Search

Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis with worldwide distribution. This study evaluated actin genotypes of T. vaginalis isolates using PCR–RFLP and sequence analysis in Tehran, Iran. Overall, 850 vaginal samples were collected from women admitted to hospitals affiliated with the Iran University of Medical Sciences in Tehran from 2020-to 2021. The samples were examined by wet mount and cultured. The parasites were harvested, and PCR–RFLP was performed using three endonuclease enzymes of HindII, MseI, and RsaI on all T. vaginalis isolates. Digestion patterns were then compared, and the genotype of these isolates was defined. The PCR products were sequenced. Overall, 12 (1.4%) isolates of T. vaginalis were identified from 850 vaginal samples collected. The most common genotypes were genotype E, seven (58.3%) and genotype G, three (25%), followed by genotype I, two (%16.7), using PCR–RFLP patterns and sequencing. No pattern indicative of mixed infection was found. PCR–RFLP is a proper technique to detect different T. vaginalis isolates, and noticeable polymorphism was found between isolates. Genotype E was the most common genotype in the studied group. The phylogenetic analysis indicated the T. vaginalis genotype E isolates in a distinct group compared to the genotypes G and I that evolved from a common ancestor. [ABSTRACT FROM AUTHOR]

Actin is a multi-functional gene family that can be divided into muscle-type actins and non-muscle-type actins. In this study, 37 unigenes encoding actins were identified from RNA-Seq data of Pacific white shrimp, Litopenaeus vannamei. According to phylogenetic analysis, four and three cDNAs belong to cytoplasmic- and heart-type actins and were named LvActinCT and LvActinHT, respectively. 10 cDNAs belong to the slow-type skeletal muscle actins, and 18 belong to the fast-type skeletal muscle actins; they were designated LvActinSSK and LvActinFSK, respectively. Some muscle actin genes formed gene clusters in the genome. Multiple alternative transcription starts sites (ATSSs) were found for LvActinCT1. Based on the early developmental expression profile, almost all LvActins were highly expressed between the early limb bud and post-larval stages. Using LvActinSSK5 as probes, slow-type muscle was localized in pleopod muscle and superficial ventral muscle. We also found three actin genes that were down-regulated in the hemocytes of white spot syndrome virus (WSSV)- and Vibrio parahaemolyticus-infected L. vannamei. This study provides valuable information on the actin gene structure of shrimp, furthers our understanding of the shrimp muscle system and helps us develop strategies for disease control and sustainable shrimp farming. [ABSTRACT FROM AUTHOR]

For consumers, honey is a natural product that should not be subjected to treatment or alteration. Since the question of the presence of genetically modified organisms concerned pollen in honey, the aim of this research was to find an alternative, however, practical and efficient method of honey and bee pollen DNA extraction for routine analysis application. Furthermore, to evaluate the extracted DNA, a real-time PCR system based on the actin gene was optimized and validated in fast mode for the first time to reduce analysis time. To develop an alternative DNA extraction protocol, two already published procedures were combined and tested with some variations, in particular without beads/filters used to grind/enrich pollen. The best approach found in terms of quantity and quality of extracted DNA was a combination of the pretreatment and the extraction method, described in the German guideline, with some modifications and the addition of a DNA purification kit. This protocol was validated with DNA extracts from honey and bee pollen and it was applied to 18 commercial honey samples. Furthermore, a sample proved positive in transgenic screening elements analysis and for transgenic event identification, a knowledge-based approach was adopted. Since the DNA extraction protocol proved suitable, it could be applied for other analysis such as molecular species characterization, the study of traceability, and environmental monitoring, considering honey as a vector of authorized and not authorized genetically modified organisms. [ABSTRACT FROM AUTHOR]

Protozoan parasites of the genus Entamoeba infect many classes of vertebrates and are primarily classified based on morphological criteria. To date, only a few species have been proven to cause disease. Here, we examined the pathology of infected pigs with hemorrhage and detected Entamoeba parasites. Isolates were characterized genetically and ultrastructurally to identify the species. Histopathologically, bleeding and thrombus formation were seen only in the large intestine mucosa, where a large number of trophozoites or some Entamoeba cysts were observed around breakdowns in the lamina propria. No screw-shaped bacteria were detected in the lesions, and no pathogenic bacteria such as Brachyspira spp. were detected in fecal cultures. Interestingly, electron microscopy revealed that the parasites possessed mitochondrial organelles, unlike other Entamoeba spp. The isolates were identified as Entamoeba suis by PCR analysis and sequencing of the small subunit ribosomal RNA (SSU rRNA) gene. In phylogenetic analyses based on the actin gene, the E. suis isolate formed a cluster with Entamoeba histolytica and Entamoeba invadens, as well as with other parasites of the Amoebidae. Whether the pathogenicity of the E. suis isolate is affected by the severity of infection or host health status remains unclear; however, our results suggest that E. suis could cause or exacerbate clinical symptoms such as hemorrhagic colitis or diarrhea. [ABSTRACT FROM AUTHOR]

