Search

Your search keyword '"Anna-Lotta Hiillos"' showing total 3 results
Start Over Author "Anna-Lotta Hiillos"
3 results on '"Anna-Lotta Hiillos"'

1. Droplet digital PCR as a tool for investigating dynamics of cryptic symbionts

Author

Anna‐Lotta Hiillos, Anne Thonig, and Karelyn Emily Knott

Subjects
apicomplexa, cryptic symbiosis, droplet digital PCR, infection dynamics, Ecology, QH540-549.5
Abstract

Abstract Interactions among symbiotic organisms and their hosts are major drivers of ecological and evolutionary processes. Monitoring the infection patterns among natural populations and identifying factors affecting these interactions are critical for understanding symbiont–host relationships. However, many of these interactions remain understudied since the knowledge about the symbiont species is lacking, which hinders the development of appropriate tools. In this study, we developed a digital droplet PCR (ddPCR) assay based on apicomplexan COX1 gene to detect an undescribed agamococcidian symbiont. We show that the method gives precise and reproducible results and enables detecting cryptic symbionts in low target concentration. We further exemplify the assay's use to survey seasonally sampled natural host (Pygospio elegans) populations for symbiont infection dynamics. We found that symbiont prevalence differs spatially but does not show seasonal changes. Infection load differed between populations and was low in spring and significantly increased towards fall in all populations. We also found that the symbiont prevalence is affected by host length and population density. Larger hosts were more likely to be infected, and high host densities were found to have a lower probability of infection. The observed variations could be due to characteristics of both symbiont and host biology, especially the seasonal variation in encounter rates. Our findings show that the developed ddPCR assay is a robust tool for detecting undescribed symbionts that are otherwise difficult to quantify, enabling further insight into the impact cryptic symbionts have on their hosts.

Published
2021
Full Text
View/download PDF

2. Coinfection patterns of two marine apicomplexans are not associated with genetic diversity of their polychaete host

Author

Anna‐Lotta Hiillos, Irin Rony, Sonja Rueckert, and K. Emily Knott

Subjects
Marosporida, vuorovaikutus, itiöeläimet, Gregarines, loiset, heterozygosity, symbiont-symbiont interactions, host-symbiont interactions, parasitismi, isäntälajit, monisukasmadot, infektiot, Microbiology
Abstract

Coinfections of two or more parasites within one host are more of a rule than an exception in nature. Interactions between coinfecting parasites can greatly affect their abundance and prevalence. Characteristics of the host, such as genetic diversity, can also affect the infection dynamics of coinfecting parasites. Here we investigate for the first time the association of coinfection patterns of two marine apicomplexans, Rhytidocystis sp. and Selenidium pygospionis, with the genetic diversity of their host, the polychaete Pygospio elegans, from natural populations. Host genetic diversity was determined with seven microsatellite loci and summarized as allelic richness, inbreeding coefficient, and individual heterozygosity. We detected nonsignificant correlations between infection loads and both individual host heterozygosity and population genetic diversity. Prevalence and infection load of Rhytidocystis sp. were higher than that of S. pygospionis and both varied spatially. Coinfections were common and almost all hosts infected by S. pygospionis were also infected by Rhytidocystis sp.. Rhytidocystis sp. infection load was significantly higher in dual infections. Our results suggest that factors other than host genetic diversity might be more important in marine apicomplexan infection patterns and experimental approaches would be needed to further determine how interactions between the apicomplexans and their host influence infection. peerReviewed

Published
2022

3. Selection for reproduction under short photoperiods changes diapause-associated traits and induces widespread genomic divergence

Author

Johanna Kinnunen, Anna-Lotta Hiillos, Hannele Kauranen, Anneli Hoikkala, R. Axel W. Wiberg, Pekka Lankinen, Michael G. Ritchie, David Hopkins, NERC, University of St Andrews. School of Biology, University of St Andrews. Centre for Biological Diversity, and University of St Andrews. Institute of Behavioural and Neural Sciences

Subjects
0106 biological sciences, Physiology, 030310 physiology, QH301 Biology, Circadian clock, Genome, Insect, 01 natural sciences, talvehtiminen, kylmänkestävyys, circadian clock, media_common, vuorokausirytmi, 0303 health sciences, luonnonvalinta, genome analyses, Reproduction, Phenotype, Adaptation, Physiological, Circadian Rhythm, Cold Temperature, Drosophila melanogaster, Female, Locomotion, endocrine system, mahlakärpäset, Period (gene), media_common.quotation_subject, Photoperiod, Zoology, reproductive diapause, fotobiologia, Aquatic Science, Diapause, Biology, 010603 evolutionary biology, 03 medical and health sciences, QH301, Quantitative Trait, Heritable, photoperiodic timer, Animals, Circadian rhythm, Molecular Biology, Gene, Ecology, Evolution, Behavior and Systematics, Selection (genetic algorithm), Critical day lenght, Genetic Variation, DAS, cold tolerance, lisääntyminen, Chromosomes, Insect, critical day length, Insect Science, perimä, hyönteiset, Linear Models, Animal Science and Zoology
Abstract

The work has been supported by the Academyof Finland to A.H. (project 267244) and Natural Environment Research Council (NERC) funding (NE/J020818/1 to M.G.R.; NE/L501852/1 to R.A.W.W.). The incidence of reproductive diapause is a critical aspect of life history in overwintering insects from temperate regions. Much has been learned about the timing, physiology and genetics of diapause in a range of insects, but how the multiple changes involved in this and other photoperiodically regulated traits are inter-related is not well understood. We performed quasinatural selection on reproduction under short photoperiods in a northern fly species, Drosophila montana, to trace the effects of photoperiodic selection on traits regulated by the photoperiodic timer and/or by a circadian clock system. Selection changed several traits associated with reproductive diapause, including the critical day length for diapause (CDL), the frequency of diapausing females under photoperiods that deviate from daily 24 h cycles and cold tolerance, towards the phenotypes typical of lower latitudes. However, selection had no effect on the period of free-running locomotor activity rhythm regulated by the circadian clock in fly brain. At a genomic level, selection induced extensive divergence from the control line in 16 gene clusters involved in signal transduction, membrane properties, immunologlobulins and development. These changes resembled those detected between latitudinally divergent D. montana populations in the wild and involved SNP divergence associated with several genes linked with diapause induction. Overall, our study shows that photoperiodic selection for reproduction under short photoperiods affects diapause-associated traits without disrupting the central clock network generating circadian rhythms in fly locomotor activity. Publisher PDF

Published
2019

Catalog

Books, media, physical & digital resources
See catalog results