1,721,382 research outputs found
Esterase-6 and the pheromonal effects of cis-vaccenyl acetate in Drosophila melanogaster
No full textTaking stock of circadian clock complexity
No full textCircadian clocks are ubiquitous! This terse sentence
has been used frequently in the last few years to mean
not only that almost all higher organisms (and some
bacteria) exhibit circadian rhythmicity controlled by
an endogenous circadian clock,1 but also that many
autonomous oscillators are present in different tissues
or organs.2,3 Clock research also represents one of
the more productive and faster evolving areas of biology,
as evidenced by the extraordinary number of
high profile publications that keep coming, thick and
fast. This in turn has produced a market for reviews
of molecular chronobiology, yet the ‘half-life’ of these
reviews is significantly affected by this explosive accumulation
of data and discourages potential authors to
undertake this (thankless) task. I am therefore particularly
pleased that a number of colleagues have committed
themselves to write these contributions for this
issue, which cover the most relevant aspects of circadian
rhythmicity in different model systems
Functional and evolutionary implications of natural variation in clock genes
No full textNearly all studies of natural variation within clock genes involve the period (per) locus, which was originally isolated in the fruit-fly. Intra- and interspecific work on per has focused mostly on a region of Thr-Gly or Ser-Gly repeats, which show rapid length and sequence evolution. The functional implications of nucleotide variation in this repetitive array have been characterised using behavioural, molecular, ecological, structural and statistical analyses. A population genetics approach to variation in per has also been useful in defining species histories within Drosophilids and, in some cases, in implicating selective processes in the evolution of the per gene. Interspecific analysis of per expression patterns reveals evolutionary alterations in this clock gene's regulation
Un ingranaggio per due orologi
No full textI risultati delle nostre ricerche collegano, per la prima volta, una proteina che svolge un ruolo cardinale nell’orologio biologico circadiano di un organismo ad un comportamento che costituisce una risposta a variazioni ambientali corrispondenti al ciclo delle stagioni. Nel loro insieme questi risultati costituiscono anche un nuovo, solido argomento a sostegno della teoria neo-darwiniana dell’evoluzione, una testimonianza concreta del come la struttura genetica di una specie possa evolvere in natura per effetto della mutazione spontanea e della selezione naturale
- …
