Effect of Breeding Structure on Population Genetic Parameters in Drosophila

Genetics ◽  
2004 ◽  
Vol 166 (2) ◽  
pp. 779-788
Author(s):  
Emmanuelle Gravot ◽  
Michèle Huet ◽  
Michel Veuille

Abstract The breeding structure of populations has been neglected in studies of Drosophila, even though Wright and Dobzhansky’s pioneering work on the genetics of natural populations was an attempt to tackle what they regarded as an essential factor in evolution. We compared the breeding structure of sympatric populations of D. melanogaster and D. simulans, two sibling species that are widely used in evolutionary studies. We recorded changes in population density and microsatellite variation patterns for 3 years in a temperate environment of southwestern France. Results were distinctively different in the two species. Maximum population levels in summer and in autumn were similar and fluctuated greatly over years, each species being in turn the most abundant. However, genetic data showed that D. melanogaster made up a continuous breeding population in time and space of practically infinite effective size. D. simulans was fragmented into isolates with a local effective size of between 50 and 350 individuals. A consequence of this was that, while a local sample provided a reliable estimate of regional genetic variability in D. melanogaster, a sample from the same area provided an underestimate of this parameter in D. simulans. In practical terms, this means that variations in breeding structure should be accounted for in sampling schemes and in designing evolutionary genetic models. More generally, this suggests the existence of differential reactions to local environments that might contribute to several genomic differences observed between these species.

2018 ◽  
Vol 194 ◽  
pp. 188-192
Author(s):  
D. I. Shokasheva

Natural populations of crayfish are in depression in Russia and local species are not cultivated. In this situation, experimental cultivation of allochtonous australian crayfish Cherax quadricarinatus is conducted. This species is distinguished by high reproductive abilities and good consumer properties. It has domesticated in Russia spontaneously and produced 9–10 generations in Astrakhan Region. Certain natural selection in the process of domestication provides adaptive ability of this species to local environments and its capabil­ity to reproduce a viable progeny, so there is no doubts in good prospects of its cultivation in industrial conditions.


1988 ◽  
Vol 15 (2) ◽  
pp. 197 ◽  
Author(s):  
E Gyuris ◽  
CJ Limpus

Population models proposed as a result of independent tagging programs of nesting Caretta caretta in Queensland are in disagreement about the size of discrete breeding units. An electrophoretic survey was conducted to assess the relevance of genetic variation as revealed by electrophoresis to the investigation of Caretta caretta population breeding structure. Low level electrophoretic variability (H*L(obs) = 0.016) was found. The geographical distribution of alleles, when compared with tag-recapture data and other aspects of life history, indicated that discrete breeding populations of C. caretta in Queensland are larger than previously thought. C. caretta nesting on the mainland beaches and on the cays of the Capricornia Section of the Great Barrier Reef Marine Park form a panmictic population. The data indicate that those nesting on the Swain Reefs cays do not interbreed with the mainland-Capricornia breeding population.


Botany ◽  
2013 ◽  
Vol 91 (10) ◽  
pp. 653-661 ◽  
Author(s):  
Anochar Kaewwongwal ◽  
Arunee Jetsadu ◽  
Prakit Somta ◽  
Sompong Chankaew ◽  
Peerasak Srinives

The objective of this research was to determine the genetic diversity and population structure of natural populations of two rare wild species of Asian Vigna (Phaseoleae, Fabaceae), Vigna exilis Tateishi & Maxted and Vigna grandiflora (Prain) Tateishi & Maxted, from Thailand. Employing 21 simple sequence repeat markers, 107 and 85 individuals from seven and five natural populations of V. exilis and V. grandiflora, respectively, were analyzed. In total, the markers detected 196 alleles for V. exilis and 219 alleles for V. grandiflora. Vigna exilis populations showed lower average values in number of alleles, allelic richness, observed heterozygosity, gene diversity, and outcrossing rate than V. grandiflora populations, namely 58.00% versus 114.60%, 51.96% versus 74.80%, 0.02% versus 0.18%, 0.40% versus 0.66%, and 3.24% versus 17.41%, respectively. Pairwise FST among populations demonstrated that V. exilis was much more differentiated than V. grandiflora. Analysis of molecular variance revealed that 41.83% and 15.06% of total variation resided among the populations of V. exilis and V. grandiflora, respectively. Seven and two genetic clusters were detected for V. grandiflora and V. exilis by STRUCTURE analysis. Our findings suggest that different strategies are required for in situ conservation of the two species. All V. exilis populations, or as many as possible, should be conserved to protect genetic resources of this species, while a few V. grandiflora populations can capture the majority of its genetic variation.


2017 ◽  
Vol 15 (1) ◽  
pp. 44 ◽  
Author(s):  
Yuri S Tokarev ◽  
Mariya A Yudina ◽  
Julia M Malysh ◽  
Roman A Bykov ◽  
Andrei N Frolov ◽  
...  

