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1.
Effects of recent acidification on Cladocera in small clear-water lakes studied by means of sedimentary remains 总被引:1,自引:1,他引:0
Cladoceran populations, as revealed by sedimentary remains, were studied in six lakes which by diatom evidence have become
strongly acidified during the past 30 years. The accumulation rates of cladoceran remains and in two of the most strongly
acidified lakes both relative and absolute numbers ofBosmina greatly increased during this period. Species numbers were not reduced, but there were shifts in relative abundances of cladoceran
species.Bosmina longispina dominated all the lakes. Low pH (4.7) seemed not to be straight-forwardly harmful toDaphnia longispina, but the relative abundances of this taxon were reduced because ofBosmina. 相似文献
2.
3.
Kristian Aspegren Leena Mannonen Anneli Ritala Riitta Puupponen-Pimiä Ulrika Kurtén Marjatta Salmenkallio-Marttila Veli Kauppinen Teemu H. Teeri 《Molecular breeding : new strategies in plant improvement》1995,1(1):91-99
Transgenic plant cell cultures have a potential for production and secretion of important proteins and peptides. To assess the possibilities of using a stable barley suspension culture for secretion of heterologous proteins in active form, we expressed the cDNA of the thermostable-glucanase (EGI) ofTrichoderma reesei in barley suspension cells. The cDNA coding for EGI and its signal sequence was placed under the control of the CaMV 35S promoter and the construction was transferred to the cells by particle bombardment. Stably transformed lines were obtained by selecting for a cotransformed antibiotic resistance marker. The expression of EGI cDNA led to accumulation of EGI in the culture medium, as shown by analysis with EGI-specific antibodies. Enzymatic assays confirmed that the EGI secreted by the suspension cells retained its activity and thermostable character. Furthermore, it was shown that the enzyme produced by the transgenic suspension culture could be used for degradation of soluble-glucans during mashing. 相似文献
4.
We studied the nest defense behavior of Eurasian kestrels (Falcotinnunculus) towards a stuffed pine marten (Martes martes) througha 3-year vole cycle (199092) in western Finland. Survivalprobability of offspring decreases with a later start of breeding,and, therefore, early breeders should protect their offspringmore than late ones. We found this true for males during theincubation period, but not for females. In addition, we expectedthe nest defense intensity to increase with offspring number.During the incubation period, this was true for females, butnot for males. During the nestling phase, parents did not adjusttheir defense effort to natural or manipulated (by one to twoyoung) brood size. Survival prospects of kestrel offspring werehighest in the increasing vole year 1991 and lowest in the decreasingvole year 1992, and, therefore, we expected the defense activityof kestrels to follow the same trend. However, the oppositeresult appeared true for females with a similar tendency formales. Most hypotheses predicting avian nest defense behaviorwere not supported by our data. Temporally heterogeneous environmentand low degree of nest-site tenacity of migratory kestrels maymake them unfamiliar with environmental variation and survivalprospects of their offspring. Therefore, fitness benefits ofparental care are not predictable, and kestrels may thus adjusttheir parental effort to their own future reproductive potential(i.e., number of future breeding attempts), rather than to somecurrent investment indicator, like offspring age and number. 相似文献
5.
T. Schultz J. Soinila R. Tolonen O. Häppölä H. Uusitalo A. Salo 《The Histochemical journal》1994,26(7):563-570
Summary The distribution and origin of neuropeptide Y in the major salivary glands of the rat was studied by indirect immunofluorescence technique. Numerous nerve fibres immunoreactive for the peptide were seen in the parotid and sublingual glands. Most of the fibres were located around blood vessels and salivary acini. In the submandibular gland the number of immunoreactive nerve fibres around the acini was lower in comparison with that in the parotid and sublingual glands. Some immunoreactive nerve fibres were also found around or along intra- and interlobular ducts in all major salivary glands.A large number of the neuropeptide-containing neuronal cell bodies and nerve fibres were detected in the sympathetic superior cervical ganglion. Sympathetic postganglionic nerve trunks of this ganglion contained numerous immunoreactive nerve fibres as well. A subpopulation of the neuronal cell bodies in the submandibular ganglion were immunoreactive to neuropeptide Y.Both uni- and bilateral superior cervical ganglionectomies caused a significant decrease in the number of immunoreactive nerve fibres around the blood vessels in all the major salivary glands. However, these denervations did not affect the density of nerve fibres around the acini and ducts. On the contrary, unilateral parasympathetic denervation by sectioning the auriculotemporal nerve reduced the fibres around the secretory acini in the parotid gland remarkably, while only a minor reduction in the density of immunoreactive fibres associated with the blood vessels of the gland was detected. Unilateral electrocoagulation of the trigeminal nerve branches caused no detectable change in the density of immunoreactive nerve fibres in any of the major salivary glands.On the basis of the present findings it is concluded that neuropeptide Y-reactive nerve fibres present in all major salivary glands around the blood vessels seem to be mainly sympathetic, whereas those around the acini and ducts seems to be of parasympathetic origin. 相似文献
6.
