Two topics, (1) meiosis and (2) acclimation to environmental temperature change, are currently addressed primarily with Drosophila melanogaster, a fly species of major importance for experimental research in molecular biology. In the past, the laboratory has used this model organism for related research concerning the identification and characterization of regulators controlling progression through the cell cycle and its coordination with developmental processes during embryogenesis: (3) cell cycle control.
Meiosis reduces chromosome ploidy from diploid to haploid. Haploid cells have only a single copy of each chromosome. They differentiate into germ cells (oocyte or sperm). The first cell of an organism resulting from fertilization of an oocyte with a sperm is again diploid (two copies of each chromosome, a maternal and a paternal copy).
Acclimation to environmental temperature change
Environmental temperature can vary extensively (between seasons, over days, day/night). Temperature affects all biological processes, but importantly not in a uniform manner. Nevertheless, cells of ectotherm organisms remain functional over an often considerable temperature range. How do they manage acclimation?
Cell cycle control
Before a progenitor cell can undergo cell division to generate two daughter cells, all components needed for the survival of these two daughter cells have to be pre-fabricated. In particular, the genetic information (stored in chromosomes in form of double stranded DNA) needs to be replicated accurately and completely. Cell cycle control prevents fatal inaccuracies and allows co-ordination of cell proliferation with other developmental and physiological processes.