Immunohistochemical study of amelogenin binding proteins in an amelogenin point mutation mouse / Estudio inmunohistoquímico de proteínas de unión de la amelogenina en un ratón con mutación puntual de amelogenina

Amelogenin is one of the enamel matrices secreted by ameloblasts. A mutation of the amelogenin gene can cause hereditary dental enamel defects known as amelogenesis imperfecta (AI). Since lysosome-associated membrane protein-1 (LAMP-1), -3 (LAMP-3), and 78kDa glucose-related protein (Grp78) were identified as binding proteins of amelogenin, several studies have suggested the involvement of these binding proteins with the cell kinetics of ameloblasts in normal or abnormal conditions. The purpose of this study is to investigate the distribution of these amelogenin binding proteins in the ameloblast cell differentiation of mice with a point mutation of the amelogenin gene (Amelx*). The incisors of Amelx* mice had a white opaque color and the tooth surface was observed to be rough under a scanning electron microscope. Among the sequential ameloblast cell differentiation in the Amelx* mice, the shape of ameloblasts at the transition stage was irregular in comparison to those in wild-type (WT) mice. Immunostaining of Grp78 revealed that the whole cytoplasm of the transition stage ameloblasts was immunopositive for Grp78 antibody, while only the distal part of cell was positive in the WT mice. Furthermore, in the Amelx* mice, the cytoplasm of the transition stage ameloblasts was immunopositive for LAMP-1 and LAMP-3. These results suggest that Amelx* may cause the abnormal distribution of amelogenin binding proteins in the cytoplasm of ameloblasts.

La amelogenina es una de las matrices de esmalte secretadas por los ameloblastos. Una mutación del gen de amelogenina puede causar defectos hereditarios del esmalte dental conocidos como amelogénesis imperfecta (AI). Dado que la proteína de membrana asociada a lisosoma-1 (LAMP-1), -3 (LAMP-3) y la proteína relacionada con la glucosa de 78 kDa (Grp78) se identificaron como proteína de unión a amelogenina, varios estudios han sugerido la participación de estas proteínas con la cinética celular de los ameloblastos en condiciones normales o anormales. El objetivo del estudio fue investigar la distribución de LAMP-1, LAM-3 y Grp78 durante la diferenciación celular de ameloblastos de ratones con una mutación puntual del gen de amelogenina (Amelx*). Los incisivos de los ratones Amelx* presentaron un color blanco opaco y se observó en microscopio electrónico de barrido que la superficie del diente era áspera. La diferenciación celular secuencial y la forma de los ameloblastos en la etapa de transición en los ratones Amelx* fue irregular en comparación con los ratones silvestres (RS). La inmunotinción de Grp78 reveló que todo el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para el anticuerpo Grp78, mientras que solo la parte distal de la célula fue positiva en los ratones RS. Además, en ratones Amelx*, el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para LAMP-1 y LAMP-3. Estos resultados sugieren que Amelx* puede causar distribución anormal de proteínas de unión a amelogenina en el citoplasma de los ameloblastos.

Alteración del gen AMELX en amelogénesis imperfecta. Una breve revisión / Alteration of the AMELX gene in amelogenesis imperfecta. A brief review

Resumen La amelogénesis imperfecta es un grupo de trastornos de desarrollo del esmalte dental asociados principalmente con mutaciones en el gen AMELX. Clínicamente presenta diferentes fenotipos que afectan la estructura y función del esmalte, tanto de la dentición primaria como secundaria. El objetivo de este estudio fue realizar una revisión bibliográfica de las funciones y mutaciones de AMELX relacionadas con amelogénesis imperfecta. Se llevó a cabo una revisión bibliográfica en dos bases de datos: PubMed y Web of Science, usando las palabras clave “AMELX”, “amelogenina”, “amelogénesis imperfecta” y “mutación de AMELX”. Fueron revisados 40 artículos y se encontró que AMELX es el gen predominante en el desarrollo del esmalte dental y de la amelogénesis imperfecta, alterando la estructura de la amelogenina. En los últimos años se han descrito las características en el proceso de amelogénesis imperfecta con diferentes fenotipos de esmalte hipoplásico o hipomineralizado y se han reportado diferentes mutaciones, con lo que se ha determinado la secuenciación del gen y las posiciones de las mutaciones.

