Molecular basis of β thalassemia in South China

Summary The phenotype of thalassemia can be caused by over 40 different mutations. To set up a prenatal diagnosis program using DNA analysis, it is important to determine the type and frequency of mutation in a particular geographic area. We have delineated the molecular lesions that cause thalassemia in the Guangdong province of China, and found six mutations in four different haplotypes. The surprising finding that five of these mutations each occur in two different haplotypes suggests the occurrence of crossing over or gene conversion events at the -globin locus. The delineation of the haplotypes and mutations will permit the choice of the appropriate probes for prenatal detection of thalassemia in this part of China.     

Characteristics of βA chromosome haplotypes in Japanese

DNA polymorphism patterns linked to the ^A-globin gene were analyzed in healthy Japanese using four different restriction endonucleases. The chromosomes with the ^A-globin gene were mapped through an evaluation of the presence of seven different restriction sites (HincII 5 to ; HindIII in ^G and ^A; HincII in, and 3 to, ₁; AvaII in ; Bam-HI 3 to ). Among 36 chromosomes analyzed, 20 chromosomes had a haplotype of [+–––––+]. Among 55 individuals examined, 7 possessed a homozygous haplotye of [+–––––+]. All Japanese with the ^AT-globin gene had a subhaplotype of [–++–+] 5 to the -globin gene. Their major haplotypes were [–++–+–+] and [–++–++–]. It was expected that the presence of the ^AT-globin gene in Japanese may be deduced from subhaplotypes 5 to the -globin gene.     

Quasirandom distribution of α and β regions in globular proteins

Distributions of α and β regions in globular proteins among clusters containing different numbers of adjacent α-helices, adjacent β regions, and “overlapping” βαβ units are considered. It is shown that these distributions do not differ greatly from what can be expected for random distributions of α and β regions along protein chains. In particular, it is shown that the amounts of relatively long α, β and βαβ clusters (which provide the basis for the conventional classification of globular proteins or domains into α, β, or α/β types) in random sequences also do not differ very much from those in real globular proteins. It follows that the possibility of structural classification of globular proteins (domains) does not imply the existence of a correlation in protein primary structure. This possibility exists even in random sequences of amino acid residues and therefore may not be the result of biological evolution.     

The presence and distribution of α and β glucosidase in root tip

A comparison was made of post and simultaneous azocoupling procedures for β glucosidase localization on unfixed and fixed root tips ofZea mays. Using this object, more detailed studies of β glucosidase distribution were undertaken, concerning the time course of enzyme reaction, its pH dependence, the effect of various buffers, the comparison of several diazonium salts and the use of different naphtholic substrates. The indigogenic reaction was also applied. Attempts were made by means of azocoupling procedures to localize a and β glucosidase in root tips ofCucurbita pepo, Lupinus albus, Piswm sativum andVicia faba in comparison withZea mays. In addition to certain technical problems, the questions of constitutive and adaptive enzymes, sugar distribution and histogenesis versus function are discussed in relation to the presence and distribution of ß glucosidase in the studied objects.     

The distribution and interaction of haemoglobin variants and the β thalassaemia gene in Liberia

In a population survey in Liberia, West Africa, 12 major tribes were examined for the prevalence of Hb S, Hb C, and the beta thalassaemia (beta Thal) gene. Hb C is rare; Hb S and beta Thal occur in polymorphic frequencies. The distribution of both genes shows an inverse correlation. The beta Thal trait was diagnosed by quantitation of Hb A2 on DE 52-microchromatography. This method proved to be reliable and useful for mass screening.     

Widely distribution of hematological parameters in thalassemia patients with similar α-globin genotype

Background

Thalassemia is known as the commonest monogenic disorder with an imbalanced rate of globin chains production of adult hemoglobin. Despite the available information about the thalassemia etiology, its phenotype varies from each patient to another. This study aimed to evaluate the hematological parameters of patients with the same -α3.7 homozygote and heterozygote genotypes to amend screening programs.

