Whole-Genome Sequencing Reveals a Novel Pathogenic GRIN2B Variant in a Patient with Neurodevelopmental Disorder and an inv(6)(p24p11.2)pat.

INTRODUCTION: Neurodevelopmental disorders (NDDs) are diverse and can be explained by either genomic aberrations or single nucleotide variants. Most likely due to methodological approaches and/or disadvantages, the concurrence of both genetic events in a single patient has hardly been reported and even more rarely the pathogenic variant has been regarded as the cause of the phenotype when a chromosomal alteration is initially identified. CASE PRESENTATION: Here, we describe a NDD patient with a 6p nonpathogenic paracentric inversion paternally transmitted and a de novo pathogenic variant in the GRIN2B gene. Molecular-cytogenetic studies characterized the familial 6p inversion and revealed a paternal 9q inversion not transmitted to the patient. Subsequent whole-genome sequencing in the patient-father dyad corroborated the previous findings, discarded inversions-related cryptic genomic rearrangements as causative of the patient's phenotype, and unveiled a novel heterozygous GRIN2B variant (p.(Ser570Pro)) only in the proband. In addition, Sanger sequencing ruled out such a variant in her mother and thereby confirmed its de novo origin. Due to predicted disturbances in the local secondary structure, this variant may alter the ion channel function of the M1 transmembrane domain. Other pathogenic variants in GRIN2B have been related to the autosomal dominant neurodevelopmental disorder MRD6 (intellectual developmental disorder, autosomal dominant 6, with or without seizures), which presents with a high variability ranging from mild intellectual disability (ID) without seizures to a more severe encephalopathy. In comparison, our patient's clinical manifestations include, among others, mild ID and brain anomalies previously documented in subjects with MRD6. CONCLUSION: Occasionally, gross chromosomal abnormalities can be coincidental findings rather than a prime cause of a clinical phenotype (even though they appear to be the causal agent). In brief, this case underscores the importance of comprehensive genomic analysis in unraveling the wide-ranging genetic causes of NDDs and may bring new insights into the MRD6 variability.

New plastome structural rearrangements discovered in core Tillandsioideae (Bromeliaceae) support recently adopted taxonomy.

Full plastome sequences for land plants have become readily accessible thanks to the development of Next Generation Sequencing (NGS) techniques and powerful bioinformatic tools. Despite this vast amount of genomic data, some lineages remain understudied. Full plastome sequences from the highly diverse (>1,500 spp.) subfamily Tillandsioideae (Bromeliaceae, Poales) have been published for only three (i.e., Guzmania, Tillandsia, and Vriesea) out of 22 currently recognized genera. Here, we focus on core Tillandsioideae, a clade within subfamily Tillandsioideae, and explore the contribution of individual plastid markers and data categories to inform deep divergences of a plastome phylogeny. We generated 37 high quality plastome assemblies and performed a comparative analysis in terms of plastome structure, size, gene content and order, GC content, as well as number and type of repeat motifs. Using the obtained phylogenetic context, we reconstructed the evolution of these plastome attributes and assessed if significant shifts on the evolutionary traits' rates have occurred in the evolution of the core Tillandsioideae. Our results agree with previously published phylogenetic hypotheses based on plastid data, providing stronger statistical support for some recalcitrant nodes. However, phylogenetic discordance with previously published nuclear marker-based hypotheses was found. Several plastid markers that have been consistently used to address phylogenetic relationships within Tillandsioideae were highly informative for the retrieved plastome phylogeny and further loci are here identified as promising additional markers for future studies. New lineage-specific plastome rearrangements were found to support recently adopted taxonomic groups, including large inversions, as well as expansions and contractions of the inverted repeats. Evolutionary trait rate shifts associated with changes in size and GC content of the plastome regions were found across the phylogeny of core Tillandsioideae.

Karyotype Evolution of Talking Thorny Catfishes Anadoras (Doradidae, Astrodoradinae): A Process Mediated by Structural Rearrangements and Intense Reorganization of Repetitive DNAs.

