Cytoplasm stored in an egg that contains nutritional reserves for the developing embryo. It is rich in polysaccharides, lipids, and proteins.

A mature haploid female germ cell extruded from the OVARY at OVULATION.

Proteins which are found in eggs (OVA) from any species.

A hard or leathery calciferous exterior covering of an egg.

The white of an egg, especially a chicken's egg, used in cooking. It contains albumin. (Random House Unabridged Dictionary, 2d ed)

Determination of parasite eggs in feces.

Allergic reaction to eggs that is triggered by the immune system.

The process of laying or shedding fully developed eggs (OVA) from the female body. The term is usually used for certain INSECTS or FISHES with an organ called ovipositor where eggs are stored or deposited before expulsion from the body.

The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.

Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.

The fertilized OVUM resulting from the fusion of a male and a female gamete.

Proteins found in eggs which are consumed as a food.

The plasma membrane of the egg.

Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.

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).

A species of trematode blood flukes of the family Schistosomatidae. It is common in the Nile delta. The intermediate host is the planorbid snail. This parasite causes schistosomiasis mansoni and intestinal bilharziasis.

Animal behavior associated with the nest; includes construction, effects of size and material; behavior of the adult during the nesting period and the effect of the nest on the behavior of the young.

A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)

Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.

The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).

The number of offspring produced at one birth by an oviparous or ovoviviparous animal.

The capability of producing eggs (OVA) from which young are hatched outside the body. While mostly referring to nonmammalian species, this does include MAMMALS of the order MONOTREMATA.

A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.

The total process by which organisms produce offspring. (Stedman, 25th ed)

A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.

Schistosomiasis caused by Schistosoma mansoni. It is endemic in Africa, the Middle East, South America, and the Caribbean and affects mainly the bowel, spleen, and liver.

An extensive order of highly specialized insects including bees, wasps, and ants.

A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.

An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.

Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.

The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.

The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.

Echinoderms having bodies of usually five radially disposed arms coalescing at the center.

Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.

Any of numerous winged hymenopterous insects of social as well as solitary habits and having formidable stings.

A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.

Proteins obtained from various species of Xenopus. Included here are proteins from the African clawed frog (XENOPUS LAEVIS). Many of these proteins have been the subject of scientific investigations in the area of MORPHOGENESIS and development.

Infection with flukes (trematodes) of the genus SCHISTOSOMA. Three species produce the most frequent clinical diseases: SCHISTOSOMA HAEMATOBIUM (endemic in Africa and the Middle East), SCHISTOSOMA MANSONI (in Egypt, northern and southern Africa, some West Indies islands, northern 2/3 of South America), and SCHISTOSOMA JAPONICUM (in Japan, China, the Philippines, Celebes, Thailand, Laos). S. mansoni is often seen in Puerto Ricans living in the United States.

A heterogeneous mixture of glycoproteins responsible for the gel structure of egg white. It has trypsin-inhibiting activity.

A species of trematode blood flukes belonging to the family Schistosomatidae whose distribution is confined to areas of the Far East. The intermediate host is a snail. It occurs in man and other mammals.

The capacity to conceive or to induce conception. It may refer to either the male or female.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

The earliest developmental stage of a fertilized ovum (ZYGOTE) during which there are several mitotic divisions within the ZONA PELLUCIDA. Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally covers the period up to 16-cell MORULA.

The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.

Transport of the OVUM or fertilized ovum (ZYGOTE) from the mammalian oviduct (FALLOPIAN TUBES) to the site of EMBRYO IMPLANTATION in the UTERUS.

Agents destructive to parasitic worms. They are used therapeutically in the treatment of HELMINTHIASIS in man and animal.

Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.

Ducts that serve exclusively for the passage of eggs from the ovaries to the exterior of the body. In non-mammals, they are termed oviducts. In mammals, they are highly specialized and known as FALLOPIAN TUBES.

A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.

A genus of intestinal nematode worms which includes the pinworm or threadworm Enterobius vermicularis.

A species of parasitic nematode usually found in domestic pigs and a few other animals. Human infection can also occur, presumably as result of handling pig manure, and can lead to intestinal obstruction.

The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.

A genus of ascarid nematodes commonly parasitic in the intestines of cats and dogs.

The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.

An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.

A species of trematode blood flukes of the family Schistosomatidae which occurs at different stages in development in veins of the pulmonary and hepatic system and finally the bladder lumen. This parasite causes urinary schistosomiasis.

