Synergy or oxymoron?

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Genetic analysis of an F2 intercross between two chicken lines divergently selected for body-weight

<p>Abstract</p> <p>Background</p> <p>We have performed Quantitative Trait Loci (QTL) analysis of an F₂intercross between two chicken lines divergently selected for juvenile body-weight. In a previous study 13 identified loci with effects on body-weight, only explained a small proportion of the large variation in the F₂population. Epistatic interaction analysis however, indicated that a network of interacting loci with large effect contributed to the difference in body-weight of the parental lines. This previous analysis was, however, based on a sparse microsatellite linkage map and the limited coverage could have affected the main conclusions. Here we present a revised QTL analysis based on a high-density linkage map that provided a more complete coverage of the chicken genome. Furthermore, we utilized genotype data from ~13,000 SNPs to search the genome for potential selective sweeps that have occurred in the selected lines.</p> <p>Results</p> <p>We constructed a linkage map comprising 434 genetic markers, covering 31 chromosomes but leaving seven microchromosomes uncovered. The analysis showed that seven regions harbor QTL that influence growth. The pair-wise interaction analysis identified 15 unique QTL pairs and notable is that nine of those involved interactions with a locus on chromosome 7, forming a network of interacting loci. The analysis of ~13,000 SNPs showed that a substantial proportion of the genetic variation present in the founder population has been lost in either of the two selected lines since ~60% of the SNPs polymorphic among lines showed fixation in one of the lines. With the current marker coverage and QTL map resolution we did not observe clear signs of selective sweeps within QTL intervals.</p> <p>Conclusion</p> <p>The results from the QTL analysis using the new improved linkage map are to a large extent in concordance with our previous analysis of this pedigree. The difference in body-weight between the parental chicken lines is caused by many QTL each with a small individual effect. Although the increased chromosomal marker coverage did not lead to the identification of additional QTL, we were able to refine the localization of QTL. The importance of epistatic interaction as a mechanism contributing significantly to the remarkable selection response was further strengthened because additional pairs of interacting loci were detected with the improved map.</p

Mitogenomic analysis of a 50-generation chicken pedigree reveals a rapid rate of mitochondrial evolution and evidence for paternal mtDNA inheritance

Mitochondrial genomes represent a valuable source of data for evolutionary research, but studies of their short-term evolution have typically been limited to invertebrates, humans and laboratory organisms. Here we present a detailed study of 12 mitochondrial genomes that span a total of 385 transmissions in a well-documented 50-generation pedigree in which two lineages of chickens were selected for low and high juvenile body weight. These data allowed us to test the hypothesis of time-dependent evolutionary rates and the assumption of strict maternal mitochondrial transmission, and to investigate the role of mitochondrial mutations in determining phenotype. The identification of a non-synonymous mutation in ND4L and a synonymous mutation in CYTB, both novel mutations in Gallus, allowed us to estimate a molecular rate of 3.13 × 10(-7) mutations/site/year (95% confidence interval 3.75 × 10(-8)-1.12 × 10(-6)). This is substantially higher than avian rate estimates based upon fossil calibrations. Ascertaining which of the two novel mutations was present in an additional 49 individuals also revealed an instance of paternal inheritance of mtDNA. Lastly, an association analysis demonstrated that neither of the point mutations was strongly associated with the phenotypic differences between the two selection lines. Together, these observations reveal the highly dynamic nature of mitochondrial evolution over short time periods

Fine mapping and replication of QTL in outbred chicken advanced intercross lines

Background: Linkage mapping is used to identify genomic regions affecting the expression of complex traits. However, when experimental crosses such as F2 populations or backcrosses are used to map regions containing a Quantitative Trait Locus (QTL), the size of the regions identified remains quite large, i.e. 10 or more Mb. Thus, other experimental strategies are needed to refine the QTL locations. Advanced Intercross Lines (AIL) are produced by repeated intercrossing of F2 animals and successive generations, which decrease linkage disequilibrium in a controlled manner. Although this approach is seen as promising, both to replicate QTL analyses and fine-map QTL, only a few AIL datasets, all originating from inbred founders, have been reported in the literature. Methods: We have produced a nine-generation AIL pedigree (n = 1529) from two outbred chicken lines divergently selected for body weight at eight weeks of age. All animals were weighed at eight weeks of age and genotyped for SNP located in nine genomic regions where significant or suggestive QTL had previously been detected in the F2 population. In parallel, we have developed a novel strategy to analyse the data that uses both genotype and pedigree information of all AIL individuals to replicate the detection of and fine-map QTL affecting juvenile body weight. Results: Five of the nine QTL detected with the original F2 population were confirmed and fine-mapped with the AIL, while for the remaining four, only suggestive evidence of their existence was obtained. All original QTL were confirmed as a single locus, except for one, which split into two linked QTL. Conclusions: Our results indicate that many of the QTL, which are genome-wide significant or suggestive in the analyses of large intercross populations, are true effects that can be replicated and fine-mapped using AIL. Key factors for success are the use of large populations and powerful statistical tools. Moreover, we believe that the statistical methods we have developed to efficiently study outbred AIL populations will increase the number of organisms for which in-depth complex traits can be analyzed