Anadoras is a thorny catfish genus widespread through the Amazon and Paraguay river basins. It includes 2 nominal species, A. grypus and A. weddellii, plus Anadoras sp. "araguaia," an undescribed species only recognized morphologically. Since Anadoras occupies a basal position within the Astrodoradinae phylogeny, it is crucial to identify its cytogenetic features to comprehend the mechanisms involved in the chromosomal diversification of this subfamily. Therefore, we performed a comparative cytogenetic analysis including all species of Anadoras. Furthermore, we applied a species delimitation analysis based on 600 bp of the mitochondrial cytochrome oxidase subunit 1 (CO1) gene to investigate the taxonomic status of the species. Cytogenetic markers revealed a high degree of similarity among Anadoras weddellii and Anadoras sp. "araguaia," both have 2n = 56 chromosomes (24m + 10sm + 22st/a), single NOR sites on acrocentric pair 28, and 5S rDNA sites on submetacentric pair 15. A. grypus has the most divergent chromosomal characteristics because, even though it also has 2n = 56 chromosomes, it exhibits several differences in the chromosome formula, heterochromatin distribution, and number/position of the rDNA sites. In sum, we believe that the chromosome diversification of Anadoras is due to 4 mechanisms: centric fusion, pericentric/paracentric inversions, nonreciprocal translocations, and activity of transposable elements. Additionally, our phylogenetic tree revealed well-supported clades and, by barcode species delimitation analysis, confirmed the existence of 3 molecular operational taxonomic units, including the putative new species Anadoras sp. "araguaia."

Health and the Megacity: Urban Congestion, Air Pollution, and Birth Outcomes in Brazil.

We studied the health effects of economic development in heavily urbanized areas, where congestion poses a challenge to environmental conditions. We employed detailed data from air pollution and birth records around the metropolitan area of São Paulo, Brazil, between 2002 and 2009. During this period, the megacity experienced sustained growth marked by the increases in employment rates and ownership of durable goods, including automobiles. While better economic conditions are expected to improve infant health, air pollution that accompanies it is expected to do the opposite. To untangle these two effects, we focused on episodes of thermal inversion-meteorological phenomena that exogenously lock pollutants closer to the ground-to estimate the causal effects of in utero exposure to air pollution. Auxiliary results confirmed a positive relationship between thermal inversions and several air pollutants, and we ultimately found that exposure to inversion episodes during the last three months of pregnancy led to sizable reductions in birth weight and increases in the incidence of preterm births. Increased pollution exposure induced by inversions also has a significant impact over fetal survival as measured by the size of live-birth cohorts.

Genetic analysis for carrier diagnosis in hemophilia A and B in the Mexican population: 25 years of experience.

Our 25 years of experience in carrier diagnosis of hemophilia A (HA) and B (HB) in Mexican population comprises linkage analysis of intragenic F8/F9 neutral variants along with, in severe HA (SHA), detection of F8 int22h and int1h inversions. In symptomatic carriers (SCs) we explored Lyonization to explain their symtomatology. From a DNA-Bank of 3,000 samples, intragenic restriction fragment length (RFLPs) and short tandem repeats (STRs) of F8/F9 genes were assessed by PCR-PAGE and GeneScan. In SHA patients, F8 inversions were detected by inverse shifting-PCR/diagnostic and complementary tests. In SCs, we evaluated hemorrhagic symptoms, clotting FVIII/FIX and X-chromosome inactivation (XCI) patterns were assessed by HUMARA assay and the search of XIST promoter pathogenic variants. Informativeness of linkage analysis for HA carrier diagnosis with RFLP's/STR's increased to 74% and reached 80% with five RFLPs for HB. Combined Inv22/Inv1 diagnosed 113 possible carriers, three de novo Inv22-1, and confirmed 45 mothers as obligate or sporadic carriers. Among 21 SCs, four showed extreme skewed XCI pattern (~80:20) but had normal karyotype and no C43G pathogenic variant in XIST promoter. Clotting FVIII/FIX correlated with the active X in leukocytes. Our data integrate the largest comprehensive research worldwide on the molecular diagnosis of HA and HB carriers in terms of the number of studied and diagnosed cases, in addition to the genetic analysis in SCs. Intragenic RFLPs and STRs of F8/F9 genes along with F8 int22h/int1h inversions in SHA emerge as optimal variants for molecular diagnosis in Mexican population. In counseling SCs, inheritance of skewed X-inactivation should be considered.

