The association of C-reactive protein and CRP genotype with coronary heart disease: findings from five studies with 4,610 cases amongst 18,637 participants

Background

It is unclear whether C-reactive protein (CRP) is causally related to coronary heart disease (CHD). Genetic variants that are known to be associated with CRP levels can be used to provide causal inference of the effect of CRP on CHD. Our objective was to examine the association between CRP genetic variant +1444C>T (rs1130864) and CHD risk in the largest study to date of this association.

Methods and Results

We estimated the association of CRP genetic variant +1444C>T (rs1130864) with CRP levels and with CHD in five studies and then pooled these analyses (N = 18,637 participants amongst whom there were 4,610 cases). CRP was associated with potential confounding factors (socioeconomic position, physical activity, smoking and body mass) whereas genotype (rs1130864) was not associated with these confounders. The pooled odds ratio of CHD per doubling of circulating CRP level after adjustment for age and sex was 1.13 (95%CI: 1.06, 1.21), and after further adjustment for confounding factors it was 1.07 (95%CI: 1.02, 1.13). Genotype (rs1130864) was associated with circulating CRP; the pooled ratio of geometric means of CRP level among individuals with the TT genotype compared to those with the CT/CC genotype was 1.21 (95%CI: 1.15, 1.28) and the pooled ratio of geometric means of CRP level per additional T allele was 1.14 (95%CI: 1.11, 1.18), with no strong evidence in either analyses of between study heterogeneity (I² = 0%, p>0.9 for both analyses). There was no association of genotype (rs1130864) with CHD: pooled odds ratio 1.01 (95%CI: 0.88, 1.16) comparing individuals with TT genotype to those with CT/CC genotype and 0.96 (95%CI: 0.90, 1.03) per additional T allele (I²<7.5%, p>0.6 for both meta-analyses). An instrumental variables analysis (in which the proportion of CRP levels explained by rs1130864 was related to CHD) suggested that circulating CRP was not associated with CHD: the odds ratio for a doubling of CRP level was 1.04 (95%CI: 0.61, 1.80).

Conclusions

We found no association of a genetic variant, which is known to be related to CRP levels, (rs1130864) and having CHD. These findings do not support a causal association between circulating CRP and CHD risk, but very large, extended, genetic association studies would be required to rule this out.     

Are microbial symbionts involved in the speciation of the gall-inducing aphid, <Emphasis Type="Italic">Slavum wertheimae</Emphasis>?

Microbial symbionts have come to be recognized as agents in the speciation of their eukaryote hosts. In this study, we asked if bacterial symbionts are, or were in the past, involved in the speciation of the gall-inducing aphid Slavum wertheimae (Hemiptera: Aphididae). This aphid is specific to the tree Pistacia atlantica, which has a fragmented distribution among mesic and xeric habitats, leading to corresponding fragmentation of the aphid population. Previous studies revealed genetic differentiation among populations of the gall-inducing aphid, suggesting cryptic allopatric speciation. Pistacia atlantica trees show no such variation. By means of diagnostic PCR, we screened several populations of S. wertheimae from mesic and xeric sites in Israel for the presence of nine known aphid symbionts: Arsenophonus, Hamiltonella, Regiella, Rickettsia, Rickettsiella, Serratia, Spiroplasma, Wolbachia, and X-type, as well as Cardinium, known to be a reproductive manipulator. Only one symbiont, Wolbachia, was detected in S. wertheimae. Wolbachia was found in all the aphids of the mesic populations, compared to 26% in the aphids from the xeric populations. Multilocus Sequence typing of Wolbachia revealed new haplotypes in the fbpA and coxA genes in both the mesic and xeric populations. Phylogenetic analysis showed that Wolbachia of S. wertheimae is closely related to Wolbachia strains from assorted hosts, mostly lepidopterans, but only distantly related to Wolbachia strains from other aphid species. We conclude that the cryptic speciation of mesic and xeric populations of S. wertheimae was likely driven by geographical isolation rather than by Wolbachia.     

Response of Contrasting Rice Genotypes to Zinc Sources under Saline Conditions

Abiotic stresses are among the major limiting factors for plant growth and crop productivity. Among these, salinity is one of the major risk factors for plant growth and development in arid to semi-arid regions. Cultivation of salt tolerant crop genotypes is one of the imperative approaches to meet the food demand for increasing population. The current experiment was carried out to access the performance of different rice genotypes under salinity stress and Zinc (Zn) sources. Four rice genotypes were grown in a pot experiment and were exposed to salinity stress (7 dS m⁻¹), and Zn (15 mg kg⁻¹ soil) was applied from two sources, ZnSO₄ and Zn-EDTA. A control of both salinity and Zn was kept for comparison. Results showed that based on the biomass accumulation and K⁺/Na⁺ ratio, KSK-133 and BAS-198 emerged as salt tolerant and salt sensitive, respectively. Similarly, based on the Zn concentration, BAS-2000 was reported as Zn-in-efficient while IR-6 was a Zn-efficient genotype. Our results also revealed that plant growth, relative water content (RWC), physiological attributes including chlorophyll contents, ionic concentrations in straw and grains of all rice genotypes were decreased under salinity stress. However, salt tolerant and Zn-in-efficient rice genotypes showed significantly higher shoot K⁺ and Zn concentrations under saline conditions. Zinc application significantly alleviates the harmful effects of salinity by improving morpho-physiological attributes and enhancing antioxidant enzyme activities, and the uptake of K and Zn. The beneficial effect of Zn was more pronounced in salt-tolerant and Zn in-efficient rice genotypes as compared with salt-sensitive and Zn-efficient genotypes. In sum, our results confirmed that Zn application increased overall plant’s performance under saline conditions, particularly in Zn in-efficient and tolerant genotypes as compared with salt-sensitive and Zn efficient rice genotypes.     

