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The vespertilionid bat genus Hesperoptenus, comprising only five species and showing a distribution in the tropical regions from India to Sulawesi, was hitherto underrepresented in recent taxonomic studies. Here, modern cytogenetic techniques were applied to compare the karyotypes of two Hesperoptenus species, H. tomesi and H. blanfordi. Despite having the same chromosome number, 2n = 32, the karyotypes of H. tomesi and H. blanfordi were found to differ extensively. Instead, H. tomesi was found to share all nine derived Robertsonian fusion products with the previously published karyotype of H. doriae (2n = 26), which points to a closer relationship between both species. In line with our chromosomal data, mitochondrial DNA analyses also provided evidence for a closer relationship of H. tomesi with H. doriae and H. tickelli, for which no banded karyotype has been examined. Again, H. blanfordi was clearly separated from the remaining Hesperoptenus species. As a consequence, the subgenus Milithronycteris, comprising all species of Hesperoptenus except the type species H. doriae, is rendered paraphyletic. We therefore suggest to synonymize Milthronycteris with the subgenus Hesperoptenus. A chromosomal character, found in all three Hesperoptenus species examined but absent in other vespertilionid genera studied so far, namely a particular G-banding pattern on the homolog to Myotis chromosome MMY13, may serve as a synapomorphy for the genus Hesperoptenus. [ABSTRACT FROM AUTHOR]

Phylogenetic relationships and species delimitation in African Vespertilionini have been a long-standing subject of debate and are still controversial, although recent molecular analyses have shed light onto some of these issues. In this study we employed a comparative cytogenetics approach for the delineation of chromosomal homology and for the detection of shared chromosomal characters, which were then used to support proposed phylogenetic relationships. Here, we present karyotype analyses of five African Vespertilionini, Laephotis kirinyaga (2n = 32), Neoromicia guineensis (2n = 26), Pseudoromicia brunnea (2n = 36), Nycticeinops happoldorum (2n = 24), and Nycticeinops schlieffenii (2n = 34), which were complemented by mitochondrial DNA sequence analysis for species classification of all our specimens. Our cytogenetic analyses revealed that three derived Robertsonian fusion chromosomes, 7/11, 8/9, and 10/12, characterize the karyotypes of four African Vespertilionini genera, i.e. Laephotis, Neoromicia, Afronycteris, and Pseudoromicia, for which we propose to constitute a new subtribe, Laephotina. A rare chromosomal rearrangement, an X-autosome translocation, was found in the studied N. guineensis female. The genus Nycticeinops is characterized by a high intrageneric karyotype diversity. In only two of all four analyzed species, i.e. N. happoldorum and N. crassulus, a common chromosomal feature, the fusion product 1/13 was detected. Further, for the recently described East African serotine, L. kirinyaga, we present the second record for West Africa. The cytochrome b sequence of our N. guineensis specimen from Ivory Coast showed 4% divergence to that of its closest relative, N. somalica from Kenya. [ABSTRACT FROM AUTHOR]

Detailed karyotype analysis including fluorescence in-situ hybridization with chromosome-specific and sub-regional probes revealed novel cytogenetic signatures for elucidating phylogenetic relationships in Vespertilionoidea. Two shared derived Robertsonian fusions characterize all members of this superfamily. Further, the majority of Molossidae species show karyotypes with 48 chromosomes, including six of seven species studied here, namely Ozimops petersi, Mormopterus jugularis, Tadarida teniotis, Mops mops, Molossus molossus and M. pretiosus. A shared derived feature of all molossid taxa studied is a variant homolog to Myotis myotis chromosome MMY22. Despite their overall similarity in karyotype composition with one large and three medium-sized bi-armed as well as 19 acrocentric to subtelocentric autosomal pairs, our detailed analysis revealed small differences which shed new light onto molossid phylogenetic relationships. Because of the retention of several ancestral chromosomal characters, O. petersi and M. jugularis represent early offshoots of the molossid tree. A unique derived paracentric inversion in the MMY6 homolog unites all other molossids studied so far. The next species to branch off is T. tadarida, followed by a group composed of M. mops and all studied New World taxa, united by a further derived inversion in the MMY5 homolog. In the light of our findings, we recommend to elevate the subspecies M. t. griseiventer to species rank, because the specimen from Venezuela with a 2n = 42 karyotype differed clearly from the nominate subspecies Molossops t. temminckii with 2n = 48. Further, karyotypes of Miniopterus and Natalus were studied. In the 2n = 46 chromosomal complement of the family Miniopteridae a large number of autapomorphic characters were found. Based on the observation of a common derived condition of the MMY22 homolog, we assume that long-winged bats (Miniopteridae) are closer related to vespertilionids than to molossids. Finally, karyotype comparison in Natalus revealed two autapomorphic characters in the 2n = 36 chromosomal complement. [ABSTRACT FROM AUTHOR]