Long-range forces and charge inversions in model charged colloidal dispersions at finite concentration.

In charged colloidal dispersion systems the interest is in finding their stability conditions, phase transitions, and transport properties, either in bulk or confinement, among other physicochemical quantities, for which the knowledge of the dispersions' molecular structure and the associated macroion-macroion forces is crucial. To investigate these phenomena simple models have been proposed. Most of the theoretical and simulation studies on charged particles suspensions are at infinite dilution conditions. Hence, these studies have been focused on the electrolyte structure around one or two isolated central particle(s), where phenomena as charge reversal, charge inversion and surface charge amplification have been shown to be relevant. However, experimental studies at finite volume fraction exhibit interesting phenomenology which imply very long-range correlations. A simple, yet useful, model is the Colloidal Primitive Model, in which the colloidal dispersion is modeled as a mixture of size (and charge) asymmetrical hard spheres, at finite volume fraction. In this paper we review recent integral equations solutions for this model, where very long-range attractive-repulsive forces, as well as new long-range, giant charge inversions are reported. The calculated macroions radial distribution functions, charge distributions, and macroion-macroion forces are qualitatively consistent with existing experimental results, and Monte Carlo and molecular dynamics simulations.

Divergence with gene flow is driven by local adaptation to temperature and soil phosphorus concentration in teosinte subspecies (Zea mays parviglumis and Zea mays mexicana).

Patterns of genomic divergence between hybridizing taxa can be heterogeneous along the genome. Both differential introgression and local adaptation may contribute to this pattern. Here, we analysed two teosinte subspecies, Zea mays ssp. parviglumis and ssp. mexicana, to test whether their divergence has occurred in the face of gene flow and to infer which environmental variables have been important drivers of their ecological differentiation. We generated 9,780 DArTseqTM SNPs for 47 populations, and used an additional data set containing 33,454 MaizeSNP50 SNPs for 49 populations. With these data, we inferred features of demographic history and performed genome wide scans to determine the number of outlier SNPs associated with climate and soil variables. The two data sets indicate that divergence has occurred or been maintained despite continuous gene flow and/or secondary contact. Most of the significant SNP associations were to temperature and to phosphorus concentration in the soil. A large proportion of these candidate SNPs were located in regions of high differentiation that had been identified previously as putative inversions. We therefore propose that genomic differentiation in teosintes has occurred by a process of adaptive divergence, with putative inversions contributing to reduced gene flow between locally adapted populations.

Exploring atmospheric stagnation during a severe particulate matter air pollution episode over complex terrain in Santiago, Chile.

A severe air quality degradation event occurred in the Santiago Metropolitan Area (SMA), Chile, in June 2014. Meteorological and air quality measurements from 11 stations in the area as well as numerical simulations using the Weather and Research Forecasting (WRF) model were used to explain the main reasons for the occurrence of elevated particulate matter (PM) concentrations. The conditions were characterized with formation of a coastal low in central Chile between the southeastern anticyclone and a high-pressure system over Argentina. At a local scale, these conditions generated a depression at the base of the inversion layer, an increase in the vertical thermal stability, lower humidity and low-wind conditions, which were conducive to a decrease in pollutant dispersion and insufficient ventilation of the polluted air. Measurements and simulations using the WRF model revealed a vertical structure of the boundary layer during these stagnant conditions and provided a basis for a trajectory analysis. The back-trajectory calculation showed that the transport of air parcels was contained in the valley during the highest concentrations. The analysis also enabled the definition of the threshold values of a simple indicator of air pollution (ventilation coefficient, VC), which confirmed the evolution of the episode and divided the observed daily concentrations into two groups, with one including values above the limits prescribed by the national air quality standards (NAQS) and the other including values below these limits. For the SMA, the daily PM concentrations above the NASQ limits were associated with an overall mean threshold value of VC below 500 m2 s-1 (for PM2.5) and 300 m2 s-1 (for PM10). To apply the VC analysis to other pollutants and different geographic locations, different threshold values should be evaluated.

