SUMOylation of spastin promotes the internalization of GluA1 and regulates dendritic spine morphology by targeting microtubule dynamics.

Dendritic spines are specialized structures involved in neuronal processes on which excitatory synaptic contact occurs. The microtubule cytoskeleton is vital for maintaining spine morphology and mature synapses. Spastin is related to microtubule-severing proteases and is involved in synaptic bouton formation. However, it is not yet known if spastin can be modified by Small Ubiquitin-like Modifier (SUMO) or how this modification regulates dendritic spines. Spastin was shown to be SUMOylated at K427, and its deSUMOylation promoted microtubule stability. In addition, SUMOylation of spastin was shown to affect signalling pathways associated with long term synaptic depression. SUMOylated spastin promoted the development of dendrites and dendritic spines. Moreover, SUMOylated spastin regulated endocytosis and affected the transport of the AMPA receptor, GluA1. Our findings suggest that SUMOylation of spastin promotes GluA1 internalization and regulates dendritic spine morphology through targeting of microtubule dynamics.

Population data and mutation rates of 19 STR loci in seven provinces from China based on Goldeneye™ DNA ID System 20A.

Short tandem repeat (STR) analysis is a primary tool in forensic casework. Population data and mutation rates of STRs are very important for paternity testing and forensic genetics. However, the population data and mutation rates of STRs in Han nationality based on large samples have still not been fully described in China. In this study, the allelic frequencies, forensic parameters, and mutation rate of 19 STR loci (D19S433, D5S818, D21S11, D18S51, D6S1043, D3S1358, D13S317, D7S820, D16S539, CSFIPO, PentaD, vWA, D8S1179, TPOX, Penta E, TH01, D12S391, D2S1338, and FGA) based on the Goldeneye™ DNA ID System 20A in Southern China Han nationality among seven provinces were investigated. Furthermore, population stratification of Southern China Han nationality among seven provinces was established. The multidimensional scaling (MDS) plot based on genetic distances (Fst) showed that the studied populations can be clustered into two major groups. However, relationships among populations were weak (Fst < 0.0043). A total of 376 cases of mutation were detected from the 19 selected loci in 15,396 meioses. The average mutation rate for the 19 loci was estimated to be 1.3 × 10-3 per meiosis. The mutation was mainly single step; the paternal mutation rate was higher than the maternal; and paternal mutation rate increases with paternal age.

Potential of 13 linked autosomal short tandem repeat loci in pairwise kinship analysis.

In this study, a panel of 13 STR loci locate on chromosome 3, 4, and 17 (D3S2402, D3S2452, D3S1766, D3S4554, D3S2388, D3S3051, D3S3053, D4S2404, D4S2364, AC001348A, AC001348B, D17S975, and D17S1294) were assessed for pairwise kinship analysis. Map distances between these STR loci ranged from 0.07 cM to 97.03 cM. The population genetic study of Chinese Han population showed that linkage disequilibrium exists in two clusters of closely linked markers (D4S2404-D4S2364 and D17S975-D17S1294), in which the recombination fractions were 0.0026 and 0.0001, respectively. The recombination fractions derived from the Rutgers Map for the closely linked markers (genetic distance < 0.5 cM) were significant underestimates in comparison to those of direct observation of STR transmissions in families. When effect of linkage on pairwise kinship testing was evaluated by comparing likelihood ratio (LR) values taking linkage into account, overall LR values increased. But extremely low LRs were also observed. Finally, the power of the 13 STR loci to discriminate relationship among full-sibs, half-sibs, grandparent-grandchild, uncle-niece, and unrelated pairs was assessed with a category fraction. The results showed that about 72.64% of full-sib pairs and about 82.84% of unrelated pairs could be classified correctly. But the category fractions of second-degree relationships drastically reduced to 7.34-35.48%. If only pairs of grandparent-grandchild, half-sibs, and uncle-niece were distinguished, the category fraction was 0.5512, 0.1147, and 0.4362, respectively. Our study results demonstrated that linked STRs were helpful to differentiate the most frequent relationships in pairwise kinship analysis.

Recombination analysis of autosomal short tandem repeats in Chinese Han families.