Classical and molecular cytogenetic methods were applied to study the karyotypes of one species of Hipposideridae and three taxa of the Rhinolophidae subgenus Aquias from Malaysian Borneo. Except for four chromosomal pairs with autapomorphic arm combinations, the karyotype of Coelops robinsoni was found to be similar to the closely related Aselliscus stoliczkanus. From the three Rhinolophus taxa studied, only R. trifoliatus was found to share the karyotype with conspecifics from Peninsular Malaysia. In contrast, the karyotype of R. luctus foetidus from Sarawak, Borneo differed in the composition of the Y-autosomal translocation products from the closely related R. morio from Peninsular Malaysia, formerly also a subspecies of R. luctus. Therefore, elevation to specific rank is suggested for R. l. foetidus. Examination of the chromosomal set of male R. sedulus specimens from Borneo with 2n = 45 and a Neo-X1X2Y sex chromosome system revealed extreme differences to the karyotype of specimens from Peninsular Malaysia with 2n = 28, to date also classified as R. sedulus. Therefore, with Sarawak, Borneo, as the type locality for R. sedulus, the taxon from Peninsular Malaysia is here described as a new species. [ABSTRACT FROM AUTHOR]

The only representatives of Emballonuridae in the Neotropics are Diclidurini from the subfamily Emballonurinae. In this tribe, karyotype comparison based on G-banding patterns has revealed extensive chromosomal divergence. Here, we present for the first time a detailed karyotype analysis of a Diclidurini species, Saccopteryx bilineata (SBI), by G-banding and cross-species fluorescence in-situ hybridization (FISH) with Myotis myotis (Vespertilionidae) painting probes. The 25 evolutionarily conserved units (ECUs) ancestral to all Chiroptera were found as 37 segments on the 2n = 26 SBI karyotype. Comparison with the karyotype of another Emballonuridae (Emballonura monticola) from South-East Asia revealed a single common derived segment combination, MMY3+MMY22i, pointing to a fast karyotype evolution in Emballonurinae. [ABSTRACT FROM AUTHOR]

To preserve material for future genetic studies, human B-lymphocytes from whole blood samples are routinely transformed into lymphoblastoid cell lines (LCLs) by in vitro infection with Epstein–Barr virus. To determine the rate and frequency of chromosomal changes during long-term culture, we established 10 LCLs (from eight individuals). Before transformation, these cases showed a normal karyotype (three cases), a small supernumerary marker chromosome (three cases), or an aberrant karyotype (four cases). Chromosome analyses were performed at 8-week intervals over a period of at least 1 year, up to 3 years. Surprisingly, we demonstrate that chromosomal instability is the rule, rather than the exception, during long-term culture of LCLs. The most commonly observed acquired clonal aberration was trisomy 12, which emerged in all cell lines within 21 to 49 weeks after infection. Telomeric fusions indicating telomere shortening were found after ~21 weeks. After 1 year of cultivation, the proportion of cells with the original karyotype decreased to ≤10% in 7 of the 10 cell lines. To preserve cells with aberrant genomes, we conclude the cultivation time of LCLs must be restricted to the absolute minimum time required: [ABSTRACT FROM AUTHOR]

