Improving yield and quality traits of durum wheat by introgressing chromosome segments from hexaploid wheat

Durum wheat (Triticum turgidum durum; 2n = 4x = 28; genome AABB) has long been an important food resource for human diets. The projected increase of the world's population to 9.1 billion by 2050 has highlighted the importance and urgency for improving the yield and quality performance of durum wheat. A backcrossed population, which was derived from the durum wheat variety 'Bellaroi' (recurrent parent) and the hexaploid genotype 'CSCR6' (donor parent), was used to investigate the feasibility of improving yield- and quality-related traits of durum wheat by introgressing chromosome fragments from hexaploid wheat. The population means for grain protein content, gluten content, spike length, and spikelet number were improved compared with those of the recurrent parent 'Bellaroi'. A small proportion of the backcross population lines showed significant improvements in spike length and spikelet number compared with the recurrent parent 'Bellaroi'. Some loci with significant effects for plant height, spike length, spikelet number, and thousand-grain weight were identified. Several of these loci affected more than one trait. These results showed that the introgression of chromosome fragments from 'CSCR6' into the durum genetic background could be an effective method for improving yield and quality traits of durum wheat. In addition, the loci showing significant effects on desired traits in this study could be fine mapped using an F2 population obtained by backcrossing the lines that carry the positive allele(s) with the recurrent parent.

Population pharmacokinetics of valnemulin in swine

This study was carried out in 121 pigs to develop a population pharmacokinetic (PPK) model by oral (p.o.) administration of valnemulin at a single dose of 10 mg/kg. Serum biochemistry parameters of each pig were determined prior to drug administration. Three to five blood samples were collected at random time points, but uniformly distributed in the absorption, distribution, and elimination phases of drug disposition. Plasma concentrations of valnemulin were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The concentration-time data were fitted to PPK models using nonlinear mixed effect modeling (NONMEM) with G77 FORTRAN compiler. NONMEM runs were executed using Wings for NONMEM. Fixed effects of weight, age, sex as well as biochemistry parameters, which may influence the PK of valnemulin, were investigated. The drug concentration-time data were adequately described by a one-compartmental model with first-order absorption. A random effect model of valnemulin revealed a pattern of log-normal distribution, and it satisfactorily characterized the observed interindividual variability. The distribution of random residual errors, however, suggested an additive model for the initial phase (<12 h) followed by a combined model that consists of both proportional and additive features (≥ 12 h), so that the intra-individual variability could be sufficiently characterized. Covariate analysis indicated that body weight had a conspicuous effect on valnemulin clearance (CL/F). The featured population PK values of Ka , V/F and CL/F were 0.292/h, 63.0 L and 41.3 L/h, respectively.

Comparison of different fluorescence spectrum analysis techniques to characterize humification levels of waste-derived dissolved organic matter

In the present work, the humification level of waste-derived dissolved organic matter (DOM) at different waste biostability was investigated, by using fluorescent excitation-emission matrix (EEM) scanning. Different fluorescence spectrum analysis techniques were applied and compared. Experimental results demonstrate that parallel factor (PARAFAC) analysis was sensitive to reflect DOM humification, and the most reasonable to deconstruct DOM compositions, when compared with other spectrum analysis techniques. It suggests applying the DOM-EEM-PARAFAC pipeline for rapid estimation of waste biostability.

Population pharmacokinetics of cefquinome in pigs

This study was performed in 145 pigs to develop a population pharmacokinetics (PPK) model by i.m. administration of cefquinome (CEQ) at the dose of 2 mg/kg in the neck muscle. Serum physiological and biochemical parameters for each pig were determined before administration. After administration, 2-4 samples were collected at random, with the sampling point evenly distributed in the three periods (<1 h, 1-4 h and >4 h). The plasma concentration of CEQ was determined by high performance liquid chromatography with UV detector. The pharmacostatistical analyses of concentration-time data, weight, age, gender, serum physiological and biochemical parameters were performed with nonlinear mixed effect modeling (NONMEM). A one-compartmental model with first-order absorption and elimination adequately described the data from the study group. The optimal random effect model of pharmacokinetics parameters was of log-normal distribution and the residual errors assumed a mixed-type model (proportional and additive) to best explain intra-individual variability. Covariate analysis showed that body weight is positively correlated with apparent volume of distribution (V/F) and body clearance (CL/F). The typical PPK parameters of Ka , CL, and V were 0.564/h, 5.15 L/h, and 1.36 L, respectively.