Recombination fractions between forensic STRs can be extrapolated from the International HapMap Project, but the concordance between recombination fractions predicated from genetic maps and derived from observation of STR transmissions in families is still ambiguous for autosomal STRs because of limited family studies. Therefore, the main goal of this study is to compare recombination fractions estimated by pedigree analysis with those derived from HapMap phase SNP data. Genotypes of nine autosomal STR pairs (TPOX-D2S1772, D5S818-CSF1PO, D7S3048-D7S820, D8S1132-D8S1179, TH01-D11S2368, vWA-D12S391, D13S325-D13S317, D18S51-D18S1364, and D21S11-PentaD) from 207 two-generation families with two to five children (the number of families with five, four, three, and two children was 2, 3, 20, and 182, respectively) were used to analyze the recombination. The linkage analysis showed that significant linkage was observed at six STR pairs (D5S818-CSF1PO, D8S1132-D8S1179, TH01-D11S2368, vWA-D12S391, D13S325-D13S317, and D18S51-D18S1364) with genetic distances <36.22 cM in HapMap. Their recombination fractions calculated from family data were very close to those derived from HapMap. However, three STR pairs of TPOX-D2S1772, D7S3048-D7S820, and D21S11-PentaD showed no significant linkage with genetic distances from 43.38 to 91.49 cM. Our results indicate that recombination fractions extrapolated from HapMap can provide a substitute if empirical data are unavailable for the linkage STR pair with a genetic distance spanned <36.22 cM.

Genetic polymorphism of 13 non-CODIS STR loci in three national populations from China.

The aim of this study was to investigate a 13 non-CODIS STR loci database using three national populations from China. A new multiplex PCR system that simultaneously amplified 13 loci in the same PCR reaction was developed. This multiplex system included the 13 STR markers (D3S2402, D3S2452, D3S1766, D3S4554, D3S2388, D3S3051, D3S3053, D4S2364, D4S2404, AC001348A, AC001348B, D17S975, and D17S1294), which were successfully analyzed by using 441 DNA samples from three national populations in China (154 Mongol, 177 Kazakh, and 110 Uigur). Allele frequencies and mutation rates of the 13 non-CODIS STR loci were investigated. A total of 4-10 alleles at each locus were observed and altogether 84, 88, and 87 alleles for the all selected loci were found in the Mongol, Kazakh, and Uigur, respectively. Eight mutations were detected from the 13 selected loci in 9880 meioses in kinship cases. These results indicate that this multiplex system may provide significant polymorphic information for kinship testing and relationship investigations.

9-(2-Chloro-phen-yl)-4a-hy-droxy-3,4,4a,5,6,7,9,9a-octa-hydro-2H-xanthene-1,8-dione.

In the title compound, C19H19ClO4, the di-hydro-pyran ring and the cyclo-hexane ring adopt a half-chair conformation and a chair conformation, respectively. The cyclo-hexene ring has an envelope conformation with the central CH2 C atom as the flap. This atom is disordered over two positions [site-occupancy ratio = 0.744 (12):0.256 (12)] above and below the mean plane formed by the other five atoms. In the crystal, O-H⋯O hydrogen bonds between hy-droxy and carbonyl groups link mol-ecules into chains propagating along [001].

X chromosomal recombination--a family study analyzing 26 X-STR Loci in Chinese Han three-generation pedigrees.

The aim of this study is to investigate genetic linkage and recombination fractions of 26 X chromosomal (X-STR) loci with two multiplex PCR systems (MX15-STR and MX12-STR). MX15-STR (including DXS7133, DXS6801, DXS981, DXS6809, DXS7424, DXS6789, DXS9898, DXS7132, GATA165B12, DXS101, DXS10075, DXS6800, GATA31E08, DXS10074, and DXS10079) and MX12-STR (including DXS6854, DXS9902, DXS6800, GATA172D05, DXS7423, HPRTB, DXS6807, DXS6803, DXS6804, DXS6799, DXS8378, and DXS8377) were successful analyzed on 206 two-generation families with two or more children and 33 three-generation families with 72 grandsons. Segregation analysis and calculation of recombination fractions between pairs of markers were performed. Linkage analysis of pairs of markers showed that there existed significant linkage (maximum LOD scores >2.0) within the physical distance of 48.5 Mb. Recombination events could be observed within the clusters of closed linked makers spanning <1.0 Mb. These results indicate that close cluster X-STRs used and recombination fractions of the selected loci will be very useful for biostatistical calculations in complex kinship analysis.