Two species of the monogeneric family Nycteridae were studied for the first time with chromosome banding techniques and chromosome painting. The diploid chromosome number of Nycteris macrotis and N. tragata is 40 and 38, respectively. Both karyotypes differ by a translocation, a telomeric fusion and a pericentric inversion. The genus Nycteris shows a highly derived karyotype where the 25 chiropteran evolutionarily conserved units (ECUs) are represented in 37 segments. Chromosome painting with Myotis probes revealed three common features of Nycteris and Emballonura, which are not present in Taphozous. From a cytogenetic point of view, Nycteris is therefore closer related to Emballonura than to Taphozous. Further, an additional synapomorphy for Vespertilioniformes is described, i.e. the synteny of a segment homologous to human chromosome 13 and ECU12a-22a in elements homologous to Myotis chromosome MMY6. [ABSTRACT FROM AUTHOR]

We present a comparative molecular cytogenetic investigation of six emballonurid species using chromosome banding and cross-species chromosome painting with probes from Myotis myotis, supplemented by selected probes from human, tree shrew, and lemur. The main differences between the 2n = 42 Taphozous karyotype and the 2n = 44 chromosomal complement of Saccolaimus can be explained by one Robertsonian fusion, one type-b, and one type-c whole arm reciprocal translocation. The 2n = 24 karyotype of Emballonura is highly derived by splitting of 11 of the 25 chiropteran evolutionarily conserved units resulting in a total number of 36 segments. In contrast to the presence of several autapomorphies in the karyotypes of studied species from both subfamilies, no cytogenetic synapomorphy uniting Taphozoinae and Emballonurinae was found. [ABSTRACT FROM AUTHOR]

The possibility to generate cardiomyocytes from pluripotent stem cells in vitro has enormous significance for basic research, disease modeling, drug development and heart repair. The concept of heart muscle reconstruction has been studied and optimized in the rat model using rat primary cardiovascular cells or xenogeneic pluripotent stem cell derived-cardiomyocytes for years. However, the lack of rat pluripotent stem cells (rPSCs) and their cardiovascular derivatives prevented the establishment of an authentic clinically relevant syngeneic or allogeneic rat heart regeneration model. In this study, we comparatively explored the potential of recently available rat embryonic stem cells (rESCs) and induced pluripotent stem cells (riPSCs) as a source for cardiomyocytes (CMs). We developed feeder cell-free culture conditions facilitating the expansion of undifferentiated rPSCs and initiated cardiac differentiation by embryoid body (EB)-formation in agarose microwell arrays, which substituted the robust but labor-intensive hanging drop (HD) method. Ascorbic acid was identified as an efficient enhancer of cardiac differentiation in both rPSC types by significantly increasing the number of beating EBs (3.6 ± 1.6-fold for rESCs and 17.6 ± 3.2-fold for riPSCs). These optimizations resulted in a differentiation efficiency of up to 20% cTnTpos rPSC-derived CMs. CMs showed spontaneous contractions, expressed cardiac markers and had typical morphological features. Electrophysiology of riPSC-CMs revealed different cardiac subtypes and physiological responses to cardio-active drugs. In conclusion, we describe rPSCs as a robust source of CMs, which is a prerequisite for detailed preclinical studies of myocardial reconstruction in a physiologically and immunologically relevant small animal model. [ABSTRACT FROM AUTHOR]

Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62). As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within distinct bat lineages (especially Phyllostomidae, Hipposideridae and Rhinolophidae), focusing on two perspectives: evolution of genome architecture, modes of chromosomal evolution, and the use of chromosome data to resolve taxonomic problems. [ABSTRACT FROM AUTHOR]

5-Methylcytosine-rich heterochromatic regions were demonstrated in metaphase chromosomes of 5 species of Chiroptera by indirect immunofluorescence using a monoclonal anti-5-methylcytosine antibody. These species belong to 4 genera and 2 families and are characterized by divergent karyotypes. One species (Glauconycteris beatrix) has an extremely low diploid chromosome number of 2n = 22 with only meta- to submetacentric elements and remarkably large amounts of constitutive heterochromatin located in the centromeric and pericentromeric regions of all chromosome pairs. Two species (G. beatrix and Neoromicia cf. guineensis) possess X-autosome translocations. In all species, the hypermethylated chromosome segments correspond to constitutive heterochromatin, and the numbers and positions of hypermethylated chromosome segments in the karyotypes are constant and species-specific. In some species (Pipistrellus hesperidus, Neoromicia cf. somalicus), there are several smaller chromosome pairs in which the bright anti-5-methylcytosine antibody labeling is not restricted to constitutively heterochromatic regions but is observed along the whole lengths of these chromosomes. The nature of these additional hypermethylated regions is discussed. The analysis of 5-methylcytosine-rich chromosome regions elucidates valuable data for chiropteran cytogenetics and reflects the high pace of evolution of the repetitive DNA fraction in their genomes. [ABSTRACT FROM AUTHOR]

