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1.
A total of 20990 Finnish Ayrshire cows were phenotyped for the major milk proteins by isoelectric focusing in polyacrylamide gels. The predominant alleles in the Finnish Ayrshire were αS1-casein B (0.999), αS2-casein A (0.991), β-casein A1 (0.509) and α2 (0.490), α22-casein A (0.612) and β-lactoglobulin B (0.716). The K-casein E allele (0.307) was also rather common in the Finnish Ayrshire. A new K-casein variant (K-casein F) was demonstrated in two Finnish Ayrshire cows, a dam and a daughter.  相似文献   

2.
Genetic variation in blue whiting Micromesistius poutassou was investigated by starch gel electrophoresis of enzymes in tissue extracts. A total of 130 specimens from the spawning areas west of the British Isles were collected from trawl catches in 1990 ( n = 30) and 1992 ( n = 100). In 25 tissue enzyme loci screened for genetic variants in the 1990 sample, polymorphisms (0.95 criterion) were found at IDDH-2 *, IDHP-2 * and PGM-1 *, giving a frequency of polymorphic loci of P 0.95= 0.12. In pooled samples the average heterozygosity per locus was estimated at H e =0.043 and the effective number of alleles per locus at 2.20, 1.45 and 1.53, respectively, for IDDH-2 *, IDHP-2 * and PGM-1 *.  相似文献   

3.
4.
Borrelia burgdorferi , the causative agent of Lyme disease, activates multiple signalling pathways leading to induction of pro-inflammatory mediators at sites of inflammation. Binding of B. burgdorferi to integrin α3β1 on human chondrocytes activates signalling leading to release of several pro-inflammatory mediators, but the B. burgdorferi protein that binds integrin α3β1 and elicits this response has remained unknown. A search of the B. burgdorferi genome for a canonical integrin binding motif, the RGD (Arg–Gly–Asp) tripeptide, revealed several candidate ligands for integrins. In this study we show that one of these candidates, BBB07, binds to integrin α3β1 and inhibits attachment of intact B. burgdorferi to the same integrin. BBB07 is expressed during murine infection as demonstrated by recognition by infected mouse sera. Recombinant purified BBB07 induces pro-inflammatory mediators in primary human chondrocyte cells by interaction with integrin α3β1. This interaction is specific, as P66, another integrin ligand of B. burgdorferi , does not activate signalling through α3β1. In summary, we have identified a B. burgdorferi protein, BBB07, that interacts with integrin α3β1 and stimulates production of pro-inflammatory mediators in primary human chondrocyte cells.  相似文献   

5.
Fertilization of bean plants grown in perlite with 1 and 3 mM CaCl2 or Ca(NO3)2 reduced severity of grey mould as compared with control plants or plants fertilized with 5 mM of the compounds. Fertilization with Ca(NO3)2 reduced severity leaf grey mould and fruit ghost spots of tomato plants grown in perlite by 70 and 45%, respectively. The rate of decrease varied with the position of the fruits on the plants. Leaves from plants treated with calcium or otherwise [KNO3, (NH4)2SO4] produced less ethylene than leaves of nontreated plants. Rate of growth of B. cinerea was lower on growth medium prepared from washings from leaves of calcium fertilized plants than from leaves from other treatments. The fertilizer combination Ca(H2PO4)2+ CaSO4 (1 and 3 g/kg soil) applied once to tomato plants grown in soil reduced severity of leaf grey mould by 80 % (significant at P = 0.05) but 1–3 g CaSO4/kg soil only tended to reduce disease severity (30–40 %, not significant) as compared with the control. The compounds CaCl2 and Ca(NO3)2 increased significantly ( P = 0.05) the growth of B. cinerea on synthetic medium when applied at rates of 1 0–10.0 mM whereas reduction of growth was observed with 0.1 mM of the compounds and of CaSO4.  相似文献   

