rDNA Intergenic Spacer Research Articles

5s rDNA intergenic spacer of some species of Cruciata and Chondrophyllae sections and its application in taxonomy of genus Gentiana

Aim. The 5S rDNA intergenic spacer (IGS) region is a convenient tool for studying genome evolution and systematics of higher plants. The aim was to investigate the nucleotide sequence of 5S rDNA in some species of the sections Cruciata and Chondrophyllae, as well as to study the peculiarities of this region organisation by comparative analysis with other Gentiana species. Methods. Polymerase chain reaction, cloning, sequencing, bioinformatic analysis. Results. The cloned IGS regions of G. laciniata, G. cruciata and G. dahurica were sequenced and analysed. Typical regulatory elements were found in the regions of terminator and external promoter of 5S rRNA gene. Based on the comparative analysis, two groups of species were distinguished that differ significantly in the organisation of this region. One includes G. asclepiadea and species of the sections Gentiana, Ciminalis and Calathianae, and the other includes species of the sections Cruciata and Pneumonanthe. G. laciniata (sect. Chondrophyllae) differs in the IGS organization from species of both groups. Conclusions. The results of taxon grouping are generally consistent with the genus systematics and indicate that 5S rDNA IGS region can be a convenient tool for studying evolution and systematics of the genus.

Molecular evidence for the origin of the little-known hybrid Potamogeton ×vilnensis

A combined study of morphology, stem anatomy, and the genetic markers (ITS1-ITS4 region of nuclear ribosomal DNA and rpl20-rps12 intergenic spacer of chloroplast DNA) was used to verify the identity of hybrid Potamogeton ×vilnensis Galinis previously recognized as P. gramineus × P. praelongus. Authentic herbarium material and newly collected specimens morphologically similar to the hybrid from the locus classicus (SE Lithuania) were used for comparative morphological, anatomical and molecular analyses. The study proved the paternity of P. lucens and P. praelongus and excluded the involvement of P. gramineus in hybridization and identity with P. ×angustifolius. This hybrid formula is shared with plants recorded in the Czech Republic and Denmark under the name P. ×jutlandicus Zalewska-Galosz. The site in Lithuania, known since 1961, is the first natural habitat of long-lived hybrid between P. lucens and P. praelongus whose origin has been confirmed by molecular markers. The scarce records of this taxon indicate that the knowledge of the hybrid species of Potamogeton and their distribution is insufficient and that more extensive regional studies, including molecular methods, are needed.

RDNA and mtDNA analysis for the identification of genetic characters in the hybrid grouper derived from hybridization of Cromileptes altivelis (female) × Epinephelus lanceolatus (male)

BackgroundHybridization is a useful strategy to produce offspring with more desirable phenotypic characteristics than those of parents. The hybrid grouper derived from the cross of Cromileptes altivelis (♀, 2n = 48) with Epinephelus lanceolatus (♂, 2n = 48) exhibits improved growth compared with its female parent, which makes it valuable to aquaculture. However, the genetic traits of the hybrid grouper are poorly understood.ResultsThe observations showed that the hybrid grouper was diploid (2n = 48) and displayed intermediate morphology with the parent's measurable characteristics. The ribosomal DNA (rDNA) and mitochondria DNA (mtDNA) were characterized at molecular and phylogenetic level. High similarity and low genetic distance of 5S rDNA and mtDNA sequences between the hybrid grouper and C. altivelis showed that the hybrid grouper had a closer genetic relationship with female parents. The reconstructed phylogenetic tree based on COI gene and D-loop region of mtDNA recovered that mtDNA was maternally inherited in the hybrid grouper. Additionally, the DNA methylation level of 5S rDNA intergenic spacers (IGS) sequence was tested in here. The results showed that the DNA methylation status of the hybrid grouper was significantly lower than that of C. altivelis.ConclusionResults of this study provide important data on the genetic characteristics of the hybrid derived from the cross of C. altivelis and E. lanceolatus, and contribute the knowledge of both evolution and marine fish breeding.

