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Single Copy Gene (single + copy_gene)
Selected AbstractsApis mellifera ultraspiracle: cDNA sequence and rapid up-regulation by juvenile hormoneINSECT MOLECULAR BIOLOGY, Issue 5 2004A. R. Barchuk Abstract Two hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH) are key regulators of insect development including the differentiation of the alternative caste phenotypes of social insects. In addition, JH plays a different role in adult honey bees, acting as a ,behavioural pacemaker'. The functional receptor for 20E is a heterodimer consisting of the ecdysone receptor and ultraspiracle (USP) whereas the identity of the JH receptor remains unknown. We have cloned and sequenced a cDNA encoding Apis mellifera ultraspiracle (AMUSP) and examined its responses to JH. A rapid, but transient up-regulation of the AMUSP messenger is observed in the fat bodies of both queens and workers. AMusp appears to be a single copy gene that produces two transcripts (,4 and ,5 kb) that are differentially expressed in the animal's body. The predicted AMUSP protein shows greater sequence similarity to its orthologues from the vertebrate,crab,tick,locust group than to the dipteran,lepidopteran group. These characteristics and the rapid up-regulation by JH suggest that some of the USP functions in the honey bee may depend on ligand binding. [source] No evidence for the ,Meselson effect' in parthenogenetic oribatid mites (Oribatida, Acari)JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2006I. SCHAEFER Abstract It has been hypothesized that in ancient apomictic, nonrecombining lineages the two alleles of a single copy gene will become highly divergent as a result of the independent accumulation of mutations (Meselson effect). We used a partial sequence of the elongation factor-1, (ef-1,) and the heat shock protein 82 (hsp82) genes to test this hypothesis for putative ancient parthenogenetic oribatid mite lineages. In addition, we tested if the hsp82 gene is fully transcribed by sequencing the cDNA and we also tested if there is evidence for recombination and gene conversion in sexual and parthenogenetic oribatid mite species. The average maximum intra-specific divergence in the ef-1, was 2.7% in three parthenogenetic species and 8.6% in three sexual species; the average maximum intra-individual genetic divergence was 0.9% in the parthenogenetic and 6.0% in the sexual species. In the hsp82 gene the average maximum intra-individual genetic divergence in the sexual species Steganacarus magnus and in the parthenogenetic species Platynothrus peltifer was 1.1% and 1.2%, respectively. None of the differences were statistically significant. The cDNA data indicated that the hsp82 sequence is transcribed and intron-free. Likelihood permutation tests indicate that ef-1, has undergone recombination in all three studied sexual species and gene conversion in two of the sexual species, but neither process has occurred in any of the parthenogenetic species. No evidence for recombination or gene conversion was found for sexual or parthenogenetic oribatid mite species in the hsp 82 gene. There appears to be no Meselson effect in parthenogenetic oribatid mite species. Presumably, their low genetic divergence is due to automixis, other homogenizing mechanisms or strong selection to keep both the ef-1, and the hsp82 gene functioning. [source] Antisense-Mediated Depletion of Tomato Chloroplast Omega-3 Fatty Acid Desaturase Enhances Thermal ToleranceJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 9 2006Xun-Yan Liu Abstract A chloroplast-localized tomato (Lycopersicon esculentum Mill.) ,-3 fatty acid desaturase gene (LeFAD7) was isolated and characterized with regard to its sequence, response to various temperatures, and function in antisense transgenic tomato plants. The deduced amino acid sequence had four histidine-rich regions, of which three regions were highly conserved throughout the whole ,-3 fatty acid desaturase gene family. Southern blotting analysis showed that LeFAD7 was encoded by a single copy gene and had two homologous genes in the tomato genome. Northern blot showed that LeFAD7 was expressed in all organs and was especially abundant in leaf tissue. Meanwhile, expression of LeFAD7 was induced by chilling stress (4 °C), but was inhibited by high temperature (45 °C), in leaves. Transgenic tomato plants were produced by integration of the antisense LeFAD7 DNA under the control of a CaMV35S promoter into the genome. Antisense transgenic plants with lower 18:3 content could maintain a higher maximal photochemical efficiency (Fv/Fm) and O2 evolution rate than