6.
LEAF INFECTION OF COTTON BY XANTHOMONAS MALVACEARUM (E.F.SM.) DOWSON   总被引:1,自引:0,他引:1  
Xanthomonas malvacearum spread more rapidly along vascular tissue than into mesophyll when inoculated to the main veins of susceptible cotton leaves. The extent of spread varied with the concentrations of inocula, tissue age and cotton variety.
Increasing concentrations of inocula accelerated the initial spread of disease.
Bacteria spread more rapidly in young leaves than in old—increasing age greatly decreased disease in the mesophyll. The initial invasion was quicker in young leaves of young plants than in young leaves of old plants.
Three types of behaviour, according to the host's reaction, distinguish Knight's resistance factors: ( a ) where X. malvacearum spread extensively along veins and into mesophyll of plants containing factors B3 and B5; ( b ) where it was restricted to the point of inoculation in plants containing B 4, B9 and combinations with B 6m; and ( c ) where it spread along veins but not appreciably into mesophyll in varieties containing B 2 and B 2 B 3.
From this and four other different types of tests, factors B 2 and B 3 seem to increase mesophyll resistance but only B 2 gives appreciable vascular resistance. Further, the vascular bundles in varieties with B 2 seem to be surrounded by an additional 'barrier' which resists X. malvacearum.  相似文献   

7.
Calcium/calmodulin-dependent kinase II (CaMKII) facilitates L-type calcium channel (LTCC) activity physiologically, but may exacerbate LTCC-dependent pathophysiology. We previously showed that CaMKII forms stable complexes with voltage-gated calcium channel (VGCC) β1b or β2a subunits, but not with the β3 or β4 subunits ( Grueter et al. 2008 ). CaMKII-dependent facilitation of CaV1.2 LTCCs requires Thr498 phosphorylation in the β2a subunit ( Grueter et al. 2006 ), but the relationship of this modulation to CaMKII interactions with LTCC subunits is unknown. Here we show that CaMKII co-immunoprecipitates with forebrain LTCCs that contain CaV1.2α1 and β1 or β2 subunits, but is not detected in LTCC complexes containing β4 subunits. CaMKIIα can be specifically tethered to the I/II linker of CaV1.2 α1 subunits in vitro by the β1b or β2a subunits. Efficient targeting of CaMKIIα to the full-length CaV1.2α1 subunit in transfected HEK293 cells requires CaMKII binding to the β2a subunit. Moreover, disruption of CaMKII binding substantially reduced phosphorylation of β2a at Thr498 within the LTCC complex, without altering overall phosphorylation of CaV1.2α1 and β subunits. These findings demonstrate a biochemical mechanism underlying LTCC facilitation by CaMKII.  相似文献   

8.
New blue whale ovarian corpora data from illegal Soviet catches in the Southern Hemisphere and northern Indian Ocean were recovered from the original logbooks. Catches north of 52°S were assumed to be pygmy blue whales ( Balaenoptera musculus brevicauda , n = 1,272); those south of 56°S were assumed to be Antarctic (true) blue whales ( B. m. intermedia , n = 153). Three probable Antarctic blue whales north of 52°S were excluded. Lengths at which 50% and 95% of females become sexually mature ( L 50 and L 95) were estimated from a Bayesian logistic model. These estimates are more precise than previous Japanese estimates because Soviet catches below the legal minimum of 70 ft (21.3 m) were 32 times greater. For pygmy blue whales L 50 was 19.2 m (95% interval 19.1–19.3 m) and L 95 was 20.5 m (95% interval 20.4–20.7 m). Antarctic L 50 (23.4 m, 95% interval 22.9–23.9 m) was much longer than L 50 for pygmy blue whale regions (18.4–19.9 m). The median L 50 for the northern Indian Ocean was 0.5–0.6 m shorter than for pygmy blue whales from other regions; although statistically significant, these small length differences provide little support for northern Indian Ocean blue whales being a separate subspecies, B. m. indica .  相似文献   

9.
The objective of this work was to study the effect of the oviductal glycoprotein 1 ( OVGP1 ) genotype and mRNA expression on litter size and other fertility measures, as OVGP1 has positive effects on fertilization and early embryo development. We have analysed an F2 cross of two lines of rabbits divergently selected for uterine capacity. The OVGP1 mRNA expression was analysed in both lines, but no differences were observed between them. The promoter region and mRNA were sequenced in the F0 generation, and 17 polymorphic sites were found to co-segregate in three haplotypes (A, B and C). An association study was performed between several reproductive traits and a triallelic microsatellite identified in the promoter region as well as a non-synonymous SNP located in exon 11 [g.12944C>G (p.Arg468Gly)]. The alleles g.12944G and g.325(GT)14T(G)5 of the B haplotype have a positive effect on the total number of kits born, number born alive, number of implanted embryos and foetal and prenatal embryo survival.  相似文献   