Anopheles arabiensis continues to be the primary vector of Plasmodium falciparum after decades of malaria control in southwestern Ethiopia

BackgroundInvestigating the species distribution and their role in malaria transmission is important as it varies from place to place and is highly needed to design interventions appropriate to the site. The current study aimed to investigate the Anopheles mosquito species distribution and their infection rate in southwestern Ethiopia.MethodsThe study was conducted in 14 malaria-endemic kebeles (the smallest administrative unit), which were situated in eight different malaria-endemic districts and four zones in southwestern Ethiopia. Ten per cent of households in each village were visited to collect adult mosquitoes using Centers for Disease Control and Prevention (CDC) light traps. The larval and pupal collection was done from breeding sites within the villages, and reared to adults. Female mosquitoes were morphologically identified. The head and thorax of adult Anopheles mosquitoes were tested for circumsporozoite proteins (CSPs) using ELISA. At the same time, legs, wings, and abdomen were used to identify sibling species using PCR targeting the rDNA intergenic spacers region for species typing of the Anopheles funestus group and the internal transcribed spacer 2 region genes for Anopheles gambiae complex.ResultsA total of 1445 Anopheles mosquitoes comprising eight species were collected. Of 813 An. gambiae complex tested by PCR, 785 (97%) were Anopheles arabiensis, and the remaining 28 (3%) were not amplified. There were 133 An. funestus group captured and tested to identify the species, of which 117 (88%) were positive for Anopheles parensis, and 15 (11%) were not amplified. A single specimen (1%) showed a band with a different base pair length from the known An. funestus group species. Sequencing revealed this was Anopheles sergentii. Among 1399 Anopheles tested for CSPs by ELISA, 5 (0.4%) An. arabiensis were positive for Plasmodium falciparum and a single (0.07%) was positive for Plasmodium vivax.ConclusionsAnopheles arabiensis continues to play the principal role in malaria transmission despite implementing indoor-based interventions for decades. Sequencing results suggest that An. sergentii was amplified by the An. funestus group primer, producing PCR amplicon size of different length. Therefore, relying solely on amplifying a specific gene of interest in grouping species could be misleading, as different species may share the same gene.

Identificação de isolados de leveduras do gênero Trichosporon de infecções superficiais em pacientes do sexo masculino do Brasil Central: uma abordagem sobre a diversidade de infecções causadas por esse fungo basidiomiceto

Abstract The genus Trichosporon are currently recognized as opportunistic pathogens capable of causing superficial "white piedra" infections and potentially fatal invasive diseases (Trichosporonosis). In this work, determine the agent Trichosporon spp. isolated from the skin and appendages of a male population group in the Central-West region of Brazil. The isolates were analyzed by phenotypic, biochemical and molecular methods. Twenty-five strains of Trichosporon were isolated: T. asahii (18; 72%), followed by T. inkin (4; 16%) and T. faecale (3; 12%). Skin infections were the most affected (16; 64%) and the genitocrural region (13; 52%) was the most affected. The highest rate of isolation occurred between the ages of 21 and 30 years (9; 36%), with black men (African descent) (13; 52%) being the most affected by this type of superficial infection. After the advent of molecular techniques, more than 50 subspecies and about 16 different strains have been reported to cause human disease. In this series, three species of the genus Trichosporon of medical importance were highlighted, colonizing the genital and perigenital region of the studied population. For the identifications, classical phenotypic methods associated with genotypic identification were carried out, using molecular techniques based on the study of DNA; using sequence analysis of the DNA intergenic spacer region 1 (IGS1).

Molecular phylogenetic identification of Artemisia l. Species from Mongolia

The Artemisia L. genus, one of the largest genera in the Asteraceae family, consists of many medicinally important and phylogenetically unresolved species. To define the phylogenetic relationship of Artemisia species, nucleotide sequences of the nuclear ITS (Intergenic spacer DNA) region, chloroplast trnL-trnF intergenic spacer, partial sequences of plastid rbcL gene were identified from medicinally important 12 species included in 3 subgenera. The phylogenetic tree was constructed through the Neighbor-Joining and Maximum Parsimony analysis, respectively. The results of study revealed that the combination of the nucleotide sequences from the ITS and rbcL region was more efficient in determining the phylogenic relationship of species.