Abstract Amelogenesis imperfecta is a group of developmental disorders of the dental enamel that is mainly associated with mutations in the AMELX gene. Clinically, it presents different phenotypes that affect the structure and function of dental enamel both in primary and secondary dentition. The purpose of this study was to conduct a literature review on the AMELX functions and mutations that are related to amelogenesis imperfecta. A literature search was carried out in two databases: PubMed and Web of Science, using the keywords “AMELX”, “amelogenin”, “amelogenesis imperfecta” and “AMELX mutation”. Forty articles were reviewed, with AMELX being found to be the predominant gene in the development of dental enamel and amelogenesis imperfecta by altering the structure of amelogenin. In the past few years, the characteristics of the amelogenesis imperfecta process have been described with different phenotypes of hypoplastic or hypo-mineralized enamel, and different mutations have been reported, by means of which the gene sequencing and the position of mutations have been determined.

Detection and Analysis of 12 Suspected Amelogenin Allelic Loss Cases / 法医学杂志

OBJECTIVES@#To observe and analyse the Amelogenin allelic loss in parent-child identification cases, and to explore the type and mechanism of Amelogenin allelic loss as well as its influence on gender identification and solutions.@*METHODS@#After the detection by SiFaSTR™ 23plex DNA identification system, samples had the characteristics of the peak area of Amelogenin X was the same as the one of adjacent heterozygote or lower than one half of adjacent homozygote in females while Amelogenin X loss was observed in males were selected. X chromosome STR （X-STR） typing and Amelogenin X sequencing were performed. The samples with Amelogenin Y loss in males were confirmed by the detection of Y chromosome STR typing and sex-determining region of Y （SRY）. The type and rate of Amelogenin allelic loss were confirmed and calculated, and the mechanism and influence of this variation were also analysed.@*RESULTS@#Amelogenin X allelic loss was observed in one male sample, the mutation in primer-binding region was confirmed by sequencing. The suspected Amelogenin X allelic loss was observed in four female samples, but the mutation in primer-binding region was confirmed by sequencing in only one sample. Amelogenin Y allelic loss was observed in seven male samples, SRY positive cases was detected in five of them, and two were SRY negative. Y-STR type was detected in four cases of the five SRY positive cases, which was not detected in the two SRY negative cases. The rate of Amelogenin allelic loss was about 0.029%.@*CONCLUSIONS@#Amelogenin X allelic loss does not affect the gender identification, but Amelogenin Y allelic loss may cause wrong gender identification. Thus, Y-STR or SRY should be detected for gender confirmation. When Y-STR genotypes are not detected in a "male" whose SRY detection is also negative, then the chromosome karyotype analysis and sex differentiation related genes test should be taken to further confirm the gender.

Diversidad del ADN mitocondrial en restos óseos prehispánicos / Mitochondrial DNA diversity in prehispanic bone remains on the eastern Colombian Andes

Resumen Introducción. El ADN antiguo que se extrae de los restos óseos humanos permite analizar la composición genética de las poblaciones precolombinas y determinar las dinámicas poblacionales que dieron origen a la diversidad de las poblaciones contemporáneas. Objetivo. Determinar la diversidad genética y la relación con otras comunidades contemporáneas y antiguas de América, de los restos óseos asociados al Templo del Sol en Sogamoso, Colombia. Materiales y métodos. Se analizaron 13 individuos pertenecientes al periodo precolombino muisca (siglos IX-XVI d. C.), provenientes de los alrededores del Templo del Sol en Sogamoso, Boyacá, Andes orientales colombianos. Se amplificó el ADN mitocondrial (ADNmt) y se determinaron los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism, RFLP) para los cuatro haplogrupos amerindios (A, B, C y D). Además, se amplificaron y analizaron los marcadores autosómicos, incluida la amelogenina, y los marcadores de los polimorfismos de repeticiones cortas en tándem (Short Tandem Repeat, STR) del cromosoma Y. Resultados. El haplogrupo A fue el linaje mitocondrial más frecuente en esta población, seguido de los haplogrupos B y C; no se detectó el haplogrupo D. Los análisis de variación genética indicaron una diversidad semejante a la de las poblaciones pertenecientes a la familia lingüística chibcha, contemporánea en Colombia y Centroamérica. Se logró hacer la determinación molecular del sexo de los individuos estudiados y compararla con los datos osteológicos. Con una sola excepción, los datos bioantropológicos y moleculares concordaron. Conclusiones. Estos resultados aportan nuevos elementos a la hipótesis del origen centroamericano de los grupos chibchas del altiplano cundiboyacense con base en marcadores genéticos, y permitieron establecer el sexo y las relaciones de parentesco.

