170 research outputs found
Karyotype evolution in the horseshoe bat Rhinolophus sedulus by whole-arm reciprocal translocation (WART)
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
Phylogenetic Relationships of the Family Agamidae (Reptilia: Iguania) Inferred from Mitochondrial DNA Sequences
Supplementation of Sucrose and n-source in Culture Medium Towards Bacteriocin Production of Lactic Acid Bacteria Isolated from Ampel Bamboo Shoot (Bambusa vulgaris) Pickle
Penelitian tentang penggunaan sukrosa dalam media BAL dari rebung masih terbatas. Tujuan dari penelitian ini
adalah untuk mengetahui pengaruh sukrosa dalam media kultur terhadap produksi bakteriosin BAL yang diisolasi
dari acar rebung Ampel pada kondisi fermentasi yang berbeda. Fermentasi rebung dilakukan pada konsentrasi
garam 2,5% pada suhu 15ÂșC selama 5 hari (kondisi A) dan pada konsentrasi garam 5,0% pada suhu 30ÂșC selama
4 hari (kondisi B). Isolasi BAL dari air garam fermentasi rebung menghasilkan 35 isolat yang terdiri atas 16
isolat kondisi A dan 19 isolat kondisi B. Analisis aktivitas antimikroba menunjukkan bahwa semua isolat memiliki
aktivitas antimikroba terhadap bakteri patogen (E. coli FNCC 0091, L. monocytogenes FNCC 0156 dan S. aureus
FNCC 0047). Semua isolat ditumbuhkan dalam media MRS-B yang dilengkapi dengan sukrosa sebagai sumber
karbon dan ekstrak yeast serta pepton sebagai sumber nitrogen. Aktivitas penghambatan bakteriosin antara 13-3274
mm2
ml-1. Daya hambat tertinggi ditemukan pada isolat B16 yang ditumbuhkan pada MRS-B yang disuplementasi
sukrosa 2% terhadap S. aureus FNCC 0047 (3274,99 mm2
ml-1). Tiga belas isolat menunjukkan produksi bakteriosin
setelah diinokulasi pada MRS-B dengan kombinasi sumber karbon dan nitrogen. Berdasarkan 32 isolat dalam
penelitian ini, hanya 4 isolat A14, A17, A18 dan B9 yang menunjukkan aktivitas penghambatan bakteriosin
terhadap semua indikator patogen E. coli FNCC 0091, L. monocytogenes FNCC 0156 dan S. aureus FNCC 0047
Phylogenetic Relationships of the Flying Lizards, Genus Draco (Reptilia, Agamidae)
Phylogenetic relationships among 12 species of the genus Draco were inferred from 779 base pairs of mitochondrial 12S and 16S rRNA genes and allozymes for 20 presumptive loci. Results indicated the presence of at least four distinct lineages within the genus. The first lineage consists of D. volans and D. cornutus, whereas the second only of D. lineatus, which exhibits a great genetic divergence between two subspecies. The third is monotypic with D. dussumieri, the only species distributed in southern India. The fourth included all the remaining species. The third and fourth lineages are supposed to exclusively share a common ancestor. It is likely that the common ancestor of whole Draco originally diverged into three groups, the ancestors of the first, second, and third and fourth lineages, by vicariance. In the fourth lineage, D. blanfordii, D. haematopogon, D. melanopogon, D. obscurus and D. taeniopterus are likely to be exclusively close to each other. The resultant phylogenetic tree contradicts the dichotomous relationships previously hypothesized on the basis of morphological characters
Evolution of Asian and African Lygosomine Skinks of the Mabuya Group (Reptilia: Scincidae): A Molecular Perspective
Phylogenetic relationships among Asian and African lygosomine skinks of the Mabuya group were inferred from 825 base pairs of DNA sequences of mitochondrial 12S and 16S rRNA genes. Results indicated the presence of two distinct lineages within this group, of which one consisted of Lamprolepis and Lygosoma, and the other of Apterygodon, Dasia, and Asian and African Mabuya. Within the latter, African species of Mabuya first diverged from the remainder, leaving the Asian congeners together with the Apterygodon-Dasia clade. Our results, while suggesting the non-monophyly of the genus Mabuya, do not support the currently prevailing phylogeographical hypothesis which assumes the independent origins of Lamprolepis and Lygosoma from the Asian Mabuya-like stock. On the other hand, our results suggest that morphological and karyological similarities between the Apterygodon-Dasia clade and Lamprolepis are attributable to symplesiomorphy, while their ecological similarity to convergence. Morphological and karyological character states unique to Apterygodon are supposed to have evolved from those exhibited by Dasia
