to grow, accumulating nutrients and organelles required for future development.
3. First meiotic division: The primary oocyte undergoes an incomplete first meiotic division, resulting in two haploid cells - a secondary oocyte and a smaller cell called the first polar body. This division is arrested in prophase I until puberty.
4. Second meiotic division: At ovulation or just before fertilization, the secondary oocyte completes the second meiotic division, producing another small cell, the second polar body, and a mature ovum (egg) with 23 chromosomes.
5. Fertilization: The mature ovum can be fertilized by a sperm, restoring the normal diploid number of chromosomes in the resulting zygote.

Oogenesis is a complex and highly regulated process that involves various hormonal signals and cellular interactions to ensure proper development and maturation of female gametes for successful reproduction.

A "fat body" is not a medical term that is typically used to describe human anatomy. It is more commonly used in the context of insects and other invertebrates, where it refers to a specialized tissue that functions to store energy in the form of fat.

However, in humans, we do have adipose tissue, which is the medical term for body fat. Adipose tissue is found throughout the body, but is particularly concentrated in certain areas such as the abdomen, hips, and thighs. It serves a variety of functions, including storing energy, insulating the body, and producing hormones that regulate metabolism and appetite.

If you are looking for information on obesity or excess body fat in humans, there are many medical resources available to help you understand these topics better.

An ovary is a part of the female reproductive system in which ova or eggs are produced through the process of oogenesis. They are a pair of solid, almond-shaped structures located one on each side of the uterus within the pelvic cavity. Each ovary measures about 3 to 5 centimeters in length and weighs around 14 grams.

The ovaries have two main functions: endocrine (hormonal) function and reproductive function. They produce and release eggs (ovulation) responsible for potential fertilization and development of an embryo/fetus during pregnancy. Additionally, they are essential in the production of female sex hormones, primarily estrogen and progesterone, which regulate menstrual cycles, sexual development, and reproduction.

During each menstrual cycle, a mature egg is released from one of the ovaries into the fallopian tube, where it may be fertilized by sperm. If not fertilized, the egg, along with the uterine lining, will be shed, leading to menstruation.

Egg proteins, also known as egg white proteins or ovalbumin, refer to the proteins found in egg whites. There are several different types of proteins found in egg whites, including:

1. Ovalbumin (54%): This is the major protein found in egg whites and is responsible for their white color. It has various functions such as providing nutrition, maintaining the structural integrity of the egg, and protecting the egg from bacteria.
2. Conalbumin (13%): Also known as ovotransferrin, this protein plays a role in the defense against microorganisms by binding to iron and making it unavailable for bacterial growth.
3. Ovomucoid (11%): This protein is resistant to digestion and helps protect the egg from being broken down by enzymes in the digestive tract of predators.
4. Lysozyme (3.5%): This protein has antibacterial properties and helps protect the egg from bacterial infection.
5. Globulins (4%): These are a group of simple proteins found in egg whites that have various functions such as providing nutrition, maintaining the structural integrity of the egg, and protecting the egg from bacteria.
6. Avidin (0.05%): This protein binds to biotin, a vitamin, making it unavailable for use by the body. However, cooking denatures avidin and makes the biotin available again.

Egg proteins are highly nutritious and contain all nine essential amino acids, making them a complete source of protein. They are also low in fat and cholesterol, making them a popular choice for those following a healthy diet.

Juvenile hormones (JHs) are a class of sesquiterpenoid compounds that play a crucial role in the regulation of insect development, reproduction, and other physiological processes. They are primarily produced by the corpora allata, a pair of endocrine glands located in the head of insects.

JHs are essential for maintaining the larval or nymphal stage of insects, preventing the expression of adult characteristics during molting. As the concentration of JH decreases in the hemolymph (insect blood), a molt to the next developmental stage occurs, and if the insect has reached its final instar, it will metamorphose into an adult.

In addition to their role in development, JHs also influence various aspects of insect reproductive physiology, such as vitellogenesis (yolk protein synthesis), oocyte maturation, and spermatogenesis. Furthermore, JHs have been implicated in regulating diapause (a period of suspended development during unfavorable environmental conditions) and caste determination in social insects like bees and ants.

Overall, juvenile hormones are vital regulators of growth, development, and reproduction in insects, making them attractive targets for the development of novel pest management strategies.