Anneli Ritala Kristian Aspegren Ulrika Kurtén Marjatta Salmenkallio-Marttila Leena Mannonen Riitta Hannus Veli Kauppinen Teemu H. Teeri Tor-Magnus Enari 《Plant molecular biology》1994,24(2):317-325
Transgenic, fertile barley (Hordeum vulgare L.) from the Finnish elite cultivar Kymppi was obtained by particle bombardment of immature embryos. Immature embryos were bombarded to the embryonic axis side and grown to plants without selection. Neomycin phosphotransferase II (NPTII) activity was screened in small plantlets. One out of a total of 227 plants expressed the transferred nptII gene. This plant has until now produced 98 fertile spikes (T0), and four of the 90 T0 spikes analyzed to date contained the nptII gene. These shoots were further analyzed and they expressed the transferred gene. From green grains, embryos were isolated and grown to plantlets (T1). The four transgenic shoots of Toivo (the T0 plant) produced 25 plantlets as T1 progeny. Altogether fifteen of these T1 plants carried the transferred nptII gene as detected with the PCR technique, fourteen of which expressed the nptII gene. The integration and inheritance of the transferred nptII gene was confirmed by Southern blot hybridization. Although present as several copies, the transferred gene was inherited as a single Mendelian locus into the T2 progeny. 相似文献
7.
Yrjö Helariutta Paula Elomaa Mika Kotilainen Pauli Seppänen Teemu H. Teeri 《Plant molecular biology》1993,22(2):183-193
We are approaching corolla differentiation in Compositae by studying the regulation of flavonoid pathway genes during inflorescence development in gerbera. We have cloned a dfr cDNA from a ray floret corolla cDNA library of Gerbera hybrida var. Regina by a PCR technique based on homologies found in genes isolated from other plant species. The functionality of the clone was tested in vivo by complementing the dihydrokaempferol accumulating petunia mutant line RL01. By Southern blot analysis, G. hybrida var. Regina was shown to harbour a small family of dfr genes, one member of which was deduced to be mainly responsible for the DFR activity in corolla. Dfr expression in corolla correlates with the anthocyanin accumulation pattern: it is basipetally induced, epidermally specific and restricted to the ligular part of corolla. By comparing the dfr expression in different floret types during inflorescence development, we could see that dfr expression reflects developmental schemes of the outermost ray and trans florets, contrasted with that of the disc florets. 相似文献
8.
Lyzel S. Elias-Sonnenschein Seppo Helisalmi Teemu Natunen Anette Hall Teemu Paajanen Sanna-Kaisa Herukka Marjo Laitinen Anne M. Remes Anne M. Koivisto Kari M. Mattila Terho Lehtim?ki Frans R. J. Verhey Pieter Jelle Visser Hilkka Soininen Mikko Hiltunen 《PloS one》2013,8(4)
Objectives
To understand the relation between risk genes for Alzheimer’s disease (AD) and their influence on biomarkers for AD, we examined the association of AD in the Finnish cohort with single nucleotide polymorphisms (SNPs) from top AlzGene loci, genome-wide association studies (GWAS), and candidate gene studies; and tested the correlation between these SNPs and AD markers Aβ1–42, total tau (t-tau), and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF).Methods
We tested 25 SNPs for genetic association with clinical AD in our cohort comprised of 890 AD patients and 701-age matched healthy controls using logistic regression. For the correlational study with biomarkers, we tested 36 SNPs in a subset of 222 AD patients with available CSF using mixed models. Statistical analyses were adjusted for age, gender and APOE status. False discovery rate for multiple testing was applied. All participants were from academic hospital and research institutions in Finland.Results
APOE-ε4, CLU rs11136000, and MS4A4A rs2304933 correlated with significantly decreased Aβ1–42 (corrected p<0.05). At an uncorrected p<0.05, PPP3R1 rs1868402 and MAPT rs2435211 were related with increased t-tau; while SORL1 rs73595277 and MAPT rs16940758, with increased p-tau. Only TOMM40 rs2075650 showed association with clinical AD after adjusting for APOE-ε4 (p = 0.007), but not after multiple test correction (p>0.05).Conclusions
We provide evidence that APOE-ε4, CLU and MS4A4A, which have been identified in GWAS to be associated with AD, also significantly reduced CSF Aβ1–42 in AD. None of the other AlzGene and GWAS loci showed significant effects on CSF tau. The effects of other SNPs on CSF biomarkers and clinical AD diagnosis did not reach statistical significance. Our findings suggest that APOE-ε4, CLU and MS4A4A influence both AD risk and CSF Aβ1–42. 相似文献9.
10.