Schroderus E.,University of Jyvaskyla |
Koivula M.,Biotechnology and Food Research |
Koskela E.,University of Jyvaskyla |
Mappes T.,University of Jyvaskyla |
And 2 more authors.
BMC Evolutionary Biology | Year: 2012
Background: To maximize their fitness, parents are assumed to allocate their resources optimally between number and size of offspring. Although this fundamental life-history trade-off has been subject to long standing interest, its genetic basis, especially in wild mammals, still remains unresolved. One important reason for this problem is that a large multigenerational pedigree is required to conduct a reliable analysis of this trade-off. Results: We used the REML-animal model to estimate genetic parameters for litter size and individual birth size for a common Palearctic small mammal, the bank vole (Myodes glareolus). Even though a phenotypic trade-off between offspring number and size was evident, it was not explained by a genetic trade-off, but rather by negative correlations in permanent and temporary environmental effects. In fact, even positive genetic correlations were estimated between direct genetic effects for offspring number and size indicating that genetic variation in these two traits is not necessarily antagonistic in mammals. Conclusions: Our results have notable implications for the study of the life-history trade-off between offspring number and size in mammals. The estimated genetic correlations suggest that evolution of offspring number and size in polytocous mammals is not constrained by the trade-off caused by antagonistic selection responses per se, but rather by the opposing correlative selection responses in direct and maternal genetic effects for birth size. © 2012 Schroderus et al; licensee BioMed Central Ltd.
Partanen K.,Animal Production Research |
Siljander-Rasi H.,Animal Production Research |
Karhapaa M.,Animal Production Research |
Ylivainio K.,Plant Production Research |
Tupasela T.,Biotechnology and Food Research
Livestock Science | Year: 2010
A performance trial was carried out with 117 growing barrows (25-65kg) to study the effects of different levels of dietary phosphorus (P) on the pigs' performance and bone characteristics and on the content and solubility of P in faeces. Isoenergetic diets (9.0MJNEkg-1) were used containing 0.10, 0.55, 1.00, 1.45, 1.90, and 2.35% of monocalcium phosphate, and a constant calcium (Ca) to P ratio of 1.2:1. The analysed total P content ranged from 4.1 to 9.5gkg-1. The diets were calculated to contain 1.6, 2.5, 3.5, 4.5, 5.5, to 6.5gkg-1 of nonphytate P, respectively. The diet with the lowest nonphytate P content resulted in slightly lower average daily gain than the diets with ≥2.5gkg-1 of nonphytate P. The feed to gain ratio was increased when the diets contained more than 3.5gkg-1 of nonphytate P. The bending moment of rib and metacarpal bones was increased until the nonphytate P content reached 4.5 and 2.5gkg-1 feed, respectively, while 4.5gkg-1 of nonphytate P was required to maximise the Ca and P content of metacarpals. In accordance with the Hedley fractionation, the amount of water-soluble P was not affected by increased dietary phosphate content, but the amounts of NaHCO3-, NaOH-, and HCl-soluble P fractions increased. In conclusion, the nonphytate P content of 2.5gkg-1 feed was recommended for growing pigs of 25-65kg body weight. © 2010 Elsevier B.V.
Garkava-Gustavsson L.,Swedish University of Agricultural Sciences |
Antonius K.,Biotechnology and Food Research |
McDonagh D.,Science Center West |
Gallagher T.,Science Center West |
Nybom H.,Swedish University of Agricultural Sciences
Acta Horticulturae | Year: 2011
In many European countries, preservation of genetic resources in apple is directed mainly, or even exclusively, to so-called heirloom cultivars, i.e., old and presumably indigenous cultivars. However, there is very little information about the extent to which such collections contain a unique and desirable set of genes as opposed to just a random sample of genes from the global population of apple germplasm. Molecular markers, especially Simple Sequence Repeats (SSR), are commonly used for quantification of the amount of diversity in national collections of various plant crops. Provided that the same SSR primers are used and that allele sizing is standardized, data obtained in different studies can be pooled, thus allowing us to estimate not only diversity but also the degree of differentiation among e.g., apple collections preserved in different national gene banks. We have now used primer pairs from a 'standard set', defined by the European Community for Plant Genetic Resources working group on molecular markers, to analyse a total of 144 apple cultivars preserved in Sweden, Finland and Ireland, as well as some other European and non-European cultivars. Preliminary SSR data indicate that the Swedish, Finnish and Irish heirloom cultivars are very diverse. The groups are, however, only slightly differentiated from one another, with the other European cultivars being quite evenly distributed among the cultivars from the three national collections.