Abstract Introduction: DNA extracted from ancient human bones allows to analyze the genetic makeup of preColumbian populations and to determine the dynamics that gave rise to the diversity of contemporary populations. Objective: To determine the genetic diversity of skeletal remains associated with the Templo del Sol (Sun Temple) and their relationship with other contemporary and ancient communities of America. Materials and methods: We analyzed 13 individuals belonging to the pre-Columbian Muisca Period (IX-XVI centuries AD) from the vicinities of the Templo del Sol (Sun Temple) (Sogamoso, Boyacá) in the eastern Colombian Andes. Mitochondrial DNA was amplified and RFLPs were performed in order to type the four traditional Amerindian haplogroups (A, B, C and D). In addition, autosomal markers including amelogenin and Y-chromosome STRs were amplified. Results: Among the observed mitochondrial lineages, haplogroup A was the most frequent, followed by haplogroups B and C; no evidence of haplogroup D was found. The genetic variation analysis indicated a similar diversity of pre-Columbian Muiscas to that of contemporary populations belonging to the Chibcha linguistic family from Colombia and Central America. Molecular sexing was accomplished and it was compared to osteological data. With only one exception, anthropological and molecular data were consistent. Conclusions: Our results contribute new genetic elements supporting the hypothesis of Central American origin of the Chibcha groups of the Cundiboyacense plateau, and allowed sex typing and kinship evaluations.

Application of the Peak Area Ratio of STR Loci to Amelogenin Locus in the Estimation of DNA Degradation / 法医学杂志

OBJECTIVE@#To explore the change rules of peak area ratio of STR loci to Amelogenin (AMEL) locus (STR/AMEL), a sex-determining gene in DNA degradation, and to evaluate the application of STR/AMEL value in the estimation of DNA degradation degree.@*METHODS@#DNA was extracted from iliopsoas, and the variations of STR/AMEL value (Penta E/AMEL, Penta D/AMEL, FGA/AMEL) were analyzed after the artificial degradation was made by DNase I, and the changes of these three ratios of the iliopsoas naturally degraded in an outdoor environment were also analyzed. The regression curves were analyzed using the periods of DNA degradation and outside the body as the independent variable (x) and the STR/AMEL value as the dependent variable (y) and three curve equations under two conditions were established.@*RESULTS@#Both under the conditions of artificial and natural degradation, STR/AMEL value had a negative relationship with the degradation time. The relationship between STR/AMEL and degradation time can be well simulated by the cubic function. R2 was over 0.99 under controlled degradation condition and over 0.86 under natural degradation condition.@*CONCLUSION@#The STR/AMEL value (Penta E/AMEL, Penta D/AMEL, FGA/AMEL) is negatively related with the DNA degradation degree, which follows mathematical regression models strictly, and it might be applied to evaluate the DNA degradation degree.

Research Progress on Gene Alterations of Amelogenin Locus in Gender Identification / 法医学杂志

There are two kinds of amelogenin gene mutation, including mutation in primer-binding region of amelogenin gene and micro deletion of Y chromosome encompassing amelogenin gene, and the latter is more common. The mechanisms of mutation in primer-binding region of amelogenin gene is nucleotide point mutation and the mechanism of micro deletion of Y chromosome encompassing amelogenin gene maybe non-allelic homologous recombination or non-homologous end-joining. Among the population worldwide, there is a notably higher frequency of amelogenin gene mutations in Indian population, Sri Lanka population and Nepalese population which reside within the Indian subcontinent. Though amelogenin gene mutations have little impact on fertility and phenotype, they might cause incorrect result in gender identification. Using composite-amplification kit which including autosomal STR locus, amelogenin gene locus and multiple Y-STR locus, could avoid wrong gender identification caused by amelogenin gene mutation.

