Alkaloid Quantities in Endophyte-Infected Tall Fescue are Affected by the Plant-Fungus Combination and Environment.

Many grass species are symbiotic with systemic, vertically-transmitted, asymptomatic Epichloë endophytic fungi. These fungi often produce alkaloids that defend the host against herbivores. We studied how environmental variables affect alkaloids in endophyte-infected tall fescue (Schedonorus phoenix) from three Northern European wild origins and the widely planted US cultivar 'Kentucky-31' (KY31). The plants were grown in identical common garden experiments in Finland and Kentucky for two growing seasons. Plants were left as controls (C) or given water (W), nutrient (N) or water and nutrient (WN) treatments. For 8-10 replications of each plant origin and treatment combination in both experiments, we analyzed ergot alkaloids, lysergic acid, and lolines. In Finland, tall fescue plants produced 50 % more ergot alkaloids compared to plants of the same origin and treatments in Kentucky. Origin of the plants affected the ergot alkaloid concentration at both study sites: the wild origin plants produced 2-4 times more ergot alkaloids than KY31, but the ergot alkaloid concentration of KY31 plants was the same at both locations. Overall lysergic acid content was 60 % higher in plants grown in Kentucky than in those grown in Finland. Nutrient treatments (N, WN) significantly increased ergot alkaloid concentrations in plants from Finland but not in plants from Kentucky. These results suggest that the success of KY31 in US is not due to selection for high ergot alkaloid production but rather other traits associated with the endophyte. In addition, the environmental effects causing variation in alkaloid production of grass-endophyte combinations should be taken into account when using endophyte-infected grasses agriculturally.

Seasonally varying diet quality and the quantitative genetics of development time and body size in birch feeding insects.

Genetic variance-covariance structures (G), describing genetic constraints on microevolutionary changes of populations, have a central role in the current theories of life-history evolution. However, the evolution of Gs in natural environments has been poorly documented. Resource quality and quantity for many animals and plants vary seasonally, which may shape genetic architectures of their life histories. In the mountain birch-insect herbivore community, leaf quality of birch for insect herbivores declines profoundly during both leaf growth and senescence, but remains stable during midsummer. Using six sawfly species specialized on the mountain birch foliage, we tested the ways in which the seasonal variation in foliage quality of birch is related to the genetic architectures of larval development time and body size. In the species consuming mature birch leaves of stable quality, that is, without diet-imposed time constraints for development time, long development led to high body mass. This was revealed by the strongly positive phenotypic and genetic correlations between the traits. In the species consuming growing or senescing leaves, on the other hand, the rapidly deteriorating leaf quality prevented the larvae from gaining high body mass after long development. In these species, the phenotypic and genetic correlations between development time and final mass were negative or zero. In the early-summer species with strong selection for rapid development, genetic variation in development time was low. These results show that the intuitively obvious positive genetic relationship between development time and final body mass is a probable outcome only when the constraints for long development are relaxed. Our study provides the first example of a modification in guild-wide patterns in the genetic architectures brought about by seasonal variation in resource quality.

Effect of maternal and paternal line on spatial and temporal marine distribution in Atlantic salmon.

We examined the inheritance of the sea migration pattern of Atlantic salmon, Salmo salar, in a crossing and tagging experiment in the Baltic Sea. Individuals from the parental stocks, Neva and Iijoki, and their reciprocal hybrids were released as 2-year-old smolts, into the same estuary of the Bothnian Sea in 1994. Two thousand smolts from each of the four groups were marked with Carlin tags. The recapture rate of the tags was nearly 10%. We used log-linear models to analyse the marine distribution of the salmon groups from the tag recovery data. The pure stocks and their pooled hybrid groups all showed statistically significant differences between each other in spatial and temporal sea distribution. The Iijoki salmon were more frequently (9%) caught outside the Bothnian Sea than were the Neva salmon (2%). The majority of the Iijoki salmon (55%), but fewer Neva salmon (40%), were caught in the second sea year. In spatial distribution, the hybrids seemed to be intermediate between the parental stocks, with no differences between reciprocal female and male lines. In duration of sea migration and age at maturity, however, the hybrids were very similar to their maternal line, the effect of which was thus clearly stronger than that of the paternal line. Copyright 2000 The Association for the Study of Animal Behaviour.

A coevolutionary predator-prey model with quantitative characters.