10.
Abstract: Mouse N18TG2 neuroblastoma and rat C6 glioma cell lines were injected into male nude mice, and the tumors were passaged serially. At each generation, tumors were analyzed for δ opioid binding using [3H][ d -Ala2, d -Leu5]enkephalin and for σ1 and σ2 binding with 1,3-[3H]di- o -tolylguanidine in the presence and absence of 1 µ M pentazocine. Receptor density ( B max) and affinity ( K D) were estimated by homologous competition binding assays. Opioid and σ B max values in the solid tumors were significantly lower than their original levels in vitro. K D values for opioid/σ ligands were similar in vitro and in vivo. With successive passages in the murine host, δ opioid and σ1 binding of the neuroblastoma-derived solid tumors became undetectable. In contrast, σ2 receptor B max values were unchanged with successive passages of the neuroblastoma-derived tumors and doubled in the nude mouse-borne gliomas. When neuroblastoma-derived solid tumors that were devoid of δ opioid binding were returned to culture, opioid receptors appeared to be up-regulated as compared with their original in vitro levels. Serial passaging of these recultured cells in vivo again resulted in a rapid decline in opioid receptor content. The opioid data are consistent with our prior findings on opioid binding diminution in human brain tumors. The pattern of change for σ binding was more complex, with the σ2 response in late passages of the glioma being reminiscent of the formerly observed increase in number of σ sites in transformed human meninges, kidney, and colon tissue.  相似文献   

11.
Marek's disease (MD) is a lymphoproliferative disease caused by a member of the herpesvirus family, and the best understood genetic resistance to MD involves the chicken major histocompatibility complex (MHC) B -complex. Preliminary observations have suggested that MHC-like Rfp-Y genes might also influence the incidence of MD. This study describes the differentiation and definition of unique Rfp-Y genes in inbred lines 63 and 72, lines that possess identical B -complex genes, but that are resistant or susceptible to MD, respectively. To assess if Rfp-Y genes affect susceptibility to MD, 265 63× 72 F2 chickens were challenged with the JM strain of MD virus at 1 week of age and were evaluated for MD lesions at up to 10 weeks of age. Genotyping of the F2 chickens for Rfp-Y haplotypes was performed by restriction fragment length polymorphism analysis of genomic DNA using Taq I and a B-FIV probe. Analysis of variance and interval mapping procedures were used to determine association between the Rfp-Y haplotypes and the phenotypic MD values of the F2 chickens. The cosegregation analysis of 265 F2 chickens indicated that there was no association between Rfp-Y haplotypes and MD susceptibility. Furthermore, the fact that the Rfp-Y haplotypes fit the 1:2:1 segregation ratio and the Rfp-Y allele frequencies did not differ significantly from 0·5 in the full population or in selected subpopulations (of either 40 MD-resistant or 39 MD-susceptible chickens) also indicated that Rfp-Y haplotypes do not significantly influence MD susceptibility. We conclude that Rfp-Y haplotypes do not play a major role in determining the genetic susceptibility to MD in 63× 72 F2 White Leghorn chickens.  相似文献   

12.
Observations have been made on the mode of burrow construction in the snake blenny, Lumpenus lampretaeformis , under laboratory conditions. It appears that head probing and lateral oscillations of the body are principally responsible for the excavation of the burrow which is completed within 24 h. The burrow structure has been analysed in detail, showing a mean depth of 7.2 cm with a maximum observed length of 73 cm, with most systems between 20 and 35 cm in length. Initially linear burrows with two openings are usually provided with a small side tunnel, giving the system a characteristic Y-shape.
Burrow irrigation was investigated for the first time in L. lampretaeformis. The mean duration of burrow irrigation, by flexions of the tail of the fish, was 21 s with over 13 min h−1 spent in irrigating the burrow. The mean water displacement per irrigation period was 3.1 ml. The PO 2 and PCO 2 were measured in both surface water and within the burrow system of L. lampretaeformis. Surface water values for PO 2 were high (> 150 Torr) and PCO 2 low (<0.4 Torr). Hypoxic and hypercapnic conditions were measured in the burrow system itself, with PO 2 values ranging between 57 and 129 Torr and PCO 2 rising to > 1.3 Torr in some burrows.
A comparative study of Cepola rubescens burrows indicated similar surface water PO 2 and PCO 2 values as in L. lampretaeformis. Burrow water PO 2 values ranged between 60 and 94 Torr, with PCO 2 values as high as 1.5 Torr being recorded. These results are discussed in relation to the adaptation of both species to a burrowing lifestyle.  相似文献   

