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Adenotrophic Viviparity
Adenotrophic viviparity means "gland fed, live birth". This is the reproductive mode of insects such as tsetse flies (Glossinidae), keds (Hippoboscidae) and bat flies (Streblidae and Nycteribiidae), as adenotrophic viviparity is a characteristic feature of the superfamily Hippoboscoidea. It has also been observed in members of the subfamily Mesembrinellinae. In adenotrophic viviparity, the eggs (usually one at a time) are retained within the female's body, hatch, and are nourished through "milk glands" until the developed larvae are ready to pupate. The larvae are then 'larviposited' and immediately pupate. This is one way insects avoid predation during their most vulnerable life stage. Following the birth of the juvenile, lactation ceases and a period of involution of the milk gland secretory cells begins where they return to their original size. During this period, embryogenesis begins in the next egg. The glands producing the milk secretions differ between the Hippoboscoidea and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viviparity
Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the mother. The term 'viviparity' and its adjective form 'viviparous' derive from the Latin ''vivus'' meaning "living" and ''pario'' meaning "give birth to". Reproductive mode Five modes of reproduction have been differentiated in animals based on relations between zygote and parents. The five include two nonviviparous modes: ovuliparity, with external fertilisation, and oviparity, with internal fertilisation. In the latter, the female lays zygotes as eggs with a large vitellus, yolk; this occurs in all birds, most reptiles, and some fishes. These modes are distinguished from viviparity, which covers all the modes that result in live birth: *Histotrophic viviparity: the zygotes develop in the female's oviducts, but find their nutrients b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryogenesis
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervous sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wigglesworthia Glossinidia
''Wigglesworthia glossinidia'' is a species of gram-negative bacteria which was isolated from the gut of the tsetse fly. ''W. glossinidia'' is a bacterial endosymbiont of the tsetse fly. Because of this relationship, ''Wigglesworthia'' has lost a large part of its genome and has one of the smallest known genomes of any living organism, consisting of a single chromosome of 700,000 bp and a plasmid of 5,200. Together with ''Buchnera aphidicola'', ''Wigglesworthia'' has been the subject of genetic research into the minimal genome necessary for any living organism. ''Wigglesworthia'' also synthesizes key B-complex vitamins which the tsetse fly does not get from its diet of blood. Without the vitamins ''Wigglesworthia'' produces, the tsetse fly has greatly reduced growth and reproduction.Nogge, G. 1976. Sterility in tsetse flies (Glossina morsitans Westwood) caused by loss of symbionts. Experientia 32, 995−996. Since the tsetse fly is the primary vector of ''Trypanosoma brucei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosymbiont
An ''endosymbiont'' or ''endobiont'' is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship. (The term endosymbiosis is from the Greek: ἔνδον ''endon'' "within", σύν ''syn'' "together" and βίωσις ''biosis'' "living".) Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside reef-building corals and bacterial endosymbionts that provide essential nutrients to insects. There are two types of symbiont transmissions. In horizontal transmission, each new generation acquires free living symbionts from the environment. An example is the nitrogen-fixing bacteria in certain plant roots. Vertical transmission takes place when the symbiont is transferred directly from parent to offspring. It is also possible for both to be involved in a mixed-mode transmission, where symbionts are transferred vertically for some generation bef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins (CSN1S1, αS1, aS2, CSN2, β, K-casein, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in breast milk, human milk. Sheep's milk, Sheep and buffalo milk have a higher casein content than other types of milk with human milk having a particularly low casein content. Casein has a wide variety of uses, from being a major component of cheese, to use as a food additive. The most common form of casein is sodium caseinate. In milk, casein undergoes phase separation to form colloidal casein micelles, a type of secreted biomolecular condensate. As a food source, casein supplies amino acids, carbohydrates, and two essential elements, calcium and phosphorus. Composition Casein contains a high number of proline amino acids which hinder the formation of common secondary structural motifs of proteins. There are also no di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipocalin
The lipocalins are a family of proteins which transport small hydrophobic molecules such as steroids, bilins, retinoids, and lipids and most lipocalins are also able to bind to complexed iron (via siderophores or flavonoids) as well as heme. They share limited regions of sequence homology and a common tertiary structure architecture. This is an eight stranded antiparallel beta barrel with a repeated + 1 topology enclosing an internal ligand binding site. These proteins are found in gram negative bacteria, vertebrate cells, and invertebrate cells, and in plants. Lipocalins have been associated with many biological processes, among them immune response, pheromone transport, biological prostaglandin synthesis, retinoid binding, and cancer cell interactions. Function Immune response Lipocalin proteins are important key players of nutritional immunity by withholding and sequestering micronutrients. They are thereby able to regulate inflammatory and detoxification processe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatheca
The spermatheca (pronounced plural: spermathecae ), also called receptaculum seminis (plural: receptacula seminis), is an organ of the female reproductive tract in insects, e.g. ants, bees, some molluscs, oligochaeta worms and certain other invertebrates and vertebrates. Its purpose is to receive and store sperm from the male or, in the case of hermaphrodites, the male component of the body. Spermathecae can sometimes be the site of fertilization when the oocytes are sufficiently developed. Some species of animal have multiple spermathecae. For example, certain species of earthworms have four pairs of spermathecae—one pair each in the 6th, 7th, 8th, and 9th segments. The spermathecae receive and store the spermatozoa of another earthworm during copulation. They are lined with epithelium and are variable in shape: some are thin, heavily coiled tubes, while others are vague outpocketings from the main reproductive tract. It is one of the many variations in sexual reproduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accessory Glands
Male accessory glands (MAG) in humans are the seminal vesicles, prostate gland, and the bulbourethral glands (also called Cowper's glands). In insects, male accessory glands produce products that mix with the sperm to protect and preserve them, including seminal fluid proteins. Some insecticides can induce an increase in the protein content of the male accessory glands of certain types of insects. This has the unintended effect of increasing the number of offspring they produce. These glands secrete fluid for nourishment of sperm. Accessory glands The male accessory glands are the ampullary gland, seminal vesicles, prostate, bulbourethral gland, and urethral glands. The products of these glands serve to nourish and activate the spermatozoa, to clear the urethral tract prior to ejaculation, serve as the vehicle of transport of the spermatozoa in the female tract, and to plug the female tract after placement of spermatozoa to help ensure fertilization. Although the glands are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Involution (medicine)
Involution is the shrinking or return of an organ to a former size. At a cellular level, involution is characterized by the process of proteolysis of the basement membrane (basal lamina), leading to epithelial regression and apoptosis, with accompanying stromal fibrosis. The consequent reduction in cell number and reorganization of stromal tissue leads to the reduction in the size of the organ. Examples Thymus The thymus continues to grow between birth and puberty and then begins to atrophy, a process directed by the high levels of circulating sex hormones. Proportional to thymic size, thymic activity (T cell output) is most active before puberty. Upon atrophy, the size and activity are dramatically reduced, and the organ is primarily replaced with fat. The atrophy is due to the increased circulating level of sex hormones, and chemical or physical castration of an adult results in the thymus increasing in size and activity. Uterus Involution is the process by which the uterus is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsetse Flies
Tsetse ( , or ) (sometimes spelled tzetze; also known as tik-tik flies), are large, biting flies that inhabit much of tropical Africa. Tsetse flies include all the species in the genus ''Glossina'', which are placed in their own family, Glossinidae. The tsetse are obligate parasites, which live by feeding on the blood of vertebrate animals. Tsetse have been extensively studied, because of their role in transmitting disease. They have a prominent economic impact in sub-Saharan Africa, as the biological vectors of trypanosomes, causing human and animal trypanosomiasis. Tsetse are multivoltine and long-lived, typically producing about four broods per year, with up to 31 broods over their lifespans. Tsetse can be distinguished from other large flies by two easily-observed features: Primarily, tsetse fold their wings over their abdomens completely when they are resting (so that one wing rests directly on top of the other); Secondly, tsetse also have a long proboscis, extending d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pupate
A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages thereof being egg, larva, pupa, and imago. The processes of entering and completing the pupal stage are controlled by the insect's hormones, especially juvenile hormone, prothoracicotropic hormone, and ecdysone. The act of becoming a pupa is called pupation, and the act of emerging from the pupal case is called eclosion or emergence. The pupae of different groups of insects have different names such as ''chrysalis'' for the pupae of butterflies and ''tumbler'' for those of the mosquito family. Pupae may further be enclosed in other structures such as cocoons, nests, or shells. Position in life cycle The pupal stage follows the larval stage and precedes adulthood (''imago'') in insects with complete metamorphos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesembrinellinae
Mesembrinellinae is a subfamily of Neotropical flies in the order Diptera, and formerly included in the Calliphoridae. There are 33 described living species. Taxonomy *'' Albuquerquea'' Mello, 1967 :*'' A. latifrons'' Mello, 1967 *'' Eumesembrinella'' Townsend, 1931 :*'' E. benoisti'' ( Séguy, 1925) :*'' E. cyaneicincta'' ( Surcouf, 1919) :*'' E. quadrilineata'' (Fabricius, 1805) :*'' E. randa'' ( Walker, 1849) *''Giovanella'' Bonatto and Marinoni, 2005 :*'' G. bolivar'' Bonatto and Marinoni, 2005 :*'' G. carvalhoi'' Wolff et al., 2013 *''Henriquella'' Bonatto and Marinon, 2005 :*'' H. spicata'' (Aldrich, 1925) *'' Huascaromusca'' Townsend, 1931 :*'' H. aeneiventris'' ( Wiedemann, 1830) :*'' H. bequaerti'' ( Séguy, 1925) :*'' H. decrepita'' ( Séguy, 1925) :*'' H. lara'' Bonatto and Marinoni, 2005 :*'' H. purpurata'' (Aldrich, 1922) :*'' H. semiflava'' (Aldrich, 1925) :*'' H. uniseta'' (Aldrich, 1925) :*'' H. vogelsangi'' Mello, 1967 *'' Mesembrinella'' Giglio-Tos, 1893 :* ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