DNA methylation analysis of AKT1 promoter and HTR2A exon-I of Malaysian schizophrenia multiplex families with lower cognitive performance
Dysfunction of cognitive performance in schizophrenia has been associated with aberrant alteration of DNA methylation of several schizophrenia-risk genes. AKT1 and HTR2A are among the candidate genes for schizophrenia. Their expressions were found reduced in schizophrenia patients. Thus, we aimed to study the methylation status of AKT1 promoter and HTR2A exon-I in Malaysian schizophrenia patients and their affected family members. In this study, each participant was required to perform Trail Making Test (TMT) part A and B to measure their cognitive performance. Genomic DNA extracted from the peripheral blood of 12 Malaysian schizophrenia families and 12 controls families, was subjected to bisulfite conversion. The methylation status of CpG sites of AKT1 promoter at Chr14: 104796054 and HTR2A exon-I at Chr13: 46896918 were identified using methylation-specific polymerase chain reaction (MSP). Our results showed that schizophrenia patients performed worse in both TMT-A and B (p<0.0001) than healthy controls. The patients also displayed significantly (p=0.023) high level of methylation in AKT1 promoter compared to controls. Meanwhile, no significant difference (p=0.248) in methylation status was observed in HTR2A exon-I between schizophrenia and control groups. Therefore, methylation of AKT1 promoter in peripheral bloods of patients may involve in cognitive impairment and schizophrenia pathology. In addition, we were able to demonstrate the heritability of DNA methylation status across family members
Molecular phylogeny of long-tailed giant rats (Muridae: genus leopoldamys) based on mitochondrial cytochrome B sequences
Two species of Leopoldamys long-tailed giant rats are found in Peninsular Malaysia. They are currently referred to as Leopoldamys ciliatus which inhabits montane habitat, and Leopoldamys vociferans which usually inhabits the lowland forest. To date, there is no report on the phylogenetic relationship of L. ciliatus with the other Leopoldamys taxa. The present study was carried out to determine its relationship, based on the mitochondrial cytochrome b (cyt b) gene sequence, with L. vociferans of Peninsular Malaysia and other congeners. Phylogenetic analysis shows that L. ciliatus is a sister-species to the lineage L1 of L. herberti and L. revertens, and is distantly related to L. edwardsi. L. vociferans, and L. sabanus form a distinct clade (lineage L5) from the other Leopoldamys taxa from Indochina. The Sumatra taxon currently known as L. sabanus is genetically distinct to L. vociferans with K2P distances between 0.065 and 0.069. Contrary to previous opinions, L. herberti, L. revertens, and L. neilli of Indochina are valid species based on more than 2.5% threshold genetic distance. Both the L. edwardsi and L. neilli species complexes are represented by several sibling species. A more extensive taxon sampling from various regions (particularly Sumatra and other regions of Indonesia) as well as the use of morphological and molecular (mitogenomes or multiple genes) data sets are needed to provide a robust phylogeny and systematics
The Climate Range Expansion of Aedes albopictus (Diptera: Culicidae) in Asia Inferred From the Distribution of Albopictus Subgroup Species of Aedes (Stegomyia)
éæȹ性ćŠçć·„ç 究ćèȘç¶ă·ăčăă We compared climatic distribution ranges between Aedes albopictus (Skuse) (Diptera: Culicidae) and the five wild (nondomesticated) species of Albopictus Subgroup of Scutellaris Group of Aedes (Stegomyia) in southern Asia. Distribution sites of the wild species concentrate in seasonal forest and savannah climate zones in India, Indochina, and southern China. The distribution of Ae. albopictus is broader than the wild species under 1) tropical rain-forest climate, 2) steppe and temperate savannah climate, and 3) continental climate with large seasonal temperature variation (hot summer and cold winter) at temperate lowlands (northernmost sites 40°N in Ae. albopictus vs 32°N in the wild species). However, the distribution of Ae. albopictus is more limited at tropical and subtropical highlands where the climate is cool but less continental (small seasonal variation, mild summer, and winter). We discuss a possibility that the broader climate ranges of Ae. albopictus are ecological or eco-evolutionary consequences of adaptation to human habitats. We also propose a general scenario for the origin, dispersal, and adaptation of Ae. albopictus in Asia as a hypothesis for future research. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: [email protected] Period 12 month
