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1.
Kaarina Matilainen Ismo Strandén Gert Pedersen Aamand Esa A. Mäntysaari 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2018,135(5):337-348
Joint Nordic (Denmark, Finland, Sweden) genetic evaluation of female fertility is currently based on the multiple trait multilactation animal model (BLUP). Here, single step genomic model (ssGBLUP) was applied for the Nordic Red dairy cattle fertility evaluation. The 11 traits comprised of nonreturn rate and days from first to last insemination in heifers and first three parities, and days from calving to first insemination in the first three parities. Traits had low heritabilities (0.015–0.04), but moderately high genetic correlations between the parities (0.60–0.88). Phenotypic data included 4,226,715 animals with records and pedigree 5,445,392 animals. Unknown parents were assigned into 332 phantom parent groups (PPG). In mixed model equations animals were associated with PPG effects through the pedigree or both the pedigree and genomic information. Genotype information of 46,914 SNPs was available for 33,969 animals in the pedigree. When PPG used pedigree information only, BLUP converged after 2,420 iterations whereas the ssGBLUP evaluation needed over ten thousand iterations. When the PPG effects were solved accounting both the pedigree and the genomic information, the ssGBLUP model converged after 2,406 iterations. Also, with the latter model breeding values by ssGBLUP and BLUP became more consistent and genetic trends followed each other well. Models were validated using forward prediction of the young bulls. Reliabilities and variance inflation of predicted genomic breeding values (values for parent averages in brackets) for the 11 traits ranged 0.22–0.31 (0.10–0.27) and 0.81–0.95 (0.83–1.06), respectively. The ssGBLUP model gave always higher validation reliabilities than BLUP, but largest increases were for the cow fertility traits. 相似文献
2.
Dey and Joshi (Reports, 21 April 2006, p. 434) studied replicate laboratory populations of Drosophila and reported that low migration led to asynchrony among subpopulations. We argue that this unexpected outcome may be due to variation in the initial size of the subpopulations and uncontrolled stochasticity in the experiments. 相似文献
3.
D. Arias J. Peñaloza-Ramírez O. Dorado P. Cuevas-Reyes Esaú Leyva Ana Luisa Albarrán-Lara G. Rangel-Altamirano 《Genetic Resources and Crop Evolution》2010,57(8):1227-1238
Jacaratia mexicana A. DC. (Caricaceae) is a tropical tree distributed throughout Mexico and Mesoamerica. Some evidence in Mexico indicates the
presence of an incipient domestication process in this species. Phylogeographical analyses can potentially determine contemporary
patterns of gene flow, isolation between population lineages, as well as historical processes such as population bottlenecks
or expansions on their geographical areas. In this study we reconstruct the phylogeographical patterns in populations of J. mexicana A. DC., in order to find differences between genetic variation among wild and cultivated populations utilizing chloroplast
DNA and nuclear DNA sequences. We generate a Bayesian phylogenetic tree, to estimate the divergence time between clades using
calibrated mutation rates. We also infer the demographic history of these populations using neutrality tests among wild and
cultivated accessions. We identified higher levels of haplotype and nucleotide diversity for the cpDNA and ITS types in wild
populations than in domesticated populations. These results indicate a reduction of genetic diversity derived from human selection
on domestication traits. Neutrality test suggests population expansion detected by the significant negative values of Fu’s
Fs in the cultivated populations of this specie. These process results in an excess of rare polymorphism with the fixation
of certain advantageous mutation throughout time, this implication are in accordance with the role of the strong selection
in the fruit traits of J. mexicana. The dated phylogeny constructed with BEAST program indicated a dispersion pattern for the J. mexicana ancestors across the South Pacific and South Eastern populations during the late Pliocene. Posterior dispersion and divergence
in the clades from Central Mexico and North Pacific are in agreement with the episodes of mountain-building in different regions
of Mexico. 相似文献
4.