The vitelline membrane is a thin, transparent, flexible, and protective membrane that surrounds the yolk in bird, reptile, and some insect eggs. It provides nutrition and physical protection to the developing embryo during incubation. In medical terms, it is not directly relevant as it does not have a counterpart or equivalent structure in mammalian embryology.

Dietary egg proteins refer to the proteins found in eggs, specifically in egg whites. These proteins are a complete source of essential amino acids, making them high-quality proteins. The two main protein components in egg whites are ovalbumin and ovotransferrin. Other minor proteins include ovomucoid, ovomucin, and lysozyme.

Egg white proteins have a high biological value, which means they are easily digested and absorbed by the body. They also have various functional properties, such as foaming, emulsifying, and gelling, making them useful in food production and cooking. Additionally, egg white proteins have been studied for their potential health benefits, including their role in immune function and wound healing.

Genetic pleiotropy is a phenomenon in genetics where a single gene or genetic variant has multiple effects on different phenotypic traits. This means that the gene influences more than one trait, and changes in the gene can result in variations in multiple traits. The term "pleiotropy" comes from the Greek words "pleion," meaning "more," and "trope," meaning "turning."

An example of genetic pleiotropy is the gene that causes sickle cell anemia, a severe form of hemolytic anemia. This same gene also provides resistance to malaria in heterozygotes (individuals who inherit one normal and one mutated copy of the gene). Therefore, the single gene has multiple effects on different traits: red blood cell shape and susceptibility to malaria.

Understanding genetic pleiotropy is essential for understanding how complex traits are inherited and how genes contribute to various diseases and conditions. It also highlights that modifying or treating one trait may have unintended consequences on other traits influenced by the same gene.

Oncorhynchus mykiss is the scientific name for a species of fish that is commonly known as the Rainbow Trout. According to the medical or clinical definition provided by the US National Library of Medicine, Oncorhynchus mykiss is "a freshwater fish that is widely cultured and an important food source in many parts of the world." It is also a popular game fish and is often stocked in lakes and rivers for recreational fishing. Rainbow trout are native to cold-water tributaries that flow into the Pacific Ocean in Asia and North America. They have been introduced widely throughout the world and can now be found in freshwater systems on every continent except Antarctica. Rainbow trout are a valuable species for both commercial and recreational fisheries, and they also play an important role in the food web as both predators and prey.

"Eels" is not a term that has a medical definition. It refers to a type of long, snake-like fish that belong to the order Anguilliformes. There are several species of eels found in fresh and saltwater environments around the world. While there may be some references to "eels" in a medical context, such as in the name of certain medical conditions or procedures, these would be specific and unrelated to the fish themselves.

The egg yolk is the nutrient-rich, inner portion of an egg that is surrounded by a protective layer of egg white. It is typically yellowish-orange and has a creamy consistency. The egg yolk contains various essential nutrients such as proteins, fats, vitamins (like A, D, E, and K), minerals (such as calcium, phosphorus, zinc, and iron), and antioxidants (like lutein and zeaxanthin). It is also a significant source of cholesterol. The egg yolk plays an essential role in the development of embryos in birds and reptiles, providing them with necessary nutrients for growth and energy. In culinary applications, egg yolks are often used as emulsifiers, thickeners, and leavening agents in various dishes.

Ecdysteroids are a class of steroid hormones that are primarily known for their role in the regulation of molting and growth in arthropods, such as insects and crustaceans. They are structurally similar to vertebrate steroid hormones, such as estrogens and androgens, but have different physiological functions.

Ecdysteroids bind to specific receptors in the cell nucleus, leading to changes in gene expression that regulate various processes related to molting and growth, including the synthesis of new exoskeleton components and the breakdown of old ones. They also play a role in other physiological processes, such as reproduction, development, and stress response.

In recent years, ecdysteroids have attracted interest in the medical community due to their potential therapeutic applications. Some studies suggest that certain ecdysteroids may have anabolic effects, promoting muscle growth and protein synthesis, while others have shown anti-inflammatory, antioxidant, and immunomodulatory properties. However, more research is needed to fully understand the potential therapeutic uses of ecdysteroids in humans.

