LARVAL INSTARS AND IMMATURE DEVELOPMENT OF A BRAZILIAN POPULATION OF PHARAOHS ANT, MONOMORIUM-PHARAONIS (L) (HYM, FORMICIDAE)

The immature development of pharaoh's ant, Monomorium pharaonis, workers was s died in a naturally collected Brazilian population. Three larval instars were confirmed by measuring maximal cephalic widths in cohorts of known age. Minimum egg to adult duration was 25 days, while the maximum duration was 54 days, both of which are larger than those reported for European populations. Larval instar development is cyclical at the colony level, suggesting reproductive bursts followed by lower reproductive activity of the queens.

REPRODUCTIVE STRATEGIES OF THE EXOTIC PHARAOH ANT, MONOMORIUM-PHARAONIS (L) (HYMENOPTERA, FORMICIDAE) IN BRAZIL

The production of sexual forms in laboratory colonies of Monomorium pharaonis was followed over a 19-month period. Cycles of production occurred at intervals of 4 months, with male investment inversely proportional to the number of gynes produced. There was a tendency for colonies to produce only males or females as total sexual production increased. Sperm counts of known-aged males suggest that they mate twice, in contrast to European populations. Sex-ratio was heavily female-biased, contrary to predictions for polygynous ant species.

Prevalence of hereditary risk factors for thrombophilia in Belém, Brazilian Amazon

Different risk factors for venous thromboembolism (VTE) have been identified, including hereditary abnormalities in the mechanisms of coagulation and fibrinolysis. We investigated five genetic polymorphisms (FVL G1691A, FII G20210A, MTHFR C677T, TAFI A152G and TAFI T1053C) associated with VTE in individuals from the city of Belém in the Brazilian Amazon who had no history of VTE. No significant difference was found between the observed and expected genotype frequencies for the loci analyzed. We found high frequencies of MTHFR C677T (33.9%) and TAFI T1053C (74%) and low frequencies of FVL (1.6%), FII G20210A (0.8%) and TAFI A152G (0.8%). The FVL G1691A, FII G20210A and MTHFR C677T frequencies were similar to those for European populations and populations of European descent living in the city of Ribeirão Preto in the Brazilian state of São Paulo. The frequency of the two TAFI mutations in the Belém individuals was not significantly different from that described for individuals from Ribeirão Preto. We suggest that the risks for VTE in the population of Belém are of the same magnitude as that observed in European populations and in populations with an expressive European contribution.

Ethnicity and Cutaneous Melanoma in the City of Sao Paulo, Brazil: A Case-Control Study

Background: Over the last century the incidence of cutaneous melanoma has increased worldwide, a trend that has also been observed in Brazil. The identified risk factors for melanoma include the pattern of sun exposure, family history, and certain phenotypic features. In addition, the incidence of melanoma might be influenced by ethnicity. Like many countries, Brazil has high immigration rates and consequently a heterogenous population. However, Brazil is unique among such countries in that the ethnic heterogeneity of its population is primarily attributable to admixture. This study aimed to evaluate the contribution of European ethnicity to the risk of cutaneous melanoma in Brazil. Methodology/Principal Findings: We carried out a hospital-based case-control study in the metropolitan area of Sao Paulo, Brazil. We evaluated 424 hospitalized patients (202 melanoma patients and 222 control patients) regarding phenotypic features, sun exposure, and number of grandparents born in Europe. Through multivariate logistic regression analysis, we found the following variables to be independently associated with melanoma: grandparents born in Europe-Spain (OR = 3.01, 95% CI: 1.03-8.77), Italy (OR = 3.47, 95% CI: 1.41-8.57), a Germanic/Slavic country (OR = 3.06, 95% CI: 1.05-8.93), or >= 2 European countries (OR = 2.82, 95% CI: 1.06-7.47); eye color-light brown (OR = 1.99, 95% CI: 1.14-3.84) and green/blue (OR = 4.62; 95% CI 2.22-9.58); pigmented lesion removal (OR = 3.78; 95% CI: 2.21-6.49); no lifetime sunscreen use (OR = 3.08; 95% CI: 1.03-9.22); and lifetime severe sunburn (OR = 1.81; 95% CI: 1.03-3.19). Conclusions: Our results indicate that European ancestry is a risk factor for cutaneous melanoma. Such risk appears to be related not only to skin type, eye color, and tanning capacity but also to others specific characteristics of European populations introduced in the New World by European immigrants.

