scholarly journals Bidirectional selection for body weight on standing genetic variation in a chicken model

2018 ◽  
Author(s):  
Mette Lillie ◽  
Christa F. Honaker ◽  
Paul B. Siegel ◽  
Örjan Carlborg
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Model Organisms ◽  
Founder Population ◽  
Genomic Signatures ◽  
History Of ◽  
Signatures Of Selection ◽  
Genomic Regions ◽  
Bidirectional Selection

AbstractExperimental populations of model organisms provide valuable opportunities to unravel the genomic impact of selection in a controlled system. The Virginia body weight chicken lines represent a unique resource to investigate signatures of selection in a system where long-term, single-trait, bidirectional selection has been carried out for more than 60 generations. Using pooled genome resequencing of paired generations of these lines, we reveal the within and between-line genomic signatures of selection. At 55 generations of divergent selection, 14.2% of the genome showed extreme differentiation between the selected lines were contained within 395 genomic regions. The lines often displayed a duality of the sweep signatures: an extended region of homozygosity in one line, in contrast to mosaic pattern of heterozygosity in the other line. These haplotype mosaics consist of short, distinct haploblocks of variable between-line divergence. Formed during what probably was a complex history of bottlenecks, inbreeding, and introgressions, these mosaics represent the standing genetic variation available at the onset of selection in the founder population. Selection on standing genetic variation can thus result in different signatures depending on the intensity and direction of selection.

Abstract P051: Lifestyle Change In Mid-life And Long-term Weight Gain In Women With And Without History Of Gestational Diabetes Mellitus

Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Jiaxi Yang ◽  
Janet Rich-Edwards ◽  
Molin Wang ◽  
Wafaie W Fawzi ◽  
Cuilin Zhang ◽  
...  
Keyword(s):  
Physical Activity ◽  
Diabetes Mellitus ◽  
Body Weight ◽  
Weight Gain ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Weight Change ◽  
Lifestyle Change ◽  
History Of

Introduction: Identifying strategies to mitigate gradual long-term weight gain is critical for preventing obesity and its related chronic diseases, particularly for persons at high risk, such as women with a history of gestational diabetes mellitus (GDM). We prospectively examined the independent associations between lifestyle changes in mid-life with long-term weight change among women with and without a history of GDM. Hypothesis: We hypothesized that favorable improvements in lifestyle would be associated with less long-term weight gain, particularly among women with a history of GDM. Methods: We used data from the longitudinal Nurses’ Health Study II, with self-reported lifestyle, diet via food frequency questionnaire, and body weight updated every 2-4 years. We analyzed repeated 4-year changes of the following lifestyle factors among parous women after age 40: adherence to a healthy dietary pattern (Alternate Healthy Eating Index score [AHEI]), physical activity (MET-hrs/wk), moderate alcohol intake (servings/d), and non-smoking, in relation to concurrent 4-year change in body weight (lb). We used multivariable generalized estimating equation models to estimate the least-squares mean of 4-year weight change and 95% confidence interval (CI) for each lifestyle change category (e.g., decrease, remain stable, and increase). Results: Our analysis included 61,637 women, of which 3,444 (5.6%) had a history of GDM. Mean of repeated 4-year weight change after age 40 was 3.0 lb (SD=14.3). Improving diet was associated with favorable 4-year weight change, particularly among women with a history of GDM vs. without GDM (AHEI score change from low to high: -6.3 lb [CI: -9.3, -3.4] vs. -2.7 lb [CI: -3.2, -2.2], respectively; p-interaction=0.04). Increasing physical activity was associated with weight maintenance for GDM women only (MET-hrs/wk change from low to high: 0.6 lb [95% CI: -0.6, 1.7] vs. 2.0 lb [95% CI: 1.8, 2.2] for GDM vs. non-GDM, respectively; p-interaction=0.01). Reducing alcohol (decreased servings/d: 1.9 lb [95% CI: 1.2, 2.6] and 2.8 lb [95% CI: 2.6, 2.9] for GDM vs. non-GDM, respectively) and smoking cessation (recent quitter: 9.8 lb [95% CI: 7.1, 12.5] and 8.5 lb [95% CI: 8.0, 9.1] for GDM vs. non-GDM, respectively) were associated with similar patterns in weight change for women with and without prior GDM. Further, the joint association of improving both diet and physical activity from low to high was related to -12.3 lb (95% CI: -19.5, -5.0) and -6.1 lb (95% CI: -8.0, -4.2) of weight loss for GDM vs. non-GDM women, respectively. Conclusions: We observed that attainable improvements in diet quality and physical activity were associated with weight gain prevention. These findings support continued efforts to improve lifestyle as a beneficial strategy to prevent long-term weight gain, particularly among women with a history of GDM.