The search for hybrids between Myriophyllum sibiricum and M. spicatum (Haloragaceae) in North Eurasia allowed to clarify their morphological differences and distribution

Myriophyllum sibiricum and M. spicatum are sympatric in large part of their vast ranges in Eurasia and North America and have different habitat preferences only in East Europe and Siberia. Such absence of both geographic and ecological isolation should trigger extensive hybridization between these species that is indeed observed in North America. The hybrid could be reliably documented only with genetic markers, and in Eurasia this was done only in China. Using genetic markers (ITS2 region of nuclear ribosomal DNA and trnL-trnF intergenic spacer of cpDNA) we documented hybrids between M. sibiricum and M. spicatum on the North Asian Pacific islands with dynamic geological history and climate (Commander and the southern Kuril islands). The hybrid also originated in East Europe (Ivanovo Region) as a result of ecological isolation break due to rapid artificial habitat change. Using genetically verified material throughout temperate Eurasia we clarified morphological characters discriminating M. sibiricum and M. spicatum and, basing on them, refined the species distribution. For the first time we provide a full morphological characteristic of the hybrid between M. sibiricum and M. spicatum and suggest a name for it, M. × hybridum.

DNA Barcoding of Pomegranate (Punica granatum L.) Cultivars in Duhok Province- Kurdistan Region/ Iraq Using 18S–28S rRNA and ITS Region

Pomegranate is a tree species with a significant plant diversity, therefore molecular methods are necessary to define and verify approaches to recognize rapidly and correctly. This research looks at a genetic strategy for identifying pomegranate varieties in Duhok KRG. The approach is based on application of ITS region, PCR-RFLP, sequencing and SNP identification. For this study, 14 pomegranate accessions were taken from various regions, namely the Center of Duhok, Amedi, Akre, Zaxo, the South of Duhok, and Sulav. The PCR product of the 18S–28S rDNA intergenic spacer was 854bp, and the sequence analysis revealed a 99.94 percent similarity with other accession numbers in NCBI, demonstrating the use of the 18S–28S rDNA intergenic spacer for identifying and barcoding pomegranate cultivars. The PCR product of the ITS region was 700bp. This result was then employed for PCR-RFLP using two restriction enzymes namely RsaI GT/AC and HaeIII GG/CC which helped grouping as well as genetic similarities. This study Further involved sequencing examined genes were compared using the NCBI BLASTn tool and clustalo (Version 1.2.4) to determine gene location and SNP. According to this study, the result of PCR-RFLP revealed poor association between pomegranate physical morphology and genetic features, while SNP identification was identified between studied cultivars. Moreover, this result showed possible DNA barcoding of pomegranate cultivars under the study.

First report of 'Candidatus Phytoplasma asteris' associated with yellowing, scorching and decline of almond trees in India.

The almond, a commercially important tree nut crop worldwide, is native to the Mediterranean region. Stone fruit trees are affected by at least 14 'Candidatus Phytoplasma' species globally, among which 'Candidatus Phytoplasma asteris' is one of the most widespread phytoplasma infecting Prunus dulcis, causing aster yellows disease. Recently, almond plantations of Nauni region were consistently affected by phytoplasma, as evidenced by visible symptoms, fluorescent microscopic studies and molecular characterization. During several surveys from May to September 2020-2022, almond aster yellows phytoplasma disease showing symptoms such as chlorosis, inward rolling, reddening, scorching and decline with an incidence as high as 40%. Leaf samples were collected from symptomatic almond trees and the presence of phytoplasma was confirmed through fluorescent microscopic studies by employing DAPI (4, 6-diamino-2-phenylindole) that showed distinctive light blue flourescent phytoplasma bodies in phloem sieve tube elements. The presence of phytoplasma in symptomatic almond trees was further confirmed using nested PCR with specific primer pairs followed by amplification of 16S rDNA and 16S-23S rDNA intergenic spacer (IS) fragments. Sequencing and BLAST analysis of expected amplicon of the 16S rDNA gene confirmed that the almond phytoplasma in Himachal Pradesh was identical to the aster yellows group phytoplasma. Phylogenetic analysis of 16S rDNA almond phytoplasma also grouped 'Prunus dulcis' aster yellows phytoplasma within 16SrI-B subgroup showed 94% nucleotide identity with 'Prunus dulcis' phytoplasma PAEs3 and 'Prunus dulcis' phytoplasma PAE28 from Iran. This research presents the first host report of 'Candidatus Phytoplasma asteris' infecting almonds in India, expanding the knowledge of the diversity and distribution of phytoplasma strains affecting almond trees globally.

