Linking genetic and species diversities in a community of freshwater gastropods

Summary Biodiversity is usually studied through species or genetic diversities. To date, these two levels of diversity have remained the independent .fields of investigations of community ecologists and population geneticists. However, recent joint analyses of species and genetic diversities have suggested that common processes may underlie the two levels. Positive correlations between species diversity and genetic diversity may arise when the effects of drift and migration overwhelm selective effects. The first goal of this thesis was to make a joint investigation of the patterns of species and genetic diversity in a community of freshwater gastropods living in a floodplain habitat. The second goal was to determine, as far as possible, the relative influences of the processes underlying the patterns observed at each level. In chapter 2 we investigate the relative influences of different evolutionary forces in shaping the genetic structure of Radix balthica populations. Results revealed that the structure inferred using quantitative traits was lower or equal to the one inferred using neutral molecular markers. Consequently, the pattern of structure observed could be only due to random drift, possibly to uniform selection, but definitely not to selection for local optima. In chapter 3, we analyze the temporal variation of species and genetic diversities in five localities. An extended period of drought occurred at the end of the study period leading to decay of both species and genetic diversities. This parallel loss of diversity following a natural perturbation highlighted the role sometimes predominant of random drift over selection on patterns of biodiversity in a floodplain habitat. In chapter 4, we compare the spatial genetic structures of two sympatric species: Radix balthica and Planorbis carinatus. We found that R. balthica populations are weakly structured and have moderate to high values of gene diversity. In contrast, P. carinatus populations are highly structured and poorly diverse. Then we measured correlations between various indices of species and genetic diversity using genetic data .from the two species. We found only one significant correlation: between species richness and gene diversity of P. carinatus. This result highlights the .need to use genetic date from more than one species to infer correlations between species and genetic diversities. Overall, this thesis provided new insights into the common processes underlying patterns of species and genetic diversity. Résumé La biodiversité est généralement étudiée au niveau de la diversité génétique ou spécifique. Ces deux niveaux sont restés jusqu'à maintenant les domaines d'investigation séparés des généticiens des populations et des écologistes des communautés. Cependant, des analyses conjointes des diversités génétique et spécifique ont récemment suggéré que des processus similaires pouvaient influencer ces deux niveaux. Des corrélations positives entre les diversités génétique et spécifique pourraient être dues aux effets de migration et de dérive qui dominent les effets sélectifs. Le premier but de cette thèse était de faire une étude conjointe des diversités génétique et spécifique dans une communauté de gastéropodes d'eau douce. Le second objectif était de déterminer les influences relatives des différents processus liés à chaque niveau de diversité. Dans le chapitre 2 nous cherchons à déterminer quelles forces évolutives influencent la structure génétique de quatre populations de Radix balthica. La structure mesurée sur des traits quantitatifs s'est révélée être plus faible ou égale à celle mesurée avec des marqueurs moléculaires neutres. La structure observée pourrait ainsi être due uniquement à la dérive génétique, potentiellement à la sélection uniforme, mais en aucun cas à la sélection locale pour différents optima. Dans le chapitre 3 nous analysons la variation temporelle des diversités génétique et spécifique dans cinq localités. Une récente période de sécheresse a causé une diminution parallèle des deux niveaux de diversité. Cette perturbation à mis en évidence le rôle parfois prépondérant de la dérive par rapport à celui de la sélection dans le déterminisme de la biodiversité dans un écosytème alluvial. Dans le chapitre 4, nous comparons la structure génétique spatiale de deux espèces vivant en sympatrie : Radix balthica et Planorbis carinatus. Les populations de R. balthica sont peu structurées et présentent un niveau de diversité relativement élevé alors que celles de P. carinatus sont fortement structurées et peu diversifiées. Nous avons ensuite mesuré différentes corrélations entre les diversités génétique et spécifique, mais la seule relation significative a été trouvée entre la richesse spécifique et la diversité génétique de P. carinatus. Ainsi, cette thèse a permis de découvrir de nouveaux aspects des processus qui influencent en parallèle la diversité aux niveaux génétique et spécifique.