Methods

In this observational study, we evaluated 1301 thalassemia suspected patients who referred to the Thalassemia and Hemoglobinopathy Research Center of Ahvaz University of Medical Sciences, Khuzestan, Iran during 2014–2016. According to the genotyping studies, patients divided into 2 groups with -α3.7/αα (n = 646) and -α3.7/-α3.7 (n = 181) genotypes. Thereafter, distribution of hematological parameters evaluated in both groups.

Results

The mean age in heterozygous and homozygous groups was 25.7±4.5 and 26±4.4 years old, respectively. The degree of anemia was considerably varied in patients with the same genotype. MCV, RBC and MCH showed a wide distribution in patients.

Conclusion

The findings presented here suggest that other molecular mechanisms along with α-globin gene mutations could be involved in determining the phenotypes of alpha thalassemia patients.

     

Determination of β haplotypes in patients with sickle-cell anemia in the state of Rio Grande do Norte, Brazil

β(S) haplotypes were studied in 47 non-related patients with sickle-cell anemia from the state of Rio Grande do Norte, Brazil. Molecular analysis was conducted by PCR/RFLP using restriction endonucleases XmnI, HindIII, HincII and HinfI to analyze six polymorphic sites from the beta cluster. Twenty-seven patients (57.5%) were identified with genotype CAR/CAR, 9 (19.1%) CAR/BEN, 6 (12.8%) CAR/CAM, 1 (2.1%) BEN/BEN, 2 (4.3%) CAR/Atp, 1 (2.1%) BEN/Atp and 1 (2.1%) with genotype Atp/Atp. The greater frequency of Cameroon haplotypes compared to other Brazilian states suggests the existence of a peculiarity of African origin in the state of Rio Grande do Norte.     

DNA haplotype distribution in Algerian β thalassaemia patients

Summary An evaluation of thalassaemia mutations and the associated chromosomal haplotypes has been made among Algerian thalassaemic patients in this extended series. The major features of our findings are: (i) due to elevated proportion of consanguinity, the frequency of true homozygotes for a defect is high; (ii) Despite this high homozygosity within families, the number of molecular defects resulting in thalassaemia are very heterogeneous within this population. This is exemplified not only by the high heterogeneity of haplotypes and associated mutations, but also by the definition of several new haplotypes, among which two of them were found to be associated with novel mutations. Family studies have been performed in parallel to evaluate the degree of feasibility of antenatal diagnosis in this population.     

Comparison of α and β keratin in reptiles

Summary The different patterns of keratin formation that have evolved in the class Reptilia are all variations of a common process. In Squamata (snakes and lizards), a sequence of layers composed of or keratin is formed periodically, after which the old epidermal generation is shed. In Chelonia (turtles and tortoises), the epidermis of the shell is composed of only keratin, whereas the skin of the neck and leg is composed exclusively of keratin. Molting in toto does not occur and shedding is a continuous process comparable to that in avian and mammalian epidermis. In Crocodilia (crocodiles, caimans, alligators) there is only a single layer of cornified cells, but the composition of the layer varies in different parts of the scale. The hinge regions have many of the morphological characteristics of and keratin whereas the center resembles keratin. The living cells beneath contain accumulations of keratohyalin.There are four ultrastructural characteristics of a keratinized layer: 1) cellular outlines remain distinct, 2) a thickened plasma membrane forms during keratinization, 3) 80 Å filaments embedded in an amorphous matrix can be seen, and 4) PAS-positive material accumulates in extracellular spaces between the desmosomes.The layer exhibits none of these features. Instead the cells more or less (depending on species) coalesce into a compact layer which becomes attenuated in the hinge regions. A 30 Å filament pattern can be seen.The mesos layer of squamates resembles the hinge region of crocodilians, exhibiting a combination of the characteristics of both and keratin.This study constitutes publication No. 464 from the Oregon Regional Primate Research Center, supported in part by NIH Grant No. FR-00163.     