A new model for coevolution in generalized predator-prey systems is presented by incorporating quantitative characters relevant to predation in both prey and predator. Malthusian fitnesses are derived from ecological models, and they include interspecific frequency and density dependence. Both prey and predator characters are under stabilizing selection even without predation, and predation adds an additional linear selection component to both characters. The nonlinear system of differential equations is studied analytically by using local linearization near the equilibrium points. Parameters related to intrinsic growth and death rates and stabilizing selection determine whether there are zero, one, or two equilibria. Additive genetic variances do not have an effect on the equilibrium points, but genetic variability is crucial for determining their stability. Analysis of the linearized model shows that at most one equilibrium can be stable, and stability is achieved when additive genetic variance is high enough in both the prey and predator populations. The stability properties are illustrated by numerical examples of the full dynamics of the original nonlinear model.

Smoking and the occurrence of congenital malformations and spontaneous abortions: multivariate analysis.

A multivariate analysis was carried out with retrospective data on the effects of tobacco smoking on congenital malformations and spontaneous abortions. Congenital malformations were collected from the Finnish Register of Congenital Malformation. Tens of possible confounding variables, including maternal and family characteristics, obstetric history, medicine taking, and diseases during the pregnancy, were taken into consideration. In the final analysis 13 confounders were controlled. The odds ratios for the smoker's child to be born with central nervous system, oral cleft, or musculoskeletal malformations were 1.25, 1.25, and 0.75, respectively. All the differences were statistically nonsignificant. The effect of smoking on spontaneous abortions was analyzed by means of a questionnaire study on hospital personnel. The smokers of over 10 cigarettes per day had more spontaneous abortions than the nonsmokers, but the differences were not significantly statistically. The data were controlled for age, parity, and coffee and alcohol drinking.

PIP: A multivariate analysis was carried out with retrospective data on the effects of tobacco smoking on congenital malformations and spontaneous abortions. Congenital malformations were collected from the Finnish Register of Congenital Malformation. Numerous possible confounding variables, including maternal and family characteristics, obstetric history, medicine taking, and diseases during the pregnancy, were taken into consideration. In the final analysis, 13 confounders were controlled. The odds ratios for the smoker's child to be born with central nervous system, oral cleft, or musculoskeletal malformations were 1.25, 1.25, and 0.75, respectively. All differences were statistically nonsignificant. The effect of smoking on spontaneous abortions was analyzed by means of a questionnaire study on hospital personnel. The smokers of over 10 cigarettes/day had more spontaneous abortions than nonsmokers, but the differences were not statistically significant. Data were controlled for age, parity, and coffee and alcohol drinking.

Gastroschisis and omphalocele in Finland in the 1970s: prevalence at birth and its correlates.

Information on liveborn and stillborn children with gastroschisis and omphalocele was collected from hospital and register sources in Finland from 1970 to 1979. The apparent prevalence of gastroschisis at birth increased from 0.77/10 000 births in 1970-4 to 1.42/10 000 in 1975-9. The prevalence of omphalocele (1.96/10 000) was unchanged during the decade. Even for gastroschisis the apparent increase in prevalence was noted for northern Finland only, while for southern Finland the prevalence has been stable during the 1970s, possibly suggesting diagnostic or reporting differences between various parts of the country. Some correlates of increased risk of gastroschisis included: low birth weight, low maternal age, urban residence, and maternal employment in commercial and sales work.

Spontaneous abortions in hospital staff engaged in sterilising instruments with chemical agents.

Spontaneous abortions in hospital sterilising staff were analysed using data from a postal questionnaire and a hospital discharge register. The study included all the sterilising staff employed in Finnish hospitals in 1980; the controls were nursing auxiliaries. Data from the questionnaire showed that the frequency of spontaneous abortions was 11.3% for the sterilising staff and 10.6% for the nursing auxiliaries. When the staff were concerned in sterilising procedures during their pregnancy the frequency was 16.7% compared with 5.6% for the non-exposed pregnancies. Adjustment for age, parity, decade of pregnancy, smoking habits, and intake of coffee and alcohol did not affect the differences. The increased frequency of spontaneous abortion correlated with exposure to ethylene oxide but not with exposure to glutaraldehyde or to formaldehyde. Analysis of spontaneous abortions from the hospital discharge register confirmed the findings. Thus the results from the two independent analyses suggest that exposure to ethylene oxide in hospitals may carry a risk of spontaneous abortion among sterilising staff.

Childhood cancer and parental occupation in Finland.