CRISPR-Cas Detection Coupled with Isothermal Amplification of Bursaphelenchus xylophilus.

The pine wood nematode (PWN), Bursaphelenchus xylophilus, causes significant damage to pine trees and, thus, poses a serious threat to pine forests worldwide, particularly in China, Korea, and Japan. A fast, affordable, and ultrasensitive detection of B. xylophilus is urgently needed for disease diagnosis. Recently, clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostics have reshaped molecular diagnosis, with high speed, precision, specificity, strength, efficiency, and versatility. Herein, we established two isothermal diagnostics methods based on CRISPR-based platforms (CRISPR/Cas12a and CRISPR/Cas13a) for B. xylophilus-specific detection via fluorescence or lateral-flow strip readout. The guide RNA and CRISPR RNA were designed to target the 5S ribosomal DNA intergenic spacer sequences region of B. xylophilus. Recombinase-aided amplification was used for preamplification whose reaction condition was 37°C for 15 min. The sensitivity of CRISPR/Cas12a could reach 94 copies/µl of plasmid DNA, or 2.37 copies/µl of purified genomic DNA (gDNA) within 45 min at 37°C, while the sensitivity of CRISPR/Cas13a was 1,000 times higher than that of CRISPR/Cas12a of plasmid DNA in 15 min or 100 times higher of purified gDNA at the minimum reaction time of 4 min via fluorescence measurement. The CRISPR/Cas12a assay enabled the detection of 0.01 PWNs per 100 mg of pine wood, 10 times higher than that of the CRISPR/Cas13a assay. This work enriches molecular detection approaches for B. xylophilus and provides huge potential for ultrasensitive and rapid methods to detect B. xylophilus in pine wood, facilitating point-of-sample diagnostic processing for pine wilt disease management.

Identification of Fusarium oxysporum f. sp. lactucae Race 1 as the Causal Agent of Lettuce Fusarium Wilt in Greece, Commercial Cultivars' Susceptibility, and Temporal Expression of Defense-Related Genes.

Fusarium wilt of lettuce is found throughout the world, causing significant yield losses. Lettuce is the most-cultivated leafy vegetable in Greece, affected by a large number of foliar and soil-borne pathogens. In this study, 84 isolates of Fusarium oxysporum, obtained from soil-grown lettuce plants exhibiting wilt symptoms, were characterized as belonging to race 1 of F. oxysporum f. sp. lactucae based on sequence analysis of the translation elongation factor 1-alpha (TEF1-α) gene and the rDNA intergenic spacer (rDNA-IGS) region. The isolates were also assigned to one single race through PCR assays with specific primers targeting race 1 and race 4 of the pathogen. In addition, four representative isolates were confirmed to be associated with race 1 based on the pathogenicity tests with a set of differential lettuce cultivars. Artificial inoculations on the most commonly cultivated lettuce cultivars in Greece revealed that the tested cultivars varied regarding their susceptibility to F. oxysporum f. sp. lactucae race 1. Cultivars (cvs.) "Cencibel" and "Lugano" were found to be highly susceptible, while cvs. "Sandalina" and "Starfighter" were the most resistant ones. Expression analysis of 10 defense-related genes (PRB1, HPL1, LTC1, SOD, ERF1, PAL1, LOX, MPK, BG, and GST) was carried out on artificially inoculated lettuce plants of the four above cultivars at different time points after inoculation. In resistant cultivars, a higher induction rate was observed for all the tested genes in comparison with the susceptible ones. Moreover, in resistant cultivars, all genes except LTC1, MPK, and GST showed their highest induction levels in their earliest stages of infection. The results of this study are expected to contribute to the implementation of an integrated management program to control Fusarium wilt of lettuce, based mainly on the use of resistant cultivars.