Development of multiplex PCR system with 15 X-STR loci and genetic analysis in three nationality populations from China.

The aim of this study is to develop a new multiplex PCR system that simultaneously amplifies the 15 X-chromosome short tandem repeats (X-STRs) loci in the same PCR reaction, and to obtain the 15 X-STR loci database in three nationality populations from China. This multiplex system includes DXS7133, DXS6801, DXS981, DXS6809, DXS7424, DXS6789, DXS9898, DXS7132, GATA165B12, DXS101, DXS10075, DXS6800, GATA31E08, DXS10074, and DXS10079, which were successfully analyzed on 1251 DNA samples (670 males and 581 females) from Guangdong Han population, Xinjiang Uigur and Kazakh. The allele frequencies and mutation rates of the 15 loci were investigated, and the allele frequency distribution among different populations was compared. A total of 6-17 alleles for each locus were observed and altogether 170 alleles for all the selected loci were found. Thirteen cases with mutation of the above loci were detected in 11,850 meioses. Pairwise comparisons of the allele frequencies distribution showed significant differences in most loci among different populations. The results indicate that this multiplex system may provide high polymorphism information for kinship testing and relationship investigations, and it is necessary to gain allele frequency and mutation rate of different population for forensic application.

Development and population study of the 12 X-STR loci multiplexes PCR systems.

To develop a multiplex polymerase chain reaction (PCR) system with 12 X-chromosomal short-tandem repeat (X-STR) loci and to investigate their polymorphism and linkage and/or independence, the 12 loci (DXS6807, DXS8378, DXS9902, DXS6800, DXS6803, DXS6799, DXS6804, GATA172D05, DXS6854, HPRTB, DXS8377, and DXS7423) were simultaneously analyzed in 1,005 unrelated individuals (574 males and 431 females) from Guangdong Han individuals and Kazakh populations living in China. The allele frequencies and mutation rates were investigated. Allele frequency distribution among different populations was compared. Haplotypes of linkage disequilibrium markers (DXS6807-DXS8378-DXS9902) and linked markers (DXS6804-GATA172D05 and DXS8377-DXS7423) were also reported. A total of 117 alleles, ranging from five to 20 for each locus, were observed in our selected populations. Eight cases with mutation of the selected loci were detected in 9,480 meioses. Pairwise comparisons of allele frequencies distribution showed statistically significant differences at most loci among different populations. Haplotype diversity of linked markers was 0.9404-0.9694. The results indicated that this multiplex system is very useful for forensic analysis and may be complementarities for X-12 kits or X-8 kits in forensic case.

Genetic data of nine non-CODIS STRs in Chinese Han population from Guangdong Province, Southern China.

Nine non-combined DNA index system tetranucleotide short tandem repeat (STR) loci D2S1772, D6S1043, D7S3048, D8S1132, D11S2368, D12S391, D13S325, D18S1364, and GATA198B05 were amplified in a multiplex polymerase chain reaction system. The distribution of alleles of the nine STRs was reported from a Chinese Han population in Guangdong Province, Southern China. The combined power of exclusion in trios and duos for the nine loci was 0.999981 and 0.999025, respectively. Mutation rates range from 0 to 0.005618. Pairwise analysis of linkage disequilibrium, which included PowerPlex 16 System loci, did show statistically significant deviation from independence even though loci locate on the same chromosomes. The nine STRs are highly informative and suitable to extend the results obtained with other STRs commonly analyzed for difficult paternity and kinship analysis.

Development of the nine X-STR loci typing system and genetic analysis in three nationality populations from China.

This study is to develop a new multiplex polymerase chain reaction (PCR) system that simultaneously amplifies the nine X-chromosome short tandem repeats loci in the same PCR reaction, and to explore their polymorphism and mutation rate among three nationality populations from China. These loci included DXS6854, DXS9902, DXS6809, GATA172D05, HPRTB, DXS7423, DXS6807, DXS8378, and DXS8377. The samples of 890 (484 males and 406 females) unrelated individuals from Guangdong Han population, Xinjiang Uigur, and Inner-Mongolia Mongol were successfully analyzed using this multiplex system. The allele frequencies and mutation rates of the nine loci were investigated, and the comparison of allele frequency distribution among different populations was performed. There were 87 alleles for all the loci, and six to 18 alleles for each locus observed by our new multiplex PCR system. Polymorphism information content was 0.4998-0.9101, and power of discrimination in females was 0.6518-0.9846. Five cases with mutation of above loci were detected in 5,310 meioses. Pair-wise comparisons of allele frequencies distribution showed significant differences for most loci among different populations. Our results indicate that this multiplex system is very useful for identification analysis, and that the information about polymorphism and mutation rate is necessary for forensic application in three nationality populations from China.