An anthelmintic used in most schistosome and many cestode infestations.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

A human disease caused by the infection of parasitic worms SCHISTOSOMA HAEMATOBIUM. It is endemic in AFRICA and parts of the MIDDLE EAST. Tissue damages most often occur in the URINARY TRACT, specifically the URINARY BLADDER.

A genus of nematode worms comprising the whipworms.

Elements of limited time intervals, contributing to particular results or situations.

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.

Infections by nematodes, general or unspecified.

A suborder of HEMIPTERA, called true bugs, characterized by the possession of two pairs of wings. It includes the medically important families CIMICIDAE and REDUVIIDAE. (From Dorland, 28th ed)

A relatively small nodular inflammatory lesion containing grouped mononuclear phagocytes, caused by infectious and noninfectious agents.

A widely distributed order of perching BIRDS, including more than half of all bird species.

A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.

Infections caused by infestation with worms of the class Trematoda.

Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.

Infection with nematodes of the genus ENTEROBIUS; E. vermicularis, the pinworm of man, causes a crawling sensation and pruritus. This condition results in scratching the area, occasionally causing scarification.

A phylum of metazoan invertebrates comprising the segmented worms, and including marine annelids (POLYCHAETA), freshwater annelids, earthworms (OLIGOCHAETA), and LEECHES. Only the leeches are of medical interest. (Dorland, 27th ed)

Sexual activities of animals.

A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.

A superfamily of nematodes. Most are intestinal parasites of ruminants and accidentally in humans. This superfamily includes seven genera: DICTYOCAULUS; HAEMONCHUS; Cooperia, OSTERTAGIA; Nematodirus, TRICHOSTRONGYLUS; and Hyostrongylus.

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

A large order of insects characterized by having the mouth parts adapted to piercing or sucking. It is comprised of four suborders: HETEROPTERA, Auchenorrhyncha, Sternorrhyncha, and Coleorrhyncha.

An order of fish with 26 families and over 3,000 species. This order includes the families CYPRINIDAE (minnows and CARPS), Cobitidae (loaches), and Catostomidae (suckers).

Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.

The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)

Liver diseases caused by infections with PARASITES, such as tapeworms (CESTODA) and flukes (TREMATODA).

The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.

The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.

Infections of the lungs with parasites, most commonly by parasitic worms (HELMINTHS).

Infections of the INTESTINES with PARASITES, commonly involving PARASITIC WORMS. Infections with roundworms (NEMATODE INFECTIONS) and tapeworms (CESTODE INFECTIONS) are also known as HELMINTHIASIS.

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.

The study of the development of an organism during the embryonic and fetal stages of life.

A family of Urodela consisting of 15 living genera and about 42 species and occurring in North America, Europe, Asia, and North Africa.

A class in the phylum MOLLUSCA comprised of SNAILS and slugs. The former have coiled external shells and the latter usually lack shells.

A species of trematode flukes of the family Opisthorchidae. Many authorities consider this genus belonging to Opisthorchis. It is common in China and other Asiatic countries. Snails and fish are the intermediate hosts.

Cellular proteins encoded by the c-mos genes (GENES, MOS). They function in the cell cycle to maintain MATURATION PROMOTING FACTOR in the active state and have protein-serine/threonine kinase activity. Oncogenic transformation can take place when c-mos proteins are expressed at the wrong time.

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

Class of parasitic flukes consisting of three subclasses, Monogenea, Aspidogastrea, and Digenea. The digenetic trematodes are the only ones found in man. They are endoparasites and require two hosts to complete their life cycle.

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.

Deoxyribonucleic acid that makes up the genetic material of helminths.

Changes that occur to liberate the enzymes of the ACROSOME of a sperm (SPERMATOZOA). Acrosome reaction allows the sperm to penetrate the ZONA PELLUCIDA and enter the OVUM during FERTILIZATION.

A genus of trichuroid nematodes parasitic in the liver and intestines of many mammals and birds. Two species, C. hepatica and C. philippinensis, produce often fatal infections in man.

Agents that act systemically to kill adult schistosomes.

Morphological and physiological development of EMBRYOS.

Poisoning caused by ingestion of food harboring species of SALMONELLA. Conditions of raising, shipping, slaughtering, and marketing of domestic animals contribute to the spread of this bacterium in the food supply.

A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.

Protein kinase that drives both the mitotic and meiotic cycles in all eukaryotic organisms. In meiosis it induces immature oocytes to undergo meiotic maturation. In mitosis it has a role in the G2/M phase transition. Once activated by CYCLINS; MPF directly phosphorylates some of the proteins involved in nuclear envelope breakdown, chromosome condensation, spindle assembly, and the degradation of cyclins. The catalytic subunit of MPF is PROTEIN P34CDC2.

Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.

Transfer of preovulatory oocytes from donor to a suitable host. Oocytes are collected, fertilized in vitro, and transferred to a host that can be human or animal.

Infections with nematodes of the order ENOPLIDA.

Commonly known as parasitic worms, this group includes the ACANTHOCEPHALA; NEMATODA; and PLATYHELMINTHS. Some authors consider certain species of LEECHES that can become temporarily parasitic as helminths.

Infection by nematodes of the genus ASCARIS. Ingestion of infective eggs causes diarrhea and pneumonitis. Its distribution is more prevalent in areas of poor sanitation and where human feces are used for fertilizer.

A genus of parasitic nematode worms which infest the duodenum and stomach of domestic and wild herbivores, which ingest it with the grasses (POACEAE) they eat. Infestation of man is accidental.

PASSERIFORMES of the suborder, Oscines, in which the flexor tendons of the toes are separate, and the lower syrinx has 4 to 9 pairs of tensor muscles inserted at both ends of the tracheal half rings. They include many commonly recognized birds such as CROWS; FINCHES; robins; SPARROWS; and SWALLOWS.

Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d 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.

Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.

A genus of nematodes of the superfamily ASCARIDOIDEA whose species usually inhabit the intestine.

Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.

The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.

The deposit of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.

Infection of the biliary passages with CLONORCHIS SINENSIS, also called Opisthorchis sinensis. It may lead to inflammation of the biliary tract, proliferation of biliary epithelium, progressive portal fibrosis, and sometimes bile duct carcinoma. Extension to the liver may lead to fatty changes and cirrhosis. (From Dorland, 27th ed)

The immature stage in the life cycle of those orders of insects characterized by gradual metamorphosis, in which the young resemble the imago in general form of body, including compound eyes and external wings; also the 8-legged stage of mites and ticks that follows the first moult.

A species of fruit fly much used in genetics because of the large size of its chromosomes.

A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.

The presence of bacteria, viruses, and fungi in food and food products. This term is not restricted to pathogenic organisms: the presence of various non-pathogenic bacteria and fungi in cheeses and wines, for example, is included in this concept.

The discharge of an OVUM from a rupturing follicle in the OVARY.

The number of males per 100 females.

An order of BIRDS including over 300 species that primarily inhabit coastal waters, beaches, and marshes. They are comprised of shorebirds, gulls, and terns.

The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.

Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.

A subclass of segmented worms comprising the tapeworms.

A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.

A genus of small tapeworms of birds and mammals.

An ethylmercury-sulfidobenzoate that has been used as a preservative in VACCINES; ANTIVENINS; and OINTMENTS. It was formerly used as a topical antiseptic. It degrades to ethylmercury and thiosalicylate.

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.

Diseases of birds which are raised as a source of meat or eggs for human consumption and are usually found in barnyards, hatcheries, etc. The concept is differentiated from BIRD DISEASES which is for diseases of birds not considered poultry and usually found in zoos, parks, and the wild.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A superfamily of nematode parasitic hookworms consisting of four genera: ANCYLOSTOMA; NECATOR; Bunostomum; and Uncinaria. ANCYLOSTOMA and NECATOR occur in humans and other mammals. Bunostomum is common in ruminants and Uncinaria in wolves, foxes, and dogs.

A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.

Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.

Infection with nematodes of the genus TRICHURIS, formerly called Trichocephalus.

A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.

INSECTS of the order Coleoptera, containing over 350,000 species in 150 families. They possess hard bodies and their mouthparts are adapted for chewing.

Proteins found in any species of helminth.

Proteins found in any species of insect.

A species of parasitic nematode found in the intestine of dogs. Lesions in the brain, liver, eye, kidney, and lung are caused by migrating larvae. In humans, these larvae do not follow normal patterns and may produce visceral larva migrans (LARVA MIGRANS, VISCERAL).

The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.

Infection by round worms of the genus TOXOCARA, usually found in wild and domesticated cats and dogs and foxes, except for the larvae, which may produce visceral and ocular larva migrans in man.

A superfamily of polymyarian nematode worms. An important characteristic of this group is the presence of three prominent lips around the mouth of the organism.

Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.

Infestation of animals with parasitic worms of the helminth class. The infestation may be experimental or veterinary.

Infection by roundworms of the superfamily TRICHOSTRONGYLOIDEA, including the genera TRICHOSTRONGYLUS; OSTERTAGIA; Cooperia, HAEMONCHUS; Nematodirus, Hyostrongylus, and DICTYOCAULUS.

