游仆虫信息素Er-1和Er-2对四膜虫的种间作用

信息素是生物体向外释放的化学物质,在细胞及生物体中具有种内信息传递的生理学功能。信息素这一类分子广泛分布于系统发生史中,它们的特异活性在单细胞生物、昆虫以及脊椎动物中均有报道。脊椎动物中信息素的信号传输已被证实是一嗅觉依赖过程,7TM-受体被认为是信号传输过程中的信号转换器。在低等单细胞生物(例如:来可夫游仆虫)的细胞膜上存在有信息素异构体,作为信息素分子的有效结合位点而行使其功能。本研究主要探讨单细胞的信息素(Er-1和Er-2)的基础细胞生理学作用是仅限于产生该信息素的物种,还是对其它的原生动物(例如:四膜虫)或对系统发育中分类地位较高的细胞(例如:MRC5成纤维细胞或J774巨噬细胞)均具有调节活性。研究结果表明,游仆虫的两种信息素对梨形四膜虫GL的生长调节有显著不同的作用:当信息素浓度为10-11M时,Er-1具有正调控作用,而Er-2具有抑制剂的作用。这两种配体的趋化作用也有很不同:Er-1具有一种广范的化学排斥特性,而Er-2具有一个双峰的化学吸引剂的性质。计算机检测发现,与Er-2的作用不同,Er-1可略微降低被测细胞的游动速率。趋化现象的选择特性表明Er-2信息素的受体有一种“短期”的特性;而Er-1是不能选择任何亚种群的,这也支持了我们先前的研究数据,即这两种信息素在四膜虫GL内产生两种不同的信号。四膜虫对信息素特异性的反应表明四膜虫能辨别非常近似但带有微小差异的配体(如Er-1和Er-2的电荷差异)。     

Seasonal changes in phosphorylation of myosin regulatory light chains and C-protein in myocardium of hibernating ground squirrel Citellus undulatus

A comparative study concerning the extent of phosphorylation of myosin regulatory light chains and C-protein from the left ventricle of hibernating ground squirrel Citellus undulatus during the periods of hibernation and activity was carried out. During hibernation, regulatory light chains of ground squirrel were found to be completely dephosphorylated. In active animals, the share of phosphorylated light chains averages 40-45% of their total amount. The extent of phosphorylation of the cardiac C-protein during hibernation is about two times higher than that in the active state. Seasonal differences in phosphorylation of the two proteins of ground squirrel myocardium are discussed in the context of adaptation to hibernation.     

Regulation of the adaptation to zinc deficiency in plants

The molecular mechanisms by which plants sense their micronutrient status, and adapt to their environment in order to ensure a sufficient micronutrient supply, are poorly understood. Zinc is an essential micronutrient for all living organisms. when facing a shortage in zinc supply, plants adapt by enhancing the zinc uptake capacity. The molecular regulators controlling this adaptation were recently identified. in this mini-review, we highlight recent progress in understanding the adaptation to zinc deficiency in plants and discuss the future challenges to fully unravel its molecular basis.Key words: adaptation, zinc deficiency, biofortification, molecular regulators, plant nutritionIn an increasingly populated world, agricultural production is an essential element of social development. Agriculture is the primary source of all nutrients required for human life, and nutrient sufficiency is the basis for good health and welfare of the human population.¹ Soils with zinc deficiency are widespread in the world, affecting large areas of cultivated soils in India, Turkey, China, Brazil and Australia,^2,3 making zinc the most common crop micronutrient deficiency.⁴ In addition, risk of inadequate zinc diet and zinc malnutrition are estimated to affect one-third of the global human population, i.e., around two billion people.⁵ Most affected are people living in developing countries, where diets are rich in cereal-based foods. Cereal grains are rich in phytate, which is a potent anti-nutrient, limiting micronutrient bioavailability.⁶ Zinc deficiency in crop production can be easily ameliorated through zinc fertilization, making agronomic biofortification an important strategy,³ however in the poorer regions, the required infrastructure to provide a reliable supply of zinc fertilizers of sufficient quality, is often not available. In those situations, biofortified crops, in which the zinc status of crops is genetically improved by selective breeding or via biotechnology, offer a rural-based intervention that will more likely reach the population.⁷ Different traits can be targeted to developing such improved crops, such as plant zinc deficiency tolerance, zinc use efficiency and the accumulation of zinc in edible parts. However, insufficient knowledge on the molecular mechanisms and the regulation of the zinc homeostasis network in plants is a serious bottleneck when pursuing zinc biofortification.     