Genetic analysis of the 10 ChrX STRs loci in Chinese Han nationality from Guangdong province.

This study is to explore the polymorphic nature of X-Chromosome short tandem repeats (ChrX STRs) loci, and to determine its application in kinship tests for forensic cases. A new fluorescent multiplex PCR that simultaneously amplifies the 10 ChX STRs loci in the same PCR reaction had been set up. DXS7132, DXS981, DXS6801, DXS6809, DXS6789, DXS7424, DXS101, DXS7133, GATA165B12 and GATA31E08 were analyzed in a sample of 511 (399 males and 112 females) unrelated individuals from Guangdong Han nationality in China. One hundred and one alleles were observed in all the loci. Here, we investigated the allele frequencies and mutation rates of the ten loci, and then made the comparison of allele frequencies distribution among different populations. The results show the ten loci in the multiplex systems may provide high polymorphism information for kinship testing and relationship investigations, and it is necessary to gain allele frequency and mutation rate of different population for forensic application.

[Development and application of X-chromosomal STR multiplex amplification system].

OBJECTIVE: To explore the application of X-chromosomal STR(X-STR) for forensic identification and paternity testing. METHODS: Six X-STR loci DXS6801, DXS9902, DXS6809, DXS6803, DXS6804 and DXS6799 were amplified in a single PCR reaction. PCR products were analyzed using capillary electrophoresis and 3100 Genetic Analyzer and GeneMapper ID v3.1 Analysis Software. RESULTS: The alleles of all six X-STR loci were successfully obtained with unambiguous genotyping, high sensitivity and reproducibility. CONCLUSION: The multiplex PCR of six X-STR loci is useful in forensic identification, particularly for sisters cases.

Two loci concurrent mutations in non-exclusion parentage cases using 19 STR profiles.

Two loci concurrent mutations in non-exclusion paternity case were reported based on 19 STR loci available from Goldeneye™ DNA ID System 20A (Peoplespot, Beijing, China). When 9508 family trios with Paternity index (PI) threshold of >10,000 was analyzed, 14 families show mutations at two loci. The paternity was confirmed by using an additional 19 STR markers. When the probability of occurrence of two mutations was compared with the expected probability deduced from binomial model, the observed mutational probability was significantly larger than the expectation. However, the characteristics of mutations agree with those reported previously. Our result indicates that larger samples is still need to estimate mutation rates accurately and reveal the relationship between mutations with multiple loci and the characterization of human mutations based on microsatellites.

[Development and forensic application of a pentaplex X-STR loci typing system].

A fluorescent multiplex PCR that simultaneously amplifies five X-chromosomal short tandem repeat (X-STR) loci (DXS6803, DXS981, DXS6809, DXS6789 and DXS7132)was set up to study their polymorphic nature and to determine its use in kinship tests for forensic cases. PCR products were analyzed using capillary electrophoresis and ABI prism 3100 Genetic Analyzer with GeneMapper ID 3.1 Analysis Software. The pentaplex system gave satisfactory results as its sensitivity, reproducibility and unambiguous genotyping. About 20 ng DNA was routinely used, although 0.25 ng DNA was sufficient for allele typing. The results demonstrate that the multiplex system of the five X-STR loci provides a fast technology for forensic identification and paternity testing. The X-STR pentaplex system can complement the analysis of AS-STR and Y-STR efficiently, especially in complex cases of kinship testing.

Population structure of Han nationality in Central-Southern China.