Single Copies of the 5S rRNA Inserted into 45S rDNA Intergenic Spacers in the Genomes of Nototheniidae (Perciformes, Actinopterygii).

In the vast majority of Animalia genomes, the 5S rRNA gene repeats are located on chromosomes outside of the 45S rDNA arrays of the nucleolar organiser (NOR). We analysed the genomic databases available and found that a 5S rDNA sequence is inserted into the intergenic spacer (IGS) between the 45S rDNA repeats in ten species of the family Nototheniidae (Perciformes, Actinopterigii). We call this sequence the NOR-5S rRNA gene. Along with Testudines and Crocodilia, this is the second case of a close association between four rRNA genes within one repetitive unit in deuterostomes. In both cases, NOR-5S is oriented opposite the 45S rDNA. None of the three nucleotide substitutions compared to the canonical 5S rRNA gene influenced the 5S rRNA secondary structure. In transcriptomes of the Patagonian toothfish, we only found NOR-5S rRNA reads in ovaries and early embryos, but not in testis or somatic tissues of adults. Thus, we consider the NOR-5S gene to be a maternal-type 5S rRNA template. The colocalization of the 5S and 45S ribosomal genes appears to be essential for the equimolar production of all four rRNAs in the species that show rDNA amplification during oogenesis. Most likely, the integration of 5S and NOR rRNA genes occurred prior to Nototheniidae lineage diversification.

Morphological and molecular characterization of Rhizoctonia solani AG-3 associated with tobacco target leaf spot in China.

Tobacco target leaf spot is a leaf disease that seriously affects both the quantity and quality of commercial tobacco crops and has caused huge economic losses in many countries and also pandemics in China since 2006. The anastomosis group-3 (AG-3) pathogen is divided into different subgroups namely AG-3 PT (potato type), AG-3TB (tobacco type), and AG-3 TM (tomato type), based on their host and the combined data from the ribosomal DNA internal transcribed spacer (rDNA-ITS), rDNA intergenic spacer 1 (rDNA-IGS1) regions, andtranslation elongation factor 1-α (tef-1α) gene. In this study, we collected tobacco leaves showing target spot symptom from four fields in China. We obtained 49 isolates from southwest China (Yunnan Provinces) and six isolates from northeast China (Liaoning Province). Phylogenetic tree based on rDNA-ITS region indicated that 51 isolates (49 isolates from Yunnan and two isolates from Liaoning) and 4 isolates from Liaoning belonged to AG-3 TB and AG-3 TM, respectively.

Organization of the 5S rDNA Intergenic Spacer and Its Use in the Molecular Taxonomy of the Genus Aconitum L.

Organization of the 5S rDNA Intergenic Spacer and Its Use in the Molecular Taxonomy of the Genus Aconitum L.

Plant Growth-Promoting (PGP) Traits of Endophytic Bacteria from In Vitro Cultivated Tectona grandis L.f