BamHI-SacI RFLP and Gm analysis of the immunoglobulin IGHG genes in the Northern Selkups (west Siberia): new haplotypes with deletion, duplication and triplication

Gm immunoglobulin allotypes have been studied in 1157 individuals of seven Northern Selkup populations, which account for 80% of the entire population of this west Siberian tribe. This study confirms that the northern Selkup populations are a Caucasoid-Mongoloid hybrid. Restriction fragment length polymorphism (RFLP) analysis of the IGHG genes using double BamHI-SacI digests, performed on 475 DNA samples, allowed us to describe nine new BamHI-SacI haplotypes (BS47 to BS55), eight of them being characterized by IGHG gene deletion or duplication: G1 (BS49) or G4 (BS55) deletion, G4 duplication (BS51), GP-G2-G4 multigene deletion (BS50), duplication (BS48, BS53 and BS54) or triplication (BS52). A new rare Gm haplotype 15,16*;1,17;23 has been found associated with BS52. The BS51 haplotype characterized by a duplicated G4 gene (additional 7.85 kb G4 band identifying a new G4*C5 allele) was always found associated with the Gm 5*;3;23 haplotype. A high RFLP diversity has been observed for the Northern-Mongoloid haplotype Gm 15,16*;1,17;.. which was found (1) with the BS27 haplotype characterized by a 3-exon hinge G3 gene, (2) with two different GP-G2-G4 multigene duplications, BS53 and BS54 haplotypes, which differ by the size of the duplicated G4 genes, and (3) with the BS55 haplotype characterized by a G4 deletion. In the Northern Selkups, haplotypes with duplicated genes were observed at a higher frequency (24%) than haplotypes with deleted genes (6%).     

Polymorphism of the serotonin system genes in some Finno-Ugric populations

Polymorphic sites in the genes encoding monoamine oxidase A (MAO-A), serotonin transporter (hSERT) and 5-HT2A receptor were typed in Khant and Komi ethnic groups with the purpose of revealing possible interpopulation differences in genotype and allele frequencies. No statistically significant differences in the hSERT and 5-HT2A gene frequencies were detected. At the same time, the populations examined had statistically significantly different MAO-A genotype and allele frequencies. These results obtained indicate the prevalence of the site gain alleles of the EcoRV and Fnu4HI RFLP loci at the MAO-A gene in Komis and the of the corresponding site loss alleles in Khants.     

Dipole models of alpha-rhythm generators

Different hypothesis of the alpha rhythm origin were tested by dipole simulation of the alpha rhythm sources. EEG was recorded during driving photic stimulation in order to increase the signal-to-noise ratio. Models with fixed and moving dipoles were analyzed. Dipole sources were compared with magnetic resonance imaging (MRI) scans to find the exact location of oscillations in brain anatomical structures. A two-level multiple dipole model was found to fit the EEG most adequately. The first level was represented by two oscillators localized in the thalamic reticular nuclei, and the second level is associated with two modality-specific oscillators localized in the respective cortical areas.     

Polymorphism of CYP1A1 and CYP2D6 genes in tundra nentses and European populations of western Siberia

Data on the first examination of the CYP1A1 and CYP2D6 genes' polymorphism in the populations of Tundra Nentsis (Yamalo-Nenetskii Autonomous District) and migrant population of Western Siberia (Novosibirsk oblast and Altaiskii krai) are presented. The frequency of the 2D6*4 mutant allele in Tundra Nentsis, characterized by a two-component Caucasoid and Mongoloid origin, was shown to be intermediate in Caucasoid and Mongoloid populations. The frequencies of the 2D6*4 and 1A1Val* mutant alleles across migrant inhabitants of Western Siberia (Caucasoid populations) were similar to that reported for the Caucasoid populations overall. Distribution of the CYP1A1 genotypes (Ile/Ile, Ile/Val*, and Val*/Val*) in Tundra Nentsis was similar to that found in Mongoloid groups. However, the frequency of the 1A1Val* allele in Tundra Nentsis was 1.5 times higher than that in the Southern Mongoloid populations (Chinese, Koreans, and Japanese).