Division of labor in insect societies : genetic components and physiological regulation

The shift from solitary to social organisms constitutes one of the major transitions in evolution. The highest level of sociality is found in social insects (ants, termites and some species of bees and wasps). Division of labor is central to the organization of insect societies and is thought to be at the root of their ecological success. There are two main levels of division of labor in social insect colonies. The first relates to reproduction and involves the coexistence of queen and worker castes: while reproduction is usually monopolized by one or several queens, functionally sterile workers perform all the tasks to maintain the colony, such as nest building, foraging or brood care. The second level of division of labor, relating to such non-reproductive duties, is characterized by the performance of different tasks or roles by different groups of workers. This PhD aims to better understand the mechanisms underlying division of labor in insect societies, by investigating how genes and physiology influence caste determination and worker behavior in ants. In the first axis of this PhD, we studied the nature of genetic effects on division of labor. We used the Argentine ant Linepithema humile to conduct controlled crosses in the laboratory, which revealed the existence of non-additive genetic effects, such as parent-of-origin and genetic compatibility effects, on caste determination and worker behavior. In the second axis, we focused on the physiological regulation of division of labor. Using Pogonomyrmex seed- harvester ants, we performed experimental manipulation of hibernation, hormonal treatments, gene expression analyses and protein quantification to identify the physiological pathways regulating maternal effects on caste determination. Finally, comparing gene expression between nurses and foragers allowed us to reveal the association between vitellogenin and worker behavior in Pogonomyrmex ants. This PhD provides important insights into the role of genes and physiology in the regulation of division of labor in social insect colonies, helping to better understand the organization, evolution and ecological success of insect societies. - L'une des principales transitions évolutives est le passage de la vie solitaire à la vie sociale. La socialité atteint son paroxysme chez les insectes sociaux que sont les fourmis, les termites et certaines espèces d'abeilles et de guêpes. La division du travail est la clé de voûte de l'organisation de ces sociétés d'insectes et la raison principale de leur succès écologique. La division du travail s'effectue à deux niveaux dans les colonies d'insectes sociaux. Le premier niveau concerne la reproduction et implique la coexistence de deux castes : les reines et les ouvrières. Tandis que la reproduction est le plus souvent monopolisée par une ou plusieurs reines, les ouvrières stériles effectuent les tâches nécessaires au bon fonctionnement de la colonie, telles que la construction du nid, la recherche de nourriture ou le soin au couvain. Le second niveau de division du travail, qui concerne les tâches autres que la reproduction, implique la réalisation de différents travaux par différents groupes d'ouvrières. Le but de ce doctorat est de mieux comprendre les mécanismes sous-jacents de la division du travail dans les sociétés d'insectes en étudiant comment les gènes et la physiologie influencent la détermination de la caste et le comportement des ouvrières chez les fourmis. Dans le premier axe de ce doctorat, nous avons étudié la nature des influences génétiques sur la division du travail. Nous avons utilisé la fourmi d'Argentine, Linepithema humile, pour effectuer des croisements contrôlés en laboratoire. Cette méthode nous a permis de révéler l'existence d'influences génétiques non additives, telles que des influences dépendantes de l'origine parentale ou des effets de compatibilité génétique, sur la détermination de la caste et le comportement des ouvrières. Dans le second axe, nous nous sommes intéressés à la régulation physiologique de la division du travail. Nous avons utilisé des fourmis moissonneuses du genre Pogonomyrmex pour effectuer des hibernations artificieHes, des traitements hormonaux, des analyses d'expression de gènes et des mesures de vitellogénine, ce qui nous a permis d'identifier les mécanismes physiologiques régulant les effets maternels sur la détermination de la caste. Enfin, la comparaison d'expression de gènes entre nourrices et fourrageuses suggère un rôle de la vitellogénine dans la régulation du comportement des ouvrières chez les fourmis moissonneuses. En détaillant les influences des gènes et de la physiologie dans la régulation de la division du travail dans les colonies d'insectes sociaux, ce doctorat fournit d'importantes informations permettant de mieux comprendre l'organisation, l'évolution et le succès écologique des sociétés d'insectes.

Genetic Factors in the Regulation of Striatal and Extrastriatal Dopamine D2 Receptor Expression