For the majority of Rhinolophus species a karyotype consisting of either 58 or 62 chromosomes was reported. The members of the R. trifoliatus clade are therefore distinguished from other rhinolophids by low diploid chromosome numbers (2 n) and a high rate of chromosomal changes. Recently, based on cytogenetic characters, a cryptic species, R. luctoides, was described and a subspecies, R. luctusmorio, was elevated to species rank. In the present work, the karyotypes of a male bat from Vietnam and a female one from China, both classified as R. luctus by morphological characters, were studied by G-banding and fluorescence in situ hybridization with whole chromosome painting probes derived from Aselliscus stoliczkanus. In the male specimen from Vietnam, the composition of the 15 autosomal bi-armed pairs (2 n = 32, FN = 60) is identical to that of R. luctoides from Malaysia. For reason of differences in body size and baculum length as well as in skull morphology, this specimen is provisionally treated as R. cf. luctoides. The karyotype of the female specimen from Sichuan province, China, differs from R. luctoides by a whole arm reciprocal translocation resulting in an altered arm composition of pairs 3 and 4. For this reason, the elevation of the Chinese subspecies of R. luctus, i.e. R. lanosus, to species rank is suggested. The karyotype of the endemic Taiwanese species R. formosae with a diploid number of 2 n = 52 is mainly composed of acrocentric autosomal pairs. Of the five bi-armed pairs, only the two smallest show the same arm composition as found in the 2 n = 32 karyotypes of other members of the R. trifoliatus clade. The composition of the remaining three bi-armed pairs is unique and represents an apomorphic feature for R. formosae. [ABSTRACT FROM AUTHOR]

In Europe, 2 different diploid chromosome numbers, 2n = 54 and 2n = 56, have been described in the lesser horseshoe bat (Rhinolophus hipposideros) . The eastern form with 2n = 56 extends from the Czech Republic to Greece. To date, specimens with 54 chromosomes have been reported only from Spain and Germany. This study expands the distributional area of the western variant to Ireland. Strikingly, this distribution of European chromosomal variants is in contrast to the available molecular data that indicate little genetic differentiation of R. hipposideros populations spanning Northwestern to Central Europe. Further, we have developed an optimized protocol for establishing fibroblast cell cultures, suitable for karyotype analyses, from 3-mm wing membrane biopsies. This is a useful technique for cytogenetic studies of endangered bat species, as this nonlethal sampling method imposes only minimum stress to the animal without lasting adverse effects and is routinely used to sample tissue probes for molecular genetic studies in bats. [ABSTRACT FROM AUTHOR]

Background: Defining factors that contributed to the fixation of a high number of underdominant chromosomal rearrangements is a complex task because not only molecular mechanisms must be considered, but also the uniqueness of natural history attributes of each taxon. Ideally, detailed investigation of the chromosome architecture of an organism and related groups, placed within a phylogenetic context, is required. We used multiple approaches to investigate the dynamics of chromosomal evolution in lineages of bats with considerable karyotypic variation, focusing on the different facets contributing to fixation of the exceptional chromosomal changes in Tonatia saurophila. Integration of empirical data with proposed models of chromosome evolution was performed to understand the probable conditions for Tonatia's karyotypic evolution. Results: The trajectory of reorganization of chromosome blocks since the common ancestor of Glossophaginae and Phyllostominae subfamilies suggests that multiple tandem fusions, as well as disruption and fusions of conserved phyllostomid chromosomes were major drivers of karyotypic reshuffling in Tonatia. Considerable variation in the rates of chromosomal evolution between phyllostomid lineages was observed. Thirty-nine unique fusions and fission events reached fixation in Tonatia over a short period of time, followed by ~12 million years of chromosomal stasis. Physical mapping of repetitive DNA revealed an unusual accumulation of LINE-1 sequences on centromeric regions, probably associated with the chromosomal dynamics of this genus. Conclusions: Multiple rearrangements have reached fixation in a wave-like fashion in phyllostomid bats. Different biological features of Tonatia support distinct models of rearrangement fixation, and it is unlikely that the fixations were a result of solely stochastic processes in small ancient populations. Increased recombination rates were probably facilitated by expansion of repetitive DNA, reinforced by aspects of taxon reproduction and ecology. [ABSTRACT FROM AUTHOR]