Oksanen T.A.,University of Jyva skyla |
Koivula M.,Biotechnology and Food Research |
Koskela E.,University of Jyva skyla |
Mappes T.,University of Jyva skyla |
Soulsbury C.D.,University of Jyva skyla
Ecology and Evolution | Year: 2012
Life-history traits are influenced by environmental factors throughout the lifespan of an individual. The relative importance of past versus present individuals born in low-density enclosures would do better overwintering in low-density enclosures than in high-density enclosures and vice versa.Our results show that the effect of summer (past) density was strong especially on survival and body mass. The response of body mass to summer density was negative in both winter (present) density groups, whereas the response of survival probability was nonlinear and differed between the winter density groups. In particular, our data show a trend for higher overwintering success of int environment on individual fitness, therefore, is a relevant question in populations that face the challenge of temporally varying environment. We studied the interacting effects of past and present density on body mass, condition, and survival in enclosure populations of the bank vole (Myodes glareolus) using a reciprocal transplant design. In connection with the cyclic dynamics of natural vole populations, our hypothesis was thadividuals originating from the lowest summer densities in lowwinter density and vice versa.We therefore conclude that the capacity of individuals to respond to a change in density was constrained by the delayed density-dependent effects of environment experienced in the past. These effects have the potential to contribute to vole population dynamics. Possible mechanisms mediating the effects of past environment into present performance include both intrinsic and environmental factors. © 2012 The Authors.
Honkatukia M.,Biotechnology and Food Research |
Tuiskula-Haavisto M.,Biotechnology and Food Research |
Ahola V.,Biotechnology and Food Research |
Ahola V.,University of Helsinki |
And 9 more authors.
BMC Genetics | Year: 2011
Background: Occurrence of blood and meat inclusions is an internal egg quality defect. Mass candling reveals most of the spots, but because brown eggshell hampers selection in brown chicken lines it has not been possible to eliminate the defect by selection. Estimated frequency of blood and meat inclusions in brown layers is about 18% whereas it is 0.5% in white egg layers. Several factors are known to increase the incidence of this fault: genetic background, low level of vitamin A and/or D, stress or infections, for instance. To study the genetic background of the defect, a mapping population of 1599 F2hens from a cross of White Rock and Rhode Island Red lines was set up.Results: Our histopathological analyses show that blood spots consist of mainly erythrocytes and that meat spots are accumulations of necrotic material. Linkage analysis of 27 chromosomes with 162 microsatellite markers revealed one significant quantitative trait locus (QTL) affecting blood spot and meat spot frequency. We sequenced a fragment of a candidate gene within the region, ZO-2, coding for a tight junction protein. Nine polymorphisms were detected and two of them were included in fine-mapping and association analysis. Fine-mapping defined the QTL result. To further verify the QTL, association analyses were carried out in two independent commercial breeding lines with the marker MCW241 and surrounding SNPs. Association was found mainly in a 0.8 Mb-wide chromosomal area on GGAZ.Conclusions: There was good agreement between the location of the QTL region on chromosome Z and the association results in the commercial breeds analyzed. Variations found in tight junction protein ZO-2 and microRNA gga-mir-1556 may predispose egg layers to blood and meat spot defects. This paper describes the first results of detailed QTL analyses of the blood and meat spots trait(s) in chickens. © 2011 Honkatukia et al; licensee BioMed Central Ltd.