Positron emission tomography (PET) studies on healthy individuals have revealed a marked interindividual variability in striatal dopamine D2 receptor density that can be partly accounted for by genetic factors. The examination of the extrastriatal lowdensity D2 receptor populations has been impeded by the lack of suitable tracers. However, the quantification of these D2 receptor populations is now feasible with recently developed PET radioligands. The objective of this thesis was to study brain neurobiological correlates of common functional genetic variants residing in candidate genes relevant for D2 receptor functioning. For this purpose, healthy subjects were studied with PET imaging using [₁₁C]raclopride and [₁₁C]FLB457 as radioligands. The candidate genes examined in this work were the human D2 receptor gene (DRD2) and the catechol-Omethyltransferase gene (COMT). The region-specific genotypic influences were explored by comparing D2 receptor binding properties in the striatum, the cortex and the thalamus. As an additional study objective, the relationship between cortical D2 receptor density and a cognitive phenotype i.e. verbal memory and learning was assessed. The main finding of this study was that DRD2 C957T genotype altered markedly D2 receptor density in the cortex and the thalamus whereas in the striatum the C957T genotype affected D2 receptor affinity, but not density. Furthermore, the A1 allele of the DRD2-related TaqIA polymorphism showed increased cortical and thalamic D2 receptor density, but had the opposite effect on striatal D2 receptor density. The DRD2 –141C Ins/Del or the COMT Val158Met genotypes did not change D2 receptor binding properties. Finally, unlike previously reported, cortical D2 receptor density did not show any significant correlation with verbal memory function. The results of this study suggest that the C957T and the TaqIA genotypes have region-specific neurobiological correlates in brain dopamine D2 receptor availability in vivo. The biological mechanisms underlying these findings are unclear, but they may be related to the region-specific regulation of dopamine neurotranssion, gene/receptor expression and epigenesis. These findings contribute to the understanding of the genetic regulation of dopamine and D2 receptor-related brain functions in vivo in man. In addition, the results provide potentially useful endophenotypes for genetic research on psychiatric and neurological disorders.

Examining life-course influences on chronic disease: the Ribeirão Preto and São Luís birth cohort studies (Brazil)

More than any other low- and middle-income country, Brazil has the longest research tradition of establishing, maintaining and exploiting birth cohort studies. This research pedigree is highlighted in the present issue of the Brazilian Journal of Medical and Biological Research, which contains a series of twelve papers from the Ribeirão Preto and São Luis birth cohort studies from the Southeast and Northeast of Brazil, respectively. The topics covered in this raft of reports vary and include predictors of perinatal health and maternal risk factors, early life determinants of cardiovascular risk factors in childhood and adolescence, use of health services, and a description of dietary characteristics of young adults, amongst other topics. There is also a guide to the background, objectives, sampling and protocols employed across these studies, which, together with similar pieces published in past issues of the Brazilian Journal, serve as a very useful starting point, particularly for potential collaborators. In the fervent hope that further follow-up of these cohorts will take place - we provide our own justification for cohort maintenance and extension in this issue - future data collection could include: genetic material, atherosclerosis, ascertained, for instance, by intima-media thickness, and IQ testing in children - scores from which are emerging as potentially important predictors of adult health outcomes up to six decades later.

Demographic and genetic attributes of dispersing and resident individuals of an enclosed Microtus pennsylvanicus population

A dispersal polymorphism may exist in emigrants from cyclic populations of Microtus '~nnsylvanicus biasing trap-revealed movements of unenclosed animals in favour of sedentary or colonizing individuals. The dispersal tendency of emigrants from an enclosed population was investigated by releasing animals via tubes into one of two adjacent enclosures, one vacant and one inhabited. Individuals from the enclosed population were monitored for age, sex, weight and electrophoretically detectable serum transferrin genotype in an intensive live-trapping program. In 1973 the minimum number alive in the introduced enclosed study population reached approximately l67/ha when breeding stopped in October. In 1974 intensive breeding increased the population density to 333/ha by mid-July when a long decline in numbers and breeding intensity began without an intervening plateau. An adjacent unenclosed area had a much lower density and longer breeding season in 1974. The growth rate of young males in the enclosed population tended to be lowest during the decline period in 1974. Survival of the enclosed population was high throughout but was lowest during the decline phase in both sexes, especially males. Low transferrin heterozygote survival during the decline coincided with a significant heterozygote deficiency in females whereas in males genotype frequencies did not depart from Hardy-Weinberg equilibrium values throughout th.e study. Twenty-nine suitable ani.mals were released during the decline in five periods from July to November 1974. The proportions of males and transferrin heterozygotes in the released graun were generally greater than in the source population~ In the test enclosures 21% of the released animals continued their movement through the vacant area while 41% (no significant difference) moved through the inhabited enclosure. In the vacant test area, females had a greater tendency than males to continue dispersal whereas no difference was noted in the inhabited area. Low frequency of captures in the tubes, predator disturbances and cold weather forced the termination of the study. The role of dispersal as a population regulating mechanism was further substantiated. The genetic differences between emigrant and resident animals lend support to Howard's hypothesis that a genetic polymorphism influences the tendency to disperse. Support is also given to Myers' and Krebs' contention that among dispersers an additional density dependent polymorphism influences the distance dispersed.

