Isolation of Chloroplast DNA from Pinus

Chloroplast DNA isolated from Japanese black pine [Pinus thunbergii)was digested with three restriction endonucleases. The sizeof this DNA was estimated to be 120 kbp. Chloroplast DNA fromJapanese red pine (P. densiflora) could be distinguished fromthat of P. thunbergii by BamHI restriction patterns. ³Present address: Kanto Forest Tree Breeding Institute, Kasahara,Mito, Ibaraki 310, Japan. (Received December 10, 1985; Accepted March 8, 1986)     

Aquaporin-4 expression in distal myopathy with rimmed vacuoles

ABSTRACT: BACKGROUND: Distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy is clinically characterized by the early involvement of distal leg muscles. The striking pathological features of the myopathy are muscle fibers with rimmed vacuoles. To date, the role of aquaporin-4 water channel in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy has not been studied. CASE PRESENTATION: Here, we studied the expression of aquaporin-4 in muscle fibers of a patient with distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy. Immunohistochemical and immunofluorescence analyses showed that sarcolemmal aquaporin-4 immunoreactivity was reduced in many muscle fibers of the patent. However, the intensity of aquaporin-4 staining was markedly increased at rimmed vacuoles or its surrounding areas and in some muscle fibers. The fast-twitch type 2 fibers were predominantly involved with the strong aquaporin-4-positive rimmed vacuoles and TAR-DNA-binding protein-43 aggregations. Rimmed vacuoles with strong aquaporin-4 expression seen in the distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy patient were not found in control muscles without evidence of neuromuscular disorders and the other disease-controls. CONCLUSIONS: Aquaporin-4 might be crucial in determining the survival or degeneration of fast-twitch type 2 fibers in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy.     

Effectiveness of zooprophylaxis in malaria control: a theoretical inquiry, with a model for mosquito populations with two bloodmeal hosts

A model for a vector mosquito population with two bloodmeal hosts (man and a domestic animal) was developed to study the influences of domestic animals on the frequency of mosquito bites on man and the endemicity of human malaria. The vector population model, including blood-feeding success in the adult stage (depending on host density and biting efficiency) and density-dependent regulation in the larval stage, was combined with the Ross-Macdonald malaria transmission model. Model analyses suggested that introduction of domestic animals easily fed upon by mosquitoes increases mosquito density and, in some situations, frequency of mosquito bites on man and the infection rate of malaria through increased success of blood-feeding. Extinction of malaria was predicted only when an extremely large number of easily accessible (as compared to man) domestic animals are introduced. Limitations in the concept of zooprophylaxis and problems of livestock management in malaria control are discussed.     

Complete nucleotide sequence of the <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>D. Don. chloroplast genome and comparative chloroplast genomics: diversified genomic structure of coniferous species

Background  

The recent determination of complete chloroplast (cp) genomic sequences of various plant species has enabled numerous comparative analyses as well as advances in plant and genome evolutionary studies. In angiosperms, the complete cp genome sequences of about 70 species have been determined, whereas those of only three gymnosperm species, Cycas taitungensis, Pinus thunbergii, and Pinus koraiensis have been established. The lack of information regarding the gene content and genomic structure of gymnosperm cp genomes may severely hamper further progress of plant and cp genome evolutionary studies. To address this need, we report here the complete nucleotide sequence of the cp genome of Cryptomeria japonica, the first in the Cupressaceae sensu lato of gymnosperms, and provide a comparative analysis of their gene content and genomic structure that illustrates the unique genomic features of gymnosperms.     

Univoltine and bivoltine life cycles in insects: A model with density-dependent selection

Selection for univoltine and bivoltine life cycles in insects under resource-limited but favourable temperature conditions is analyzed with a difference equation model including density-dependent population dynamics based on the conceptual framework of an evolutionarily stable strategy. The model predicts that the bivoltine type can spread in a univoltine population when the fraction of density-independent rate of annual increase by producing a second generation exceeds the survival rate during diapause of the univoltine type, but monopoly of the bivoltine type is not possible unless it attains an equilibrium population density exceeding that of the univoltine type. The applicability of the model prediction in explaining the occurrence of a partial bivoltine cycle in predominantly univoltine population in the temperate zones is discussed.     

Marriage season, promptness of successful pregnancy and first-born sex ratio in a historical natural fertility population – evidence for sex-dependent early pregnancy loss?

 We investigated population-based vital records of the seventeenth and eighteenth century French Canadian population to assess the effects of marriage season on the outcome of the first births under natural fertility conditions (n=21,698 marriages). Promptness of the first successful conception after marriage differed according to marriage season; the proportion of marriages with a marriage-first birth interval of 8.0–10.0 months was lowest (34%) for marriages in August–October (P=0.001). Although the male/female sex ratio of the babies born with an interval of 8.0–10.0 months was generally higher (1.10) than those with an interval of 10.0–24.0 months (1.05), the marriages in August–October resulted in a significantly reduced sex ratio (0.96) among only the prompt conceptions (P=0.026). We discuss whether this seasonal reduction of the sex ratio could be partly explained by a clustered pregnancy loss of male zygotes in early pregnancy. Received: 5 January 1998 / Accepted: 9 September 1998     

Effects of capacity on resource input and the aquatic metazoan community structure in phytotelmata

Aquatic metazoan communities in treeholes and bamboo stumps were studied on Tsushima Island, Japan, in March and June in relation to the habitat size and the resouce amount. The amount of leaf detritus increased with an increase in the capacity (volume) of the phytotelma. The input rate of leaves depended upon the opening area of the phytotelma. Twenty-one metazoan inhabitant taxa consisted of 17 dipteran saprophages, a helodid beetle larva, a nematoda, a naidid, and a predator,Toxorhynchites towadensis mosquito larva. Treeholes harbored 17 taxa and bamboo stumps 20; 16 taxa were common in both phytotelmata. The number of taxa and the biomass of metazoa per phytotelma was positively correlated with the capacity. The densities of dominant saprophages such as helodid, chironomid, andCulicoides larvae were positively correlated with the capacity of phytotelmata, and the variation in their abundance contributed much to the variation in the species composition in individual phytotelmata. With an increase in capacity, treeholes harbored more helodids andCulicoides, whereas bamboo stumps harbored more chironomids andDasyhelea. Thus, the amount of resource, species richness and biomass per phytotelma largely depended upon the capacity, and the difference in community structure between treeholes and bamboo stumps was attributable to the differential colonization patterns of different taxa.