Genetical genomics of growth in a chicken model

Background: The genetics underlying body mass and growth are key to understanding a wide range of topics in biology, both evolutionary and developmental. Body mass and growth traits are affected by many genetic variants of small effect. This complicates genetic mapping of growth and body mass. Experimental intercrosses between individuals from divergent populations allows us to map naturally occurring genetic variants for selected traits, such as body mass by linkage mapping. By simultaneously measuring traits and intermediary molecular phenotypes, such as gene expression, one can use integrative genomics to search for potential causative genes. Results: In this study, we use linkage mapping approach to map growth traits (N = 471) and liver gene expression (N = 130) in an advanced intercross of wild Red Junglefowl and domestic White Leghorn layer chickens. We find 16 loci for growth traits, and 1463 loci for liver gene expression, as measured by microarrays. Of these, the genes TRAK1, OSBPL8, YEATS4, CEP55, and PIP4K2B are identified as strong candidates for growth loci in the chicken. We also show a high degree of sex-specific gene-regulation, with almost every gene expression locus exhibiting sex-interactions. Finally, several trans-regulatory hotspots were found, one of which coincides with a major growth locus. Conclusions: These findings not only serve to identify several strong candidates affecting growth, but also show how sex-specificity and local gene-regulation affect growth regulation in the chicken.Funding Agencies|Carl Tryggers Stiftelse; Swedish Research Council (VR); Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS); Linkoping University Neuro-network; European Research Council [GENEWELL 322206]</p

On Service Innovation and Realization in Manufacturing Firms

Service innovation is increasingly becoming a basis for manufacturing firms to reach and sustain competitive advantages. While traditional product innovation typically includes how new technology can be utilized in new products, service innovation spans a broader area that is not exclusively focused on new technology, but rather how resources can be developed into value propositions and then integrated in the customer’s process in order to support customer value creation through realization. However, manufacturing firms that infuse services struggle with service innovation; this becomes especially evident in the realization phase. This thesis is a compilation of five papers discussing different aspects of service innovation realization and the inherited challenges. The study builds upon empirical data from four Swedish manufacturing firms that infuse services and develop new value propositions that include both products and services to support customer processes. The thesis illustrates realization as a phase in service innovation where the firm interacts with its customer in order to adjust, revise and further find new ways of improving the customer’s processes through for example customer training. Realization is characterized by a deployment phase and a post-deployment phase that represent the ongoing relationship between the customer and the firm. Depending on who has the competencies or ability to integrate the resources that are needed for service innovation, different interaction patterns are identified. Through indirect interaction, the firm facilitates the customer’s value creation through, for example, preventive maintenance, while through direct interaction the firm acts as a co-creator in the service innovation process and hence work jointly together with the customer in order to improve customer value creation. This thesis contributes to the literature by characterizing service innovation realization and by increasing the understanding for different interaction patterns in the service innovation process

On Service Innovation and Realization in Manufacturing Firms

Service innovation is increasingly becoming a basis for manufacturing firms to reach and sustain competitive advantages. While traditional product innovation typically includes how new technology can be utilized in new products, service innovation spans a broader area that is not exclusively focused on new technology, but rather how resources can be developed into value propositions and then integrated in the customer’s process in order to support customer value creation through realization. However, manufacturing firms that infuse services struggle with service innovation; this becomes especially evident in the realization phase. This thesis is a compilation of five papers discussing different aspects of service innovation realization and the inherited challenges. The study builds upon empirical data from four Swedish manufacturing firms that infuse services and develop new value propositions that include both products and services to support customer processes. The thesis illustrates realization as a phase in service innovation where the firm interacts with its customer in order to adjust, revise and further find new ways of improving the customer’s processes through for example customer training. Realization is characterized by a deployment phase and a post-deployment phase that represent the ongoing relationship between the customer and the firm. Depending on who has the competencies or ability to integrate the resources that are needed for service innovation, different interaction patterns are identified. Through indirect interaction, the firm facilitates the customer’s value creation through, for example, preventive maintenance, while through direct interaction the firm acts as a co-creator in the service innovation process and hence work jointly together with the customer in order to improve customer value creation. This thesis contributes to the literature by characterizing service innovation realization and by increasing the understanding for different interaction patterns in the service innovation process

Manufacturer go green : A typology of offerings and capability requirements

Environmental sustainability is becoming an increasingly important motivator for the development of new offerings on business-to-business markets. Taking environmental concerns into account in the creation of new offerings can increase the complexity of the offering development process. Green offering development is therefore associated with new or emphasized capability requirements. This paper aims to explore these capability requirements through a multiple case study of manufacturing firms. It introduces a typology of three distinct kinds of green offering development, and suggests capabilities that are especially important for each type of green offering. The three types of offering are: internally oriented green production, externally oriented green application, and finally, reshaped green networks, which entails modifications in the boundaries between production and use

A critical review and synthesis

The number of service innovation articles has increased dramatically in the past 25 years. By reviewing 128 articles published between 1986 and 2010, primarily in leading marketing and innovation journals, this study analyzes the progression of service innovation research according to topicality and perspective. The authors summarize prior research by clustering it into three evolutional phases and drawing parallels with the evolution of the wider services marketing field. Overall, the view of service innovation has evolved, from a complement of traditional product innovation to a multidimensional, all-encompassing notion that entails several functions, both within and outside the firm

How sustainable is the sharing business model? : Toward a conceptual framework

The sharing economy, which is considered a better way of utilizing existing resources, is associated with positive effects not only on the financial aspects of sustainability but also on its environmental and social dimensions. But is this true? Previous research has typically discussed either the positive or negative aspects of the sharing business model in specific contexts. This study adopts a dual perspective regarding the sustainability of sharing business models by critically analyzing the relationship between sharing business models and sustainability. Building on the resource-based view of the firm and practice theory, the current research develops a conceptual framework for evaluating the sustainability of sharing business models at the level of the individual, the firm, and society. Our proposed dual-process model suggests that two competing processes contribute to sustainability. The study's conceptual model and propositions advance theory and provide a research agenda for future empirical studies. This research also provides valuable guidance to managers and policymakers regarding the sustainability of sharing business models, which can inform the business model innovation process