Showing video clip 3 can help facilitate the discussion. Heterogeneous genetic divergence can accumulate across the genome when populations. This dataset included radseq data generated from three populations that were previously analyzed 30,37, and three for which. Genomic releaserecapture experiment in the wild reveals. Stickleback exhibit remarkable patterns of parallel adaptation among populations across their range, most notably repeated colonization and adaptation in freshwater habitats from ancestral marine or anadromous forms and repeated diversification into different. Studies of threespine stickleback developmental evolution. Threespine stickleback populations provide a striking example of local adaptation. If students watch the short film and complete the entire activity in class. With the exception of a few identified genes, the genetic basis of this remarkable parallel adaptation is unclear. Repeated selection of alternatively adapted haplotypes. Another study, utilizing landscape genetics on stickleback, suggested that salinity facilitates divergence between fresh and saltwater stickleback occurring along the saint lawrence river mccairns and bernatchez 2008. The freshwater stickleback fish were collected from several alaskan lakes, including bear paw lake, boot lake, and whale lake. Compare the outcome of the f 1 cross from part 2 to the f 1 data from dr. Evolving switches, evolving bodies time requirement this activity requires a minimum of one 50minute class period with the expectation that students will complete the activity as homework.
Individually or in pairs, students collect a random sample of paper stickleback fish from loberg lake and plot them by lateral plate number on a bar graph. Natural selection and the genetics of adaptation in. Institute of ecology and evolution, university of oregon. Molecular evolutionary and population genomic analysis of. Some freshwater sticklebacks, however, either partially or completely lack a pelvis. Loberg lake stickleback data collection change over time and variability stickleback crosses and the candidate gene approach heritability reproductive advantage in sticklebacks. However, apart from these two studies, migration patterns of stickleback have rarely been studied, especially with respect to. Spatially variable selection between marine and freshwater habitats has had a significant and heterogeneous impact on patterns of genetic variation across the genome of threespine stickleback fish. Sequencing the genome of threespine sticklebacks gasterosteus. In lakes on the haida gwaii archipelago off western canada, stickleback have undergone a remarkable local radiation and show phenotypic diversity matching that seen throughout the species distribution.
The threespined stickleback gasterosteus aculeatus is a wellsuited model for studying population genetics in cultivated areas, since it is tolerant to a broad range of environmental conditions. The iberian populations of threespined stickleback lie at the southwestern periphery of the european distribution of gasterosteus aculeatus. Evolving bodies, evolving switches indepth film guide description the bodies of threespine stickleback fish in certain populations evolved as they adapted from living in the ocean to a life exclusively in freshwater environments. Using genetic crosses to analyze a stickleback trait overview this handson activity serves as an extension of the making of the fittest short film entitled evolving switches, evolving bodies. A similar combination of genetic and genomic studies can now be applied to many of the other dramatic differences between stickleback populations. Population genomics of parallel adaptation in threespine stickleback using sequenced rad tags. Population genetic divergence and environment influence. Radseq was first applied to investigation of the genetics of an important ecological trait in the threespine stickleback gasterosteus aculeatus, the genome of which has been sequenced.
All stickleback species show similar, unusual mating behaviour. Pdf natural selection and the genetics of adaptation in. Pdf natural selection and the genetics of adaptation in threespine. Threespined sticklebacks generally are euryhaline, but slight differences in salt tolerance between anadromous and resident freshwater sticklebacks. Paper stickleback sampling abstract does the lateral plate trait in a population of stickleback fish change over time. While it has proved to be a useful baseline for understanding the genetic variation we see in species today, this model is now rightfully understood as incomplete for many. It shows great morphological variation throughout its range, ideal for questions about evolution and population genetics. The only exception is the far larger fifteenspined stickleback spinachia spinachia, which can reach 22 cm approx. In order to confirm and quantify the previously observed genetic structure and substructure of the six oregon stickleback populations, we used principal component analyses pca in r version 3. The canonical model for the genetics of adaptation has long been the sequential fixation of new mutations maynard smith and haigh 1974. Cresko1 1center for ecology and evolutionary biology, university of oregon, eugene, oregon, united states of america, 2institute of molecular biology, university of oregon. The results of the crosses with the f 1 progeny from the marine x bear paw lake cross are shown in table 3. The lateral plate armor of the stickleback is present in oceanic populations but has been lost independently in many derived freshwater populations.