F8 inversions of introns 22 and 1 confer a moderate risk of inhibitors in Mexican patients with severe hemophilia A. Concordance analysis and literature review.

Intron-22 (Inv22) and intron-1 (Inv1) inversions account for approximately one half of all severe cases of hemophilia A (SHA) worldwide. Inhibitor development against exogenous factor VIII (FVIII) represents a major complication in HA. The causative F8 mutation is considered the most decisive factor conditioning inhibitor development. We aimed to investigate prevalence of Inv22 and Inv1 mutations, and its association as risk factors for developing inhibitors to FVIII. We investigated Inv22 and Inv1 in 255 SHA Mexican patients from 193 unrelated families using the inverse shifting-polymerase chain reaction (IS-PCR). We analyzed the association between inversions and inhibitor development via logistic regression introducing as covariates the populations, the inversions, F8-haplotypes and the age of patients at enrollment. Inv22 was found in 91/193 (47.2%: 38.9% exhibited Inv22-1 and 8.3% Inv22-2), and Inv1 in 2/193 (1.0%) independent families. Absolute inhibitor prevalence (IP) for Inv22 in unrelated patients was 15% (10-19). The cohorts and age of patients were independent predictors of inhibitor risk, but not inversions or haplotypes. Inversions presence in our population was associated to a moderate risk of developing inhibitors. Inv1 was found for the first time in two Mexican families. A relevant genetic component was observed by the strong concordance among brother-pairs.

Chromosome Painting in Tyrant Flycatchers Confirms a Set of Inversions Shared by Oscines and Suboscines (Aves, Passeriformes).

Tyrannidae is the largest family of Passeriformes in the Neotropical region. However, despite an interesting chromosomal diversity, there are only few cytogenetic studies of this family, and most of these are based on conventional cytogenetics. Hence, we analyzed here the chromosomal diversity and karyotypical evolution of this group by chromosome painting in 3 different species - Pitangus sulphuratus, Serpophaga subcristata, and Satrapa icterophrys - and make comparisons with previous data. In addition to chromosome painting with Gallus gallus (GGA) and Leucopternis albicollis (LAL) probes, karyotypes were analyzed by conventional staining, C-banding, and FISH with 18S rDNA and telomeric probes. Although this family is characterized by extensive chromosomal variation, we found similar karyotypes and diploid numbers ranging from 2n = 80 in P. sulphuratus to 2n = 82 in S. subcristata and S. icterophrys. Constitutive heterochromatin was located centromerically in all 3 species. Clusters of 18S rDNA were present in 1 pair of microchromosomes, except in S. subcristata, where 2 pairs of microchromosomes were labeled. No interstitial telomeric sequences were detected. GGA and LAL whole-chromosome probes revealed the occurrence of fissions and both paracentric and pericentric inversions commonly seen in other Passeriformes. In general terms, tyrants show the typical karyotype found in Passeriformes, suggesting that the observed rearrangements occurred before the division of the suborders Oscines and Suboscines.

Breaking Good: Accounting for Fragility of Genomic Regions in Rearrangement Distance Estimation.

Models of evolution by genome rearrangements are prone to two types of flaws: One is to ignore the diversity of susceptibility to breakage across genomic regions, and the other is to suppose that susceptibility values are given. Without necessarily supposing their precise localization, we call "solid" the regions that are improbably broken by rearrangements and "fragile" the regions outside solid ones. We propose a model of evolution by inversions where breakage probabilities vary across fragile regions and over time. It contains as a particular case the uniform breakage model on the nucleotidic sequence, where breakage probabilities are proportional to fragile region lengths. This is very different from the frequently used pseudouniform model where all fragile regions have the same probability to break. Estimations of rearrangement distances based on the pseudouniform model completely fail on simulations with the truly uniform model. On pairs of amniote genomes, we show that identifying coding genes with solid regions yields incoherent distance estimations, especially with the pseudouniform model, and to a lesser extent with the truly uniform model. This incoherence is solved when we coestimate the number of fragile regions with the rearrangement distance. The estimated number of fragile regions is surprisingly small, suggesting that a minority of regions are recurrently used by rearrangements. Estimations for several pairs of genomes at different divergence times are in agreement with a slowly evolvable colocalization of active genomic regions in the cell.

Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies.

First cytogenetic record for a species of Otothyropsis Ribeiro, Carvalho & Melo, 2005 (Loricariidae, Hypoptopomatinae)

Hypoptopomatinae is a monophyletic subfamily that includes 147 species, distributed in 20 genera. Otothyropsis is a genus of Hypoptopomatinae, recently described. Here, we provided the first cytogenetic information of Otothyropsis . The specimens were collected from córrego Dourado, a small tributary of rio Iguatemi, which flows into rio Paraná. The specimens of Otothyropsis cf. polyodon were analyzed with respect to diploid number, C-Band and Ag-NOR patterns. The diploid number was 54 chromosomes, distributed in 18 metacentric, 28 submetacentric, and 8 subtelocentric chromosomes, with single Ag-NOR and conspicuous heterochromatic blocks on the short and long arms of the 24th pair of chromosomes. Our study highlights the conservation trend of the diploid number (2n=54) and fundamental number (FN = 108) among the species of Hypoptopomatinae. However, the karyotype formula (18m+28sm+8st) seems to be specific to O. cf. polyodon , considering the other Hypoptopomatinae species already analyzed.(AU)

Hypoptopomatinae é uma subfamília monofilética que inclui 147 espécies distribuídas em 20 gêneros, sendo Otothyropsis um gênero recentemente descrito. Aqui, fornecemos a primeira informação citogenética do gênero Otothyropsis . Espécimes foram coletados no córrego Dourado, um pequeno tributário do rio Iguatemi, o qual deságua no rio Paraná. Espécimes de Otothyropsis cf. polyodon foram analisados em relação ao número diploide e padrões de Banda-C e Ag-NOR. O número diploide foi de 54 cromossomos, distribuídos em 18 metacêntricos, 28 submetacêntricos e 8 subtelocêntricos, com Ag-NOR simples e blocos heterocromáticos evidentes no braços curto e longo do par de cromossomos 24. Nosso estudo destaca a tendência de conservação do número diploide (2n=54) e número fundamental (NF=108) entre as espécies de Hypoptopomatinae. Entretanto, a fórmula cariotípica (18m+28sm+8st) parece ser específica para O. cf. polyodon, considerando as outras espécies de Hypoptopomatinae já analisadas.(AU)

First cytogenetic record for a species of Otothyropsis Ribeiro, Carvalho & Melo, 2005 (Loricariidae, Hypoptopomatinae)

Hypoptopomatinae is a monophyletic subfamily that includes 147 species, distributed in 20 genera. Otothyropsis is a genus of Hypoptopomatinae, recently described. Here, we provided the first cytogenetic information of Otothyropsis . The specimens were collected from córrego Dourado, a small tributary of rio Iguatemi, which flows into rio Paraná. The specimens of Otothyropsis cf. polyodon were analyzed with respect to diploid number, C-Band and Ag-NOR patterns. The diploid number was 54 chromosomes, distributed in 18 metacentric, 28 submetacentric, and 8 subtelocentric chromosomes, with single Ag-NOR and conspicuous heterochromatic blocks on the short and long arms of the 24th pair of chromosomes. Our study highlights the conservation trend of the diploid number (2n=54) and fundamental number (FN = 108) among the species of Hypoptopomatinae. However, the karyotype formula (18m+28sm+8st) seems to be specific to O. cf. polyodon , considering the other Hypoptopomatinae species already analyzed.