Diversity of the KIR gene cluster in an urban Brazilian population

The activity of natural killer cells depends on the balance between activating and inhibitory signals coming from their receptors. Among these are the killer cell immunoglobulin-like receptors (KIR) that recognize specific HLA class I allotypes. Here we characterized KIR genetic diversity and their HLA ligands in the population of Curitiba, Parana State (n = 164), and compared it with other worldwide populations. The distribution of 2DL4 alleles was also analyzed. The Curitiba population did not differ significantly from European and Euro-descendant populations, but as an admixed population showed higher genetic diversity. We found 27 KIR profiles, many of them uncommon in European populations, in agreement with the elevated historically recent gene flow in the study population. The frequencies of KIR genes and their respective HLA ligands were distributed independently and none of the analyzed individuals lacked functional KIR-HLA ligand combinations. KIR gene frequencies of 33 worldwide populations were consistent with geographic and ethnic distribution, in agreement with demography being the major factor shaping the observed gene content diversity of the KIR locus.

Brazilian urban population genetic structure reveals a high degree of admixture

Advances in genotyping technologies have contributed to a better understanding of human population genetic structure and improved the analysis of association studies. To analyze patterns of human genetic variation in Brazil, we used SNP data from 1129 individuals - 138 from the urban population of Sao Paulo, Brazil, and 991 from 11 populations of the HapMap Project. Principal components analysis was performed on the SNPs common to these populations, to identify the composition and the number of SNPs needed to capture the genetic variation of them. Both admixture and local ancestry inference were performed in individuals of the Brazilian sample. Individuals from the Brazilian sample fell between Europeans, Mexicans, and Africans. Brazilians are suggested to have the highest internal genetic variation of sampled populations. Our results indicate, as expected, that the Brazilian sample analyzed descend from Amerindians, African, and/or European ancestors, but intermarriage between individuals of different ethnic origin had an important role in generating the broad genetic variation observed in the present-day population. The data support the notion that the Brazilian population, due to its high degree of admixture, can provide a valuable resource for strategies aiming at using admixture as a tool for mapping complex traits in humans. European Journal of Human Genetics (2012) 20, 111-116; doi:10.1038/ejhg.2011.144; published online 24 August 2011

Region 8q24 Is a Susceptibility Locus for Nonsyndromic Oral Clefting in Brazil

BACKGROUND: Nonsyndromic cleft lip with or without cleft palate is a relatively common craniofacial defect with multifactorial inheritance. The association of the rs987525 single nucleotide variant, located in a gene desert at 8q24.21 region, has been consistently replicated in European populations. We performed a structured association approach combined with transcriptional analysis of the MYC gene to dissect the role of rs987525 in oral clefting susceptibility in the ethnically admixed Brazilian population. METHODS: We performed the association study conditioned on the individual ancestry proportions in a sample of 563 patients and 336 controls, and in an independent sample of 221 patients and 261 controls. The correlation between rs987525 genotypes and MYC transcriptional levels in orbicularis oris muscle mesenchymal stem cells was also investigated in 42 patients and 4 controls. RESULTS: We found a significant association in the larger sample (p = 0.0016; OR = 1.80 [95% confidence interval {CI}, 1.21-2.69], for heterozygous genotype, and 2.71 [95% CI, 1.47-4.96] for homozygous genotype). We did not find a significant correlation between rs987525 genotypes and MYC transcriptional levels (p = 0.14; r = -0.22, Spearman Correlation). CONCLUSIONS: We present a positive association of rs987525 in the Brazilian population for the first time, and it is likely that the European contribution to our population is driving this association. We also cannot discard a role of rs987515 in MYC regulation, because this locus behaves as an expression quantitative locus of MYC in another tissue. Birth Defects Research (Part A) 94:464-468, 2012. (C) 2012 Wiley Periodicals, Inc.