Metal bioaccumulation and cellular fractionation in an epigeic earthworm (Lumbricus rubellus): the interactive influences of population exposure histories, site-specific geochemistry and mitochondrial genotype

Subcellular fractionation techniques were used to describe temporal changes (at intervals from T0 to T70 days) in the Pb, Zn and P partitioning profiles of Lumbricus rubellus populations from one calcareous (MDH) and one acidic (MCS) geographically isolated Pb/Zn-mine sites and one reference site (CPF). MDH and MCS individuals were laboratory maintained on their native field soils; CPF worms were exposed to both MDH and MCS soils. Site-specific differences in metal partitioning were found: notably, the putatively metal-adapted populations, MDH and MCS, preferentially partitioned higher proportions of their accumulated tissue metal burdens into insoluble CaPO4-rich organelles compared with naive counterparts, CPF. Thus, it is plausible that efficient metal immobilization is a phenotypic trait characterising metal tolerant ecotypes. Mitochondrial cytochrome oxidase II (COII) genotyping revealed that the populations indigenous to mine and reference soils belong to distinct genetic lineages, differentiated by 13%, with 7 haplotypes within the reference site lineage but fewer (3 and 4, respectively) in the lineage common to the two mine sites. Collectively, these observations raise the possibility that site-related genotype differences could influence the toxico-availability of metals and, thus, represent a potential confounding variable in field-based eco-toxicological assessments.

Genotypic and environmental influences on the performance of wheat root systems

Genetic and environmental factors interact to determine the growth and activity of crop root systems. This paper examines the effects of agronomic management and genotype on wheat root systems in the UK and Australia, and suggests ways in which root limitations to crop performance might be alleviated. In a field study in the UK which examined late-season growth and activity, fungicide maintained the size of the root system during early grain-filling, and there were significant differences between cultivars in root distribution with depth below 0.3 m. Shamrock had a longer root system below 0.3 m than varieties such as Hereward and Consort. Fungicide significantly increased root growth at 0.1-0.2 m in one season. In Australia, a wheat line selected for high shoot vigour had associated root vigour during early seedling growth but the effect on root growth did not persist. The results provide examples of genotypic differences in wheat root growth under field conditions which interact with agronomic management in ways which can be exploited to benefit growth and yield in diverse environments.

Gene-nutrient interactions with dietary fat modulate the association between genetic variation of the ACSL1 gene and metabolic syndrome

Long-chain acyl CoA synthetase 1 (ACSL1) plays an important role in fatty acid metabolism and triacylglycerol (TAG) synthesis. Disturbance of these pathways may result in dyslipidemia and insulin resistance, hallmarks of the metabolic syndrome (MetS). Dietary fat is a key environmental factor that may interact with genetic determinants of lipid metabolism to affect MetS risk. We investigated the relationship between ACSL1 polymorphisms (rs4862417, rs6552828, rs13120078, rs9997745, and rs12503643) and MetS risk and determined potential interactions with dietary fat in the LIPGENE-SU.VI.MAX study of MetS cases and matched controls (n = 1,754). GG homozygotes for rs9997745 had increased MetS risk {odds ratio (OR) 1.90 [confidence interval (CI) 1.15, 3.13]; P = 0.01}, displayed elevated fasting glucose (P = 0.001) and insulin concentrations (P = 0.002) and increased insulin resistance (P = 0.03) relative to the A allele carriers. MetS risk was modulated by dietary fat, whereby the risk conferred by GG homozygosity was abolished among individuals consuming either a low-fat (<35% energy) or a high-PUFA diet (>5.5% energy). In conclusion, ACSL1 rs9997745 influences MetS risk, most likely via disturbances in fatty acid metabolism, which was modulated by dietary fat consumption, particularly PUFA intake, suggesting novel gene-nutrient interactions.

APOA5 genotype influences the association between 25-hydroxyvitamin D and high density lipoprotein cholesterol

OBJECTIVE: Circulating levels of 25-hydroxyvitamin D (25OHD) are positively associated with high density lipoprotein (HDL) cholesterol. We sought to replicate a previously reported interaction between APOA5 genotype and vitamin D, and to examine whether HDL-associated genetic loci modify the association between serum 25OHD and HDL cholesterol. METHODS: We examined whether 42 single nucleotide polymorphisms (SNPs) modify the association between serum 25OHD and HDL cholesterol in the 1958 British Birth cohort (aged 45 years, n = 4978). RESULTS: We identified a borderline interaction between the SNP rs12272004 (near the APOA5) and serum 25OHD on HDL cholesterol (P(interaction) = 0.05). The interaction was particularly prominent among the samples collected during winter (P(interaction) = 0.001). None of the other loci showed an interaction with serum 25OHD concentrations on HDL cholesterol. CONCLUSIONS: Our study in 4978 British Whites provides further support that APOA5 genotype modifies the association between vitamin D metabolites and HDL cholesterol.