13.
The problem of whether a given amount of active ingredient is more effectively applied in concentrated or dilute form is discussed. If y is percentage mortality and x 1 and x 2 are respectively log-concentration of active ingredient and log-volume (or deposit) of insecticide applied, y may be regarded as a uniform, continuous function of x 1 and x 2. The amount of active ingredient is constant, i.e. x 1+ x 2= k , so that
dx/dx1=−dy/dx2=δy/δx1−δy/δx2
Probit mortality, Y , can be substituted for y in (4). Thus, whether an active ingredient is better applied in concentrated or dilute form depends on the relative magnitudes of ∂ y /∂ x 1 and ∂ y /∂ x 2, or of ∂ Y /∂ x 1 and ∂ Y /∂ x 2. Equation (4) is true whenever an insecticide consists of an active ingredient in a diluent, whatever the dosage-mortality relationship. Previous work is discussed in the light of (4) and its probit form, and it appears that the concentration at which an active ingredient is best applied can depend upon the nature and quantity of the active ingredient, and the method of application of the spray. There may be other facto*** The probit form of (4) is applied to the probit plane and confirmed experimentally. Flour beetles, Tribolium castaneum Herbst were sprayed with pyrethrins in Shell oil P 31, and it was found that ∂ Y /∂ x 1 > ∂ Y /∂ x 2, so that a given quantity of pyrethrins was more toxic in concentrated solution than in dilute.  相似文献   

14.
Routine oxygen consumption ( M o 2) was 35% higher in 1 day starved and 21% higher in 4 day starved adult transgenic coho salmon Oncorhynchus kisutch relative to end of migration ocean-ranched coho salmon. Critical swimming speed ( U crit) and M o 2 at U crit ( M o 2max) were significantly lower in 4 day starved transgenic coho salmon (1·25 BL s−1; 8·79 mg O2 kg−1 min−1) compared to ocean-ranched coho salmon (1·60 BL s−1; 9·87 mg O2 kg−1 min−1). Transgenic fish swam energetically less efficiently than ocean-ranched fish, as indicated by a poorer swimming economy at U crit ( M o 2max     ). Although M o 2max was lower in transgenic coho salmon, the excess post-exercise oxygen consumption (EPOC) measured during the first 20 min of recovery was significantly larger in transgenic coho salmon (44·1 mg O2 kg−1) compared with ocean-ranched coho salmon (34·2 mg O2 kg−1), which had a faster rate of recovery.  相似文献   

15.
Abstract Besides putrescine, cadaverine, spermidine, spermine and thermospermine, three novel polyamines were detected in a slightly halophilic eubacterium Halococcus acetoinfaciens (IAM 12094, ATCC 25861). These novel polyamines were found to be N -3-aminopropylcadaverine [NH2(CH2)3NH(CH2)5NH2] and its aminopropyl derivatives: aminopentylnorspermidine [NH2(CH2)3NH(CH2)3NH(CH2)5NH2] and N , N ' -bis(3-aminoprophyl)cadaverine [NH2(CH2)3 NH(CH2)5NH(CH2)3NH2]. Aminopropylcadaverine was also detected in two other species, Halococcus agglomeratus (IAM 12095, ATCC 25862) and Halococcus nondenitrificans (IAM 12096, ATCC 25863).  相似文献   

16.
Summary. Two-dimensional agarose gel (pH 8.6)-horizontal polyacrylamide gel (pH 9.0) electrophoresis of horse serum samples, followed by general protein staining, revealed genetic polymorphism of an unidentified protein tentatively designated serum protein 3 (SP3). The SP3 fractions appeared distinctly when a 14% concentration of acrylamide was used in the separation gels. The 2-D mobilities of SP3 fractions were quite similar to that of albumin. Family data were consistent with the hypothesis that the observed SP3 phenotypes were controlled by four co-dominant, autosomal alleles ( D,F,I,S ). Evidence was provided that the F allele can be further divided into two alleles ( F 1 and F 2); the mobilities of F1 and F2 variants were very similar. Each of the SP3 alleles gave rise to one fraction and each of the heterozygous types showed two fractions. More than 600 horses representing five different breeds (Swedish Trotter, North-Swedish Trotter, Thoroughbred, Arab and Polish Tarpan) were typed for SP3, and allele frequency estimates were calculated. SP3 was highly polymorphic in all breeds studied.  相似文献   