Background. Endosymbiotic bacteria of the genus Wolbachia are widespread in arthropods and often cause reproductive abnormalities in lepidopteran insects, including corn borers of the genus Ostrinia. Wolbachia-Ostrinia is a promising model for studies of parasite-host interactions yet parasite prevalence in natural insect host populations remains unknown. Materials and Methods. Molecular genetic screening and statistical analysis is applied to evaluate prevalence rates of Wolbachia in sympatric populations of two corn borer species. Individual genomic DNA samples were extracted from last instar larvae collected in nature from different forage plants. For each sample of DNA showing positive signal with insect-specific primers the detection is performed using three diagnostic loci of Wolbachia: 16SrRNA, gatB and fbpA. Results. Wolbachia-positive signal is obtained for 13.5% larvae of Ostrinia nubilalis (N = 141) and 31.9% larvae of Ostrinia scapulalis (N = 138). In different localities the Wolbachia prevalence ranged from 2.9% (N = 34) to 65.8% (N = 38). Significantly higher rates of Wolbachia prevalence in insects from mugwort and hemp (O. scapulalis) as compared to those from corn (O. nubilalis) are revealed in three out of four localities. Conclusions. Endosymbiotic bacteria of the genus Wolbachia are revealed in natural populations of corn borers for the first time for Eastern Europe. The prevalence rates can be high and this should be taken into consideration when reproductive isolation is examined in population of these hosts as well as establishment of laboratory cultures is performed.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Valentina Mastrantonio ◽  
Sandra Urbanelli ◽  
Daniele Porretta

AbstractHybridization between heterospecific individuals has been documented as playing a direct role in promoting paternal leakage and mitochondrial heteroplasmy in both natural populations and laboratory conditions, by relaxing the egg-sperm recognition mechanisms. Here, we tested the hypothesis that hybridization can lead to mtDNA heteroplasmy also indirectly via mtDNA introgression. By using a phylogenetic approach, we showed in two reproductively isolated beetle species, Ochthebius quadricollis and O. urbanelliae, that past mtDNA introgression occurred between them in sympatric populations. Then, by developing a multiplex allele-specific PCR assay, we showed the presence of heteroplasmic individuals and argue that their origin was through paternal leakage following mating between mtDNA-introgressed and pure conspecific individuals. Our results highlight that mtDNA introgression can contribute to promote paternal leakage, generating genetic novelty in a way that has been overlooked to date. Furthermore, they highlight that the frequency and distribution of mtDNA heteroplasmy can be deeply underestimated in natural populations, as i) the commonly used PCR-Sanger sequencing approach can fail to detect mitochondrial heteroplasmy, and ii) specific studies aimed at searching for it in populations where mtDNA-introgressed and pure individuals co-occur remain scarce, despite the fact that mtDNA introgression has been widely documented in several taxa and populations.


Author(s):  
Andrew P. Hendry

This chapter outlines how to conceptualize and predict adaptive evolution based on information about selection and genetic variation. It introduces and explains adaptive landscapes, a concept that has proven useful in guiding the understanding of evolution. The chapter also reviews empirical data to answer fundamental questions about adaptation in nature, including to what extent short- and long-term evolution is predictable, how fast is phenotypic change, to what extent is adaptation constrained by genetic variation, and how well adapted natural populations are to their local environments. Moving beyond selection and adaptation within populations, the chapter shows how eco-evolutionary dynamics will be shaped by biological diversity: that is, different populations and species have different effects on their environment.


1975 ◽  
Vol 28 (4) ◽  
pp. 405 ◽  
Author(s):  
Stephen W McKechnie

Sympatric populations of D. tryoni and D. neohumeralis are difficult to completely distinguish taxonomically. Using five pigmentation characters, each of some taxonomic value, a small proportion of individuals cannot be assigned to either species nor definitely classified as hybrids. To aid in species discrimination and hybrid identification gene frequencies in natural populations were estimated at three polymorphic protein loci, an alcohol dehydrogenase (Adh), an octanol dehydrogenase (Odh) and an esterase (E-2). Samples of flies were taken from four sites spread over 1200 miles along the Australian eastern coast.


Phytotaxa ◽  
2015 ◽  
Vol 205 (1) ◽  
pp. 1 ◽  
Author(s):  
Hong-Zheng Ma ◽  
Zhe Cai ◽  
Fu-Min Zhang ◽  
Hui Zhang ◽  
Song Ge ◽  
...  

Miscanthus species including the famous energy plant M. × giganteus are considered to be second-generation energy crops. Miscanthus nudipes is an endemic species from Himalaya-Hengduan Mountains and provides important germplasm for Miscanthus breeding given its high tolerance to frost and drought. However, the taxonomy of this species remains controversial in terms of intraspecific classification, with one to nine subspecies or species recognized previously. The variation patterns of the morphological characters are not understood clearly as there have been no intensive analyses of the morphological variation across individuals and populations. Here, by sampling 15 natural populations from the entire distribution area of M. nudipes, we investigate patterns of population variation based on 39 quantitative and nine qualitative morphological characters and 14 microsatellite loci, with the aim to provide a reliable taxonomic treatment of this important species. Morphological analyses from ANOVA, UPGMA and PCA indicate that M. nudipes populations show significant differences between the Himalayas and Hengduan Mountains. A neighbor-joining tree and principle coordinates analysis of the microsatellite data support the results of the morphological analyses. Based on our results, we recognize two subspecies under Miscanthus nudipes (M. nudipes subsp. nudipes and M. nudipes subsp. yunnanensis) and provide a taxonomic treatment for the species. We propose three diagnostic characters for the subspecies identification, i.e., the ratio of callus hair length to spikelet length, the hairiness of the panicle axis and the hairiness of the peduncle.


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