Population expanding with the phalanx model and lineages split by environmental heterogeneity: a case study of Primula obconica in subtropical China

BACKGROUND

Current and historical events have both affected the current distribution patterns and intraspecific divergence of plants. While numerous studies have focused on the Qinghai-Tibetan Plateau (QTP), the impacts of such events on the flora of subtropical China remain poorly understood. Subtropical China is famous for its highly complex topography and the limited impact from glaciation during the Pleistocene; this may have resulted in a different genetic legacy for species in this region compared to fully glaciated areas.

METHODOLOGY/PRINCIPAL FINDINGS

We used plastid and nuclear DNA sequence data and distribution modeling to analyze the divergence patterns and demographic history of Primula obconica Hance, a widespread herbaceous montane species in subtropical China. The phylogenetic analysis revealed two major lineages (lineage A and lineage B), representing a west-east split into the Yunnan and Eastern groups, and the Sichuan and Central groups, respectively. The Eastern and Central groups comprised relatively new derived haplotypes. Nested Clade Analysis and Bayesian Skyline Plot analyses both indicated that P. obconica mainly experienced a gradual expansion of populations. In addition, the simulated distribution of P. obconica during the Last Glacial Maximum was slightly larger than its present-day distribution.

CONCLUSION/SIGNIFICANCE

Our results are the first to identify a west-east migration of P. obconica. The gradual expansion pattern and a larger potential distribution range in cold periods detected for P. obconica indicate that the population expansion of this species is consistent with the phalanx model. In addition, the current patterns of genetic differentiation have persisted as a result of the extensive environmental heterogeneity that exists in subtropical China.

Ectopic expression of glucagon receptor in skeletal muscles improves glucose homeostasis in a mouse model of diabetes

AIMS/HYPOTHESIS

Excessive secretion of glucagon partially contributes to the development of diabetic hyperglycaemia. However, complete blocking of glucagon action will lead to adverse effects, since glucagon exerts certain beneficial effects via its receptor in many organs. We aimed to study the effects of a 'decoy receptor' for circulating glucagon on modulating beta cell function and glucose homeostasis in mice by over-producing the glucagon receptor (GCGR) in skeletal muscles.

METHODS

We generated transgenic mice in which the expression of Gcgr is driven by the muscle specific creatine kinase (Mck) promoter, and assessed the effects of glucagon on the modulation of glucose homeostasis under conditions of extremes of glucose influx or efflux.

RESULTS

Mck/Gcgr mice showed increased circulating levels of glucagon and insulin, resulting in an unchanged ratio of glucagon-to-insulin. The levels of hepatic glucose-6-phosphatase (G6PC) and fructose-1,6-bisphosphatase (F1,6P2ase) were significantly decreased, whereas the phosphorylation level of pancreatic cAMP-response-element-binding-protein (CREB) was significantly increased in these transgenic mice. Under basal conditions, the mice displayed normal blood glucose levels and unchanged glucose tolerance and insulin sensitivity when compared with their age-matched wild-type (WT) littermates. However, following multiple low-dose streptozotocin injections, Mck/Gcgr mice exhibited a delay in the onset of hyperglycaemia compared with the WT controls. This was associated with preserved beta cell mass and beta cell secretory capacity in response to glucose challenge.

CONCLUSIONS/INTERPRETATION

We suggest that mild and chronic hyperglucagonaemia, through a strategy involving neutralising peripheral glucagon action, provides beneficial effects on beta cell function and glucose homeostasis. Mck/Gcgr mice thus represent a novel mouse model for studying the physiological effects of glucagon.

Peptide aptamers with biological and therapeutic applications

Peptide aptamers are combinatorial protein molecules with specific bind affinity to given target proteins under intracellular conditions. The typical structure of peptide aptamers is a short peptide region inserted within a scaffold protein. The short peptide region is responsible for binding with its target protein and the scaffold protein helps to enhance the binding affinity and specificity through restriction on the conformation of the binding peptide. This unique structural feature allows peptide aptamers to bind with their target proteins with strong affinity and high specificity. Applications of peptide aptamers thus vary from in vitro detection of various proteins in a complex mixture to in vivo modulation on proteins and cell functions. Peptide aptamers have also been considered as therapeutic molecules because of their anticancer and antivirus activity. Due to the importance of peptide aptamers, a general review on the structure, selection and applications of peptide aptamers in biological study as well as in therapeutics will be presented in this paper.