The genetic signature of Neolithic in Greece

The Neolithic is characterized by the transition from a subsistence economy, based on hunting and gathering, to one based on food producing. This important change was paralleled by one of the most significant demographic increase in the recent history of European populations. The earliest Neolithic sites in Europe are located in Greece. However, the debate regarding the colonization route followed by the Middle-eastern farmers is still open. Based on archaeological, archaeobotanical, craniometric and genetic data, two main hypotheses have been proposed. The first implies the maritime colonization of North-eastern Peloponnesus from Crete, whereas the second points to an island hopping route that finally brought migrants to Central Greece. To test these hypotheses using a genetic approach, 206 samples were collected from the two Greek regions proposed as the arrival point of the two routes (Korinthian district and Euboea). Expectations for each hypothesis were compared with empirical observations based on the analysis of 60 SNPs and 26 microsatellite loci of Y-chromosome and mitochondrial DNA hypervariable region I. The analysis of Y-chromosome haplogroups revealed a strong genetic affinity of Euboea with Anatolian and Middle-eastern populations. The inferences of the time since population expansion suggests an earlier usage of agriculture in Euboea. Moreover, the haplogroup J2a-M410, supposed to be associated with the Neolithic transition, was observed at higher frequency and variance in Euboea showing, for both these parameters, a decreasing gradient moving from this area. The time since expansion estimates for J2a-M410 was found to be compatible with the Neolithic and slightly older in Euboea. The analysis of mtDNA resulted less informative. However, a higher genetic affinity of Euboea with Anatolian and Middle-eastern populations was confirmed. These results taken as a whole suggests that the most probable route followed by Neolithic farmers during the colonization of Greece was the island hopping route.

Populationsgenetik kupfer- und bronzezeitlicher Bevölkerungen der osteuropäischen Steppe

Mit der vorliegenden Arbeit wurden erstmals prähistorische Bevölkerungsstrukturen in der osteuropäischen Steppe von der Oberthrakischen Tiefebene bis zur Wolga populationsgenetisch untersucht. Mit Multiplex-PCR und 454-Sequencing wurden von 65 kupfer- und bronzezeitlichen Individuen die Hypervariable Region I und 30 Abschnitte der coding region der mitochondrialen DNA analysiert. Außerdem wurden bis zu 20 putativ selektierte autosomale SNPs und ein geschlechtsspezifischer Locus genotypsiert. Zu Vergleichszwecken wurden veröffentlichte prähistorische DNA-Daten aus Westeurasien und moderne DNA-Sequenzen herangezogen. Die Ergebnisse stützen die Annahme, dass frühneolithische Bauern aus Südosteuropa durch demische Diffusion an der Etablierung der Viehwirtschaft in der Steppe beteiligt waren. Die durchweg niedrigen FST-Werte zwischen der frühbronzezeitlichen Jamnaja-Kultur in der Steppe und den aufeinanderfolgenden neolithischen Kulturen Mitteleuropas sprechen für regelmäßige Kontakte. Die der Jamnaja-Kultur nachfolgende Katakombengrabkultur ist von einem hohen Anteil der in nord- und osteuropäischen Jäger/Sammler-Populationen verbreiteten Haplogruppe U4 geprägt. Niedrige FST-Werte zwischen den prähistorischen Steppenpopulationen und der heutigen Bevölkerung Mittel- und Osteuropas weisen auf genetische Kontinuität hin. Die nukleären Genotypenfrequenzen bestätigt dies. Der moderne europäische Genpool lässt sich nach aktuellem Kenntnisstand auf drei Wurzeln zurückführen: indigene Mesolithiker, frühe Bauern aus dem Nahen Osten und eine nordeurasische Komponente jungpalaeolithischen Ursprungs. Letztere könnte vielleicht über die nordpontische Population in das Erbgut spätneolithischer Europäer gelangt sein.

