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941.
Matti Janhunen Nina Peuhkuri Craig R. Primmer Irma Kolari Jorma Piironen 《Evolutionary biology》2011,38(1):68-78
Genetic theories of sexual selection predict that most ornamental secondary sexual traits provide reliable indication of the
genetic quality of their bearers. Accordingly, also the offspring of mates with elaborate mating display should perform better
than those of less conspicuous counterparts. In this study, we used Arctic charr (Salvelinus alpinus) as a model species to investigate whether the variation in a carotenoid-based red breeding coloration (a sexually dichromatic
trait) in different sexes would reflect differences in individual genetic variability, one measure of individual quality,
and/or indirectly, be manifested in variation in the offspring’s early viability and growth. We created maternal half-sibling
families by artificially fertilizing the eggs with milt from bright- and pale-coloured males and then held the resulting progenies
under identical hatchery conditions. The expression of red coloration among parental fish was not associated with their genetic
diversity estimates in either sex nor did offspring sired by bright males consistently differ in terms of embryo survival
or endogenous growth efficiency from offspring sired by pale males. By contrast, maternal effects were notably strong and,
additionally, the degree of female coloration was negatively linked to their reproductive potential. The more intensely coloured
females had a smaller relative fecundity and they also produced offspring of lower viability, implying a significant trade-off
in resource allocation between ornamentation and offspring. Our results indicate that the red breeding ornamentation of Arctic
charr is likely to be informative rather among females than males when the reproductive quality is predicted on grounds of
the number of offspring produced. Nevertheless, this study does not support the direct selection hypothesis in explaining
the evolution of female ornamentation, but rather suggests that the less intense coloration of female charr compared to males
may reflect inter-sexual differences in the trade-off between natural and sexual selection. 相似文献
942.
943.
944.
Structure and function of the SH3 domain 总被引:16,自引:0,他引:16
945.
Martin Lodenius Jussi Josefsson Kari Heliövaara Esa Tulisalo Matti Nummelin 《Insect Science》2009,16(1):93-98
Ash fertilization of forests returns nutrients to forest ecosystems and has a positive effect on soil pH, but it also may elevate Cd concentrations of forest biota. Cadmium concentrations of some forest insects ( Formica ants, carabids and Coleopteran larvae from decaying wood) were investigated in southern Finland, where two plots were fertilized with wood ash, while two other plots represented unfertilized control plots. In ants, mean Cd concentration was 3.6 ± 1.4 mg/kg, with nest workers having significantly higher concentrations than workers trapped in pitfall traps. Concentrations at fertilized and unfertilized plots were similar. In carabid beetles, the average Cd concentration of Carabus glabratus was 0.44 ± 0.36 mg/kg, with no significant difference between control plots and fertilized plots. In another carabid beetle, Pterostichus niger , mean Cd concentration was higher at fertilized plots compared to control plots. We conclude that the variation of Cd concentrations in the insects studied is more efficiently controlled by species-specific differences than fertilization history of the forest floor. 相似文献
946.
947.
Antti Vuolanto Ossi Pastinen Hans E. Schoemaker Matti Leisola 《Biocatalysis and Biotransformation》2002,20(4):235-240
We describe novel tetrose isomerizations and C-2 epimerizations by the industrially important d -xylose ketol-isomerase (E.C.5.3.1.5) with both the d - and l -forms of the sugars. We further show that in addition to isomerization to d -fructose, d -glucose is slowly C-2 epimerized to d -mannose. The formation rate of the C-2 epimer was 0.03 mg mg -1 min -1 from d -glucose, 0.56 mg mg -1 min -1 from d -arabinose and 3.0 mg mg -1 min -1 from d -erythrose. The equilibria of the reaction products as a function of temperature were measured for threose/erythrulose/erythrose, arabinose/ribulose/ ribose and glucose/fructose/mannose. 相似文献
948.
Background
Answers to several fundamental questions in statistical genetics would ideally require knowledge of the ancestral pedigree and of the gene flow therein. A few examples of such questions are haplotype estimation, relatedness and relationship estimation, gene mapping by combining pedigree and linkage disequilibrium information, and estimation of population structure. 相似文献949.
950.
Fungal strains were compared for their ability to produce milk-coagulating enzyme with low non-specific proteinase activity.Rhizomucor miehei VTT-D-82193 (ATCC 16457) was chosen as the best source of microbial rennin. The enzyme produced compared favourably with two commercial coagulant preparations of microbial origin. The work provides a basis for comparison with other production processes for microbial rennin, including recombinant chymosin. 相似文献