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1.
An analysis of patterns of cleavage of mtDNA by restriction endonucleases was performed for nine individuals from the Philippine population of native cattle. MtDNA polymorphisms were detected in the restriction patterns generated by the following six enzymes,BamHI,BglII,EcoRV,HindIII,PstI, andScaI. The restriction patterns showing polymorphisms were distributed nonrandomly among the nine individuals examined from the Philippine population of native cattle, indicating the existence of two separate types of mtDNA. These two types of mtDNA are very different from each other, at the level of subspecies. Since the native Philippine cattle are considered to represent an admixture of European and Indian cattle, the two types of mtDNA must be derived from the mtDNAs of both varieties. The polymorphic sites in mtDNA have been located on a restriction map, and the nucleotide substitutions at some of the sites have also been estimated.  相似文献   
2.
The cleavage patterns of mitochondrial DNAs (mtDNAs) were investigated from 15 lines of domestic fowls, Gallus gallus domesticus, using 11 restriction endonucleases. The cleavage patterns with 10 restriction endonucleases were identical in all the lines. A variant was found in a line of White Leghorn in the pattern with MspI digestions. Cleavage patterns of the red jungle fowl, Gallus gallus gallus, were identical to the common patterns shown by the 14 lines of domestic fowls.  相似文献   
3.
An analysis by restriction endonuclease digestion of ribosomal DNA (rDNA) was carried out in natural populations of Apodemus speciosus, a field mouse that is endemic to Japan. Two restriction sites, the EcoRI (E3) and DraI (D4) sites, in the nontranscribed spacer region downstream from the gene for 28S RNA showed polymorphism within and between individuals in the populations from the Japanese main islands. By contrast, populations from the small adjoining islands which are thought to have separated from the main islands 1–2 × 104 years ago showed relatively low levels of polymorphism within and between individuals, i.e., one of the polymorphic bands in the case of each enzyme was predominant in these populations, irrespective of the variants. These results indicate that the rate of fixation of site variations depends on population size and that the direction of fixation is random. Furthermore, each polymorphic restriction site seems to be fixed independently.Correspondence to: H. Suzuki  相似文献   
4.
Laboratory matings were attempted to establish breeding colonies of red-backed voles (Clethrionomys rufocanus bedformidae) as experimental animals. For these mating, 10 pairs of red-backed voles which were captured in the Tohbetsu region of Hokkaido, Japan and their litters were used. In the results for two years, 1987 to 1988, the rates of pregnancy, birth and weaning were 35.4%, 94.5% and 79.5%, respectively. The mean litter size was 5:1 +/- 1.6 with a range of 1 to 9. The mean gestation period was 20.0 +/- 0.7 days with a range of 18 to 22. These results suggest that planned production of red-backed voles in the laboratory is possible. To determine intraregional variations of red-backed voles with a view to the establishment of a strain by inbreeding, restriction patterns of mitochondrial DNAs using seven restriction endonucleases were compared. Four different patterns were obtained from wild red-backed voles used in the present study.  相似文献   
5.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been transmitted across all over the world, in contrast to the limited epidemic of genetically- and virologically-related SARS-CoV. However, the molecular basis explaining the difference in the virological characteristics among SARS-CoV-2 and SARS-CoV has been poorly defined. Here we identified that host sialoglycans play a significant role in the efficient spread of SARS-CoV-2 infection, while this was not the case with SARS-CoV. SARS-CoV-2 infection was significantly inhibited by α2-6-linked sialic acid-containing compounds, but not by α2–3 analog, in VeroE6/TMPRSS2 cells. The α2-6-linked compound bound to SARS-CoV-2 spike S1 subunit to competitively inhibit SARS-CoV-2 attachment to cells. Enzymatic removal of cell surface sialic acids impaired the interaction between SARS-CoV-2 spike and angiotensin-converting enzyme 2 (ACE2), and suppressed the efficient spread of SARS-CoV-2 infection over time, in contrast to its least effect on SARS-CoV spread. Our study provides a novel molecular basis of SARS-CoV-2 infection which illustrates the distinctive characteristics from SARS-CoV.  相似文献   
6.
Species of fleshy yellow Cantharellus are known as chanterelles, which are among the most popular wild edible mycorrhizal mushrooms in the world. However, pure culture isolates of Cantharellus are rare. We report an efficient isolation technique of the Japanese golden chanterelle, Cantharellus anzutake, from its ectomycorrhizal root tips. Field-sampled fresh ectomycorrhizal root tips of C. anzutake on various hosts such as pines, spruce, and oaks were vortexed with 0.005% Tween 80 solution, surface sterilized with 1% calcium hypochlorite solution, rinsed with sterilized distilled water, and placed on modified Norkrans’ C (MNC) agar plate medium. Most ectomycorrhizal root tips of C. anzutake produced yellowish mycelial colonies within a few months. In contrast, tissue isolation from basidiomata provided limited cultures of C. anzutake but much contamination of bacteria and molds, even on media that contained antibiotics. The established C. anzutake cultures had clamp connections on the hyphae and contained intracellular oily droplets. These cultured isolates were identified as C. anzutake by sequence analysis of the rRNA internal transcribed spacer (ITS) region and translation elongation factor EF1-alpha (tef-1) genes.  相似文献   
7.
ABSTRACT