Use of MSG1 protein in a novel blocking ELISA for the detection of Mycoplasma suis infection

A blocking ELISA based on the monoclonal antibody (MAb) 1A7 was developed to detect antibodies against Mycoplasma suis. The MAb was produced by immunising BALB/c mice with recombinant MSG1 protein (rMSG1) from M. suis expressed in E. coli. Following identification by Western blotting, the MAb was purified and labelled with horseradish peroxidase. The parameters of the ELISA were optimised, and the cut-off value determined as 36.35% by analysing the percentage inhibition of M. suis negative serum. The sensitivity and specificity of the ELISA were 92% and 100%, respectively. In repeatability tests, the intra- and inter-batch variation coefficients were <10%. The results suggest this blocking ELISA is specific, sensitive and reproducible, and will be a valuable tool in the serodiagnosis of M. suis infection in pigs.

Testing DNA barcoding in closely related groups of Lysimachia L. (Myrsinaceae)

It has been suggested that rbcL and matK are the core barcodes in plants, but they are not powerful enough to distinguish between closely related plant groups. Additional barcodes need to be evaluated to improve the level of discrimination between plant species. Because of their well-studied taxonomy and extreme diversity, we used Chinese Lysimachia (Myrsinaceae) species to test the performance of core barcodes (rbcL and matK) and two additional candidate barcodes (trnH-psbA and the nuclear ribosomal ITS); 97 accessions from four subgenus representing 34 putative Lysimachia species were included in this study. And many closely related species pairs in subgen. Lysimachia were covered to detect their discriminatory power. The inefficiency of rbcL and matK alone or combined in closely related plant groups was validated in this study. TrnH-psbA combined with rbcL + matK did not yet perform well in Lysimachia groups. In contrast, ITS, alone or combined with rbcL and/or matK, revealed high resolving ability in Lysimachia. We support ITS as a supplementary barcode on the basis of core barcode rbcL and matK. Besides, this study also illustrates several mistakes or underlying evolutionary events in Lysimachia detected by DNA barcoding.

Simultaneous determination of ten ginsenosides in panacis quinquefolii radix by ultra performance liquid chromatography and quality evaluation based on chemometric methods

A rapid, sensitive and reliable method based on ultra performance liquid chromatography coupled with a photodiode array detector (UPLC-PAD) was developed for both the quantitative analysis of ten bioactive ginsenosides and a chemical-fingerprint analysis. The chromatography was performed on an ACQUITY UPLC BEH C18 column using a gradient elution with acetonitrile/water as the mobile phase. To compare the UPLC fingerprints and to evaluate their quality, chemometric methods including similarity analysis (SA) and hierarchical-clustering analysis (HCA) were implemented when classifying the Panacis Quinquefolii Radix samples. The Panacis Quinquefolii Radix samples were successfully grouped in accordance with their geographic origins.

Molecular diversity of bacteria in Yunnan yellow cattle (Bos taurs) from Nujiang region, China

The rumen content of four Yunnan Yellow Cattle (Bos taurs) were collected to determine the bacteria diversity by using 16S rRNA gene sequence analysis. A total of 129 sequences were examined and the sequences were referred as 107 OTU (Operational Taxonomy Unit) according to the similarity level of 97% in gene sequence. Similarity analysis revealed that Yunnan Yellow Cattle had 12 sequences (10 OTU) shared 97% or greater similarity with cultured rumen bacteria Butyrivibrio fibrisolvens, Succiniclasticum ruminis, Ruminococcus bromii, Clostridium proteoclasticum, Ruminococcus flavefaciens, Pseudobutyrivibrio ruminis, Jeotgalicoccus psychrophilus, and Prevotella ruminicola, which accounting for 9.3% of the total clones (9.2% of the total OTU). The further 12 sequences (9 OTU) shared 90-97% similarity with cultured bacteria Clostridium aminobutyricum, butyrate-producing bacterium, Schwartzia succinivorans, Prevotella ruminicola, Eubacterium ruminantium, Ruminococcus albus, and Clostridium termitidis, also accounting for 9.3% of the total sequences (8.3% of the total OTU). The remaining 105 sequences (90 OTU) shared less than 90% similarity with cultured bacteria, accounting for 81.4% of the total sequences (82.5% of the total OTU). According to the phylogenetic analysis, all sequences were phylogenetically placed within phyla of low G+C subdivision (accounting for 72.1 and 72.5% of the total clones and OTU, respectively) and CFB subdivision (Cytophaga-Flexibacter-Bacteroides; accounting for 27.9 and 27.5% of the total clones and OTU, respectively). Among the examined clones, rare bacteria Jeotgalicoccus psychrophilus was detected in the rumen of cattle.