The APOB insertion/deletion polymorphism (rs17240441) influences postprandial lipaemia in healthy adults

BACKGROUND: Apolipoprotein (apo)B is the structural apoprotein of intestinally- and liver- derived lipoproteins and plays an important role in the transport of triacylglycerol (TAG) and cholesterol. Previous studies have examined the association between the APOB insertion/deletion (ins/del) polymorphism (rs17240441) and postprandial lipaemia in response to a single meal; however the findings have been inconsistent with studies often underpowered to detect genotype-lipaemia associations, focused mainly on men, or with limited postprandial characterisation of participants. In the present study, using a novel sequential test meal protocol which more closely mimics habitual eating patterns, we investigated the impact of APOB ins/del polymorphism on postprandial TAG, non-esterified fatty acids, glucose and insulin levels in healthy adults. FINDINGS: Healthy participants (n = 147) consumed a standard test breakfast (0 min; 49 g fat) and lunch (330 min; 29 g fat), with blood samples collected before (fasting) and on 11 subsequent occasions until 480 min after the test breakfast. The ins/ins homozygotes had higher fasting total cholesterol, LDL-cholesterol, TAG, insulin and HOMA-IR and lower HDL-cholesterol than del/del homozygotes (P < 0.017). A higher area under the time response curve (AUC) was evident for the postprandial TAG (P < 0.001) and insulin (P = 0.032) responses in the ins/ins homozygotes relative to the del/del homozygotes, where the genotype explained 35% and 7% of the variation in the TAG and insulin AUCs, respectively. CONCLUSIONS: In summary, our findings indicate that the APOB ins/del polymorphism is likely to be an important genetic determinant of the large inter-individual variability in the postprandial TAG and insulin responses to dietary fat intake.

Commentary: not just genes - reclaiming a role for environmental influences on aetiology and outcome in autism. A commentary on Mandy and Lai (2016)

Mandy and Lai (2015) do the field a service in 'reclaiming' the role of pre- and postnatal environmental influences on the aetiology and course of autism spectrum conditions (ASC). This follows several decades where now discredited theories about putative psychogenic and biological disease models held sway, not least in the public mind. We discuss issues that arise from their review; including the need to identify how large the environmental influences on ASC are likely to be; the specificity of these environmental influences to ASC as opposed to a broader range of neurodevelopmental conditions and outcomes; how best to study complex interactions between genetic and environmental influences; and the promise of novel insights into their mechanisms of action. The review highlights current research that aims to better our understanding of the role of environmental factors in the aetiology and course of ASC and, in the near future, may offer the potential for personalised medicine approaches to intervention based on these discoveries.

A tillering inhibition gene influences root-shoot carbon partitioning and pattern of water use to improve wheat productivity in rainfed environments

Genetic modification of shoot and root morphology has potential to improve water and nutrient 19 uptake of wheat crops in rainfed environments. Near-isogenic lines (NILs) varying for a tillering 20 inhibition (tin) gene and representing multiple genetic backgrounds were investigated in contrasting 21 controlled environments for shoot and root growth. Leaf area, shoot and root biomass were similar 22 until tillering whereupon reduced tillering in tin-containing NILs produced reductions of up to 60% in 23 total leaf area and biomass, and increases in total root length of up to 120% and root biomass to 24 145%. Together, root-to-shoot ratio increased two-fold with the tin gene. The influence of tin on shoot 25 and root growth was greatest in the cv. Banks genetic background, particularly in the biculm-selected 26 NIL, and was typically strongest in cooler environments. A separate de-tillering study confirmed 27 greater root-to-shoot ratios with regular tiller removal in non-tin containing genotypes. In validating 28 these observations in a rainfed field study, the tin allele had a negligible effect on seedling growth but 29 was associated with significantly (P<0.05) reduced tiller number (-37%), leaf area index (-26%) and 30 spike number (-35%) to reduce plant biomass (-19%) at anthesis. Root biomass, root-to-shoot ratio at 31 early stem elongation and root depth at maturity were increased in tin-containing NILs. Soil water use 32 was slowed in tin-containing NILs resulting in greater water availability, greater stomatal 33 conductance, cooler canopy temperatures and maintenance of green leaf area during grain-filling. 34 Together these effects contributed to increases in harvest index and grain yield. In both the controlled 35 and field environments, the tin gene was commonly associated with increased root length and biomass 36 but the significant influence of genetic background and environment suggests careful assessment of 37 tin-containing progeny in selection for genotypic increases in root growth.

