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At least 487 records · Page 27Linked to original sources
PubMed2005

Disturbed population genetics: suspected introgressive hybridization between two Mnais damselfly species (Odonata).

Mnais costalis and M. pruinosa are damselflies (Odonata: Calopterygidae) with low dispersal abilities, both during their aquatic stream-living immature stage and their flying adult stage. A previous nuclear DNA (nDNA) sequencing and morphology study showed that these two species are very closely related, and cohabit widely in western Japan. The two species, however, segregate microhabitats along a stream: M. costalis lives in the lower reaches, and M. pruinosa in the upper reaches. In this study, our analyses were based on mitochondrial DNA (mtDNA), which usually mutates faster and is more variable among individuals than nDNA, and which is inherited maternally. We found that most COI haplotypes were shared between the two species, and that for most study sites interspecific riverine genetic structures were not clarified by mtDNA analysis. Incongruent population genetic structures based on nDNA and mtDNA suggested hybridization and introgression of mtDNA between the two species.

Animals↗
PubMed1999

Population genetics and phylogenetic analysis of Colorado Borrelia burgdorferi.

Borrelia burgdorferi is transmitted in an enzootic cycle in Colorado between the tick Ixodes spinipalpis and the woodrat Neotoma mexicana. The genetic relationship of Colorado isolates to other B. burgdorferi isolates is unknown nor have relationships among various Colorado isolates been determined. Portions of the flagellin (fla), 66-kD protein, and outer surface protein A (ospA) genes were amplified from 71 Colorado isolates, screened for genetic variability using single strand conformation polymorphism analysis, and unique alleles were sequenced. Colorado isolates were most similar to tick isolates from California and New York isolate 25015. Genetic distances among Colorado ospA sequences were the same or higher than distances among other isolates whereas distances among fla sequences tended to be the same or lower. The index of association (I(A)) was calculated among all loci as a measure of clonality. The I(A) among Colorado isolates was similar to I(A) previously estimated among other United States isolates.

Amino Acid Sequence↗
PubMed1999

Iberia: population genetics, anthropology, and linguistics.

Basques, Portuguese, Spaniards, and Algerians have been studied for HLA and mitochondrial DNA markers, and the data analysis suggests that pre-Neolithic gene flow into Iberia came from ancient white North Africans (Hamites). The Basque language has also been used to translate the Iberian-Tartesian language and also Etruscan and Minoan Linear A. Physical anthropometry of Iberian Mesolithic and Neolithic skeletons does not support the demic replacement in Iberia of preexisting Mesolithic people by Neolithic people bearing new farming technologies from Europe and the Middle East. Also, the presence of cardial impressed pottery in western Mediterranean Europe and across the Maghreb (North Africa) coasts at the beginning of the Neolithic provides good evidence of pre-Neolithic circum-Mediterranean contacts by sea. In addition, pre-dynastic Egyptian El-Badari culture (4,500 years ago) is similar to southern Iberian Neolithic settlements with regard to pottery and animal domestication. Taking the genetic, linguistic, anthropological, and archeological evidence together with the documented Saharan area desiccation starting about 10,000 years ago, we believe that it is possible that a genetic and cultural pre-Neolithic flow coming from southern Mediterranean coasts existed toward northern Mediterranean areas, including at least Iberia and some Mediterranean islands. This model would substitute for the demic diffusion model put forward to explain Neolithic innovations in Western Europe.

Anthropology↗
PubMed2000

[Population genetics of Chinese surnames. I. Surname frequency distribution and genetic diversity in Chinese].

This paper deals with the distributional characteristics of Chinese surnames and the factors affecting their distribution. Analysis of alpha and nu values for three periods in the last 1,000 years clearly reveals the distributional pattern of Chinese surnames. In China, communities with the same surname are widespread, especially in the central areas where there are more relatively isolated Y chromosome of the same source (communities with the same surname) and more surnames than in other areas (especially the South China). If each surname has a certain kind of mono-type Y-DNA, then, according to the distribution of surnames, there exist the most mono-type of Y-DNA in the central provinces where are the originating center of Chinese surnames. For the first time, an equation is constructed predicting the kind of Chinese surnames. It has been estimated that there are about 3,100 surnames present in use for the Han nationality.

Genetic Variation↗
PubMed2002

[Studies of population genetic relationships among 24 Chinese and exotic pig breeds using AFLP analysis].

A total of 12 AFLP primer combinations were used to detect genetic variation of pooled DNA in a sample of 19 Chinese native pig breeds, 1 cultivated pig breed and 4 European and American pig breeds. The genetic similarity coefficient of 24 pig beeds was calculated from AFLP data, UPGMA cluster analysis was also performed. The 12 primer combinations generated more than 1000 bands, of which 208 bands were polymorphic, 17.3 polymorphic markers were detected by one primer combination on the average. Thirteen putative breed specific bands were produced in the pooled DNA of 8 pig breeds. The cultivated pig breed and 4 exotic pig breeds were clustere into one group, while 19 Chinese native pig breeds were gathered into the other group in the UPGMA tree. The result indicated that AFLP analysis had high assay efficiency index (Ai) and provided a valuable tool for assaying genetic diversity and breed characterization in pigs. Chinese native pig breeds and exotic pig breeds show remarkable genetic differentiation, which had farther genetic relationships. Nanchang White pig and Large White pig, Yushan Black pig and Yanshan Black pig had intimate genetic relationships with each other respectively, which were consistent with its breeding history, geographical distribution and RAPD analysis results. In addition, the reasons for cluster results of some pig breeds from AFLP data were not consistent with morphology, geographical distribution and existing classification were discussed.

Animals↗
PubMed1975

[Population genetics of the inhabitants of Northern European USSR. I. Data on the structure of 6 villages in Archangel Oblast].

The paper deals with two demographic characteristics of 6 villages in the Archangelsk Region of the RSFSR (river Peosa region) significant from the genetical standpoint. These data were obtained by means of the examination of 843 persons (75,07% of the total number of inhabitants) and of the analysis of complete list of inhabitants permanently living in the villages studied. The proportion of the reproductivity age class was 28.94%, the numbers of men and woman among them being about equal. The average number of children per family in families that have already completed their reproductive period was 3.87, the variance being 4.51 (the data obtained on the basis of examination of over 90 families). The average age of marriage was established to be about 24 years, the duration of each generation being about 32 years. The average index of endogamy per village was observed to be 58.40%, the contribution of the gametes of the preceding generation per village being 72.86%. The migrational influx of gametes from other localities per total of 6 villages was 2.52%. It was shown by the comparison of the character of migrations with mathematical models that the matrix migrational model is the most adequate one.

Family Characteristics↗