The article presents a study on genetic diversity in Rhinolophus luctus (Chiroptera: Rhinolophidae) from Peninsular Malaysia. Topics include the description of the new species Rhinolophus luctus morio based on genetic and morphological characters and morphological examination showing differences in size of the baculum and length of the lower toothrow.

Robertsonian (centric) fusion or fission is one of the predominant modes of chromosomal rearrangement in karyotype evolution among mammals. However, in karyotypes composed of only bi-armed chromosomes, creation of new chromosomal arm combinations in one step is possible only via whole-arm reciprocal translocation (WART). Although this type of rearrangement has often been proposed to play an important role in chromosomal evolution, direct observations of WARTs remained rare, and, in most cases, were found in hybrids of chromosomal races in the genera Mus and Sorex. For the first time, we present the karyotype of the horseshoe bat species Rhinolophus sedulus (2n = 28, FNa = 52), where a WART between 2 metacentric autosomes was detected by G-banding and confirmed by FISH with painting probes of the vespertilionid bat Myotis myotis. Among the 6 specimens analyzed, 2 showed the heterozygous condition of the WART, 1 showed the presumed ancestral, and 3 specimens showed the derived homozygous state. As the existence of a hybrid zone at the sampling locality is thought to be rather improbable, the WART may indicate ongoing karyotype evolution in this taxon. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background Complex small supernumerary marker chromosomes (sSMC) constitute one of the smallest subgroups of sSMC in general. Complex sSMC consist of chromosomal material derived from more than one chromosome; the best known representative of this group is the derivative chromosome 22 {der(22)t(11;22)} or Emanuel syndrome. In 2008 we speculated that complex sSMC could be part of an underestimated entity. Results Here, the overall yet reported 412 complex sSMC are summarized. They constitute 8.4% of all yet in detail characterized sSMC cases. The majority of the complex sSMC is contributed by patients suffering from Emanuel syndrome (82%). Besides there are a der(22)t(8;22)(q24.1;q11.1) and a der(13)t(13;18)(q11;p11.21) or der(21)t(18;21)(p11.21;q11.1) = der(13 or 21)t(13 or 21;18) syndrome. The latter two represent another 2.6% and 2.2% of the complex sSMC-cases, respectively. The large majority of complex sSMC has a centric minute shape and derives from an acrocentric chromosome. Nonetheless, complex sSMC can involve material from each chromosomal origin. Most complex sSMC are inherited form a balanced translocation in one parent and are non-mosaic. Interestingly, there are hot spots for the chromosomal breakpoints involved. Conclusions Complex sSMC need to be considered in diagnostics, especially in non-mosaic, centric minute shaped sSMC. As yet three complex-sSMC-associated syndromes are identified. As recurrent breakpoints in the complex sSMC were characterized, it is to be expected that more syndromes are identified in this subgroup of sSMC. Overall, complex sSMC emphasize once more the importance of detailed cytogenetic analyses, especially in patients with idiopathic mental retardation. [ABSTRACT FROM AUTHOR]

Background: Heterochromatic variants of pericentromere of chromosome 9 are reported and discussed since decades concerning their detailed structure and clinical meaning. However, detailed studies are scarce. Thus, here we provide the largest ever done molecular cytogenetic research based on >300 chromosome 9 heteromorphism carriers. Results: In this study, 334 carriers of heterochromatic variants of chromosome 9 were included, being 192 patients from Western Europe and the remainder from Easter-European origin. A 3-color-fluorescence in situ hybridization (FISH) probe-set directed against for 9p12 to 9q13~21.1 (9het-mix) and 8 different locus-specific probes were applied for their characterization. The 9het-mix enables the characterization of 21 of the yet known 24 chromosome 9 heteromorphic patterns. In this study, 17 different variants were detected including five yet unreported; the most frequent were pericentric inversions (49.4%) followed by 9qh-variants (23.9%), variants of 9ph (11.4%), cenh (8.2%), and dicentric- (3.8%) and duplication-variants (3.3%). For reasons of simplicity, a new short nomenclature for the yet reported 24 heteromorphic patterns of chromosome 9 is suggested. Six breakpoints involved in four of the 24 variants could be narrowed down using locus-specific probes. Conclusions: Based on this largest study ever done in carriers of chromosome 9 heteromorphisms, three of the 24 detailed variants were more frequently observed in Western than in Eastern Europe. Besides, there is no clear evidence that infertility is linked to any of the 24 chromosome 9 heteromorphic variants. [ABSTRACT FROM AUTHOR]