Expression of β-glucuronidase haplotypes in prototype and congenic mouse strains

A gene complex consists of a structural gene with its associated regulatory information; together they behave as the functional and evolutionary unit of mammalian chromosomes. The use of congenic lines, in which alternate forms, or haplotypes, of a gene complex are transferred into a common genetic background by repeated backcrossing, provides a means of comparing the regulatory properties of different haplotypes of a gene complex without the complications introduced by extraneous genetic differences. We have now carried out such a study of the A, B, and H haplotypes of the -glucuronidase gene complex, [Gus], in mice. These haplotypes were derived from strains A/J, C57BL/6J, and C3H/HeJ and were compared against the C57BL/6J genetic background. Enzyme structure was compared in terms of charge (isoelectric point), stability (rate of thermal denaturation), substrate affinity (for 4 MU glucuronide), and antigenicity (reactivity with a standard antibody). Compared to the B form, the enzyme coded by the A haplotype has a lower isoelectric point, and that coded by the H haplotype is less stable. The decreased stability is the result of a lower activation energy for the thermal denaturation reaction. These differences were maintained in the congenic strains. All three enzyme forms showed identical substrate affinities. Antigenicity per enzyme unit was also identical for all three, indicating that none lacks an antigenic site possessed by the others and that they all possess the same catalytic activity per molecule. The expression of alleles of the Gus-t temporal locus within the gene complex was not affected by transfer into the C57BL/6 genetic background. The same developmental switches in enzyme activity were seen in each case. Transfer into the C57Bl/6 background also did not affect expression of the Gus-r regulator determining androgen inducibility of -glucuronidase synthesis in kidney epithelial cells. However, enzyme accumulation in induced cells was altered when the haplotypes were transferred into the C57BL/6 genetic background. Since the rate of synthesis was not affected, it suggests that the genetic differences between strains that are not linked to the [Gus] complex affect the rate of enzyme loss by degradation or secretion. -Glucuronidase in liver is present in both lysosomes and endoplasmic reticulum (microsomes). The relative amount of enzyme at each site depended on both the indentity of the structural allele and the function of unlinked genetic modifiers. Within the C57BL/6 background the percentage of total enzyme present in the microsome fraction was the order A>B>H. For the H form of the enzyme the percentage was appreciably greater in the C3H genetic background compared to C57BL/6. As expected, then, the [Gus] complex contains all of the genetic determinants of enzyme structure detected by thermal stability and isoelectric point measurements. Additionally, the complex contains all of the genetically determined differences between strains in the regulation of -glucuronidase synthesis, including the programming of synthesis during development and the responsiveness of the [Gus] complex to hormonal stimulation. In contrast, genetic determinants of posttranslational processing are located elsewhere, including factors affecting enzyme localization and secretion/degradation. These results illustrate the utility of congenic strains for minimizing other genetic variables in characterizing the regulatory properties of alternate haplotypes of a gene complex.This work was supported by USPHS Research Grant GM 19521.     

Expression and subcellular distribution of native estrogen receptor β in murine C2C12 cells and skeletal muscle tissue

We have recently described the expression and intracellular localization of ER α in murine C2C12 cells and skeletal muscle tissue. In separate studies, a protective role of 17β-estradiol against apoptosis exerted mainly at the mitochondrial level was also shown in the C2C12 muscle cell line. However, this functional evidence was in accordance with the participation of ER β. We have then here investigated the expression and subcellular distribution of native ER β in similar skeletal muscle cultured cells and tissue developed in vivo. ER β was detected by immunoblotting using specific antibodies and ligand blot analysis after subcellular fractionation. Immunolocalization was confirmed using conventional and confocal microscopy. ER β was found to a great extent in mitochondria and in lower amounts in the cytosolic fraction, differently to ER α which localizes in microsomes, cytosol, mitochondria, and also in the nucleus of muscle tissue. ER β expression was also demonstrated by RT-PCR. Finally, the mitochondrial localization of native ER β in C2C12 muscle cells was corroborated after transient transfection with specific ER β siRNAs. These data raise the possibility that the antiapoptotic action of 17β-estradiol in muscle cells may be related in part to a direct action of the hormone on mitochondria through ER β.     