Recognition of Y Fragment Deletion by Genotyping Graphs after Amplified by PowerPlex® 21 Detection Kit / 法医学杂志

OBJECTIVES@#To recognize the possibility of Y fragment deletion of Amelogenin gene intuitively and simply according to the genotyping graphs.@*METHODS@#By calculating the ratio of total peak height of genotyping graphs, the statistics of equilibrium distribution between Amelogenin and D3S1358 loci, Amelogenin X-gene and Amelogenin Y-gene, and different alleles of D3S1358 loci from 1 968 individuals was analyzed after amplified by PowerPlex® 21 detection kit.@*RESULTS@#Sum of peak height of Amelogenin X allele was not less than 60% that of D3S1358 loci alleles in 90.8% female samples, and sum of peak height of Amelogenin X allele was not higher than 70% that of D3S1358 loci alleles in 94.9% male samples.@*CONCLUSIONS@#The result of genotyping after amplified by PowerPlex® 21 detection kit shows that the possibility of Y fragment deletion should be considered when only Amelogenin X-gene of Amelogenin is detected and the peak height of Amelogenin X-gene is not higher than 70% of the total peak height of D3S1358 loci.

Triagem de mutações e polimorfismos de genes candidatos à malformação dentária em pacientes com fissura labiopalatinas / Screening of mutations and polymorphisms of candidate genes to dental malformation in patients with cleft lip and palate

O propósito deste trabalho foi investigar a ocorrência de mutações e polimorfismos em genes candidatos aos defeitos na formação do esmalte dentário em indivíduos com fissura labiopalatina (FLP) transforame incisivo unilateral ou bilateral isolada e associar o genótipo-fenótipo dos indivíduos com FLP e malformação dentária (MD) nos dentes incisivos centrais superiores permanentes. Foram coletadas amostras de saliva de 165 indivíduos de 6 a 15 anos de idade, de ambos os sexos, divididos em 4 grupos de estudo: Grupo 1 - 46 indivíduos com FLP e MD; Grupo 2 - 34 indivíduos com FLP e sem MD; Grupo 3 - 34 indivíduos sem FLP e com MD; Grupo 4 - 51 indivíduos sem FLP e MD. Foi realizada a extração do DNA genômico das amostras de saliva, seguida da Reação em Cadeia da Polimerase, sequenciamento direto dos éxons 2, 3, 4, 5, 6 e 7 do gene AMELX e genotipagem dos SNPs rs3796703, rs3796704, rs3796705, rs7671281, rs2609428 e rs35951442 no gene ENAM. Para a análise estatística dos resultados foi utilizado o Teste Exato de Fisher e o Teste do Qui-quadrado de Pearson. Em relação ao sequenciamento direto do gene AMELX, mutações foram encontradas em 30,4% (n=14), 35,3% (n=12), 11,8% (n=4) e 13,7% (n=7) dos indivíduos dos Grupos 1, 2, 3 e 4, respectivamente. Trinta e sete mutações foram detectadas e distribuídas ao longo dos éxons 2 (1 mutação - 2,7%), 6 (30 mutações - 81,08%) e 7 (6 mutações - 16,22%) do gene AMELX. Houve um aumento significativo (p=0,003) na frequência de mutações nos indivíduos com FLP (Grupos 1 e 2 - 65,7%) em relação aos indivíduos sem FLP (Grupos 3 e 4 - 25,5%). Em relação às 30 mutações encontradas no éxon 6, 43,34% (n=13), 23,33% (n=7), 13,33% (n=4) e 20% (n=6) foram encontrados nos Grupos 1, 2, 3 e 4, respectivamente. A mutação silenciosa c.261C>T (rs2106416) foi detectada em 26 indivíduos distribuídos nos quatro grupos estudados, sendo significativamente mais encontrada (p=0,003) nos grupos com FLP (23,75%), em comparação com os...