Genetic evidence reveals the precise molecular mechanism responsible for the change in pelvic structures in stickleback populations. Population mixing and the adaptive divergence of quantitative characters in discrete populations. To infer from this continuous population genomic data which genomic regions fall into one of two categories those regions affected only by neutral processes or those regions affected also by selection we employed a hidden markov model hmm in a similar vein to that previously applied in stickleback population genomics jones et al. One adaptation was the loss of pelvic spines, which are homologous to the hind. Using genetic crosses to analyze a stickleback trait. Students use photos of actual research specimens the f1 and f2 cards to obtain their data. Genetics of plate morphology in an unusual population of. Threespine stickleback populations provide a striking example of local. Author summary oceanic threespine stickleback have invaded and adapted to freshwater habitats countless times across the northern hemisphere. Dotted outlines represent lateral plates and pelvic spine present in the marine ancestor but absent or reduced in most freshwater populations.
Genetic isolation and drift may imperil peripheral populations of wideranging species more than central ones. Sequencing the genome of threespine sticklebacks gasterosteus aculeatus david kingsley, ph. Here i use genome wide association studies gwas in natural populations of stickleback to uncover genomic regions that contribute to variation of two dermal bone derived traits, lateral plate number and opercle shape. Feeling bored with reading will be singlehandedly unless you do not behind the book. Pelvic evolution in sticklebacks hhmi biointeractive. A collection of gasterosteus aculeatus from a single locality friant in madera county, california, contains individuals with low and high lateral plate morphology, and very few intermediates. Population genetic dynamics of threespined sticklebacks ncbi. Parallel genetic basis for repeated evolution of armor.
Population genomics of parallel adaptation in threespine stickleback using sequenced rad tags plos genetics, feb 2010 paul a. The f 1 generation results of those crosses are shown in table 2 below. Genetic analysis of sneaking and eggthievery in a natural. I had the fortune to receive an nserc postdoctoral fellowship 2009 2011 that allowed me to study population genetic of threespine stickleback populations from the haida gwaii archipelago. Threespine stickleback populations are model systems for studying adaptive evolution and the underlying genetics. Access free making of the fittest population genetics answers bored. How do multiple lines of evidence from the field, the fossil record, and molecular genetics work together to illustrate stickleback evolution. Population genetic dynamics of threespined sticklebacks. Most other stickleback species are roughly similar in size or somewhat smaller. Is the trait variable among individuals in the population. The threespined stickleback gasterosteus aculeatus is a wellsuited model for studying population genetics in cultivated areas, since it is tolerant to a broad. Using genetic crosses to analyze a stickleback trait page 2 of 9 teacher materials the making of the fittest. Calculations are based on measurements of two marine and 15 freshwater populations.
First, we found a finescale genetic structure in threespine sticklebacks gasterosteus aculeatus populations along the swedish coast paper i, indicating. Students apply the principles of mendelian genetics to analyze the results of genetic crosses between stickleback fish with different traits, or phenotypes. It has long been a subject of scientific study for many reasons. Threespine stickleback fish from marine populations usually have a pelvis with protective spines.
Population genomics of parallel adaptation in threespine. Students then apply the principles of mendelian genetics to analyze the results of genetic crosses between stickleback fish with different traits. Juvenile stickleback were fed paramecia, vinegar eels, and newly hatched brine shrimp, and adults were fed a mixture of frozen brine shrimp, blood worms, and dry food biooregon, warrenton, or. Population genetic structure and colonization history of short ninespine sticklebacks pungitius kaibarae article pdf available. Phylogeography and adaptation genetics of stickleback from. Cresko then took the f 1 offspring and conducted several crosses between them to produce the f 2 generations.
We would like to show you a description here but the site wont allow us. We used a total of 109 microsatellite markers to quantify the level and patterns of genomewide ld in fennoscandian ninespined stickleback pungitius pungitius populations from four viz. In a recent study, quantitative information of the genetic consequences of sneaking and egg thievery were obtained for a natural population of another stickleback species, the 15spined. Have students think about and discuss how natural selection might influence allele frequencies within a population of stickleback. The male salmon is as pugnacious as the little stickleback darwin 1871 back to hendry lab page. A few stickleback suffice for the transport of alleles to new lakes. These freshwater populations have often evolved in similar ways from the ancestral marine stock from which they independently derived.
Plausible arguments reproductive advantage give each student a copy of the checklist. We start from the observation that population densities of the threespined stickleback. Threespine stickleback fish gasterosteus aculeatus have long been an ecological and evolutionary model system. Institute of ecology and evolution, university of oregon, eugene, or. Variation in the extent and magnitude of genomewide linkage disequilibrium ld among populations residing in different habitats has seldom been studied in wild vertebrates. Therefore, information about species genetic variability and population structure is invaluable for conservation managers. The stickleback fish, gasterosteus aculeatus, is one of the most thoroughly studied organisms in the wild, and has been a particularly useful model. To date, population genetic and linkage mapping studies in ninespined stickleback have relied on markers developed from speciesspeci.
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