G5 Doctoral dissertation (article)
Adaptation to seasonality: genetics and variation in life-history traits important in overwintering (2012)
Tyukmaeva, V. (2012). Adaptation to seasonality: genetics and variation in life-history traits important in overwintering [Doctoral dissertation]. University of Jyväskylä. Jyväskylä studies in biological and environmental science, 250. http://urn.fi/URN:ISBN:978-951-39-4901-3
JYU authors or editors
Publication details
All authors or editors: Tyukmaeva, Venera
ISBN: 978-951-39-4900-6
eISBN: 978-951-39-4901-3
Journal or series: Jyväskylä studies in biological and environmental science
ISSN: 1456-9701
Publication year: 2012
Number in series: 250
Number of pages in the book: 37
Publisher: University of Jyväskylä
Place of Publication: Jyväskylä
Publication country: Finland
Publication language: English
Persistent website address: http://urn.fi/URN:ISBN:978-951-39-4901-3
Publication open access: Openly available
Publication channel open access:
Publication is parallel published (JYX): http://urn.fi/URN:ISBN:978-951-39-4901-3
Additional information: Artikkeliväitöskirjan yhteenveto-osa ja 4 eripainosta. Vuodenaikaisvaihteluun sopeutuminen : geneettinen muuntelu talvehtimiseen liittyvissä elinkiertopiireissä.
Abstract
importance for species living at high latitudes. This involves not only tolerance to
cold temperatures, but also an ability to timely predict the forthcoming cold season
from gradual changes in the environment. The forecasting systems of several
northern species have been found to rely on changes in photoperiodic cues, which
are the most reliable seasonal cue at high latitudes. In my thesis, I examine the
genetic basis of variation in one of the strongest adaptations to seasonally varying
environments in insects - adult reproductive diapause - and other associated lifehistory
traits in Drosophila montana. Study I revealed significant and predictable
clinal variation in the critical day length (CDL) for diapause incidence in presence
of high gene flow. Study II showed high variation in factors affecting the diapause
incidence both within and between the same clinal populations and showed that
while variation in females' photoperiodic responses decreases during laboratory
maintenance, the mean CDLs of the strains remain the same. Study III was carried
out with a "resonance" experiment, revealed no rhythmicity in the females'
diapause response, which suggests that the photoperiodic timer of D. montana is
based on a non-oscillatory hourglass timer or rapidly dampening circadian
oscillator. In study IV we performed a QTL analysis by crossing two D. montana
strains that differed in their diapause incidence, cold tolerance, egg-to-eclosion
development time and body weight at a specific day length. This study revealed
both unique and combined QTL for the studied traits, the most interesting result
being a large-effect QTL for diapause on the X chromosome. While we did not find
evidence for the involvement of a circadian clock in the photoperiodic regulation of
reproductive diapause in D. montana in the above-mentioned studies, some QTL
for traits regulated by different time-measuring systems were overlapping (IV).
Keywords: adaptation (change); dormancy; wintering; life cycle (natural science); genetic variation; life history
Free keywords: diapaussi; adaptaatio; vuodenaikaisvaihtelu; elinkiertopiirteet; adaptation; diapause; Drosophila montana; seasonality
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