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

The corpora allata are small endocrine glands found in the head of insects, located near the brain. They are part of the insect endocrine system and produce important hormones that regulate various physiological processes, including growth, development, reproduction, and molting. The most well-known hormone produced by the corpora allata is juvenile hormone (JH), which plays a crucial role in maintaining the larval or nymphal stage of insects and preventing metamorphosis into the adult form. As the insect grows and develops, the production of JH decreases, allowing for the initiation of metamorphosis and the emergence of the adult form.

I'm sorry for any confusion, but the term "hepatopancreas" is not a recognized term in human anatomy or pathology. It is commonly used to describe a combined exocrine organ in some invertebrates, like crustaceans, where it serves both digestive and metabolic functions. If you have any questions about human medical conditions, I'd be happy to help with those!

I'm sorry for any confusion, but "Insect Proteins" is not a recognized medical term. However, I can provide some information about insect protein from a nutritional and food science perspective.

Insect proteins refer to the proteins that are obtained from insects. Insects are a rich source of protein, and their protein content varies by species. For example, mealworms and crickets have been found to contain approximately 47-63% and 60-72% protein by dry weight, respectively.

In recent years, insect proteins have gained attention as a potential sustainable source of nutrition due to their high protein content, low environmental impact, and the ability to convert feed into protein more efficiently compared to traditional livestock. Insect proteins can be used in various applications such as food and feed additives, nutritional supplements, and even cosmetics.

However, it's important to note that the use of insect proteins in human food is not widely accepted in many Western countries due to cultural and regulatory barriers. Nonetheless, research and development efforts continue to explore the potential benefits and applications of insect proteins in the global food system.

Cockroaches are not a medical condition or disease. They are a type of insect that can be found in many parts of the world. Some species of cockroaches are known to carry diseases and allergens, which can cause health problems for some people. Cockroach allergens can trigger asthma symptoms, especially in children. Additionally, cockroaches can contaminate food and surfaces with bacteria and other germs, which can lead to illnesses such as salmonellosis and gastroenteritis.

If you have a problem with cockroaches in your home or workplace, it is important to take steps to eliminate them to reduce the risk of health problems. This may include cleaning up food and water sources, sealing entry points, and using pesticides or hiring a professional pest control service.

Hemolymph is not a term typically used in human medicine, but it is commonly used in the study of invertebrates, particularly arthropods such as insects and crustaceans. Hemolymph is the fluid that circulates within the open circulatory system of these animals, serving multiple functions similar to both blood and lymphatic systems in vertebrates.

In simpler terms, hemolymph is a combined fluid that performs the functions of both blood and lymph in invertebrates. It serves as a transport medium for nutrients, waste products, hormones, and immune cells (hemocytes) throughout the body. Hemolymph does not contain red and white blood cells like human blood; instead, hemocytes are the primary cellular components responsible for immune responses and wound healing in these animals.

An ovum is the female reproductive cell, or gamete, produced in the ovaries. It is also known as an egg cell and is released from the ovary during ovulation. When fertilized by a sperm, it becomes a zygote, which can develop into a fetus. The ovum contains half the genetic material necessary to create a new individual.

Reproduction, in the context of biology and medicine, refers to the process by which organisms produce offspring. It is a complex process that involves the creation, development, and growth of new individuals from parent organisms. In sexual reproduction, this process typically involves the combination of genetic material from two parents through the fusion of gametes (sex cells) such as sperm and egg cells. This results in the formation of a zygote, which then develops into a new individual with a unique genetic makeup.

In contrast, asexual reproduction does not involve the fusion of gametes and can occur through various mechanisms such as budding, fragmentation, or parthenogenesis. Asexual reproduction results in offspring that are genetically identical to the parent organism.

Reproduction is a fundamental process that ensures the survival and continuation of species over time. It is also an area of active research in fields such as reproductive medicine, where scientists and clinicians work to understand and address issues related to human fertility, contraception, and genetic disorders.

"Aedes" is a genus of mosquitoes that are known to transmit various diseases, including Zika virus, dengue fever, chikungunya, and yellow fever. These mosquitoes are typically found in tropical and subtropical regions around the world. They are distinguished by their black and white striped legs and thorax. Aedes aegypti is the most common species associated with disease transmission, although other species such as Aedes albopictus can also transmit diseases. It's important to note that only female mosquitoes bite and feed on blood, while males feed solely on nectar and plant juices.