Die Folgen des Libyen-Konflikts fĂŒr Afrika: GrĂ€ben zwischen der AU und dem Westen, Destabilisierung der Sahelzone
Der BĂŒrgerkrieg und die Nato-Intervention in Libyen haben Auswirkungen auf Afrika und die europĂ€ische Afrikapolitik, denen bislang zu wenig Aufmerksamkeit geschenkt wurde. Kurz- und mittelfristig droht eine weitere Destabilisierung der Sahelzone. Der im Januar 2012 neu ausgebrochene Konflikt im Norden Malis ist eine direkte Folge des libyschen BĂŒrgerkriegs, ebenso wie die RĂŒckkehr von KĂ€mpfern aus Libyen und die Zunahme des Waffenschmuggels. AuĂerdem hat der Libyen-Konflikt neue Hindernisse fĂŒr regionale Kooperation im Sahel aufgetĂŒrmt. Nicht minder gravierend sind die mittel- und langfristigen internationalen Folgen der Nato-Intervention. Sie hat Streit zwischen afrikanischen und westlichen Staaten verursacht, der die oft beschworene »Partnerschaft auf Augenhöhe« als deklaratorische Politik zu entblöĂen droht. Auch innerhalb der Afrikanischen Union hat der Umgang mit der Krise Spannungen hervorgerufen, die die HandlungsfĂ€higkeit der Organisation nach innen wie auĂen beeintrĂ€chtigen werden.
Aus diesen GrĂŒnden muss deutsche und europĂ€ische Afrikapolitik auf mehreren Ebenen reagieren. Europa muss seinen Ansatz fĂŒr den Sahel modifizieren, denn bisher wollte die EU vor allem die SicherheitskrĂ€fte in der Region stĂ€rken. Dies geht nicht nur an den eigentlichen Problemen vorbei, sondern könnte Auseinandersetzungen sogar befeuern und regionale Kooperation erschweren. Stattdessen sollte die EU weit mehr Gewicht auf die Förderung regionaler Anstrengungen legen sowie Libyen und Algerien entschlossener in ihre Sahel-Strategie einbeziehen. FĂŒr Europa wird eine funktionsfĂ€hige AU in Zukunft noch wichtiger werden. Deutschland und die EU sollten sich daher bemĂŒhen, die politischen GrĂ€ben zuzuschĂŒtten, die der Umgang mit dem Libyen-Konflikt aufgerissen hat. (Autorenreferat
Speciation of Fejervarya cancrivora from Indonesia and other Asian countries inferred from morphological observations and crossing experiments
This study was conducted to elucidate the taxonomic status and post-isolating mechanisms of Fejervarya cancrivora from Indonesia and other Asian populations. Five populations of F. cancrivora, from Selangor (Malaysia), Cianjur (Java, Indonesia), Trat (Thailand), Khulna (Bangladesh), and Makassar (Sulawesi, Indonesia), were observed morphologically and through crossing experiments. Discriminant and clustering analyses showed that the five populations could be morphologically separated into three groups corresponding to three types: a Selangor and Cianjur group (large-type), a Trat and Khulna group (mangrove-type), and a Makassar group (Sulawesi-type). The hybrids between the Selangor females and Cianjur and Trat males developed normally, but the hybrids between the Selangor females and Khulna males showed incomplete gametic isolation. Histological observations of the testes of mature males revealed pycnotic nuclei in the hybrids between the Selangor females and Khulna males, in addition to normal bundles of spermatozoa. In contrast, no pycnotic nuclei were found in the Selangor controls. Meiotic metaphases of the control were quite normal, but those of the hybrids showed abnormalities such as the appearance of univalents and an increase in rod-shaped bivalents. Based on our findings from the morphological observations and crossing experiments, we conclude that each of the three types is a distinct species, and that large-type is reproductively isolated from the mangrove-type by incomplete gametic isolation or abnormal spermatogenesis
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