Chromosome 16 contains multiple copy number variations (CNVs) that predispose to genomic disorders. Here, we differentiate pathogenic duplications of 16p11.2-p12.2 from microscopically similar euchromatic variants of 16p11.2. Patient 1 was a girl of 18 with autism, moderate intellectual disability, behavioural difficulties, dysmorphic features and a 7.71-Mb (megabase pair) duplication (16:21 521 005-29 233 146). Patient 2 had a 7.81-Mb duplication (16:21 382 561-29 191 527), speech delay and obsessional behaviour as a boy and, as an adult, short stature, macrocephaly and mild dysmorphism. The duplications contain 65 coding genes of which Polo-like kinase 1 (PLK1) has the highest likelihood of being haploinsufficient and, by implication, a triplosensitive gene. An additional 1.11-Mb CNV of 10q11.21 in Patient 1 was a possible modifier containing the G-protein-regulated inducer of neurite growth 2 (GPRIN2) gene. In contrast, the euchromatic variants in Patients 3 and 4 were amplifications from a 945-kb region containing non-functional immunoglobulin heavy chain (IGHV), hect domain pseudogene (HERC2P4) and TP53-inducible target gene 3 (TP53TG3) loci in proximal 16p11.2 (16:31 953 353-32 898 635). Paralogous pyrosequencing gave a total copy number of 3-8 in controls and 8 to >10 in Patients 3 and 4. The 16p11.2-p12.2 duplication syndrome is a recurrent genomic disorder with a variable phenotype including developmental delay, dysmorphic features, mild to severe intellectual disability, autism, obsessive or stereotyped behaviour, short stature and anomalies of the hands and fingers. It is important to differentiate pathogenic 16p11.2-p12.2 duplications from harmless, microscopically similar euchromatic variants of proximal 16p11.2, especially at prenatal diagnosis. [ABSTRACT FROM AUTHOR]

Background New World leaf-nosed bats, Phyllostomidae, represent a lineage of Chiroptera marked by unprecedented morphological/ecological diversity and extensive intergeneric chromosomal reorganization. There are still disagreements regarding their systematic relationships due to morphological convergence among some groups. Their history of karyotypic evolution also remains to be documented. Results To better understand the evolutionary relationships within Phyllostomidae, we developed chromosome paints from the bat species Macrotus californicus. We tested the potentials of these paints as phylogenetic tools by looking for chromosomal signatures in two lineages of nectarivorous phyllostomids whose independent origins have been statistically supported by molecular phylogenies. By examining the chromosomal homologies defined by chromosome painting among two representatives of the subfamily Glossophaginae (Glossophaga soricina and Anoura cultrata) and one species from the subfamily Lonchophyllinae (Lonchophylla concava), we found chromosomal correspondence in regions not previously detected by other comparative cytogenetic techniques. We proposed the corresponding human chromosomal segments for chromosomes of the investigated species and found two syntenic associations shared by G. soricina and A. cultrata. Conclusion Comparative painting with whole chromosome-specific paints of M. californicus demonstrates an extensive chromosomal reorganization within the two lineages of nectarivorous phyllostomids, with a large number of chromosomes shared by M. californicus and G. soricina. We show that the evolution of nectar-feeding bats occurs mainly by reshuffling of chiropteran Evolutionary Conserved Units (ECUs). Robertsonian fusions/fissions and inversions seem to be important modifiers of phyllostomid karyotypes, and autapomorphic character states are common within species. Macrotus californicus chromosome paints will be a valuable tool for documenting the pattern of karyotypic evolution within Phyllostomidae radiation. [ABSTRACT FROM AUTHOR]