Nano-hydroxyapatite/poly(L-lactic acid) composite synthesized by a modified in situ precipitation: preparation and properties

Nano-hydroxyapatite/poly(L-lactic acid) (nano-HA/PLLA) composites with uniform HA distribution and good mechanical performance were fabricated by a modified in situ precipitation method, using Ca(OH)(2) and H(3)PO(4) as precursors for the synthesis of HA phase. This method has solved the aggregation problem of the nano-sized particles in the polymer matrix. The X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy were used to characterize the phase composition, chemical interactions and morphology of the composites, while the mechanical properties were determined by compressive measurements. The results show that the rod-like nano-HA particles synthesized by this method were uniformly distributed in the PLLA matrix. The compressive strength and Young's modulus of the composites were greatly enhanced and reached the values of 155 MPa and 3.6 GPa at 20 wt% HA content, respectively, which are much higher than those of the reference samples fabricated by direct mixing of PLLA with nano-HA particles. This supports the potential of these composites for applications in bone tissue engineering and load bearing bone defects repair.

Identification and validation of a major QTL conferring crown rot resistance in hexaploid wheat

Crown rot (CR), caused by various Fusarium species, is a chronic wheat disease in Australia. As part of our objective of improving the efficiency of breeding CR resistant wheat varieties, we have been searching for novel sources of resistance. This paper reports on the genetic control of one of these newly identified resistant genotypes, 'CSCR6'. A population derived from a cross between CSCR6 and an Australian variety 'Lang' was analyzed using two Fusarium isolates belonging to two different species, one Fusarium pseudograminearum and the other Fusarium graminearum. The two isolates detected QTL with the same chromosomal locations and comparable magnitudes, indicating that CR resistance is not species-specific. The resistant allele of one of the QTL was derived from 'CSCR6'. This QTL, designated as Qcrs.cpi-3B, was located on the long arm of chromosome 3B and explains up to 48.8% of the phenotypic variance based on interval mapping analysis. Another QTL, with resistant allele from the variety 'Lang', was located on chromosome 4B. This QTL explained up to 22.8% of the phenotypic variance. A strong interaction between Qcsr.cpi-3B and Qcsr.cpi-4B was detected, reducing the maximum effect of Qcrs.cpi-3B to 43.1%. The effects of Qcrs.cpi-3B were further validated in four additional populations and the presence of this single QTL reduced CR severity by up to 42.1%. The fact that significant effects of Qcrs.cpi-3B were detected across all trials with different genetic backgrounds and with the use of isolates belonging to two different Fusarium species make it an ideal target for breeding programs as well as for further characterization of the gene(s) involved in its resistance.

Paired box 6 (PAX6) regulates glucose metabolism via proinsulin processing mediated by prohormone convertase 1/3 (PC1/3)

AIMS/HYPOTHESIS

Human patients with aniridia caused by heterozygous PAX6 mutations display abnormal glucose metabolism, but the underlying molecular mechanism is largely unknown. Disturbed islet architecture has been proposed as the reason why mice with complete inactivation of paired box 6 (PAX6) in the pancreas develop diabetes. This is not, however, the case in human aniridia patients with heterozygous PAX6 deficiency and no apparent defects in pancreatic development. We investigated the molecular mechanism underlying the development of abnormal glucose metabolism in these patients.

METHODS

A human aniridia pedigree with a PAX6 R240Stop mutation was examined for abnormal glucose metabolism using an OGTT. The underlying mechanism was further investigated using Pax6 R266Stop mutant small-eye mice, which also have abnormal glucose metabolism similar to that in PAX6 R240Stop mutation human aniridia patients.