The purpose of this study was to investigate the occurrence of mutations and polymorphisms (SNPs) in candidate genes to defects in the formation of enamel in individuals with cleft lip and palate (CLP) unilateral or bilateral incisive transforame isolated and associate genotype-phenotype of individuals with CLP and dental malformation (DM) in permanent teeth maxillary central incisors. For analysis of the proposed genes, saliva samples from 165 individuals from 6 to 15 years old, of both genders, were collected and divided into 4 groups: Group 1 - 46 individuals with CLP and DM; Group 2 - 34 individuals with CLP and without DM; Group 3 - 34 subjects without CLP and DM; Group 4 - 51 subjects without CLP and DM. Extraction of genomic DNA from saliva samples was performed, followed by Polymerase Chain Reaction, direct sequencing of 2, 3, 4, 5, 6 and 7 exons of AMELX gene and genotyping of SNPs rs3796703, rs3796704, rs3796705, rs7671281, rs2609428 and rs35951442 in the ENAM gene. For statistical analysis we used the Fisher's exact test and Pearson's chi-square test. Regarding direct sequencing of AMELX gene, mutations were found in 30.4% (n=14), 35.3% (n=12), 11.8% (n=4) and 13.7% (n=7) of individuals in Groups 1, 2, 3 and 4, respectively. Thirty-seven mutations were detected and distributed over the exons 2 (1 mutation - 2.7%), 6 (30 mutations - 81.08%) and 7 (6 mutations - 16.22%) of AMELX gene. There was a significant increase (p=0.003) in the frequency of mutations in individuals with CLP (Groups 1 and 2 - 65.7%) compared to subjects without CLP (Groups 3 and 4 - 25.5%). Regarding the 30 mutations found in exon 6, 43.34% (n=13), 23.33% (n=7), 13.33% (n=4) and 20% (n=6) were found in Groups 1, 2, 3 and 4, respectively. The c.261C>T silent mutation (rs2106416) was detected in 26 individuals distributed in all groups studied, and was significantly more found (p=0.003) in the groups with CLP (23.75%) compared to the groups without CLP (8.23%). In groups without...

Triagem de mutações e polimorfismos de genes candidatos à malformação dentária em pacientes com fissura labiopalatinas / Screening of mutations and polymorphisms of candidate genes to dental malformation in patients with cleft lip and palate

O propósito deste trabalho foi investigar a ocorrência de mutações e polimorfismos em genes candidatos aos defeitos na formação do esmalte dentário em indivíduos com fissura labiopalatina (FLP) transforame incisivo unilateral ou bilateral isolada e associar o genótipo-fenótipo dos indivíduos com FLP e malformação dentária (MD) nos dentes incisivos centrais superiores permanentes. Foram coletadas amostras de saliva de 165 indivíduos de 6 a 15 anos de idade, de ambos os sexos, divididos em 4 grupos de estudo: Grupo 1 - 46 indivíduos com FLP e MD; Grupo 2 - 34 indivíduos com FLP e sem MD; Grupo 3 - 34 indivíduos sem FLP e com MD; Grupo 4 - 51 indivíduos sem FLP e MD. Foi realizada a extração do DNA genômico das amostras de saliva, seguida da Reação em Cadeia da Polimerase, sequenciamento direto dos éxons 2, 3, 4, 5, 6 e 7 do gene AMELX e genotipagem dos SNPs rs3796703, rs3796704, rs3796705, rs7671281, rs2609428 e rs35951442 no gene ENAM. Para a análise estatística dos resultados foi utilizado o Teste Exato de Fisher e o Teste do Qui-quadrado de Pearson. Em relação ao sequenciamento direto do gene AMELX, mutações foram encontradas em 30,4% (n=14), 35,3% (n=12), 11,8% (n=4) e 13,7% (n=7) dos indivíduos dos Grupos 1, 2, 3 e 4, respectivamente. Trinta e sete mutações foram detectadas e distribuídas ao longo dos éxons 2 (1 mutação - 2,7%), 6 (30 mutações - 81,08%) e 7 (6 mutações - 16,22%) do gene AMELX. Houve um aumento significativo (p=0,003) na frequência de mutações nos indivíduos com FLP (Grupos 1 e 2 - 65,7%) em relação aos indivíduos sem FLP (Grupos 3 e 4 - 25,5%). Em relação às 30 mutações encontradas no éxon 6, 43,34% (n=13), 23,33% (n=7), 13,33% (n=4) e 20% (n=6) foram encontrados nos Grupos 1, 2, 3 e 4, respectivamente. A mutação silenciosa c.261C>T (rs2106416) foi detectada em 26 indivíduos distribuídos nos quatro grupos estudados, sendo significativamente mais encontrada (p=0,003) nos grupos com FLP (23,75%)...