Reciprocal transfer of male sterile and normal plasmons in Petunia

Summary The goal in this experiment was to achieve direct plasmon transfer via cell fusion. Two lines were used — a normal fertile line of P. hybrida, and a cytoplasmic male sterile (cms) line with the nuclear background of P. parodii. Two plants phenotypically similar to the original male sterile line were developed from protoplasts, but instead of being cms they were male fertile. On the other hand, two plants typical of the original normal line developed from protoplasts, but they were cms instead of fertile. Chromosome counts were done and in all cases the expected diploid number (=14) was found. Genetic analysis showed that sorting out of cms and fertile segregants was evident in the first and second backcross of the cms cybrids. The fertile type cybrids were stable fertile for several generations of selfing and proper backcrossing. These results are discussed in the light of an earlier fusion experiment in which these two parental lines were involved.Contribution from the Department of Plant Genetics and Breeding, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 991-E, 1984 series     

Somatic hybridization in Petunia

Summary Two types of cytoplasmic hybrids were obtained by protoplast fusion. These contained either one or the other original parental nucleus and heteroplasmon, a mix of plasmons inducing cytoplasmic male sterility and fertility. In subsequent generations, following selfing, stable male sterile and male fertile lines segregated from single fertile cytoplasmic hybrid plants. These data demonstrated the existence of a heteroplasmic state in the somatic hybrids and the occurrence of cytoplasmic segregation of the heteroplasmon into homoplasmons following the first and the second meiotic cycles.Contribution from the Agricultural Research Organization, The Volcani Center, Division of Plant Genetics & Breeding, Bet Dagan, Israel. No. 275-E, 1979 series     

Independent segregation of the plastid genome and cytoplasmic male sterility in Petunia somatic hybrids

Summary The chloroplast genomes of three sets of Petunia somatic hybrids were analyzed to examine the relationship between chloroplast DNA (cpDNA) composition and cytoplasmic male sterility (CMS). Chloroplast genomes of somatic hybrid plants were identified either by restriction and electrophoresis of purified cpDNAs or by hybridization of total DNA digests with cloned cpDNA probes that distinguish the parental genomes.The chloroplast genomes of a set of seven somatic hybrids derived from the fusion of Petunia CMS line 2423 and fertile line 3699 were analyzed. All seven plants were fertile, and all exhibited the cpDNA restriction pattern of the sterile cytoplasm. Similarly, four fertile somatic hybrids derived from the fusion of CMS line 3688 and fertile line 3677 were found to contain the CMS chloroplast genome. The cpDNA compositions of four fertile and two sterile somatic hybrids derived from the fusion of CMS line 3688 and fertile line 3704 were determined by restriction analysis of purified cpDNAs; all six plants exhibited the cpDNA restriction pattern of line 3704. Thus the CMS phenotype segregates independently of the chloroplast genome in Petunia somatic hybrids, indicating that CMS in Petunia is not specified by the chloroplast genome.     

Timing of callase activity and cytoplasmic male sterility in Petunia

A study of callase activity in relation to cytogenetical expressions in cytoplasmic male sterile and male fertile Petunia indicated differential timing of the localized enzyme activity. Enzyme activity was determined by a new test. The possible relations between the mode of action of the extrachromosomal gene, timing of the enzyme activity, and male sterility are discussed.Paper No. 1360-E, 1968 Series of the Volcani Institute of Agricultural Research. Supported in part by grant No. FG-Is-171 of the United States Department of Agriculture, Authorized by U.S. Public Law 480.Deceased.     

Attempts to detect extra genomial factors in cytoplasmic male-sterile petunia lines

Summary In the present study we examined the possibility that viruses, viroids or dsRNA are associated with cytoplasmic male sterile (cms) petunia. The assumption was made that if viruses or viroids were present, the treatments for elimination of viruses and viroids would produce healthy fertile plants. Male sterile plants were subjected to heat and cold treatments for 10 weeks and/ or for 5 months, after which apical meristems were isolated and cultured with the addition of antiviral factors. The mother plants, the regenerated plants and their progeny were sterile. These treatments did not affect sterility in sterile plants or the fertility of fertile plants. No dsRNA was found in cms petunia by gel electrophoresis. Thus, our data suggest that there are no viruses, viroids or dsRNA associated with cms petunia. Our data are in agreement with recent data, which suggests that the mitochondrial DNA is the site of the cytoplasmic male sterile gene in petunia.Contribution no. 2198-E, 1987 series from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel     

Seasonal and Daily Variations in Hypothalamic Monoamine Levels and Monoamine Oxidase Activity in the Teleost Channa Punctatus (Bloch)

In Channa punctatus, a significant daily variation in hypothalamic S-HT level and monoamine oxidase (MAO) activity was noticed in preparatory phase (February), but not in prespawning (May) or postspawning (November) phases. Hypothalamic dopamine (DA) and noradrenaline (NA), on the other hand, showed marked daily variation in their levels during all the three seasons with peak values in the photophase. The overall activity of MAO (mean ± SEM on 24-hr period) increased from November to May through February, whereas the 5-HT content which was high in November decreased during February and May. The NA and DA levels were low in November and Februry and high in May. The catecholamine (CA) content and MAO activity increased with increasing photoperiod and temperature which is indicative of an enhanced CA metabolism.