Hypoptopomatinae é uma subfamília monofilética que inclui 147 espécies distribuídas em 20 gêneros, sendo Otothyropsis um gênero recentemente descrito. Aqui, fornecemos a primeira informação citogenética do gênero Otothyropsis . Espécimes foram coletados no córrego Dourado, um pequeno tributário do rio Iguatemi, o qual deságua no rio Paraná. Espécimes de Otothyropsis cf. polyodon foram analisados em relação ao número diploide e padrões de Banda-C e Ag-NOR. O número diploide foi de 54 cromossomos, distribuídos em 18 metacêntricos, 28 submetacêntricos e 8 subtelocêntricos, com Ag-NOR simples e blocos heterocromáticos evidentes no braços curto e longo do par de cromossomos 24. Nosso estudo destaca a tendência de conservação do número diploide (2n=54) e número fundamental (NF=108) entre as espécies de Hypoptopomatinae. Entretanto, a fórmula cariotípica (18m+28sm+8st) parece ser específica para O. cf. polyodon, considerando as outras espécies de Hypoptopomatinae já analisadas.

Similarities and differences among the chromosomes of the wild guinea pig Cavia tschudii and the domestic guinea pig Cavia porcellus (Rodentia, Caviidae).

Cavia tschudii Fitzinger, 1867 is a wild guinea pig species living in South America that according to the analysis of mitochondrial genes is the closest wild form of the domestic guinea pig. To investigate the genetic divergence between the wild and domestic species of guinea pigs from a cytogenetic perspective, we characterized and compared the C, G and AgNOR banded karyotypes of molecularly identified Cavia tschudii and Cavia porcellus Linnaeus, 1758 specimens for the first time. Both species showed 64 chromosomes of similar morphology, although C. tschudii had four medium size submetacentric pairs that were not observed in the C. porcellus karyotype. Differences in the C bands size and the mean number of AgNOR bands between the karyotypes of the two species were detected. Most of the two species chromosomes showed total G band correspondence, suggesting that they probably represent large syntenic blocks conserved over time. Partial G band correspondence detected among the four submetacentric chromosomes present only in the C. tschudii karyotype and their subtelocentric homologues in C. porcellus may be explained by the occurrence of four pericentric inversions that probably emerged and were fixed in the C. tschudii populations under domestication. The role of the chromosomal and genomic differences in the divergence of these two Cavia species is discussed.

Comparative chromosomal analysis and evolutionary considerations concerning two species of genus Tatia (Siluriformes, Auchenipteridae).

Auchenipteridae is divided in two subfamilies, Centromochlinae and Auchenipterinae. Centromochlinae has 31 valid species, from which 13 are included in the genus Tatia Miranda Ribeiro, 1911. Among these, Tatia jaracatia Pavanelli & Bifi, 2009 and Tatia neivai (Ihering, 1930) are the only two representative species from the Paraná-Paraguay basins. This study aimed to analyze cytogenetically these two species and thus provide the first chromosomal data for the genus. Although Tatia jaracatia and Tatia neivai presented 2n=58 chromosomes, some differences were observed in the karyotypic formula. The heterochromatin was dispersed in the centromeric and terminal regions of most chromosomes of Tatia jaracatia, and only in the terminal region of most chromosomes of Tatia neivai. The AgNORs were detected in the subtelocentric pair 28 for both species, which was confirmed by FISH with 18S rDNA probe. The 5S rDNA sites were detected in four chromosome pairs in Tatia jaracatia and three chromosome pairs in Tatia neivai. Both species of Tatia presented great chromosomal similarities among themselves; however, when compared to other species of Auchenipteridae, it was possible to identify some differences in the karyotype macrostructure, in the heterochromatin distribution pattern and in the number and position of 5S rDNA sites, which until now seems to be intrinsic to the genus Tatia.

Three decades of studies on chromosomal polymorphism of Drosophila willistoni and description of fifty different rearrangements.

