RESUMEN
Ulmus chenmoui (Ulmaceae) is an endangered tree found on Langya Mountain, eastern China. To better understand the population genetics of U. chenmoui and conserve the species, we developed microsatellite markers. Using a suppression-polymerase chain reaction technique, 74 compound microsatellite primer pairs were designed. Twelve microsatellite markers were polymorphic in 39 individuals, and the number of alleles per locus ranged from 3 to 9. The observed and expected heterozygosities ranged from 0.051 to 0.769 and from 0.533 to 0.768, respectively. Significant linkage disequilibrium was detected for three pairs of loci (P < 0.01), which may be due to a recent population bottleneck and the small population size. Nine of the 12 loci deviated from the Hardy-Weinberg equilibrium (P < 0.01), which could be explained by significant inbreeding rather than the presence of null alleles. These markers will provide a solid basis for future efforts in population genetic studies of U. chenmoui, which in turn will contribute to species conservation.
Asunto(s)
Árboles/genética , Ulmus/genética , Alelos , China , Conservación de los Recursos Naturales , Sitios Genéticos , Genética de Población , Desequilibrio de Ligamiento , Repeticiones de Microsatélite , Polimorfismo GenéticoRESUMEN
In addition to the host immune response, genetic and environmental factors play crucial roles in the manifestation of hepatitis B virus (HBV) infection. The macrophage migration inhibitory factor (MIF) -173G/C polymorphism (rs755622), located in the promoter region of MIF, may play integral roles in diverse processes, including the immune response. Thus, the MIF -173G/C polymorphism may influence the immune response to HBV during natural infection. We investigated whether the MIF -173G/C polymorphism was associated with susceptibility to HBV infection in a Chinese Han population. A total of 596 HBV infection cases and 612 age-matched controls were recruited for the study. Genotyping of the MIF -173G/C polymorphism was performed using the allele-specific polymerase chain reaction method. The frequencies of the alleles and genotypes in patients and controls were compared using the χ(2) test. Carriers of the variant C allele in MIF -173 G/C were at significantly higher risk of HBV infection than carriers of the wild-type allele (P = 0.032, odds ratio = 0.799, 95% confidence interval = 0.651-0.981). However, there was no significant difference in the distribution of MIF -173G/C genotypes between case and control groups in either population (P = 0.096, degrees of freedom = 2). Our findings indicate that the G to C base change in MIF -173 G/C confers an increased risk of development of HBV infection by altering the expression of MIF in our Chinese Han population.
Asunto(s)
Hepatitis B Crónica/genética , Oxidorreductasas Intramoleculares/genética , Factores Inhibidores de la Migración de Macrófagos/genética , Adulto , Anciano , Pueblo Asiatico/genética , Estudios de Casos y Controles , China , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B Crónica/enzimología , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple , Regiones Promotoras GenéticasRESUMEN
The morphological species concept is based on morpho-logical traits, which are often subject to subjectivity or artifact. Molecular evidence is needed to test the reliability of morphological classification of taxa that are controversial and to provide appropriate taxonomic de-limitation. In this study, we used 15 single-copy nuclear loci and 2 chloroplast fragments to verify the morphological classification of the Salix matsudana Koidz. complex using phylogenetic approaches. Complete sequence alignment showed slight diversification in nuclear sequences and no variety in chloroplast DNA fragments. Phylogenetic trees revealed a monophyletic group consisting of all individuals of S. matsudana and 2 clades within this group, with a 100% bootstrap support value and 1.00 posterior probability. The topology of the phylogenetic trees was highly consistent with the morphological classification of the S. matsudana complex. Verifying the genetic background of these classification units based on remarkable morphological differences will provide a foundation for future studies of Salix and the breeding of new horticultural varieties.
Asunto(s)
Salix/genética , Genes de Plantas , Estudios de Asociación Genética , Sitios Genéticos , Tipificación Molecular , Filogenia , Proteínas de Plantas/genética , Salix/anatomía & histología , Salix/clasificación , Análisis de Secuencia de ADNRESUMEN
As a result of human activities, wild populations of Cunninghamia lanceolata (Cupressaceae) have sharply declined in recent years. The development and implementation of a valid conservation strategy require a clear understanding of the genetic makeup of this species. Eleven polymorphic microsatellite loci were isolated and characterized from samples of 52 individuals from the Provenance Test Plantation in Fenyi, Jiangxi Province, China. Among the loci, 10 were polymorphic and 1-34 (average 18.182) alleles per locus were identified. Observed and expected heterozygosities ranged from 0 to 0.750 (mean 0.456) and 0 to 0.968 (mean 0.749), respectively. These microsatellite loci may facilitate further research on the molecular breeding and population genetics of C. lanceolata and its relatives.
Asunto(s)
Cunninghamia/genética , ADN de Plantas/aislamiento & purificación , Sitios Genéticos , Repeticiones de Microsatélite/genética , ADN de Plantas/genética , Datos de Secuencia MolecularRESUMEN
Species of Populus are widely distributed worldwide, playing a significant role in both ecology and economy. However, the lack of single-copy nuclear markers limits knowledge about the phylogeny and population genetics of this genus. In the present study, primer pairs of 15 single-copy nuclear markers were developed through bioinformatic methods based on complete genomic sequences of Populus trichocarpa and Salix arbutifolia. Twenty individuals of Populus davidiana Dode and Salix matsudana Koidz were used to evaluate the basic application of these markers with respect to marker length and diversity indices, respectively. The utility of single-copy nuclear markers is anticipated to facilitate further studies about the phylogeny, population genetics, and phylogeography of this genus, in addition to providing information about the evolutionary dynamics of Salicaceae.