I apologize for any confusion, but "bass" is not a medical term. It is a term that can have several meanings depending on the context. In music, "bass" refers to a low-pitched sound or instrument. In fishing and aquatic biology, "bass" refers to various species of freshwater fish.

If you are looking for a medical term related to the human body, perhaps you meant "brachial basal sulcus" or "basilar artery." If you can provide more context or clarify your question, I would be happy to help further!

I'm sorry for any confusion, but "trout" is not a term typically used in medical definitions. Trout is a common name that refers to several species of freshwater fish belonging to the salmonid family. If you have any questions related to medical terminology or health concerns, I would be happy to try and help answer those for you.

An ovarian follicle is a fluid-filled sac in the ovary that contains an immature egg or ovum (oocyte). It's a part of the female reproductive system and plays a crucial role in the process of ovulation.

Ovarian follicles start developing in the ovaries during fetal development, but only a small number of them will mature and release an egg during a woman's reproductive years. The maturation process is stimulated by hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

There are different types of ovarian follicles, including primordial, primary, secondary, and tertiary or Graafian follicles. The Graafian follicle is the mature follicle that ruptures during ovulation to release the egg into the fallopian tube, where it may be fertilized by sperm.

It's important to note that abnormal growth or development of ovarian follicles can lead to conditions like polycystic ovary syndrome (PCOS) and ovarian cancer.