RESULTS

Paired box 6 (PAX6) deficiency, both in aniridia patients with a heterozygous PAX6 R240Stop mutation and in mice with a heterozygous Pax6 R266Stop mutation, causes defective proinsulin processing and abnormal glucose metabolism. PAX6 can bind to the promoter and directly upregulate production of prohormone convertase (PC)1/3, an enzyme essential for conversion of proinsulin to insulin. Pax6 mutations lead to PC1/3 deficiency, resulting in defective proinsulin processing and abnormal glucose metabolism.

CONCLUSIONS/INTERPRETATION

This study indicates a novel function for PAX6 in the regulation of proinsulin processing and glucose metabolism via modulation of PC1/3 production. It also provides an insight into the abnormal glucose metabolism caused by heterozygous PAX6 mutations in humans and mice.

Polymorphism of the growth hormone gene and its association with growth traits in Boer goat bucks

In the present study, the polymorphism of growth hormone (GH) gene was analyzed as a genetic marker candidate for growth traits in Boer goat bucks. Two single nucleotide polymorphisms (SNPs) - A781G (Ser/Gly35) and A1575G (Leu147), were identified by GH gene sequencing and PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) analysis. AA genotype resulted in a significant decrease in birth chest girth (P=0.03) and weaning weight (P=0.014) comparing to AB genotype, while CC genotype contributed to weaning height (P=0.04) greater than CD genotype. When in combination, AACD genotype was undesired for lower scores in a series of growth traits including body weight, length, height, and chest girth at birth and weaning, as well as the pre-weaning daily gain and body weight at age of 11 months. These results indicate that new molecular markers associated with caprine growth traits can be used in MAS (marker-assisted selection) in Boer goat bucks.

[Expression of stathmin mRNA and protein in laryngeal squamous cell carcinoma and its clinical implication]

OBJECTIVE

To investigate the expressions of stathmin gene and its coding protein in laryngeal squamous cell carcinoma, and to explore the relationship between stathmin gene and the biological behaviors of laryngeal squamous cell carcinoma for understanding the tumorigenicity and development of laryngeal squamous cell carcinoma.

METHODS

Laryngeal carcinoma tissues (studying group) in the tumors center and laryngeal normal tissues (control group) parted from 1.0 cm of the safe borderline of the tumors were took from 38 patients with laryngeal squamous cell carcinoma while they were in operation. Semiquantitative method of reverse transcriptase polymerase chain reaction (RT-PCR) was used to analyze the expression level of stathmin mRNA, and immunohistochemical staining (frozen section) was used to detect the expressions of stathmin protein, in laryngeal carcinoma tissues and laryngeal normal tissues of 38 cases, respectively.

RESULTS

mRNA of stathmin gene was all positively expressed in laryngeal carcinoma tissues and in laryngeal normal tissues of 38 cases by RT-PCR. However, stathmin mRNA was obviously overexpressed in laryngeal carcinoma tissues than that in laryngeal normal tissues (t = 9.655, P < 0.05). Immunohistochemical staining showed stathmin protein was positively expressed in laryngeal carcinoma tissues of 26 cases (26/38, 68.4%), and mild-positively expressed in laryngeal normal tissues in 13 cases (13/38, 34.2%). There was significant difference between the expression rate of stathmin protein in laryngeal carcinoma tissues and in laryngeal normal tissues (chi2 = 8.901, P < 0.05). Meanwhile, the expression level of stathmin mRNA and the positive-expressed rate of stathmin protein in laryngeal carcinoma tissues of the advanced stage patients group (III stage and IV stage) were significantly higher than these in laryngeal carcinoma tissues of I and II stage patients group (t = 6.284, chi2 = 5.810, P < 0.05), and they were also significantly higher in laryngeal carcinoma tissues of the patients group with cervical lymph node metastasis than in laryngeal carcinoma tissues of the patients group without cervical lymph node metastasis (t = 9.350, chi2 = 6.923, P < 0.05).

CONCLUSIONS

The expression levels of stathmin gene and protein were significantly higher in laryngeal squamous cell carcinoma than these in laryngeal normal tissues, the levels are also significantly higher in advanced stage patients group (III stage and IV stage) than in the early stage patients group (I and II), and they are also related to the cervical lymph node metastasis of carcinoma. Stathmin gene may play an important role in the pathogenesis and development of laryngeal carcinoma and may be related to its prognosis.