The purpose of this study was to investigate the occurrence of mutations and polymorphisms (SNPs) in candidate genes to defects in the formation of enamel in individuals with cleft lip and palate (CLP) unilateral or bilateral incisive transforame isolated and associate genotype-phenotype of individuals with CLP and dental malformation (DM) in permanent teeth maxillary central incisors. For analysis of the proposed genes, saliva samples from 165 individuals from 6 to 15 years old, of both genders, were collected and divided into 4 groups: Group 1 - 46 individuals with CLP and DM; Group 2 - 34 individuals with CLP and without DM; Group 3 - 34 subjects without CLP and DM; Group 4 - 51 subjects without CLP and DM. Extraction of genomic DNA from saliva samples was performed, followed by Polymerase Chain Reaction, direct sequencing of 2, 3, 4, 5, 6 and 7 exons of AMELX gene and genotyping of SNPs rs3796703, rs3796704, rs3796705, rs7671281, rs2609428 and rs35951442 in the ENAM gene. For statistical analysis we used the Fisher's exact test and Pearson's chi-square test. Regarding direct sequencing of AMELX gene, mutations were found in 30.4% (n=14), 35.3% (n=12), 11.8% (n=4) and 13.7% (n=7) of individuals in Groups 1, 2, 3 and 4, respectively. Thirty-seven mutations were detected and distributed over the exons 2 (1 mutation - 2.7%), 6 (30 mutations - 81.08%) and 7 (6 mutations - 16.22%) of AMELX gene. There was a significant increase (p=0.003) in the frequency of mutations in individuals with CLP (Groups 1 and 2 - 65.7%) compared to subjects without CLP (Groups 3 and 4 - 25.5%). Regarding the 30 mutations found in exon 6, 43.34% (n=13), 23.33% (n=7), 13.33% (n=4) and 20% (n=6) were found in Groups 1, 2, 3 and 4, respectively. The c.261C>T silent mutation (rs2106416) was detected in 26 individuals distributed in all groups studied, and was significantly more found (p=0.003) in the groups with CLP (23.75%) compared to the groups without CLP (8.23%). In groups without...

Development of an 18 X-InDel multiplex PCR system / 法医学杂志

OBJECTIVE@#To investigate Insertion/Deletion (InDel) polymorphism on the X chromosome and to screen 18 InDel loci for the Chinese Han population as a forensic DNA typing system auxiliary.@*METHODS@#Eighteen X-InDel markers were selected using the Human Genome Browser and dbSNP database. Multiplex PCR primer pairs of selected X-InDel markers were designed using Primer 3 software and divided into 3 groups according to the amplified fragment length, labeled by FAM, HEX and TAMRA fluorescence dye, respectively. The population genetics research and comparative analysis of Chinese Han nationality and 4 main minorities, the Hui, Wei, Mongol, and Tibetan nationalities, were investigated with the system.@*RESULTS@#A new multiplex genotyping system, named InDel X-18PLEX, was successfully developed and validated, consisted of 18 X-InDel markers on the X chromosome and 1 Amelogenin gender marker. No deviation from Hardy-Weinberg equilibrium expectations was detected in the distribution of genotypes in the 5 investigated ethnic groups. However, there was significant difference between their distributions. From the investigation of Han nationality, high female (0.9999994) and male (0.999 88) overall discrimination power values were obtained, as well as high overall mean exclusion chance values in trios (0.999 992) and in duos (0.99).@*CONCLUSION@#InDel X-18PLEX meets the requirements as a forensic DNA complementary kit, providing effective supplementary analytical tools for difficult cases.

Homologous amelogenin gene test of archaeological samples / 法医学杂志

OBJECTIVE@#Based on the sequence differences of Amelogenin homologous gene in the X and Y chromosomes, a pair of specific primers was designed to identify the sex of archaeological samples.@*METHODS@#Ancient DNA fragments were extracted from the bones and teeth of sacrificial slaves with an improved method that combines phenol-chloroform extraction, silicon dioxide adsorption with ultrafiltration concentration. The polyacrylamide gel electrophoresis (PAGE) was used to detect PCR products.@*RESULTS@#Seven in sixteen samples from eight graves showed positive results and the targeted segments were visible: a male with two bands of 106bp (Amel-X) and 112 bp (Amel-Y), while a female with only one band of 106 bp (Amel-X). Ancient DNA analyzing results from tooth samples are more marked than that from bones.@*CONCLUSION@#The improved extraction method is more effective for ancient DNA extraction, which reduced the PCR inhibitors and lowered experimental costs. The sex determination technology based on Amelogenin homologous gene is an important and feasible method in the molecular archaeological research.