The breed structure and genetic analysis of the pedigree cattle breeds in Australia. III. The Hereford

1963 ◽  
Vol 14 (1) ◽  
pp. 93 ◽  
Author(s):  
GP Davey ◽  
JSF Barker
Keyword(s):  
Genetic Variation ◽  
Genetic Analysis ◽  
Sampling Methods ◽  
Rapid Expansion ◽  
Genetic Contribution ◽  
Genetic History ◽  
Effective Generation ◽  
History Of ◽  
The One

(i) The structure and genetic history of the pedigree Hereford breed in Australia are analysed by pedigree sampling methods. (ii) The pattern of the breed structure is generally similar to that found in other breeds, but it is extremely dynamic owing to the present rapid expansion of the breed. Changes are taking place in the herd composition of the major breeders' groups and there are many new herds yet to find their level in the structure. (iii) Considerable emphasis has been placed on the use of imported animals in the development of the breed. Of all herds registering in Volume 24 of the herd book, 31.6% used imported sires, and the percentage of genes in the breed in 1949 derived from animals imported since 1880 was 97.7, and from animals imported since 1930, 53.9%. (iv) The most important herd in 1949 made a genetic contribution to the breed of 33.1%, while the contributions of the four next most important herds were 17.4, 10.1, 7.4, and 6.1%. In the four-generation pedigrees from which these figures were derived, the contribution of imported animals was 56.1%. (v) The animal with the highest relationship to the breed was Free Town Director (Imp.), with direct relationships of 5.6 and 9.2% to the 1941 and 1949 samples respectively. Of the 16 sires and one dam whose direct relationships are 3.0% or more in any of the three sample years, 12 sires were imported. (vi) The total inbreeding in 1949 (base year 1880) was 2.6%. This comprised 0.2% current inbreeding, 1.6% long-term inbreeding, and 0.8% strain inbreeding. There was no evidence of subdivision of the breed into separate strains. (vii) The effective generation length has decreased since 1930 to about 5.5 years in the 1949–50 sample. Nearly 50% of the animals in this sample were sired by bulls 4 years old or younger, while about 33% were from dams 4 years old or younger. (viii) Bulls from major breeders' herds are used widely throughout the breed, while about 90% of sires and 45% of dams were bred in herds other than the one in which they were used. Therefore, it is unlikely that there is much genetic variation between herds.

scholarly journals Pseudogenization, genome streamlining and specific gene repertoire landmark the genomes ofCarnobacterium maltaromaticumisolated from diseased sharks

2019 ◽  
Author(s):  
Laura Martinez Steele ◽  
Christopher G Lowe ◽  
Mark S Okihiro ◽  
Jesse G. Dillon ◽  
Renaud Berlemont
Keyword(s):  
Specific Gene ◽  
Shark Species ◽  
Gene Repertoire ◽  
Genomic Signatures ◽  
Thresher Shark ◽  
Independent Life ◽  
Conserved Gene ◽  
Genomic Regions ◽  
High Degree

AbstractCarnobacterium maltaromaticumis a well-known pathogen of bony fish. More recently,C. maltaromaticumhave been isolated from the brain and inner ear of disorientated and stranded common thresher (Alopias vulpinus) and salmon shark (Lamna ditropis). While thresher shark strandings are recent, salmon sharks have been stranding for decades, suggesting a long-term association betweenC. maltaromaticumand sharks. Interestingly, some strains ofC. maltaromaticumare used by the food industry for their probiotic and antimicrobial activity. Here, we sequenced the genome of 9C. maltaromaticumstrains (SK-isolates) from diseased common thresher and salmon sharks and compared them to otherC. maltaromaticumstrains in order to identify the genomic signatures that differentiate the disease-associated from the innocuousC. maltaromaticumisolates. SK strains formed a monophyletic clade, with a conserved gene repertoire, and shared a high degree of pseudogenization even though isolates were from different shark species, locations, and across years. In addition, these strains displayed few virulence associated genes and unique genomic regions, some resulting from horizontal gene transfer. The association of diseased sharks and SK strains suggests their role as potential pathogens. Although the high degree of pseudogenization suggests a transition to a host-adapted lifestyle, a set of conserved functional genes highlights the need of essential functions required for a host-independent life style. Globally, this work identifies specific genomic signatures ofC. maltaromaticumstrains isolated from infected sharks, provides the framework to elucidate the role of SK strains in the development of the disease in sharks, and further investigate the dissemination of SK strains in populations of wild fish.

