Pestrost tipov ektomikorize v smrekovem sestoju na Pokljuki

Types of ectomycorrhizae were studied in soil cores from a young regeneration center in an autochthonous Norway spruce stand on Pokljuka (Triglav National Park, 1200 m.a.s.l.). Soil cores of equal volume (274 ml, 0 - 18 cm deep) weretaken from 33 sampling plots. In the samples all the roots were counted and types of ectomycorrhizae briefly characterized. From these data diversity indices (species diversity (d) and Shannon- Weaver index of diversity (H)) were calculated. Interactions among mycorrhizae, light regime and survival of spruce seedlings were studied. Out of about 50,000 root tips approximately 1 %were non-mycorrhizal, 63 % were old unviable mycorrhizae and 36 % were identifiable ectomycorrhizal root tips, forming 27 different types of ectomycorrhizae. Sixteen types of ectomycorrhizae were briefly characterized. The Shannon diversity index for types of ectomycorrhizae was high (3.13) with respect to the above-ground diversity of vegetation (1.7). The direct site factor was shown to be negatively correlated to ~Piceirhiza cornuta. The diffuse site factor was negatively correlated to Cortinarius sp. (obtusus type) and positively correlated to Inocybe sp. The ground vegetation cover waspositively correlated to Piceirhiza gelatinosa and the total vegetation cover to Elaphomyces sp.V majhni vrzeli domnevno avtohtonega smrekovega sestoja na Pokljuki (Triglavski narodni park) smo proučevali tipe ektomikorize na smreki. Vzorce tal smo jemali na 33. zvezdasto razporejenih vzorčnih ploskvicah s sondo prostornine 274 ml iz globine 0-18 cm. Iz vsakega vzorca smo izločili vse koreninice smreke, jih prešteli, ter na kratko opisali prisotni tip ektomikorize. Izračunali smo Indeks bogastva vrst (d) in Shannonov indeks pestrosti (H). Zanimal nas je vpliv ekoloških dejavnikov (svetlobnih razmer, naravnega pomlajevanja, zastiranja vegetacije) na porazdelitev tipov ektomikorize. Od skupno 50.000 korenin smreke je bilo približno 1 % nemikoriznih, 63 % je bilo nedoločljivih, pretežno starih tipov ektomikorize ter 36 % določljivih ektomikoriznih korenin, ki so skupaj tvorile 27 tipov ektomikorize. Predstavljenih je 16 kratkih opisov za do sedaj neopisane tipe ektomikorize. Shannonov indeks pestrosti za tipe ektomikorize (3,13) je visok glede na pestrost vegetacije (1,7). Ugotovili smo negativno korelacijo direktnega sončnega sevanja s tipom ~Piceirhiza cornuta. Difuzno sončno sevanje je v negativni odvisnosti s tipom Cortinarius sp. (obtusus tip) in v pozitivni odvisnosti s tipom Inocybe sp.. Zastiranje pritalne vegetacije je v pozitivni odvisnosti s tipom Piceirhiza gelatinosa, skupno zastiranje vegetacije pa je v pozitivni odvisnosti s tipom Elaphomyces sp

Inbreeding and osteoporosis in Croatian island isolates

The aim of this study was to investigate a recessive genetic component in susceptibility to osteoporosis (OP) by comparing its prevalence in isolated villages of three Croatian islands: Brač, Hvar and Korčula with different levels of inbreeding. A random sample of 20-30% adults from 14 villages was obtained, including a total of 1, 389 examinees. The average inbreeding coefficient (F) of examinees from each village population was estimated using Wright's path method (based on genealogical information), isonymy data and average deviation from Hardy-Weinberg expectations for classic set of serogenetic polymorphisms. The variation in environmental, cultural and socio-economic factors between villages was investigated and shown to be minimal. The morphometry of the metacarpal bones was performed on hand-wrist radiographs of both hands in all examinees. OP was defined as values of cortical index smaller than 2 standard deviations based on distribution of values in examinees of the same sex under 45 years of age. Mean values of cortical index (CI) and prevalence of OP (both standardized by age and weighted for the sample size) in each village were correlated to the mean inbreeding coefficient (F). The coefficient of correlation (r) between F values and CI was -0.28 in males (p=0.08) and -0.42 in females (p=0.005), and between F and OP prevalence 0.32 in males (p<0.001) and 0.43 in females (p<0.001). These results indicate a trend of increased susceptibility to osteoporosis with increasing level of inbreeding in isolated communities of Croatian islands