Knowledge of population structure is very important for forensic genetics. However, the population substructure in Central-Southern China Han nationality has still not been fully described. In this study, we investigated the genetic diversity of 15 forensic autosomal STR loci from 6879 individuals in 12 Han populations subdivided by administrative provinces in Central-Southern China. The statistical analysis of genetic variation showed that genetic differentiation among these populations was very small with a Fst value of 0.0009. The Discriminant Analysis of Principal Components (DAPC) showed that there were no obvious population clusters in Central-Southern China Han population. In practice, the population structure effect in Central-Southern China Han population can be negligible in forensic identification and paternity testing.

Fluorescent multiplex amplification of three X-STR loci.

This study was carried out to evaluate the value of three X-STR loci (DXS6803, DXS981and DXS6809) in forensic application and thereby investigate their polymorphism. The primer for each locus was labeled with fluorochrome 6-FAM. A fluorescent multiplex PCR for simultaneously amplifying three X-STR loci was set up. The PCR products that were obtained were analyzed using capillary electrophoresis and ABI PRISM 3100 Genetic Analyzer, with GENESCAN Analysis Software. When 340 male and 195 female individuals of Han population in China were tested, 13, 12, and 11 alleles were observed for DXS6803, DXS981 and DXS6809, respectively. One hundred and eighty three haplotypes were detected in the male individuals. The haplotype diversity reached 0.9926. The results show that the three loci of the multiplex system provide significant information on polymorphism for forensic identification and paternity testing, particularly for complicated paternity deficient cases.

[Characteristics of IGF-II gene imprinting in twin placentas].

OBJECTIVE: To compare insulin-like growth factor II (IGF-II) gene imprinting in twin placentas with singleton ones and to determine whether imprinting was influenced by assisted reproductive technology, zygosity and fetal sex. METHODS: One hundred and sixty cases of twin placentas and 42 cases of singleton ones were recruited. Allele-specific IGF-II expression was determined by reverse transcription-PCR combined with analysis of an Apa I-sensitive restriction fragment length polymorphism. RESULTS: Although the incidence of IGF-II imprinting loss was higher in normal twin placentas than in singleton ones (20.6% vs 8.7%), there was no statistical significance. There were no significant differences between twins conceived by assisted reproductive technology and those conceived spontaneously (17.9% vs 24.4%), and between dizygotic and monozygotic twins (22.4% vs 16.7%). The incidence of IGF-II imprinting loss in placenta of female twins was statistically higher than that of male ones (26.4% vs 9.8%). CONCLUSION: The risk of IGF-II gene imprinting loss is higher in female twins and has no relationship with assisted reproductive technology and zygosity.

[Haplotypes of DXS10011 and DXS8377 in Guangdong Han individuals].

OBJECTIVE: To investigate genetic polymorphism of two X chromosome specific STR: DXS10011 and DXS8377 in male samples from Guangdong Han population. METHODS: The DNA samples were amplified by PCR and analyzed by polyacrylamide gel electrophoresis followed by silver staining. RESULTS: Among 113 samples, 20 alleles were found for DXS1011 and 12 alleles for DXS8377. Also, 72 DXS10011-DXS8377 haplotypes were shown. The most common haplotypes only occurred three times. When only female children were tested in motherless case, the exclusion probability of paternity was 0.9588 for DXS10011-DXS8377 haplotypes. Investigations in 83 family trios with female children and 29 pedigrees with two children suggested a co-dominant X-linked inheritance; mutations were not found. CONCLUSION: Our data indicate that DXS10011 and DXS8377 are highly informative X chromosome markers for complicated kinship analysis.

Genetic polymorphism of 22 autosomal STR markers in a Han population of Southern China.

Population genetic data and forensic statistics of 22 autosomal short tandem repeat (STR) loci (D1S1656, D2S1338, D3S3045, D4S2366, D5S2500, D6S477, D7S3048, D8S1132, D9S925, D10S1435, D11S2368, D12S391, D13S325, D14S608, D15S659, D16S539, D17S1290, D18S535, D19S253, D20S470, D21S1270 and GATA198B05) were determined for a sample of 515 unrelated individuals from Han population in Southern China. The expected heterozygosity and the discrimination power varied from 0.7358 to 0.8733 and 0.8915 to 0.9702, respectively. The probability of excluding an unrelated man as the true father (assuming no background relatedness in the population) for trios and for duos ranged from 0.5126 to 0.7415 and 0.3331 to 0.5864, respectively. The studied STRs appear to provide a significant improvement in the statistical power of kinship analysis.