The family of true toads belonging to the order Anura. The genera include Bufo, Ansonia, Nectophrynoides, and Atelopus.

Substances used in the treatment or control of nematode infestations. They are used also in veterinary practice.

The only genus in the family Oryziinae, order BELONIFORMES. Oryzias are egg-layers; other fish of the same order are livebearers. Oryzias are used extensively in testing carcinogens.

Marine, freshwater, or terrestrial mollusks of the class Gastropoda. Most have an enclosing spiral shell, and several genera harbor parasites pathogenic to man.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.

The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.

A family of intestinal flukes of the class Trematoda which occurs in animals and man. Some of the genera are Heterophyes, Metagonimus, Cryptocotyle, Stellantchasmus, and Euryhelmis.

In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

A species of parasitic nematode that is the largest found in the human intestine. Its distribution is worldwide, but it is more prevalent in areas of poor sanitation. Human infection with A. lumbricoides is acquired by swallowing fully embryonated eggs from contaminated soil.

##### I apologize, but the term "turtles" is not a recognized medical term or concept. It is commonly referred to as a group of reptiles with a shell, and does not have any direct relevance to medical definition.

Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.

The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).

An inactive stage between the larval and adult stages in the life cycle of insects.

Infection of humans or animals with hookworms other than those caused by the genus Ancylostoma or Necator, for which the specific terms ANCYLOSTOMIASIS and NECATORIASIS are available.

Phosphoprotein with protein kinase activity that functions in the G2/M phase transition of the CELL CYCLE. It is the catalytic subunit of the MATURATION-PROMOTING FACTOR and complexes with both CYCLIN A and CYCLIN B in mammalian cells. The maximal activity of cyclin-dependent kinase 1 is achieved when it is fully dephosphorylated.

Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.

Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.

Coloration or discoloration of a part by a pigment.

The study of parasites and PARASITIC DISEASES.

Gastrointestinal disturbances, skin eruptions, or shock due to allergic reactions to allergens in food.

Infections with nematodes of the order ASCARIDIDA.

Instinctual behavior pattern in which food is obtained by killing and consuming other species.

A species of the true toads, Bufonidae, found in South America.

The process by which a DNA molecule is duplicated.

A genus of parasitic nematodes widely distributed as intestinal parasites of mammals.

The rate dynamics in chemical or physical systems.

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.

A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)

The study of disease in prehistoric times as revealed in bones, mummies, and archaeologic artifacts.

Infection with tapeworms of the genus Taenia.

Insects of the suborder Heterocera of the order LEPIDOPTERA.

The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Food that is grown or manufactured in accordance with nationally regulated production standards that include restrictions on the use of pesticides, non-organic fertilizers, genetic engineering, growth hormones, irradiation, antibiotics, and non-organic ingredients.

A pyridine nucleotide that mobilizes CALCIUM. It is synthesized from nicotinamide adenine dinucleotide (NAD) by ADP RIBOSE CYCLASE.

Any aspect of the operations in the preparation, processing, transport, storage, packaging, wrapping, exposure for sale, service, or delivery of food.

A genus of aquatic newts belonging to the family Salamandridae and sometimes referred to as "spiny" tritons. There are two species P. waltlii and P. poireti. P. waltlii is commonly used in the laboratory. Since this genus adapts to aquarium living, it is easy to maintain in laboratories.

An egg yolk phosphoglycoprotein which contains about 90% of the yolk protein phosphorus. It is synthesized in the liver of the hen and transferred to the developing oocyte, where it is bound to lipoproteins within the yolk granules.

Infection with nematodes of the genus HAEMONCHUS, characterized by digestive abnormalities and anemia similar to that from hookworm infestation.

The sum of the weight of all the atoms in a molecule.

An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).

The element in plants that contains the female GAMETOPHYTES.

The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

The outermost extra-embryonic membrane surrounding the developing embryo. In REPTILES and BIRDS, it adheres to the shell and allows exchange of gases between the egg and its environment. In MAMMALS, the chorion evolves into the fetal contribution of the PLACENTA.

The presence in food of harmful, unpalatable, or otherwise objectionable foreign substances, e.g. chemicals, microorganisms or diluents, before, during, or after processing or storage.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

Geographical sites known to be extant in a remote period in the history of civilization, familiar as the names of ancient countries and empires.

The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.

The physical measurements of a body.

Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.

A glycoprotein albumin from hen's egg white with strong iron-binding affinity.

Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.

RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.