Die Expression und Regulation der CYP3A in menschlicher Haut

In Leber und Dünndarm bauen CYP3A-Enzyme eine Vielzahl von Fremdstoffen ab, die in den Körper gelangt sind. Zudem aber sind diese Enzyme auch in anderen Organen, wie der Haut exprimiert. Doch weder die genaue Zusammensetzung der CYP3A-Isozyme noch deren physiologische Rolle in der Haut sind bisher bekannt. Basierend auf begrenzten in vitro-Daten ist eine Rolle der CYP3A in der kutanen Vitamin D-Synthese denkbar. Auf der anderen Seite könnten die kutanen CYP3A auch lokal oder systemisch verabreichte Medikamente in der Haut verstoffwechseln und so zur Entstehung immunologischer und nicht-immunologischer unerwünschter Arzneimittelwirkungen beitragen, von denen sich bis zu 45 % in der Haut manifestieren.rnDie Arbeitshypothese dieses Projekts war, dass die CYP3A die kutane Synthese von Vitamin D regulieren. In dieser Funktion wurden sie zur Vermeidung von Vitamin D-Mangel-Erkrankungen wie Rachitis oder Osteomalazie in Europäern negativ selektiert. rnDie Expression und Regulation der CYP3A wurde in Hautbiopsien, einer Zelllinie epidermalen Ursprungs und primären Hautzellen wie auch in transgenen Mäusen untersucht. Die metabolische Aktivität der CYP3A gegenüber den kutanen Vitamin D-Vorstufen wurde mit Hilfe rekombinant exprimierter Enzyme untersucht. CYP3A5-mRNA war die häufigste der CYP3A in humanen Hautproben und überstieg die von CYP3A4 um das Dreifache, die von CYP3A7 um das 130-Fache. Damit entsprach diese 1,3 %, 0,01 % bzw. 0,01 % der jeweiligen hepatischen Genexpression. Die Expression von CYP3A43 war zu vernachlässigen. CYP3A5 zeigte eine bimodale Expression sowohl auf mRNA- als auch auf Proteinebene. So zeigten Träger der Wildtyp-Allels *1 eine 3,3-fach höhere mRNA- und 1,8-fach höhere Proteinmenge als homozygote Träger des Nullallels *3. CYP3A4/7- und CYP3A5-Protein wurde v. a. in den Keratinozyten der Epidermis und den Talgdrüsen, also den Bereichen der kutanen Vitamin D-Synthese lokalisiert. Die CYP3A5-Expression wurde ferner in der Haut transgener Mäusen gezeigt, die das Reportergen Luziferase unter Kontrolle des humanen CYP3A5-Promoters exprimieren. Verglichen mit der Leber war die kutane Expression des Vitamin D-Rezeptors (VDR) 100-fach höher, die der Xenosensoren CAR und PXR vergleichbar bzw. zu vernachlässigen. Dementsprechend erhöhte die Behandlung mit 1,25-Dihydroxyvitamin D, dem aktiven Vitamin D-Hormon, und dessen Vorstufen außer 7-Dehydrocholesterol, jedoch nicht der PXR-Ligand Rifampicin, die Expression der CYP3A. Wie in Zwei-Hybrid-Experimenten gezeigt, wurden die Effekte des 1,25-Dihydroxyvitamin D und dessen Vorstufen alleinig durch VDR vermittelt. Die Effektstärke hingegen war abhängig von Zellspender, Zellpassage und Zelltypus. Alle drei CYP3A-Isozyme metabolisieren Vitamin D zu einem oder mehreren unbekannten Metaboliten, jedoch nicht zu 25-Hydroxyvitamin D, dem direkten Vorläufer des aktiven Vitamin D. rnZusammengefasst legen die Daten nahe, dass die kutanen CYP3A, allen voran CYP3A5, die Vitamin D-Homöostase durch VDR-vermittelte Induktion des Abbaus von Vitamin D-Vorstufen regulieren. Dies zusammen mit Sequenzdaten liefert starke Indizien für Vitamin D als treibende Kraft der Selektion des CYP3A-Lokus in Europäern. Der Einfluss der CYP3A-Expression auf selektiv wirksame, klinisch relevante Knochenveränderungen wie Rachitis oder Osteomalazie müssen folgen.rn