Holistic anthropological research of Hvar islanders, Croatia: from parish registries to DNA studies in 33 years

The complexity of interactions between hereditary, environmental and cultural factors in determining human phenotypes is often underestimated in biomedical research. It can be most clearly demonstrated when a well-defined human isolate population is considered and multiple measurements of phenotypes, genetic characteristics and studies of environmental and cultural determinants are performed and analysed. Even in such small communities, where decreased variability in all those factors is presumed, it is often apparent how difficult it is to disentangle the effects of separate interacting factors and explain most of the variance in phenotypes of interest. In this paper, we present 33 years of holistic anthropological research that was being conducted since 1971 in the island of Hvar, Croatia. During this period, detailed characterisation of migrations, demography, isonymy, linguistic differences, anthropometric traits (head and body dimensions), physiological (cardiorespiratory) properties, quantitative and qualitative dermatoglyphic traits, radiogrammetric metacarpal bone dimensions and genetic traits (erythrocyte antigens, HLA diversity, DNA short tandem repeat (STR), mitochondrial DNA and Y-chromosome polymorphysms) was performed. The analysis of this large collection of data using both model-bound and model-free approaches showed that the complexity underlying human biological traits may be considerably greater than generally assumed, which has important implications for design of future studies into genetic determinants of complex traits

The Eysenck personality factors: psychometric structure, reliability, heritability and phenotypic and genetic correlations with psychological distress in an isolated Croatian population

We report the psychometric structure of a Croatian translation of the Eysenck Personality Questionnaire-Revised (short-form), its correlations with psychological distress (General Health Questionnaire-30), its heritability, and personality–psychological distress genetic correlations. The setting is a large (≈1000), family-based sample of men and women from an isolated Croatian island. The neuroticism and extraversion traits and the lie scale showed good psychometric characteristics. The translated psychoticism scale was unsatisfactory in this sample. It had a very low internal consistency, probably due in part to heavily biased item responses. There were significant additive genetic contributions to variation in neuroticism, extraversion, and psychological distress. Psychological distress had a very high genetic correlation with neuroticism, and a moderate genetic correlation with extraversion

Inbreeding and Susceptibility to Osteoporosis in Croatian Island Isolates

The aim of this study was to investigate a recessive genetic component in susceptibility to osteoporosis (OP) by comparing its prevalence in isolated villages of three Croatian islands: Brač, Hvar and Korčula with different levels of inbreeding. A random sample of 20–30% adults from 14 villages was obtained, including a total of 1,389 examinees. The average inbreeding coefficient (F) of examinees from each village population was estimated using Wright’s path method (based on genealogical information). The morphometry of the metacarpal bones was performed on hand-wrist radiographs of both hands in all examinees. OP was defined as values of cortical index smaller than 2 standard deviations based on distribution of values in examinees of the same sex under 45 years of age. Mean values of cortical index (CI) and prevalence of OP (both standardized by age and weighted for the sample size) in each village were correlated to the mean inbreeding coefficient (F). The coefficient of correlation ® between F values and CI was –0.28 in males (p=0.08) and –0.42 in females (p=0.005), and between F and OP prevalence 0.32 in males (p<0.001) and 0.43 in females (p<0.001). These results indicate a trend of increased susceptibility to osteoporosis with increasing level of inbreeding in isolated communities of Croatian islands

Holistic Anthropological Research of Hvar Islanders, Croatia – From Parish Registries to DNA Studies in 33 Years

The complexity of interactions between hereditary, environmental and cultural factors in determining human phenotypes is often underestimated in biomedical research. In this paper, we present 33 years of holistic anthropological research that was being conducted since 1971 in the island of Hvar, Croatia. During this period, detailed characterization of migrations, demography, isonymy, linguistic differences, anthropometric traits (head and body dimensions), physiological (cardio-respiratory) properties, quantitative and qualitative dermatoglyphic traits, radiogrammetric metacarpal bone dimensions and genetic traits (classical antigens, HLA diversity, DNA short tandem repeat -STR, mitochondrial DNA and Y-chromosome polymorphisms) was performed. The analysis of this large collection of data using both model-bound and model-free approaches showed that the complexity underlying human biological traits may be considerably greater than generally assumed, which has important implications for design of future studies into genetic determinants of complex traits

New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk

To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P<5 × 10−8), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk

New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk

To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P <5 x 10(-8)), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk.Peer reviewe