Tectona grandis L.f. (teak) is a tropical tree cultivated mainly due to its resistance, valuable wood and tolerance to biotic and abiotic factors. An abundant bacteria community exists in teak tissues and knowledge of the functional roles of teak endophytic bacteria, from in vitro tissue culture, is essential for improving micropropagation techniques. In this study, we isolated endophytic bacteria with plant growth-promoting (PGP) traits from two teak clones (Proteca® A3 and E4) in calli, leaves, and stems segments in a culture medium. We analyzed colony pigmentation, gram reaction, and evaluated PGP traits (phosphorous solubilization, nitrogen fixation and indol-acetic acid production) of 54 colonies from clone A3 and 50 colonies from clone E4. A total of 35 colonies of clone A3 and 42 colonies of clone E4 were capable of fixing nitrogen. Four isolated bacteria from clone A3 were capable of solubilizing phosphorous (P-Ca3(PO4)2), while no strain of E4 clone showed that capacity. Furthermore, 49 endophytic bacteria from clone A3 showed capacity to synthesize indol-acetic acid, while only 4 bacteria from the E4 clone presented that characteristic. We also identified six teak endophytic bacteria, by analysis of the 16S-23S rDNA intergenic spacer region, showing high identity with the genera Curtobacterium sp., Ochrobactrum sp., and Bacillus spp. Therefore, we demonstrate here that the abundant bacterial community existing in teak tissues, including those of in vitro cultivated plants, have PGP traits that can be further harnessed for preparation of bioformulations, for example. Our findings open the possibility for studying these isolated endophytic bacteria more closely in order to understand their association with teak growth.

Phenotypic and genotypic approach to characterize a Trueperella pecoris strain isolated from necrotic vestibulitis of a camel (Camelus dromedarius).

The present study was designed to characterize phenotypically and genotypically a Trueperella (T.) pecoris strain isolated from necrotic vestibulitis of a 10-year-old camel (Camelus dromedarius). The species identity of T. pecoris 203/7 investigated in the present study could be confirmed by phenotypic properties and by phylogenetic analyses based on partial sequencing of the 16S ribosomal RNA (rRNA) gene, the 16S-23S rDNA intergenic spacer region, the glyceraldehyde 3-phosphate dehydrogenase encoding gene gap, elongation factor Tu encoding gene tuf and the target gene rpoB encoding the β-subunit of bacterial RNA polymerase. T. pecoris strain 203/7 was grouped within the genus Trueperella in the family Arcanobacteriaceae. The 16S rRNA gene analysis showed a sequence identity of 99·9% to reference strain T. pecoris DSM 111392T . The present isolate was clearly identified as T. pecoris, the most recently described species of the genus Trueperella. Strain T. pecoris 203/7 was isolated in moderate numbers from necrotic vestibulitis of the camel and could be of some importance for the infectious process. However, the investigated strain represents the first isolation of T. pecoris from a camel.

Study and Physical Mapping of the Species-Specific Tandem Repeat CS-237 Linked with 45S Ribosomal DNA Intergenic Spacer in Cannabis sativa L.

Hemp (Cannabis sativa L.) is a valuable crop and model plant for studying sex chromosomes. The scientific interest in the plant has led to its whole genome sequencing and the determination of its cytogenetic characteristics. A range of cytogenetic markers (subtelomeric repeat CS-1, 5S rDNA, and 45S rDNA) has been mapped onto hemp’s chromosomes by fluorescent in situ hybridization (FISH). In this study, another cytogenetic marker (the tandem repeat CS-237, with a 237 bp monomer) was found, studied, and localized on chromosomes by FISH. The signal distribution and karyotyping revealed that the CS-237 probe was localized in chromosome 6 with one hybridization site and in chromosome 8 with two hybridization sites, one of which colocalizes with the 45S rDNA probe (with which a nucleolus organizer region, NOR, was detected). A BLAST analysis of the genomic data and PCR experiments showed that the modified CS-237 monomers (delCS-237, 208 bp in size) were present in the intergenic spacers (IGSs) of hemp 45S rDNA monomers. Such a feature was firstly observed in Cannabaceae species. However, IGS-linked DNA repeats were found in several plant species of other families (Fabaceae, Solanaceae, and Asteraceae). This phenomenon is discussed in this article. The example of CS-237 may be useful for further studying the phenomenon as well as for the physical mapping of hemp chromosomes.

Phylogeography and Population Genetics of Rosa chinensis var. spontanea and R. lucidissima Complex, the Important Ancestor of Modern Roses.