Phylogeny and phylogeography of the family Hyalidae (Crustacea: Amphipoda) along the northeast Atlantic coasts

The family Hyalidae comprises more than one hundred species, distributed worldwide. They are common and abundant in the littoral and shallow sublittoral habitats and they play an important role in the coastal food chain. Most studies about this family were dealing with taxonomy and ecology, while very little is known about phylogenetic relationship among genera and species. In the present study we aim to achieve the first approach of the phylogenetic patterns of this family in NE Atlantic Ocean and Mediterranean Sea, and to perform the first insight into the phylogeography Apohyale prevostii along both the North Atlantic coasts. In order to do that, eight species belonging to the genera Apohyale, Hyale, Serejohyale and Protohyale were investigated using the mitochondrial COI-5P barcode region. Specimens were collected along European and Moroccan Atlantic rocky shores, including Iceland, the British Isles, Macaronesia and in the Mediterranean Sea. Sequences of A. prevostii, from the NW Atlantic Ocean, available in BOLD and GenBank, were retrieved. As expected, phylogenetic analyses showed highly-divergent clades, clearly discriminating among different species clusters, confirming their morphology-based identifications. Although, within A. perieri, A. media, A. stebbingi, P. (Protohyale) schmidtii and S. spinidactylus, high genetic diversity was found, revealing putative cryptic species. The clade of A. prevostii and A. stebbingi appears well supported and divided from the other two congeneric species, and P. (Protohyale) schmidtii shows a basal divergence. The north-western Atlantic coasts were recently colonized by A. prevostii after the last glacial maximum from the European populations showing also a common haplotype in every population analysed. The use of the COI-5P as DNA barcode provided a good tool to underline the necessity of a revision of this emblematic family, as well as to discern taxonomically the possible new species flagged with this molecular device.

HLA-A*3101 and carbamazepine-induced hypersensitivity reactions in Europeans

Carbamazepine causes various forms of hypersensitivity reactions, ranging from maculopapular exanthema to severe blistering reactions. The HLA-B*1502 allele has been shown to be strongly correlated with carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS-TEN) in the Han Chinese and other Asian populations but not in European populations.