Regulation of the vertebrate actin multigene family involves the recognition of various regulatory sequences (cis-acting elements) that specify the distinct tissue type and developmental program of expression for each actin paralogue, which implies that the distribution of cis-acting elements may be unique for each paralogue gene. To elucidate the evolution of these unique distribution patterns, we improved a method to scan for cis-acting elements in the 5′ flanking regulatory region of genes and used it to analyze five cis-acting elements (SRE, MyoD binding site, Elk-1 binding site, positive and negative YY1 binding sites) of six actin paralogue genes (β and γ cytoplasmic actins, α and γ smooth muscle actins, and α skeletal and α cardiac actins) among various vertebrates. It was shown that although an element(s) may exist in all paralogue genes of the same species, its numbers, compositions, and distribution patterns or even sequences vary remarkably among paralogues, which contributes to their different tissue- and developmental-specific expression. However, each pair of coexpressed paralogues has some certain similarity in distribution patterns. Furthermore, among various orthologues of actin genes derived from diverse vertebrates, the sequences, numbers, and distribution patterns of these cis-acting elements are highly conserved or even identical in the long run of phylogeny of vertebrates. Taken together, the results described above strongly indicate that not only the structures of actins but also their expression patterns are essential in both the phylogeny and the physiology of vertebrates. The distribution patterns of cis-acting elements of various actin genes can be regarded as indicators of both horizontal (paralogous) and vertical (orthologous) evolution of actins. [ABSTRACT FROM AUTHOR]

This paper reports the cloning and sequencing of a Phytophthora megasperma actin gene. Sequence analysis revealed that the gene does not contain introns and encodes a putative actin protein remarkably diverged from any other known actins. Genomic Southern analysis indicates that there is a single actin gene per haploid genome, which is actively transcribed in vivo, as revealed by S1 mapping of the transcripts. The transcripts are heterogeneous in size because they have different 3′ termini, none of which contains the conventional AATAAA polyadenylation signal. [ABSTRACT FROM AUTHOR]

The relationship between transcriptional activity and gene association with the nuclear matrix has been investigated in Drosophila melanogaster. The nuclear matrix of Schneider cell line 2 of Drosophila was isolated and observed to conform to expected dimensions in phase contrast and scanning electron microscopic preparations. This structure contains proteins that appear similar to the intact nucleus. High salt extracted nuclei digested with DNase I released 98% of the DNA, whereas digestion with Eco RI released a maximum of 80%. These and other nuclease digestions indicate that satellite DNA as well as some unique sequence DNA are bound to the nuclear matrix. A consitutively transcribed actin gene was enriched in the nuclear matrix bound DNA. Two other nontrascribed genes, a muscle-specific actin gene and the myosin heavy chain gene, showed no enrichment in nuclear matrix DNA. [ABSTRACT FROM AUTHOR]

The actin gene family of the sea urchin Lytechinus pictus includes a single muscle actin gene, LpM, and four cytoskeletal actin genes: LpC1, LpC2, LpC3, and LpC4. The origin and relationship of these actin genes to members of the actin gene family of the sea urchin Strongylocentrotus purpuratus were considered. Comparison of deduced amino acid sequences suggested a close relationship between LpC1 and the CyI-CyII subfamily of S. purpuratus actin genes, and between LpC2 and the CyIII subfamily of S. purpuratus actin genes; the muscle actin genes were orthologous. It is proposed that two divergent cytoskeletal actin genes of the common ancestral sea urchin gave rise by duplication to the extant cytoskeletal actin genes of these species, some of which have changed 3′ noncoding sequences while others have maintained a terminus highly conserved among sea urchin actin genes. [ABSTRACT FROM AUTHOR]

Based on the results of cytological studies, it has been assumed that Cyanidioschyzon merolae does not contain actin genes. However, Southern hybridization of C. merolae cell-nuclear DNA with a yeast actin-gene probe has suggested the presence of an actin gene in the C. merolae genome. In the present study, an actin gene was isolated from a C. merolae genomic library using a yeast actin-gene probe. The C. merolae actin gene has no intron. The predicted actin is composed of 377 amino acids and has an estimated molecular mass of 42003 Da. Southern hybridization indicated that the C. merolae genome contains only one actin gene. This gene is transcribed at a size of 2.4 kb. When Southern hybridization was performed with C. merolae chromosomes separated by pulsed-field gel electrophoresis, a band appeared on unseparated chromosomes XI and XII. A phylogenetic tree based on known eucaryote actin-gene sequences revealed that C. merolae diverged after the division of Protozoa, but before the division of Fungi, Animalia and Chlorophyta. [ABSTRACT FROM AUTHOR]

Southern blot analysis of Volvox carteri DNA indicated the presence of a single actin gene; the nucleotide sequence of that gene is reported here. In comparison with plant animal and fungal actins, the derived primary structure of 377 amino acids is highly conserved yielding similarity values of 79% to 94% (including nonidentical, conservative exchanges). In contrast, the intron structure of the gene is highly unusual: in addition to one intron in the 5′ untranslated region (ten nucleotides upstream of the initiator ATG), it has eight introns in the coding region, only three of which are in locations where introns have previously been reported. Transcription starts 26 nucleotides downstream of the putative TATA box and 70 nucleotides downstream of a conspicuous CCAAT motif. A potential polyadenylation signal, TGTAA, is located 366 nucleotides downstream of the terminator TAA. Northern hybridization indicates that the actin gene is transcribed throughout the Volvox life cycle with only a slight depression during the release of juveniles from mother spheroids. This pattern of gene expression suggests that actin may assume various functional roles in the differentiation and growth of Volvox. [ABSTRACT FROM AUTHOR]

An expression vector was constructed containing the entire bovine papilloma virus (BPV-1) genome and part of the a-actin gene of Xenopus laevis cloned in the antisense orientation into the neomycin resistance gene under the control of the herpes simplex virus (HSV) thymidine kinase (TK) promoter. When this vector is microinjected into X. laevis embryos it replicates extrachromosomally, at least up to the tadpole stage, and a fusion RNA is synthesized after the mid blastula transition (MBT). The expression of the antisense gene results in a morphological abnormality of somites demonstrating that antisense RNA generated by an episomal replicating expression vector can inhibit the expression of a selected gene during early embryogenesis of X. laevis. [ABSTRACT FROM AUTHOR]