Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Introduction In holometabolous insects such as Drosophila, larval tissues

Summary: Introduction
In holometabolous insects such as Drosophila, larval tissues
are set aside from adult or imaginal tissues during early
embryogenesis (Bate and Arias, 1991). During the instars,
larval cells become polytenized and grow in size without cell
division, and most will undergo a steroid-hormone-regulated
programmed cell death at metamorphosis (Jiang et al., 1997).
By contrast, cells in the imaginal tissues proliferate and
are maintained in a strictly diploid undifferentiated state
throughout larval development. At metamorphosis, it is the
imaginal cells that will differentiate to form the adult body
plan. Because of these fundamental differences in cell fate, and
because a maternal contribution is often sufficient to sustain all
embryonic cell divisions, mutations in many genes regulating
the diploid cell cycle do not cause lethality until
metamorphosis. However, homozygous mutants eventually die
because imaginal disc structures are not present to replace the
histolyzing larval tissues. By examining mutants that display
late-larval or prepupal lethal periods, many genes have been
identified that play a role in regulating the diploid cell cycle


Source: Andres, Andrew - School of Life Sciences, University of Nevada at Las Vegas


Collections: Biology and Medicine