Computational analysis of adhesion force in the indentation of cells using atomic force microscopy

A mechanical model was developed to study the indentation of an atomic force microscopic (AFM) tip on a cell with adhesion mediated by receptor-ligand binding. The effects of indentation rate, indentation depth, indenter size, and the mechanical properties of cells on the adhesion force were investigated. It was found that the presence of adhesion between the cell and AFM tip may affect both the loading curve and unloading curve, which may in turn change the extracted elastic modulus values using the conventional indentation models. It was found that an increase in the receptor-ligand reaction rate may lead to a transition from a decrease of the maximum adhesion force with the indentation rate to an increase of the maximum adhesion force with the indentation rate. It was also found that factors such as indenter size, indentation depth, and cell mechanical properties influence the maximum adhesion force, and their corresponding underlying mechanisms were discussed.

Primary molecular features of self-incompatible and self-compatible F(1) seedling from apricot (Prunus armeniaca L.) Katy x Xinshiji

Expression of the S-RNase genes in the self-compatible (SC) apricot (Prunus armeniaca L.) cultivar Katy, the self-incompatible (SI) cultivar Xinshiji and their F(1) seedling was examined in this study. Three S-genotypes, S(9)Sc (Sc, self-compatibility S-gene absent from the style), S(8)S(9), and S(8)S(10), were obtained. Seedlings with S-RNase that migrated as a single band in gel electrophoresis were SC, despite high transcript abundance, and those with S-RNase that migrated as two bands were SI with high transcript abundance or SC with low transcript expression. S(8)-RNase was induced in SI cultivars only 24 h after self-pollination, indicating post-transcriptional regulation of S(8)-RNase in SI apricots. A Proteomic study showed that 35 protein spots were synthesized differently between SC and SI pistils. Fifteen of the 35 protein spots were identified; nine proteins, including receptor protein kinase-like protein, reversibly glycosylated polypeptide-2, and isoflavone reductase-like protein, were detected only in the SC pistils; while nine proteins, including actin 7, a putative serine/threonine kinase, and S-RNase, were detected only in the SI pistils. A mitochondrial NAD-dependent malate dehydrogenase and a probable elongation factor G were up-regulated, while heat shock cognate 70 was down-regulated in the SC pistils compared to those in the SI pistils. The results suggest that the proteins responsible for self-compatibility and self-incompatibility may be different.

Aromatic C20F20 cage and its endohedral complexes X@C20F20 (X = H−, F−, Cl−, Br−, H, He)

The structure and stability of endohedral X@C20F20 complexes (X = H-, F-, Cl-, Br-, H, He) have been computed at the B3LYP level of theory. All complexes in I (h) symmetry were found to be energy minimum structures. H-@C20F20 and F-@C20F20 complexes have negative inclusion energies, while other complexes have positive inclusion energies. Similarity between C20F20 and C20H20 has been found for X = H and He. On the basis of the computed nucleus independent chemical shift values at the cage center, both C20F20 and C20F20 are aromatic.

CCR2 allele polymorphisms in 15 Chinese ethnic populations

Chemokine receptor-2 (CCR2) is a co-receptor for the entry of human immunodeficiency virus-1 (HIV-1) into the target cells. A mutation in CCR2 (CCR2-64I) exhibited a protective effect to delay the progression of acquired immunodeficiency syndrome (AIDS). To study the mutant frequency and polymorphism of CCR2 in Chinese populations, 1082 individuals from 15 Chinese populations distributing widely from north to south were collected. The genotypes of CCR2-64I were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with the digestion of restriction endonuclease FokI. Of the 1082 individuals, 352 (32.53%) were carriers of CCR2-64I allele, 257 of whom (23.75%) were heterozygotes (CCR2-64V/I), whereas 95 (8.78%) were homozygotes (CCR2-64V/V). The frequency of the CCR2-64I allele in those tested individuals was 20.66%. This prevalence of CCR2-64I was higher than what was known for American and European populations. Moreover, the frequencies of CCR2-64I were generally higher in northern China than they were in southern China, and the frequencies had significant variance in 15 populations of China (chi2 = 27.135, P = 0.018).