Rosa chinensis var. spontanea and R. lucidissima complex are the morphologically very similar key ancestors of modern roses with high importance in rose research and breeding. Although widely distributed in subtropical central and southwestern China, these two taxa are highly endangered. We sampled a total of 221 specimens and 330 DNA samples from 25 populations across the two taxa's whole range. Leaf morphological traits were compared. Two chloroplast DNA intergenic spacers (trnG-trnS, petL-psbE) and ITS were used for population genetics and phylogenetic study to delimit the boundary between the two taxa, assess the genetic variation, uncover the possible evolutionary mechanism responsible for the differentiation within the complex, and make the conservation recommendations. The complex exhibited high levels of genetic variation (hTcpDNA = 0.768, hTITS = 0.726) and high population differentiation even over small geographic distance. We suggest R. chinensis var. spontanea and R. lucidissma be treated as independent taxa, and the northern populations around and within the Sichuan Basin being R. chinensis var. spontanea, having broader leaflets and paler full-blooming flowers, while those in the middle and southern Yunnan-Guizhou Plateau and the adjacent regions being R. lucidissma, having narrower leaflets and darker full-blooming flowers. Transitional areas between the southeastern Sichuan Basin and northeastern Guizhou are the contact or the hybridization zone of the two taxa. Ancestral haplotypes of the complex (R. lucidissma) evolved at about 1.21–0.86 Mya in southeastern Yunnan-Guizhou Plateau and its adjacent regions and survived there during the Quaternary Oscillation. Ancestral haplotypes of R. chinensis var. spontanea deviated from R. lucidissma at about 0.022–0.031 Mya at the transitional areas (Daloushan and Wulingshan Mountains) between the northeastern edge of Yunnan-Guizhou Plaeteau and the southeastern border of Sichuan Basin, where they survived the LGM. The evolution of the complex included spatial isolation and inter-species hybridization. The complex's endangered status might be the result of over-exploitation for its ornamental and medical value, or due to reforestation of some originally open habitats. We provide specific recommendations for the two taxa's in situ and ex situ conservation.

Moleculer study of acenitobacter bumannii associated with corona virus disease

In this current study, 120 samples were taken from Corona virus patients of different ages and of both sexes (males and females), who are in isolation units for Corona virus disease in hospitals in Muthanna Governorate during the period from (September to April) and were cultivated in the Chrom agar Base Acinetobacter. After determine the phenotypic and external characteristics, and conduct chemical tests, Then it was diagnosed by 16S-23S ribosomal DNA intergenic spacer region after conducting chemical and molecular tests , 24 out of 120 isolates were confirmed as Acenitobacter bumannii , Where 10 positive samples were selected for testing 16S-23S ribosomal DNA intergenic spacer region It was diagnosed as Acenitobacter bumannii. The gene was diagnosed PonA gene responsible for the enzyme penicillin-binding protein 1a, The gene responsible for the enzyme Beta-Lactamases PER-1 is the BlaPER1 gene, As the most important virulence factors in Acenitobacter bumannii , Because the two enzymes played an important role in the pathogenesis of these bacteria . And the result was (100% of the PonA gene and 40% of the blaPER1 gene).

Structure analysis of the ribosomal intergenic spacer region of Phaeoacremonium italicum as a study model

Increasing recognition of novel Phaeoacremonium species, and their recent taxonomic reassignment through phylogeny based on the β-tubulin and actin genes, have highlighted the presence of paraphyly, intraspecific variation, and incongruence of some Phaeoacremonium species. This study investigated the intergenic spacer rDNA regions of a representative collection of 31 Phaeoacremonium italicum strains, and compared their structures with those of the closest related species, Phaeoacremonium alvesii and Phaeoacremonium rubrigenum. These intergenic spacer sequences had five categories of repeat elements that were organised into distinct patterns. Morphological analyses of the P. italicum strains provided a more detailed description of P. italicum. The phylogenetic tree constructed using the intergenic spacer sequences compared with that obtained by combined analysis of β-tubulin and actin sequences indicated that the intergenic spacer rDNA region distinguished intraspecific and interspecific variations. Further molecular studies are required to determine whether intergenic spacer sequences can improve precision in defining Phaeoacremonium phylogeny, and prevent misidentification and the introduction of vague species boundaries for the genus.