Enyew Negussie Minna Koivula Esa A. Mäntysaari 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2):73-82
Abstract Genetic parameters were estimated for lactation average somatic cell score (SCS) and clinical mastitis (CM) for the first three lactations of multiparous Finnish Ayrshire cows. A multi-trait linear sire model was used for estimation of covariance components, and the efficiencies of single- versus multi-trait multi-lactation (MT) sire evaluations were compared. Heritability of SCS and CM in the first three lactations ranged from 0.11 to 0.13 and 0.02 to 0.03, respectively. Within lactation, genetic correlations between SCS and CM ranged from 0.68 to 0.72. Within both traits, across-lactation genetic correlations were lowest between 1 and 3, and highest between 2 and 3, with estimates ranging from 0.75 to 0.86 and from 0.81 to 0.98 for CM and SCS, respectively. Residual and phenotypic correlations were low and ranged from 0.09 to 0.13 and from 0.10 to 0.13, respectively. The absolute difference between genetic and residual correlations was from 0.5 to 0.6. Within-lactation genetic correlations between traits that are much less than unity suggest a multi-trait model for genetic evaluation of mastitis resistance. Comparison of model prediction performance between single-trait (ST) and MT models using a data splitting method showed that the MT model was more stable in predicting breeding values in future records of animals. Especially, for young sires and CM, the SD of EBVs from the MT model was 14 to 23% higher than the ST model, indicating more effective use of information in terms of revealing more genetic variation. 相似文献
5.
Selection of biological control agents for controlling soil and seed-borne diseases in the field 总被引：6，自引：0，他引：6
I.M.B. Knudsen J. Hockenhull D. Funck Jensen B. Gerhardson M. Hökeberg R. Tahvonen E. Teperi L. Sundheim B. Henriksen 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(9):775-784
Different screening methods for selection of biological control agents (BCAs), for controlling soil and seed-borne diseases, are discussed. The shortcomings of laboratory methods focused on mechanism of action are discussed and we conclude that these methods should be used with caution if candidates with multifactorial or plant mediated mechanisms of control are to be obtained. In vitro screens may be useful for specific groups of microorganisms, thus, screens for antibiotics may be relevant for Streptomyces spp., and promising results have been obtained using soil plating or precolonized agar methods to screen for mycoparasitism and competitive saprophytic ability. Experience with screening in the Nordic programme Biological control of seed borne diseases in cereals is summarized. Research in the four participating countries – Finland, Sweden, Norway and Denmark – followed the same paradigm: that of obtaining antagonists, well adapted to different Nordic environments, and developing them as effective BCAs. Potential antagonists were isolated from different sources and in planta screening methods were developed in order to optimize selection of antagonists effective against a range of seed borne pathogens. Screens in the laboratory or greenhouse were followed by screening in the field. The different screening procedures are compared and evaluated. 相似文献
6.
Liska WD Marcellin-Little DJ Eskelinen EV Sidebotham CG Harrysson OL Hielm-Björkman AK 《Veterinary surgery : VS》2007,36(4):293-301
Objective— To report surgical planning, technique, and outcome of custom total knee replacement (TKR) performed to manage a medial femoral condylar nonunion in a dog.
Study Design— Clinical case report.
Animal— A 3-year-old, 20 kg Karelian Bear Hound.
Methods— Computed tomographic scan of the left pelvic limb was used to build a stereolithography model of the distal portion of the femur. The model was used to create a custom augment to replace the missing medial femoral condyle and a custom stem for intramedullary condylar cemented fixation. The augment and stem were adapted to femoral and tibial components already available. The model was used to rehearse the surgery and then the custom prosthesis was implanted.
Results— Weight bearing returned 8 hours after surgery and improved thereafter. Joint alignment was normal and prosthetic joint motion was 60–165° postoperatively. The dog resumed moose hunting 3 months after surgery. Peak vertical force and impulse of the operated limb measured 17 months after surgery were 65% and 47% of the normal, contralateral limb.
Conclusion— Based on short-term follow-up, cemented canine TKR was successfully achieved for management of a severely abnormal stifle joint.
