Bodily processes in animals are controlled hormones secreted by the endocrine system, which reach target areas and relay ‘messages’ through either the hemolymph in invertebrates or blood in vertebrates. Some of these processes include the regulation of metabolism, growth, and fertility(). Understanding these processes and how altering them changes outcomes in model organisms is useful to vicariously understand of. Testing on humans can have many ethical problems, so model organisms are therefore used in laboratories instead of humans. Drosophila Melanogaster, also commonly known as a fruit D. Melanogaster, is one such model organism. They are versatile so a variety of testing can be done on them, they are inexpensive to culture, they have short lifespans, they produce many external offspring at one time, and their life cycles have been extensively mapped. The hormone which will be tested on D. Melanogaster in this lab is a juvenile hormone. It has been found to be present in D. Melanogaster mainly during the larval and pupal stage and the effects it has are what our group aims to determine.
D. Melanogaster begins their life cycles as eggs laid by adult females on fruits and are ovoid in shape. Every stage is regulated with hormones that regulate every process that occurs. Once the egg stage is nearing completion it begins the larval stage which can further be broken down into three instars separated by molting events. At the first and second instar, the larva consumes until molting, at which point it increases in size and grows for the next stage. Once at the third instar it consumes until ready to pupate. The third instar larva leaves their area of consumption for a drier environment at which point they cease moving and harden their cuticle, a thin outer layer of the larval body. The pupa remains in this stage until larval tissues have been broken down and are ready to enter the next stage, Adulthood. At Adulthood D. Melanogaster begin the mating process in which a male inseminates a female with sperm which the female stores for egg laying at a later time.