Drosophila willistoni (Insecta, Diptera) is considered a paradigm for evolutionary studies. Their chromosomes are characterized by multiple paracentric inversions that make it hard to identify and describe chromosomal polymorphisms. In the present report we attempted to systematize the description of all the 50 inversions found in the last three decades, since we have been studying the chromosomes of several individuals of 30 different populations, including the one used in the genome sequencing project (Gd-H4-1). We present the photographic register of 11 arrangements in the left arm of the X chromosome (XL), eight in the right arm (XR), 10 in the left arm of chromosome II (IIL), eight in its right arm (IIR) and 13 in chromosome III. This information also includes their breakpoints on the reference photomap. A clear geographic difference was detected in XL and XR, with different fixed arrangements depending on the origin of the population studied. Through the comparison of all X arrangements it was possible to infer the putative ancestral arrangements, i.e., those related to all the remaining arrangements through the small number of inversions that occurred in the past, which we will call XL-A and XR-A. In the autosomes (IIL/IIR and III), fixed inversions were detected, but most are segregating in different frequencies along the geographical distribution of the D. willistoni populations.

Changes in chromosomal polymorphism and global warming: The case of Drosophila subobscura from Apatin (Serbia).

In this study, chromosomal inversion polymorphism data for a natural population of Drosophila subobscura from a swampy region near the town of Apatin (Serbia) were compared with data for the same population collected approximately 15 years earlier. The pattern of chromosomal inversion polymorphism changed over time. There were significant increases in the frequency of characteristic southern latitude ("warm" adapted) chromosomal arrangements and significant decreases in the frequency of characteristic northern latitude ("cold" adapted) chromosomal arrangements in the O and U chromosomes. The chromosomal arrangements O(3+4) and O(3+4) (+) (22) (derived from the O(3+4) arrangement) showed significant increases in 2008 and 2009 with regard to the 1994 sample. There was also a significant increase (∼50%) in the U(1) (+) (2) arrangement, while U(1+8) (+) (2) (a typical southern arrangement) was detected for the first time. Since the Apatin swampy population of D. subobscura has existed for a long time in a stable habitat with high humidity that has not been changed by man our results indicate that natural selection has produced chromosomal changes in response to the increase in temperature that has occurred in the Balkan Peninsula of central southeastern European.

Changes in chromosomal polymorphism and global warming: the case of Drosophila subobscura from Apatin (Serbia)

In this study, chromosomal inversion polymorphism data for a natural population of Drosophila subobscura from a swampy region near the town of Apatin (Serbia) were compared with data for the same population collected approximately 15 years earlier. The pattern of chromosomal inversion polymorphism changed over time. There were significant increases in the frequency of characteristic southern latitude ("warm" adapted) chromosomal arrangements and significant decreases in the frequency of characteristic northern latitude ("cold" adapted) chromosomal arrangements in the O and U chromosomes. The chromosomal arrangements O3+4 and O3+4+22 (derived from the O3+4 arrangement) showed significant increases in 2008 and 2009 with regard to the 1994 sample. There was also a significant increase (~50 percent) in the U1+2 arrangement, while U1+8+2 (a typical southern arrangement) was detected for the first time. Since the Apatin swampy population of D. subobscura has existed for a long time in a stable habitat with high humidity that has not been changed by man our results indicate that natural selection has produced chromosomal changes in response to the increase in temperature that has occurred in the Balkan Peninsula of central southeastern European.

Polytene chromosomes and phylogenetic relationships in ten Drosophila species of the annulimana group (Diptera, Drosophilidae)

Polytene chromosomes banding patterns of ten of the 16 species of the Neotropical annulimana group of Drosophila were used to propose phylogenetic relationships among species. Drosophila annulimana chromosomes were used as the standard sequence and the most parsimonious series of changes (paracentric inversions) were considered. In some cases, intermediate hypothetical rearrangements were proposed to explain the sequences present in a given species. A total of 47 paracentric inversions were detected, most of them (44.7 percent) in chromosome 4. Three subgroups, partially coincident with those previously proposed based on morphological and karyotypical analyses, were classified as: 1) annulimana subgroup (Drosophila annulimana, D. aracataca, D. aragua, and D. arauna), 2) gibberosa subgroup (D. ararama, D. gibberosa, D. pseudotalamancana, and D. schineri), and 3) arassari subgroup (D. arapuan, and D. arassari).