scholarly journals Adaptation to infectious disease exposure in indigenous Southern African populations

2017 ◽  
Vol 284 (1852) ◽  
pp. 20170226 ◽  
Author(s):  
Katharine A. Owers ◽  
Per Sjödin ◽  
Carina M. Schlebusch ◽  
Pontus Skoglund ◽  
Himla Soodyall ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Extreme Values ◽  
Dual Approach ◽  
Immune Genes ◽  
Genomic Signatures ◽  
African Populations ◽  
Signatures Of Selection ◽  
Genomic Regions ◽  
Disease Exposure ◽  
Two Populations

Genetic analyses can provide information about human evolutionary history that cannot always be gleaned from other sources. We evaluated evidence of selective pressure due to introduced infectious diseases in the genomes of two indigenous southern African San groups—the ‡Khomani who had abundant contact with other people migrating into the region and the more isolated Ju|’hoansi. We used a dual approach to test for increased selection on immune genes compared with the rest of the genome in these groups. First, we calculated summary values of statistics that measure genomic signatures of adaptation to contrast selection signatures in immune genes and all genes. Second, we located regions of the genome with extreme values of three selection statistics and examined these regions for enrichment of immune genes. We found stronger and more abundant signals of selection in immune genes in the ‡Khomani than in the Ju|’hoansi. We confirm this finding within each population to avoid effects of different demographic histories of the two populations. We identified eight immune genes that have potentially been targets of strong selection in the ‡Khomani, whereas in the Ju|’hoansi, no immune genes were found in the genomic regions with the strongest signals of selection. We suggest that the more abundant signatures of selection at immune genes in the ‡Khomani could be explained by their more frequent contact with immigrant groups, which likely led to increased exposure and adaptation to introduced infectious diseases.

Physiological genetics of dietary restriction: uncoupling the body temperature and body weight responses

2007 ◽  
Vol 293 (4) ◽  
pp. R1522-R1527 ◽  
Author(s):  
Brad A. Rikke ◽  
Thomas E. Johnson
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Dietary Restriction ◽  
The Body ◽  
Strain Variation ◽  
Long Term Effects ◽  
Difficult Challenge

Numerous physiological and molecular changes accompany dietary restriction (DR), which has been a major impediment to elucidating the causal basis underlying DR's many health benefits. Two major metabolic responses to DR that potentially underlie many of these changes are the body temperature ( Tb) and body weight (BW) responses. These responses also represent an especially difficult challenge to uncouple during DR. We demonstrate in this study, using two recombinant inbred (RI) panels of mice (the LXS and LSXSS) that naturally occurring genetic variation serves as a powerful tool for modulating Tb and BW independently during DR. The correlation coefficient between the two responses was essentially zero, with R = −0.04 in the LXS and −0.03 in the LSXSS, the latter averaged across replicate cohorts. This study is also the first to report that there is highly significant ( P = 10−10) strain variation in the Tb response to DR in the LXS (51 strains tested), with strain means ranging from 2 to 4°C below normal. The results suggest that the strain variation in the Tb response to DR is largely due to differences in the rate of heat loss rather than heat production (i.e., metabolic rate). This variation can thus be used to assess the long-term effects of lower Tb independent of BW or metabolic rate, as well as independent of food intake and motor activity as previously shown. These results also suggest that murine genetic variation may be useful for uncoupling many more responses to DR.