17.
Abstract : We have isolated and characterized overlapping cDNAs encoding a novel, voltage-gated Ca2+ channel α1 subunit, α1H, from a human medullary thyroid carcinoma cell line. The α1H subunit is structurally similar to previously described α1 subunits. Northern blot analysis indicates that α1H mRNA is expressed throughout the brain, primarily in the amygdala, caudate nucleus, and putamen, as well as in several nonneuronal tissues, with relatively high levels in the liver, kidney, and heart. Ba2+ currents recorded from human embryonic kidney 293 cells transiently expressing α1H activated at relatively hyperpolarized potentials (-50 mV), rapidly inactivated (τ = 17 ms), and slowly deactivated. Similar results were observed in Xenopus oocytes expressing α1H. Singlechannel measurements in human embryonic kidney 293 cells revealed a single-channel conductance of ~9 pS. These channels are blocked by Ni2+ (IC50 = 6.6 μ M ) and the T-type channel antagonists mibefradil (~50% block at 1 μ M ) and amiloride (IC50 = 167 μ M ). Thus, α1H-containing channels exhibit biophysical and pharmacological properties characteristic of low voltage-activated, or T-type, Ca2+ channels.  相似文献   

18.
Actinophage TG1 forms stable lysogens by integrating at a unique site on chromosomes of Streptomyces strains. The phage ( attP TG1 ) and bacterial ( attB TG1 ) attachment sites for TG1 were deduced from comparative genomic studies on the TG1-lysogen and nonlysogen of Streptomyces avermitilis . The attB TG1 was located within the 46-bp region in the dapC gene (SAV4517) encoding the putative N -succinyldiaminopimelate aminotransferase. TG1-lysogens of S. avermitilis , however, did not demand either lysine or diaminopimelate for growth, indicating that the dapC annotation of S. avermitilis requires reconsideration. A bioinformatic survey of DNA databases using the fasta program for the attB TG1 sequence extracted possible integration sites from varied streptomycete genomes, including Streptomyces coelicolor A3(2) and Streptomyces griseus . The gene encoding the putative TG1 integrase ( int TG1 ) was located adjacent to the attP TG1 site. TG1 integrase deduced from the int TG1 gene was a protein of 619 amino acids having a high sequence similarity to φC31 integrase, especially at the N-terminal catalytic region. By contrast, sequence similarities at the C-terminal regions crucial for the recognition of attachment sites were moderate or low. The site-specific recombination systems based on TG1 integrase were shown to work efficiently not only in Streptomyces strains but also in heterologous Escherichia coli .  相似文献   

19.
A new allele at the Lh locus has been identified in Pisum sativum L. and named lhi . This allele results in reduced GA levels in young shoots, and a dwarf phenotype. Gas chromatography-selected ion monitoring (GC-SIM) with dideuterated internal standards has been used to demonstrate a quantitative relationship between the level of endogenous GA1 and internode length using the three alleles ( Lh, lh and lhi ) at the Lh locus. These results are consistent with previous findings in peas (for alleles at the Le locus) and other species possessing a predominant early 13-hydroxylation pathway for GA biosynthesis and support the role of GA1 as the major native GA in peas with biological activity in its own right. However, in contrast to alleles at the Le locus, GA20 levels are also reduced in lh and lhi plants. The lhi allele also has possible pleiotropic effects on seed abortion, leading to a reduction in seed yield compared to plants homozygous for the previously characterised Lh or lh alleles.  相似文献   

20.
The visual pigments in the retinal rods of elvers ( Anguilla anguilla L.) were examined by microspectrophotometry and high performance liquid chromatography. The glass elver stage had a mixture of rhodopsin P5011 and porphyropsin P5232 with the former predominating (P5011:P5232= c. 60:40). More mature pigmented elvers had a predominance of the porphyropsin P5232 (P5011:P5232= c. 10:90). The shift between the proportions of each pigment was monitored over a 7-month period and was shown to occur in individual retinal rods. This shift is a reverse of the pigment shift that occurs in adult eels during their downstream migration.  相似文献   

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