Berberine (BBR) is a protoberberine alkaloid extracted from plants such as Coptis japonica (Ranunculaceae). In a previous report, we demonstrated the existence of a 11-hydroxylation pathway employed by BBR-utilizing bacteria for metabolism of BBR. In the present study, we report the identification of the genes brhA, brhB, and brhC as encoding a multicomponent BBR 11-hydroxylase in Burkholderia sp. strain CJ1. BrhA is belonging to the Rieske non-heme iron oxygenase (RO) family, a class of enzymes known to catalyze the first step in bacterial aromatic-ring hydroxylation. We further demonstrate that BrhA activity requires BrhB (ferredoxin reductase) and BrhC (ferredoxin) as electron transport chain components. A BLAST search revealed that BrhA exhibits 38% and 33% sequence identity to dicamba O-demethylase (DdmC; AY786443) and chloroacetanilide herbicides N-dealkylase (CndA; KJ461679), respectively. To our knowledge, this work represents the first report of a bacterial oxygenase catalyzing the metabolism of a polycyclic aromatic-ring alkaloid.

Abbreviations: BBR: berberine; D-BBR: demethyleneberberine; H-BBR: 11-hydroxyberberine; HD-BBR: 11-hydroxydemethyleneberberine; HDBA: 2-hydroxy-3,4-dimethoxybenzeneacetic acid; PAL: palmatine; H-PAL: 11-hydroxypalmatine; BRU: berberrubine; Fd: ferredoxin; FdR: ferredoxin reductase; ETC: electron transport chain  相似文献   
8.
9.
The shoot apical meristem is the ultimate source of the cells that constitute the entire aboveground portion of the plant body. In Arabidopsis thaliana, meristem maintenance is regulated by the negative feedback loop of WUSCHEL-CLAVATA (WUS-CLV). Although CLV-like genes, such as FLORAL ORGAN NUMBER1 (FON1) and FON2, have been shown to be involved in maintenance of the reproductive meristems in rice (Oryza sativa), current understanding of meristem maintenance remains insufficient. In this article, we demonstrate that the FON2-LIKE CLE PROTEIN1 (FCP1) and FCP2 genes encoding proteins with similar CLE domains are involved in negative regulation of meristem maintenance in the vegetative phase. In addition, we found that WUSCHEL-RELATED HOMEOBOX4 (WOX4) promotes the undifferentiated state of the meristem in rice and that WOX4 function is associated with cytokinin action. Consistent with similarities in the shoot apical meristem phenotypes caused by overexpression of FCP1 and downregulation of WOX4, expression of WOX4 was negatively regulated by FCP1 (FCP2). Thus, FCP1/2 and WOX4 are likely to be involved in maintenance of the vegetative meristem in rice.  相似文献   
10.
Abstract

2-Bromoadenosine-substituted analogues of 2–5A, p5′A2′p-5′A2′p5′(br2A), p5′(br2A)2′p5′A2′p5′A, and p5′(br2A)2′p5′(br2A)2′p-S′(br2A), were prepared via a modification of a lead ion-catalyzed ligation reaction and were subsequently converted into the corresponding 5′-triphosphates. Both binding and activation of human recombinant RNase L by various 2-bromoadenosine-substituted 2–5A analogues were examined. Among the 2-bromoadenosine-substituted 2–5A analogues, the analogue with 2-bromoadenosine residing in the 2′-terminal position, p5′A2′p5′A2′p-5′(br2A), showed the strongest binding affinity and was as effective as 2–5A itself as an activator of RNase L. The CD spectrum of p5′A2′p-5′A2′p5′(br2A) was superimposable on that of p5′A2′p5′A2′p5′A, indicative of an anti orientation about the base-glycoside bonds as in naturally occurring 2–5A.  相似文献   
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