Keratin 8 sequence variants in patients with pancreatitis and pancreatic cancer

Keratin 8 (KRT8) is one of the major intermediate filament proteins expressed in single-layered epithelia of the gastrointestinal tract. Transgenic mice over-expressing human KRT8 display pancreatic mononuclear infiltration, interstitial fibrosis and dysplasia of acinar cells resulting in exocrine pancreatic insufficiency. These experimental data are in accordance with a recent report describing an association between KRT8 variations and chronic pancreatitis. This prompted us to investigate KRT8 polymorphisms in patients with pancreatic disorders. The KRT8 Y54H and G62C polymorphisms were assessed in a cohort of patients with acute and chronic pancreatitis of various aetiologies or pancreatic cancer originating from Austria (n=16), the Czech Republic (n=90), Germany (n=1698), Great Britain (n=36), India (n=60), Italy (n=143), the Netherlands (n=128), Romania (n=3), Spain (n=133), and Switzerland (n=129). We also studied 4,234 control subjects from these countries and 1,492 control subjects originating from Benin, Cameroon, Ethiopia, Ecuador, and Turkey. Polymorphisms were analysed by melting curve analysis with fluorescence resonance energy transfer probes. The frequency of G62C did not differ between patients with acute or chronic pancreatitis, pancreatic adenocarcinoma and control individuals. The frequency of G62C varied in European populations from 0.4 to 3.8%, showing a northwest to southeast decline. The Y54H alteration was not detected in any of the 2,436 patients. Only 3/4,580 (0.07%) European, Turkish and Indian control subjects were heterozygous for Y54H in contrast to 34/951 (3.6%) control subjects of African descent. Our data suggest that the KRT8 alterations, Y54H and G62C, do not predispose patients to the development of pancreatitis or pancreatic cancer.

Do common genetic variants in endotoxin signaling pathway contribute to predisposition to alcoholic liver cirrhosis?

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), produced by endotoxin-activated Kupffer cells, play a key role in the pathogenesis of alcoholic liver cirrhosis (ALC). Alleles TNFA -238A, IL1B -31T and variant IL1RN*2 of repeat polymorphism in the gene encoding the IL-1 receptor antagonist increase production of TNF-alpha and IL-1beta, respectively. Alleles CD14 -159T, TLR4 c.896G and TLR4 c.1196T modify activation of Kupffer cells by endotoxin. We confirmed the published associations between these common variants and genetic predisposition to ALC by means of a large case-control association study conducted on two Central European populations. METHODS: The study population comprised a Czech sample of 198 ALC patients and 370 controls (MONICA project), and a German sample of 173 ALC patients and 331 controls (KORA-Augsburg), and 109 heavy drinkers without liver disease. RESULTS: Single locus analysis revealed no significant difference between patients and controls in all tested loci. Diplotype [IL1RN 2/ 2; IL1B -31T+] was associated with increased risk of ALC in the pilot study, but not in the validation samples. CONCLUSIONS: Although cytokine mediated immune reactions play a role in the pathogenesis of ALC, hereditary susceptibility caused by variants in the corresponding genes is low in Central European populations.

Comparative genetic analyses point to HCP5 as susceptibility locus for HCV-associated hepatocellular carcinoma

BACKGROUND & AIMS: Recently, genetic variations in MICA (lead single nucleotide polymorphism [SNP] rs2596542) were identified by a genome-wide association study (GWAS) to be associated with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) in Japanese patients. In the present study, we sought to determine whether this SNP is predictive of HCC development in the Caucasian population as well. METHODS: An extended region around rs2596542 was genotyped in 1924 HCV-infected patients from the Swiss Hepatitis C Cohort Study (SCCS). Pair-wise correlation between key SNPs was calculated both in the Japanese and European populations (HapMap3: CEU and JPT). RESULTS: To our surprise, the minor allele A of rs2596542 in proximity of MICA appeared to have a protective impact on HCC development in Caucasians, which represents an inverse association as compared to the one observed in the Japanese population. Detailed fine-mapping analyses revealed a new SNP in HCP5 (rs2244546) upstream of MICA as strong predictor of HCV-related HCC in the SCCS (univariable p=0.027; multivariable p=0.0002, odds ratio=3.96, 95% confidence interval=1.90-8.27). This newly identified SNP had a similarly directed effect on HCC in both Caucasian and Japanese populations, suggesting that rs2244546 may better tag a putative true variant than the originally identified SNPs. CONCLUSIONS: Our data confirms the MICA/HCP5 region as susceptibility locus for HCV-related HCC and identifies rs2244546 in HCP5 as a novel tagging SNP. In addition, our data exemplify the need for conducting meta-analyses of cohorts of different ethnicities in order to fine map GWAS signals.