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Pupa
A pupa (; : 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 metamorphosis. The pupa is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imaginal Disc
An imaginal disc is one of the parts of a holometabolous insect larva that will become a portion of the outside of the adult insect during the pupal transformation. Contained within the body of the larva, there are pairs of discs that will form, for instance, the wings or legs or antennae or other structures in the adult. The role of the imaginal disc in insect development was first elucidated by Jan Swammerdam. During the pupal stage, many larval structures are broken down, and adult structures, including the discs, undergo rapid development. Each disc everts and elongates, with the central portion of the disc becoming the distal part of whichever appendage it is forming: the wing, leg, antenna, etc. During the larval stage, the cells in the growing disc appear undifferentiated, but their developmental fate in the adult is already determined. The experiment that demonstrates this developmental commitment is to take an imaginal disc from a third instar larva, about to undergo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclosion Assay
Eclosion assays are experimental procedures used to study the process of eclosion in insects, particularly in the model organism ''drosophila'' (fruit flies). Eclosion is the process in which an adult insect emerges from its pupal case, or a larval insect hatches from its egg. In holometabolous insects, the circadian clock regulates the timing of adult emergence. The daily rhythm of adult emergence in these insects was among the first circadian rhythms to be investigated. The circadian clock in these insects enforces a daily pattern of emergence by permitting or triggering eclosion during specific time frames and preventing emergence during other periods. The purpose of an eclosion assay is to count the number of flies that emerge over time from a developing population, which provides information on the circadian clock in the experimentally manipulated drosophila. For example, with an eclosion monitor, scientists can study how knocking out a certain gene changes the behavioral expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