The discovery of copy number variations (CNV) in the human genome opened new perspectives on the study of the genetic causes of inherited disorders and the aetiology of common diseases. Here, a single-cell-level investigation of CNV in different human tissues led us to uncover the phenomenon of mitotically derived genomic mosaicism, which is stable in different cell types of one individual. The CNV mosaic ratios were different between the 10 individuals studied. However, they were stable in the T lymphocytes, immortalized B lymphoblastoid cells, and skin fibroblasts analyzed in each individual. Because these cell types have a common origin in the connective tissues, we suggest that mitotic changes in CNV regions may happen early during embryonic development and occur only once, after which the stable mosaic ratio is maintained throughout the differentiated tissues. This concept is further supported by a unique study of immortalized B lymphoblastoid cell lines obtained with 20 year difference from two subjects. We provide the first evidence of somatic mosaicism for CNV, with stable variation ratios in different cell types of one individual leading to the hypothesis of early embryonic chromosome instability resulting in stable mosaic pattern in human tissues. This concept has the potential to open new perspectives in personalized genetic diagnostics and can explain genetic phenomena like diminished penetrance in autosomal dominant diseases. We propose that further genomic studies should focus on the single-cell level, to better understand the aetiology of aging and diseases mediated by somatic mutations. [ABSTRACT FROM AUTHOR]

A thorough study of the heterochromatin organisation in the pericentromeric region and the proximal long (q) and short (p) arms of human chromsome 9 (HSA 9) revealed homology between 9p12 and 9q1321.1, two regions that are usually not distinguishable by molecular cytogenetic techniques. Furthermore, the chromosomal regions 9p12 and 9ql 3-21.1 showed some level of homology with the short arms of the human acrocentric chromosomes. We studied five normal controls and 51 clinical cases: 48 with chromosome 9 heteromorphisms, one with an exceptionally large inversion and two with an additional derivative chromosome 9. Using fluorescence in situ hybridisation (FISH) with three differentially labelled chromosome 9-specific probes we were able to distinguish 12 heteromorphic patterns in addition to the most frequent pattern (defined as normal). In addition, we studied one inversion 9 case with the recently described multicolour banding (MCB) technique. Our results, and previously published findings, suggest several hotspots for recombination in the pericentromeric heterochromatin of HSA 9. They also demonstrate that constitutional inversions affecting the pericentromeric region of chromosome 9 carry breakpoints located preferentially in 9p12 or 9q13-21.1 and less frequently in 9q12. [ABSTRACT FROM AUTHOR]

The article presents an obituary for German biologist Otto Freiherr von Helversen-Helversheim.

A contiguous deletion encompassing the genes for dystrophin, cytochrome b(-245) beta-subunit (CYBB), retinitis pigmentosa GTPase regulator (RPGR), and OTC was detected in a female patient only suffering from OTC deficiency while symptoms of the other conditions were not present. [ABSTRACT FROM AUTHOR]

In bush-crickets, males produce a calling song to announce their presence to females. Females ready to mate respond either by a phonotactic approach or signal their presence acoustically by establishing a kind of duet. This duetting behaviour is typical of phaneropterid bush-crickets, of which many species in Europe are flightless. In the long-winged genus Phaneroptera, the females also respond acoustically to the male calling song, which is quite similar in the three west European species in this genus. After acoustical contact, however, the behaviour of males and females of the three species differ markedly. In P. nana, males and females engage in a duet in which the female responds to each syllable of the male song (and he approaches her). In P. falcata, the female only responds to certain elements of the male song that are produced at long intervals. However, after her response the male does not change its song or its position, but often increases its singing activity (and the female approaches him). In P. sparsa the female only responds to particular, very complicated and soft elements of the male song, which are typically repeated at intervals of several to many minutes. After hearing the response, the male drastically changes its song by producing only the soft elements. These parts of the song contain syllables with a unique spectral composition and others that may threaten eavesdropping rivals. In this species both sexes probably move towards each other during mate localization. At present, we can only speculate about the adaptive nature of the different strategies. [ABSTRACT FROM AUTHOR]