Vitellogenesis is the process of yolk protein formation in the oocytes of non mammalian vertebrates during sexual maturation. ... The term vitellogenesis comes from the Latin vitellus ("egg yolk"). Yolk proteins, such as Lipovitellin and Phosvitin, provides ... Wallace RA (1985). "Vitellogenesis and Oocyte Growth in Nonmammalian Vertebrates". In Browder LW (ed.). Oogenesis. Boston, MA: ... Vitellogenin production in the liver is the first step of vitellogenesis. Once Vitellogenins are released into the blood stream ...
These include 37 proteases and antiproteases, which are likely to play a role in the formation of the yolk (vitellogenesis), as ... approach to define the protease and antiprotease genes specifically expressed in the hen liver in relation to vitellogenesis by ... These include 37 proteases and antiproteases, which are likely to play a role in the formation of the yolk (vitellogenesis), as ... Some of these components might not be involved in vitellogenesis and instead contribute to liver homeostasis in response to the ...
The insect somatostatin pathway gates vitellogenesis progression during reproductive maturation and the post-mating response. ...
... vitellogenesis and oogenesis. We show that this reproductive blockage is the result of a dramatic impairment of JH biosynthesis ... Juvenile hormone and the onset of vitellogenesis in the German cockroach. Insect Biochem. Mol. Biol. 33, 1219-1225 (2003). ... Miura, K., Zhu, J., Dittmer, N. T., Chen, L. & Raikhel, A. S. A COUP-TF/Svp homolog is highly expressed during vitellogenesis ... vitellogenesis and oogenesis. We show that this reproductive blockage is the result of a dramatic impairment of JH biosynthesis ...
Evolutionarily conserved aspects of animal nutrient uptake and transport in sea anemone vitellogenesis  Lebouvier, Marion; ...
A comparative study of vitellogenesis in Echinodermata: Lessons from the sea star. Comparative Biochemistry & Physiology Part A ...
A-D) ISH staining in the early vitellogenesis stage. (E-H) ISH staining in the late vitellogenesis stage. The itr1 signal ... As shown in Figure 8, itr1-and cox2-positive signals were present in the inner follicular cell layer of late vitellogenesis- ... The single cox2 signal in the early vitellogenesis stage in the follicular layer is indicated by open arrowheads. Nuclei were ... Follicles at both stages are indicated with white arrowheads (late vitellogenesis stage oocyte follicles) and open arrowheads ( ...
Oocyte Vitellogenesis Triggers the Entry of Yeast-Like Symbionts Into the Oocyte of Brown Planthopper (Hemiptera: Delphacidae) ... In the present study, we found that YLSs do not enter the brown planthopper oocyte until it develops to late vitellogenesis. ... During oocyte vitellogenesis, the diversification and morphological changes of the follicular cells surrounding the oocyte are ... KEYWORDS: brown planthopper, Nilaparvata lugens, yeast-like symbiont, ovarial transmission, oocyte vitellogenesis. ...
Concurrent vitellogenesis and gestation indicated a clearly defined annual reproductive cycle that may be completed within the ... Brood size ranges from one to four, and vitellogenesis and gestation are concurrent. Although samples were not collected during ...
vitellogenesis Cellular Component. coated vesicle Uptake of yolk protein into coated vesicles (arrows) at the periphery of ...
Vitellogenesis is retarded in adult females homozygous for certain recessive genes (fs 2.1, ty and ap 4 ). Transplantation of ...
The early gene Broad is involved in the ecdysteroid hierarchy governing vitellogenesis of the mosquito Aedes aegypti. Chen, L ... Juvenile hormone stimulation of ornithine decarboxylase activity during vitellogenesis in Drosophila melanogaster. Birnbaum, M. ... Juvenile hormone stimulation of ornithine decarboxylase activity during vitellogenesis in Drosophila melanogaster [28]. ...
Long-term caffeine intake exerts protective effects on intestinal aging by regulating vitellogenesis and mitochondrial function ...
However, in general, females of boidae show vitellogenesis concentrated in autumn-winter (Prado, 2006Prado L.P. 2006. ...
Of total oocyte volume increase (vitellogenesis), 93% occurred within the last 12 mo. Spermatogenesis took 12 mo. S. neumayeri ... does not feed during the austral winter, and vitellogenesis is therefore predominantly decoupled from energy intake. Much of ...
Gurken is retained inside the cell in cornichon mutants, although vitellogenesis proceeds normally. Boca, however, is required ...
Brown trout, liver, vitellogenesis, estradiol receptor, ER, sex hormone binding globulin, SHBG, endocrine disruption. ...
Steiner J., Diehl P.A., Vlimant M., Vitellogenesis in Varroa jacobsoni, a parasite of honey bees, Exp. Appl. Acarol. 19 (1995) ...
After mating, vitellogenesis is initiated and the egg-maturation is completed in the ovaries. Mated queens no longer leave the ...
Vitellogenesis in some gall midges. p. 0256 , Nayar, K. K.. Effect of eyestalk removal on the rate of oxygen consumption in ...
CO2, echinoderm, gonad maturation, larval development, oxygen consumption, vitellogenesis. Abstract. This study examined the ...
Costa DDM, Neto FF, Costa MDM, Morais RN, Garcia JRE, Esquivel BM, Oliveira RCA (2010) Vitellogenesis and other physiological ...
Changes in plasma and pituitary in female blue gourami during the end of vitellogenesis and final oocyte maturation. Journal of ...
... potentially via inhibition of vitellogenesis), and/or direct inhibition of molting. Further research is needed to differentiate ... potentially via inhibition of vitellogenesis), and/or direct inhibition of molting. Further research is needed to differentiate ...
... during early vitellogenesis, and oocyte recruitment and growth in the remaining ovary were monitored. The study also set out to ... during early vitellogenesis, and oocyte recruitment and growth in the remaining ovary were monitored. The study also set out to ... Functional analysis revealed upregulation of processes associated with vitellogenesis, including lipid metabolism, cellular ... Functional analysis revealed upregulation of processes associated with vitellogenesis, including lipid metabolism, cellular ...
Key words: Determinacy / atresia / oocytes / fecundity / spawning season / maturity / vitellogenesis / Solea solea ...
Vitellogenesis. In Microscopic Anatomy of Invertebrates, vol. 11C (ed. F. W. Harrison and R. F. Foelix), pp. 933-955. New York ... Vitellogenesis. In Microscopic Anatomy of Invertebrates, vol. 11C (ed. F. W. Harrison and R. F. Foelix), pp. 933-955. New York ... In the cockroach Diploptera punctata, HDLp content increases to approximately 1.5 μg per oocyte early in vitellogenesis, but ... Large amounts of hydrocarbons accumulate during vitellogenesis in the developing basal oocytes of the German cockroach ...
clathrin-dependent endocytosis involved in vitellogenesis cleistothecium formation collenchyma cell differentiation compound ...
regulation of vitellogenesis + negative regulation of cold-induced thermogenesis positive regulation of cold-induced ...

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