Carbon storage and its distribution of forest ecosystems in Zhejiang Province,China北大核心CSCD

Aims The concentration of CO2 and other greenhouse gases in the atmosphere has considerably increased over last century and is set to rise further. Forest ecosystems play a key role in reducing CO2 concentration in the atmosphere and mitigating global climate change. Our objective is to understand carbon storage and its distribution in forest ecosystems in Zhejiang Province, China. Methods By using the 8th forest resource inventory data and 2011 2012 field investigation data, we estimated carbon storage, density and its distribution in forest ecosystems of Zhejiang Province. Important findings The carbon storage of forest ecosystems in Zhejiang Province was 602.73 Tg, of which 122.88 Tg in tree layer, 16.73 Tg in shrub-herb layer, 11.36 Tg in litter layer and 451.76 Tg in soil layer accounting for 20.39%, 2.78%, 1.88% and 74.95% of the total carbon storage, respectively. The carbon storage of mixed broadleaved forests was 138.03 Tg which ranked the largest (22.90%) among all forest types. The young and middle aged forests which accounted for 70.66% of the total carbon storage were the main body of carbon storage in Zhejiang Province. The carbon density of forest ecosystems in Zhejiang Province was 120.80 t•hm2 and that in tree layer, shrub-herb layer, litter layer and soil layer were 24.65 t•hm2, 3.36 t•hm2, 2.28 t•hm2 and 90.51 t•hm2, respectively. The significant relationship between soil organic carbon storage and forest ecosystem carbon storage indicated that soil carbon played an important role in shaping forest ecosystem carbon density. Carbon density of tree layer increased with age in natural forests, but decreased in the order over-mature > near-mature > mature > middle-aged > young forest in plantations. The proportions of young and middle aged forests were larger than any other age classes. Thereby, the carbon storage of forest ecosystems in Zhejiang Province could be increased through a proper forest management.     

Biodiversity patterns of Early–Middle Ordovician marine microphytoplankton in South China

Based on new materials from six sections and all available literature data, new diversity curves are presented for the phytoplankton (acritarchs) from South China, covering the Early–Middle Ordovician interval, when the Great Ordovician Biodiversification Event took place. The total diversity curve and the origination data imply that a major radiation of the phytoplankton occurred during the analysed interval. A peak of the total acritarch diversity curve appears in the A. suecicus graptolite biozone. The diversity changes vary in the different parts of the investigated area, most probably depending on the position of the analysed sections on the carbonate shelf or the slope, reflecting diversity differences due to the position on an inshore–offshore transect.The Early–Middle Ordovician diversity pattern of the phytoplankton is compared with those of several marine invertebrate groups. Compared with the diversity curve peak of the acritarchs, the conodonts and brachiopods reached their highest diversities before the acritarchs, while the highest diversity of the chitinozoans appears slightly later. The graptolites show two peaks during the Early–Middle Ordovician, while the trilobites diversity curve shows a peak only in the Sandbian. The different fossil groups, such as chitinozoans, conodonts, graptolites, brachiopods and trilobites show therefore different evolutionary patterns to that of the acritarchs, that are not yet fully understood, and correlations are so far difficult.The acritarch diversity changes can partly be compared to the local sea-level changes from four sections in South China. At a larger scale, the acritarch radiation coincides with a general transgression. At a regional or local scale, correlations are not straightforward, pointing out that more detailed data, based on both acritarch studies and more precise sea-level investigations, are necessary.     

Spatial,Temporal and Genetic Dynamics Characteristics of Influenza B Viruses in China, 1973–2018

Annual influenza B virus epidemics and outbreaks cause severe influenza diseases in humans and pose a threat to public health. China is an important epidemic area of influenza B viruses. However, the spatial, temporal transmission pathways and the demography history of influenza B viruses in China remain unknown. We collected the haemagglutinin gene sequences sampled of influenza B virus in China between 1973 and 2018. A Bayesian Markov chain Monte Carlo phylogeographic discrete approach was used to infer the spatial and temporal phylodynamics of influenza B virus. The Bayesian phylogeographic analysis of influenza B viruses showed that the North subtropical and South subtropical zones are the origins of the Victoria and Yamagata lineage viruses, respectively. Furthermore, the South temperate and North subtropical zones acted as transition nodes in the Victoria lineage virus dispersion network and that the North subtropical and Mid subtropical zones acted as transition nodes in the Yamagata lineage virus dispersion network. Our findings contribute to the knowledge regarding the spatial and temporal patterns of influenza B virus outbreaks in China.     