Ace gene dosage influences the development of renovascular hypertension

P>1. Clinical and experimental evidence highlights the importance of the renin-angiotensin system in renovascular hypertension. Furthermore, genetic factors affecting angiotensin-converting enzyme (ACE) could influence the development of renovascular hypertension. 2. To test the effect of small gene perturbations on the development of renovascular hypertension, mice harbouring two or three copies of the Ace gene were submitted to 4 weeks of two-kidney, one-clip (2K1C) hypertension. Blood pressure (BP), cardiac hypertrophy, baroreflex sensitivity and blood pressure and heart rate variability were assessed and compared between the different groups. 3. The increase in BP induced by 2K1C was higher in mice with three copies of the Ace gene compared with mice with only two copies (46 vs 23 mmHg, respectively). Moreover, there was a 3.8-fold increase in the slope of the left ventricle mass/BP relationship in mice with three copies of the Ace gene. Micewith three copies of the Ace gene exhibited greater increases in cardiac and serum ACE activity than mice with only two copies of the gene. Both baroreflex bradycardia and tachycardia were significantly depressed in mice with three copies of the Ace gene after induction of 2K1C hypertension. The variance in basal systolic BP was greater in mice with three copies of the Ace gene after 2K1C hypertension compared with those with only two copies of the gene (106 vs 54%, respectively). In addition, the low-frequency component of the pulse interval was higher mice with three copies of the Ace gene after 2K1C hypertension compared with those with only two (168 vs 86%, respectively). Finally, in mice with three copies of the Ace gene, renovascular hypertension induced a 6.1-fold increase in the sympathovagal balance compared with a 3.2-fold increase in mice with only two copies of the gene. 4. Collectively, these data provide direct evidence that small genetic disturbances in ACE levels per se have an influence on haemodynamic, cardiac mass and autonomic nervous system responses in mice under pathological perturbation.

Asthma Polymorphic Loci genotyping in Madeira population: identification of potential genetic markers of disease susceptibility, severity and clinical relevance

Asthma is a complex disease, influenced by both environmental and genetic factors. In this study, the analysis of multiple environmental factos assessed by questionnaire and the genotyping of SNPs IL131c.144 G/A, IL41590 C/T, IL41RP2 253183, ADRB21c.16 A/G, ADAM331V4 C/G, ADAM331S1 c.710 G/A, GSDML1236 C/T and STAT6121 C/T were performed in a sample of Madeiran asthmatic patients and their families, and their association to asthma susceptibility and severity was assessed. Family, environmental, social and individual factos such as the presence of rhinitis in one of the parents,the habitation conditions, the family smoking habits, individual food habits and allergen sensitivity, were found to account for asthma severity. IL41590*T and IL41RP2*183$ alleles as well as the combined genotypes IL41590*CT/IL41590*TT and IL41 RP2*253183/IL41RP2*253183 were associated to both asthma susceptibility and severity.GSDML1236*TT was found associated only to asthma severity.Allele ADAM331 V4*C was significantly overM transmitted to asthmatic offspring being linked with the disease by TDT. These findings suggest that in addition to environmental influences, IL41 590 C/T, IL41RP2 253183, ADAM331V4 C/G and GSDML1236 C/T SNPs may constitute important genetic factos contributing to asthmasusceptibility and/or severity in Madeira population.

Minimizing inter-genotypic competition effects to predict genetic values and selection in forestry genetic tests

The effect of competition is an important source of variation in breeding experiments. This study aimed to compare the selection of plants of open-pollinated families of Eucalyptus with and without the use of competition covariables. Genetic values were determined for each family and tree and for the traits height, diameter at breast height and timber volume in a randomized block design, resulting in the variance components, genetic parameters, selection gains, effective size and selection coincidence, with and without the use of covariables. Intergenotypic competition is an important factor of environmental variation. The use of competition covariables generally reduces the estimates of variance components and influences genetic gains in the studied traits. Intergenotypic competition biases the selection of open-pollinated eucalypt progenies, and can result in an erroneous choice of superior genotypes; the inclusion of covariables in the model reduces this influence.