A case-control study was conducted of the occupations of parents of children under 15 with diagnosed malignancies. The total series contained all childhood cancers cases reported to the Finnish Cancer Registry during the period 1959-75. The parental occupations, recorded at the time of pregnancy, were collected from maternity welfare centres. The cases were analysed as a singly group or as subgroups according to the diagnoses-brain tumours, leukaemia, and all other malignancies. The maternal occupations found more frequently among cases than controls included farmers' wives (1959-68 only), pharmacists, saleswomen, bakers, and factory work of an vehicle driving, machine repair, painting, and the work of men who gave an academic degree as their occupation. Some of these occupations involve possible exposure to harmful chemicals, although chance correlations cannot be excluded.

Congenital malformations and maternal occupation in Finland: multivariate analysis.

The Finnish Register of Congenital Malformations was used in a multivariate analysis to explore the associations between maternal occupation in industry and children born with central nervous system (CNS) or musculoskeletal or oral cleft malformations. Possible confounding factors were selected in preliminary screening of risk indicators for malformations. These factors included characteristics of the mother, the child, and the family; maternal illnesses; an maternal medication at the time of pregnancy. Tobacco smoking was a confounding factor for all type of malformations; number of children born to the mother, maternal age, malformations in the family, number of rooms occupied by the family, sex of the child, threatened abortion, and continuous medication of the mother during the first trimester confounded the association for certain type of malformations. After adjusting for confounding factors, maternal occupation in industrial trades significantly correlated with CNS, oral cleft, and musculoskeletal malformation in the offspring. Maternal occupation in industry and construction only was significantly associated with CNS malformations in the offspring but the associations with oral cleft and musculoskeletal malformations were not significant.

Transplacental carcinogens and mutagens: childhood cancer, malformations, and abortions as risk indicators.

Childhood cancer, malformations, and spontaneous abortions in Finland were analyzed according to the parents' occupations. Children of women working in the food industry and farming and of men working in motor vehicle driving and farming appeared to have an elevated risk of cancer. Women in industrial and construction occupations had an increased risk of having malformed children and spontaneous abortions.

Spontaneous abortions by occupation and social class in Finland.

A hospital discharge registry covering all general hospitals in Finland was used in the study of spontaneous abortions. Spontaneous abortions were analysed by the women's occupation and socio-economic class for 1973-75 inclusive. The risk of spontaneous abortion increased from social class 1 to 4 by about 50%. The occupational groups with an increased frequency of spontaneous abortions included industrial and construction work, agriculture, forestry and fishing, sales, transport and communication, services, and students and trainees. Decreased frequency of spontaneous abortions was noted among housewives, and in managerial and clerical occupations. The results suggest that socio-economic factors contribute to the rate of spontaneous abortions analogous to their known adverse effects on pre-term birth, birth weight and perinatal mortality.

PIP: The application of a hospital discharge registry covering all general hospitals in Finland to study spontaneous abortions is described. The frequency of spontaneous abortion in occupational and socioeconomic groups was analyzed from the registry. The data consisted of all inpatients admitted to Finnish hospitals for spontaneous abortion in 1973-1975. The Finnish National Board of Health maintains a computerized registry on all patients discharged from general hospitals. Data on patients treated for spontaneous abortions, induced abortions, and on women giving birth were extracted. The rate of spontaneous abortions increased with the age of the woman. In the active reproductive ages of 20-34 years the rate of spontaneous abortions (related to pregnancies) was around 7%. The ratio of spontaneous abortions to births was higher than the rate over all, particularly in older age groups, indicating the relative frequency of induced abortions at higher ages. Spontaneous abortions increased from social class 1 (age-standardized rate 5.88% and ratio 8.17%) to social class 4 (8.47 and 14.93%, respectively). Farmers, social class 5, had an age-standardized rate and ratio of 7.56 and 9.90%, respectively. Students and persons with unknown occupations, social class 6, had a total rate and ratio of 8.28 and 14.66%, respectively. The apparently high ratio in the 15-19 age group of social class 1 is based on small numbers and may be due to chance. The rate of spontaneous abortion was significantly increased among women employed in agriculture, forestry and fishing; among students and trainees; and industrial and construction workers. The rate significantly decreased in managerial and clerical occupations and among housewives, including farmers' wives. The ratios of spontaneous abortion showed larger differences between the occupations than the respective rates. In sum, study results revealed an increase in the frequency of hospitalized spontaneous abortions in lower social classes and in occupational groups involving demanding manual and physical work. The data indicate that environmental factors play a part in the etiology of spontaneous abortion.