Clinical Relevance— With further refinement and development of commercially available prostheses, TKR should be possible for canine patients. 相似文献
Study Design— Clinical case report.
Animal— A 3-year-old, 20 kg Karelian Bear Hound.
Methods— Computed tomographic scan of the left pelvic limb was used to build a stereolithography model of the distal portion of the femur. The model was used to create a custom augment to replace the missing medial femoral condyle and a custom stem for intramedullary condylar cemented fixation. The augment and stem were adapted to femoral and tibial components already available. The model was used to rehearse the surgery and then the custom prosthesis was implanted.
Results— Weight bearing returned 8 hours after surgery and improved thereafter. Joint alignment was normal and prosthetic joint motion was 60–165° postoperatively. The dog resumed moose hunting 3 months after surgery. Peak vertical force and impulse of the operated limb measured 17 months after surgery were 65% and 47% of the normal, contralateral limb.
Conclusion— Based on short-term follow-up, cemented canine TKR was successfully achieved for management of a severely abnormal stifle joint.
Clinical Relevance— With further refinement and development of commercially available prostheses, TKR should be possible for canine patients. 相似文献
7.
8.
Kaarina Matilainen Raphael Mrode Ismo Strandn Robin Thompson Esa A. Mntysaari 《Livestock Science》2009,122(2-3):143-148
Breeding value evaluation for UK Limousin beef cattle data was carried out by multiple-trait linear–threshold animal model with variance components assumed to be known. Polychotomous calving ease with five categories was analysed with two continuous traits: birth weight and gestation length. Field data consisted of 220,799 animals with observations with every possible combination of traits, and 270,035 animals in the pedigree. The threshold model was solved either with Newton Raphson or Expectation Maximisation algorithm, and solutions were compared to evaluation by a linear model with original and normalised scores. There were insignificant differences in solutions between the two algorithms for threshold model analyses. Furthermore, solutions of the continuous traits were similar by the threshold and linear models. For the categorical trait, correlations for random effects from the threshold and linear models were high. In case of normalised scores (original scores case in brackets) correlations with solutions from the threshold and linear model were 0.97 (0.94) and 0.97 (0.93) for direct and maternal genetic effects and 0.95 (0.89) for permanent maternal effects. Even so, at least one third of the top 1% ranking of bulls differed between the linear and the threshold models. Predictive abilities as correlations between estimated breeding values and pedigree indices were almost equal between the linear and threshold models for both continuous and categorical traits. In conclusion, despite the higher computational demand, the linear–threshold animal model can be seen worthwhile in the genetic evaluation of the national UK beef cattle data set. 相似文献
9.
dos Santos Luis F. C. Ruiz-Sánchez Esaú Gamboa-Angulo Marcela González-Coloma Azucena 《植物病害和植物保护杂志》2019,126(2):107-114
Journal of Plant Diseases and Protection - The present work was carried out to gain insight into the chemical defense of maize against phytophagous insects. Leaves of sixteen landrace populations... 相似文献
10.
Hanna Haikka Timo Knürr Outi Manninen Leena Pietilä Mika Isolahti Esa Teperi Esa A. Mäntysaari Ismo Strandén 《Plant Breeding》2020,139(3):550-561
Genomic selection has been adopted in many plant breeding programmes. In this paper, we cover some aspects of information necessary before starting genomic selection. Spring oat and barley breeding data sets from commercial breeding programmes were studied using single, multitrait and trait-assisted models for predicting grain yield. Heritabilities were higher when estimated using multitrait models compared to single-trait models. However, no corresponding increase in prediction accuracy was observed in a cross-validation scenario. On the other hand, forward prediction showed a slight, but not significant, increase in accuracy of genomic estimated breeding values for breeding cohorts when a multitrait model was applied. When a correlated trait was used in a trait-assisted model, on average the accuracies increased by 9%–14% for oat and by 11%–28% for barley compared with a single-trait model. Overall, accuracies in forward validation varied between breeding cohorts and years for grain yield. Forward prediction accuracies for multiple cohorts and multiple years’ data are reported for oat for the first time. 相似文献