Onshore–offshore variations of copepod community in northern South China Sea

Previous studies which have tested the feeding preferences of shredders for fungal species and the food quality of fungi used detritus uniformly colonized by a fungus, which is not the case for decaying leaves in streams. It is not known whether shredders in different development stages exhibit variations in feeding preference and larval performance. This study examined the feeding preferences and the growth of the third and the fifth instars of Pycnopsyche gentilis larvae using fungal-colonized patches and whole leaves, respectively, having different fungal species compositions (Alatospora acuminata, Anguillospora filiformis, Articulospora tetracladia, Tetrachaetum elegans, and all species combined). The aquatic hyphomycetes used were co-dominant on leaves in the stream inhabited by the caddisfly. During 14 d of feeding, the larvae of both instars did not show significant differences in feeding preferences for the patches growing on oak leaves, although the third instar larvae were slightly more selective than the fifth instar larvae. When fed with maple leaves for 18 d, larval growth rates, gross growth efficiencies, and survivorship were not significantly different among the fungal treatments. However, the larval growth of both instars fed with fungal-colonized leaves was always significantly greater than the growth of larvae fed with diets of uncolonized leaves. The third instar larvae grew faster than the fifth instar larvae, but the growth efficiencies of the two instars were similar. These results suggest that P. gentilis larvae exhibit less selectivity in their feeding than other caddisfly shredders that have been examined and that the dominant fungi colonizing leaves in their habitat are similar in palatability and food quality for this shredder. Handling editor: B. Oertli     

Characteristics and processing of Pol Ⅳ-dependent transcripts in Arabidopsis

<正>In plants,RNA-directed DNA methylation(RdDM)plays an essential role in silencing transposable elements that would otherwise have a deleterious effect on genome integrity.RdDM is an important pathway that establishes and maintains de novo DNA methylation in all three sequence contexts:CG,CHG,and CHH(where H is A,C,or T),and the methylation is targeted by 24-nt     

Regional distribution of α-neo-endorphin in rat brain and pituitary

α-Neo-endorphin was isolated as the first form of “big” Leu-enkephalin and its complete amino acid sequence has recently been established. Using an antiserum raised against synthetic α-neo-endorphin, a highly sentitive and specific radioimmunoassay was developed. The antiserum practically possesses no cross-reactivity to Leu-enkephalin, dynorphin[1–13] and PH-8P, and very little to β-neo-endorphin. Distribution of α-neo-endorphin has been determined in rat brain and pituitary by the use of the highly specific antiserum. The highest concentration was observed at posterior lobe of pituitary. Furthermore, immunoreactive α-neo-endorphin was characterized by gel-filtration and high performance liquid chromatography, and shown to be identical with authentic α-neo-endorphin.     

Study of changes in life zone distribution in north-east China by climate–vegetation classification

Life zones and their changes in distribution in north-east China were studied based on climate–vegetation relationships. The warmth index (WI) and aridity index (the ratio of evaporation [evaporation rate, ER] to precipitation) were used to represent the site condition. The typical site condition of each vegetation type was determined as the classification criterion. The boundaries of the four potential vegetation zones were estimated based on the combinations of WI and ER in relation to vegetation (i.e. cold-temperate conifer forest zone, temperate broad-leaved conifer mixed forest zone, warm-temperate deciduous forest zone, and temperate steppe zone). The distribution changes in vegetation zone caused by human activities were estimated by comparing the potential vegetation with the actual one. The percentage cover of forest has shrunk from about 70% to the present 27%. About 23% of the study area was replaced by agricultural vegetation and industrial use. Nearly half of the region could have been covered by broad-leaved conifer mixed forest which was shrunk to a small area, less than 5% of the region. The broad-leaved deciduous forest zone in the southern part could have occupied about 7% of the area, and had almost no virgin stand.