Search results for "Montana"
showing 10 items of 43 documents
Karaistumisen ja lisääntymisdiapaussin vaikutukset Drosophila montana -mahlakärpästen kylmänkestävyyteen
2011
Kylmyys on yksi tärkeimmistä lajien levinneisyyteen ja runsauteen vaikuttavista stressitekijöistä. Karaistuminen ja lisääntymisdiapaussi ovat esimerkkejä hyönteisten fysiologisesta ja biokemiallisesta sopeutumista mataliin lämpötiloihin. Karaistumisella tarkoitetaan lyhyen ajan sisällä tapahtuvaa kylmänkestävyyden kasvamista, ja sillä voi olla huomattava vaikutus kylmistä olosuhteista selviytymiseen. Lisääntymisdiapaussin laukaisee ympäristöstä tulevat ärsykkeet, kuten muutokset päivän pituudessa ja lämpötilassa. Se parantaa naaraiden mahdollisuuksia selvitä epäedullisista vuodenajoista ja siirtää jälkeläisten tuoton ajankohtaan jolloin munien ja jälkeläisten selviytyminen on parhaimmillaan…
Couch potato -kandidaattigeenissä esiintyvän mutaation vaikutus Drosophila montana -naaraiden lisääntymislepokauteen
2010
Diapaussi on fysiologinen lepotila, jonka aikana eliön elintoiminnot, kasvu ja kehitys hidastuvat ja ääriolosuhteiden, kuten alhaisten lämpötilojen ja kuivuuden, sietokyky paranee. Lisääntymislepokaudella tarkoitetaan aikuisilla hyönteisillä esiintyvää diapaussin muotoa, jonka aikana lisääntymiseen liittyvät toiminnot hidastuvat tai pysähtyvät kokonaan. Drosophila melanogaster -lajin lisääntymislepokauteen on liitetty useita kandidaattigeenejä, joista yksi on couch potato (cpo), ja tämän geenin yhteydestä lisääntymislepokauteen on saatu viitteitä myös pohjoisella D. montana -lajilla. Pro gradu -työssäni tarkasteltiin cpo-geenissä esiintyvän 19 emäsparin kokoisen deleetiomutaation yleisyyttä…
Data from: Inter- and intra-specific genomic divergence in Drosophila montana shows evidence for cold adaptation
2018
D. montana gff fileGenome annotation file for D. montana genome (Accession number: LUVX00000000)D.mont_freeze_v1.4.gff.txt
Data from: The genetic architecture of sexually selected traits in two natural populations of Drosophila montana
2015
We investigated the genetic architecture of courtship song and cuticular hydrocarbon traits in two phygenetically distinct populations of Drosophila montana. In order to study natural variation in these two important traits, we analysed within-population crosses among individuals sampled from the wild. Hence, the genetic variation analysed should represent that available for natural and sexual selection to act upon. In contrast to previous between-population crosses in this species, no major QTLs were detected, perhaps because the between-population QTL were due to fixed differences between the populations. Partitioning the trait variation to chromosomes suggested a broadly polygenic geneti…
Data from: Two distinct genomic regions, harbouring the period and fruitless genes, affect male courtship song in Drosophila montana
2011
Acoustic signals often play a significant role in pair formation and in species recognition. Determining the genetic basis of signal divergence will help to understand signal evolution by sexual selection and its role in the speciation process. An earlier study investigated QTL for male courtship song carrier frequency in Drosophila montana using microsatellite markers. We refined this study by adding to the linkage map markers for ten candidate genes known to affect song production in D. melanogaster. We also extended the analyses to additional song characters (pulse train length, pulse number, interpulse interval, pulse length and cycle number). Our results indicate that loci in two diffe…
Data from: Reproductive isolation among allopatric Drosophila montana populations
2014
An outstanding goal in speciation research is to trace the mode and tempo of the evolution of barriers to gene flow. Such research benefits from studying incipient speciation, in which speciation between populations has not yet occurred but where multiple potential mechanisms of reproductive isolation (RI: i.e. premating, postmating-prezygotic (PMPZ), and postzygotic barriers) may act. We used such a system to investigate these barriers among allopatric populations of Drosophila montana. In all heteropopulation crosses we found premating (sexual) isolation which was either symmetric or asymmetric depending on the population pair compared. Postmating isolation was particularly strong in cros…
Data from: Multiple quantitative trait loci influence intra-specific variation in genital morphology between phylogenetically distinct lines of Droso…
2011
The evolution of animal genitalia has gained renewed interest, because of their potential roles during sexual selection and early stages of species formation. Although central to understanding the evolutionary process, knowledge of the genetic basis of natural variation in genital morphology is limited to a very few species. Using an out-bred cross between phylogenetically distinct lines of Drosophila montana, we characterized quantitative trait loci (QTLs) affecting the size and shape of the distiphallus, a prominent part of the male intromittent organ. Our microsatellite-based linkage analysis shows that intra-specific variation of the distiphallus involves several QTLs of largely additiv…
Data from: Postmating-prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm compet…
2017
Postmating but prezygotic (PMPZ) interactions are increasingly recognized as a potentially important early-stage barrier in the evolution of reproductive isolation. A recent study described a potential example between populations of the same species: single matings between Drosophila montana populations resulted in differential fertilisation success because of the inability of sperm from one population (Vancouver) to penetrate the eggs of the other population (Colorado). As the natural mating system of D. montana is polyandrous (females remate rapidly), we set up double matings of all possible crosses between the same populations to test whether competitive effects between ejaculates influe…
Data from: Localization of QTL for diapause and other photoperiodically regulated life-history traits important in adaptation to seasonally varying e…
2015
Seasonally changing environments at high latitudes present great challenges for the reproduction and survival of insects, and photoperiodic cues play an important role in helping them to synchronize their life cycle with prevalent and forthcoming conditions. We have mapped quantitative trait loci (QTL) responsible for the photoperiodic regulation of four life history traits, female reproductive diapause, cold tolerance, egg-to-eclosion development time and juvenile body weight in Drosophila montana strains from different latitudes in Canada and Finland. The F2 progeny of the cross was reared under a single photoperiod (LD cycle 16:8), which the flies from the Canadian population interpret a…
Sexual selection on song and cuticular hydrocarbons in two distinct populations of Drosophila montana
2011
Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F1–3 offspring of wild- collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana that represent different phylogeographic clades that have been separate for ca. 0.5 million years (MY), and differ to some extent in both traits. Here, we characterize the nature and identify …