scholarly journals Intestinal Microbiota and Host Cooperate for Adaptation as a Hologenome

mSystems ◽  
2022 ◽  
Author(s):  
Hao Zhou ◽  
Lingyu Yang ◽  
Jinmei Ding ◽  
Ronghua Dai ◽  
Chuan He ◽  
...  
Keyword(s):  
Body Weight ◽  
Intestinal Microbiota ◽  
Founder Population ◽  
Term Selection ◽  
Common Founder ◽  
Selection For

The hologenome concept has broadened our perspectives for studying host-microbe coevolution. The multiomic analyses reported here involved two lines of chickens, from a common founder population, that had undergone long-term selection for high (HWS) or low (LWS) 56-day body weight.

scholarly journals The history, status and trends of the Endangered Seychelles Magpie-robin Copsychus sechellarum

2016 ◽  
Vol 26 (4) ◽  
pp. 505-523 ◽  
Author(s):  
APRIL J. BURT ◽  
JULIE GANE ◽  
IAIN OLIVIER ◽  
LICIA CALABRESE ◽  
ARJAN DE GROENE ◽  
...  
Keyword(s):  
Social Conflict ◽  
Critically Endangered ◽  
Population Increase ◽  
Founder Population ◽  
Status And Trends ◽  
History Of ◽  
Steep Decline ◽  
Term Management ◽  
Unpublished Information

SummaryThe once ‘Critically Endangered’ Seychelles Magpie-robin was down to just 12 individuals in 1960 on one island of the granitic Seychelles. In 2015, due to intensive long-term management the population stands at around 280 birds on five islands, marking a significant success for this species. Translocations to the islands of Cousin and Cousine have led to population saturation and stability, a translocation to Denis Island has resulted in a continuing population increase and the founder population on Frégate Island is likewise increasing. The latest translocation to Aride Island in 2002 resulted in population increase then stability but is now showing a steep decline throughout 2014 into 2015. Reasons for this decline are yet unknown though disease, lack of recruitment, the impacts of social conflict and the possibility of genetic issues are discussed. This report summarises the history of management for this species, compiling all available published and unpublished information, to provide a comprehensive account of the Seychelles Magpie-robin recovery.

scholarly journals Bidirectional Selection for Body Weight on Standing Genetic Variation in a Chicken Model

2019 ◽  
pp. g3.400038.2019 ◽  
Author(s):  
Mette Lillie ◽  
Christa F. Honaker ◽  
Paul B. Siegel ◽  
Örjan Carlborg
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Selection For ◽  
Bidirectional Selection ◽  
Chicken Model

scholarly journals Standing genetic variation as a major contributor to adaptation in the Virginia chicken lines selection experiment

2015 ◽  
Author(s):  
Zheya Sheng ◽  
Mats E Pettersson ◽  
Christa F Honaker ◽  
Paul B Siegel ◽  
Örjan Carlborg
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Selection Response ◽  
Selective Sweeps ◽  
Base Population ◽  
A Genome ◽  
Wide Scale ◽  
Genomic Regions

Artificial selection has, for decades, provided a powerful approach to study the genetics of adaptation. Using selective-sweep mapping, it is possible to identify genomic regions in populations where the allele-frequencies have diverged during selection. To avoid misleading signatures of selection, it is necessary to show that a sweep has an effect on the selected trait before it can be considered adaptive. Here, we confirm candidate selective-sweeps on a genome-wide scale in one of the longest, on-going bi-directional selection experiments in vertebrates, the Virginia high and low body-weight selected chicken lines. The candidate selective-sweeps represent standing genetic variants originating from the common base-population. Using a deep-intercross between the selected lines, 16 of 99 evaluated regions were confirmed to contain adaptive selective-sweeps based on their association with the selected trait, 56-day body-weight. Although individual additive effects were small, the fixation for alternative alleles in the high and low body-weight lines across these loci contributed at least 40% of the divergence between them and about half of the additive genetic variance present within and between the lines after 40 generations of selection. The genetic variance contributed by the sweeps corresponds to about 85% of the additive genetic variance of the base-population, illustrating that these loci were major contributors to the realised selection-response. Thus, the gradual, continued, long- term selection response in the Virginia lines was likely due to a considerable standing genetic variation in a highly polygenic genetic architecture in the base-population with contributions from a steady release of selectable genetic variation from new mutations and epistasis throughout the course of selection.

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