wild-type plants. These results suggested that silence of the LeFAD7 gene alleviated high-temperature stress. There was also a correlation between the low content of 18:3 resulting from silence of the LeFAD7 gene and tolerance to high-temperature stress. (Managing editor: Li-Hui Zhao) [source] Petunia Germinating Pollen S/D3 Interacts with S-RNases in Petunia hybrida Vilm.JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 5 2006Yan-Xia Guo Abstract Self-incompatibility (SI) is a genetic mechanism of self/non-self pollen recognition to prevent self-fertilization in many flowering plants and, in most cases, this is controlled by a multi-allelic S-locus. S-RNase and S-locus F box (SLF) proteins have been shown to be the female and male determinants of gametophytic self-incompatibility (GSI), respectively, in the Solanaceae, Scrophulariaceae and Rosaceae. Nevertheless, it is thought that additional factors are required for the SI response. Herein, we constructed a mature anther cDNA library from a self-incompatible Petunia hybrida Vilm. line of the S3S3 haplotype. Using AhS2-RNase from Antirrhinum hispanicum as a bait for yeast two-hybrid screening, we found that petunia germinating pollen (PGP) S/D3 was capable of interacting physically with the bait. However, the interaction lacked haplotype specificity. The PGPS/D3 gene is a single copy gene that is expressed in tissues such as the style, ovary, pollen, and leaf. The PGPS/D3::GFP (green fluorescence protein) construct was detected in both the membrane and cytoplasm. The implications of these findings in the operation of S-RNase-based SI are discussed. (Managing editor: Li-Hui Zhao) [source] Shorter telomeres are associated with mortality in those with APOE ,4 and dementiaANNALS OF NEUROLOGY, Issue 2 2006Lawrence S. Honig MD Objective Reduced telomere length may be a marker of biological aging. We hypothesized that telomere length might thus relate to increased risk for dementia and mortality. Methods This nested case,control study used stored leukocyte DNA from 257 individuals (mean age, 81.4 ± 7.9 years; 64.6% female; 44.7% Hispanic, 33.5% non-Hispanic black, and 21.8% non-Hispanic white). Our assay used real-time polymerase chain reaction, with two separate reactions amplifying telomere sequence and reference single copy gene (ribosomal-protein-P0), providing a calculated telomere-to-single copy gene (T/S) ratio. Results Mean telomere length was shorter among subjects dying during follow-up than in those surviving (0.453 ± 0.211 vs 0.525 ± 0.226 [± standard deviation]; p < 0.009). It was also shorter in those with Alzheimer's disease compared with control subjects (0.458 ± 0.207 vs 0.516 ± 0.229; p < 0.03). For participants with Alzheimer's disease, compared with those with the longest telomeres, the mortality odds ratio (OR) was 4.8 (95% confidence interval [CI], 1.7,13.8) in those with intermediate-length telomeres and 7.3 (95% CI, 2.4,22.0) in those with the shortest telomeres. The presence of an ,4 allele also increased the mortality OR, with an OR of 5.8 (95% CI, 1.3,26.4) for intermediate-length telomeres and an OR of 9.0 (95% CI, 1.9,41) for the shortest telomeres. Interpretation Our findings suggest that leukocyte telomere length is related to both dementia and mortality and may be a marker of biological aging. Ann Neurol 2006; [source] Isolation and characterization of farnesyl diphosphate synthase from the cotton boll weevil, Anthonomus grandisARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2009A. Huma Taban Abstract Farnesyl diphosphate synthase (FPPS) catalyzes the consecutive condensation of two molecules of isopentenyl diphosphate with dimethylallyl diphosphate to form farnesyl diphosphate (FPP). In insects, FPP is used for the synthesis of ubiquinones, dolicols, protein prenyl groups, and juvenile hormone. A full-length cDNA of FPPS was cloned from the cotton boll weevil, Anthonomus grandis (AgFPPS). AgFPPS cDNA consists of 1,835 nucleotides and encodes a protein of 438 amino acids. The deduced amino acid sequence has high similarity to previously isolated insect FPPSs and other known FPPSs. Recombinant AgFPPS expressed in E. coli converted labeled isopentenyl diphosphate in the presence of dimethylallyl diphosphate to FPP. Southern blot analysis indicated the presence of a single copy gene. Using molecular modeling, the three-dimensional structure of coleopteran FPPS was determined and compared to the X-ray crystal structure of avian FPPS. The ,-helical fold is conserved in AgFPPS and the size of the active site cavity is consistent with the enzyme being a FPPS. © 2009 Wiley Periodicals, Inc. [source] | ||||||||||