Average Heterozygosity Values Research Articles

Nuclear DNA polymorphisms in a wild population of yellow baboons (Papio hamadryas cynocephalus) from Mikumi National Park, Tanzania.

Yellow baboons (Papio hamadryas cynocephalus) from Mikumi National Park, Tanzania were studied for polymorphisms in nuclear DNA. The study population consists of four social groups that inhabit overlapping home ranges and exchange males. As a result, these groups are considered to be members of a single interbreeding population. Human DNA clones were used as probes to screen five loci (AT3, REN, HEXB, VIM, and APOB) for restriction fragment length polymorphisms (RFLP). A total of 14 polymorphisms, at least one at each locus, was detected in a panel of 27 baboons tested using six restriction enzymes for each locus. Eleven of these RFLP systems have average heterozygosity values greater than 0.40. This initial screening demonstrates that human DNA clones can be used to detect significant numbers of informative DNA polymorphisms in single-copy nuclear genes of this species and suggests that the average proportion of nucleotides polymorphic across nuclear loci in this population may be between 1.0% and 1.3%.

Genetics, ethnohistory, and linguistics of Brač, Yugoslavia.

Serogenetic data involving 21 genetic systems were collected from 12 villages on the island of Brač (Yugoslavia) in 1987. Maximum sample size was 709 individuals. The UPGMA dendrogram based on genetic distances was readily interpretable within the contexts of village settlement history, social relationships, and sample size considerations. The gene diversity value (H = 0.3029 ± 0.0119) was both quite high and extremely similar to the average heterozygosity value on the neighboring Pelješac peninsula. Quadratic assignment procedures were used to investigate genetic-linguistic-geographic correspondences. Unlike the Pelješac peninsula, where the distance matrix correlations between genetics and linguistics, genetics and geography, and linguistics and geography were all positive and highly statistically significant; on Brač, only the linguistics-geography correlation achieved statistical significance. Reasons for the differences are sought in the different migrational characteristics of these two population systems, in the complex interaction between evolutionary forces promoting population differentiation (genetic drift) and homogeneity (gene flow), and in known patterns of sociocultural interaction that might have skewed the genetic-geographic associations on Brač.

Chromosomal C-band variation inAllium sch?noprasum (Liliaceae) in eastern North America

Variation in C-banding was studied in seven populations ofAllium schœnoprasum from eastern N. America, including populations referable to var.sibiricum, var.laurentianum, and ± intermediate. 23 bands were recognized on five pairs of chromosomes, and were treated as 23 loci. No banding site was monomorphic throughout the plants studied. The level of polymorphism per population was >60%, and the average heterozygosity values varied from 0.21 to 0.27. The various “banding patterns” of chromosomes were shown to depend on the random combination of individual bands. Nei's genetic distances between populations varied from 0 to 0.070 (mean: 0.033). The matrix of genetic distances was analysed by non-metric multidimensional scaling, and the results showed a significant relationship between longitude and population scores on the ordination. The chromosomal data did not clearly discriminate between the two native varieties ofA. schœnoprasum, but were interpreted as a longitudinal cline. It is suggested that studies of C-banding variation in vascular plants should focus on individual banding sites, rather than on whole chromosome banding patterns.

Genetic variability in natural populations of the Brazilian night monkey (Aotus infulatus)

Seventy-one night monkeys from both banks of the Tocantins River in Brazilian Amazonia were examined for 12 blood protein loci. The results indicate remarkable differences between the subpopulations of the two banks for the CA2, PGD, and GPI polymorphic systems. The average heterozygosity values of Aotusfor the west and east bank populations were 2.2 and 5.9, respectively. These results and the difficulties in delimiting species in this genus may indicate a relatively recent spur of evolutionary differentiation.

Studies on enzymatic polymorphism in rye (Secale cereale L.) cultivars

An electrophoretic study of seed peroxidases of eight rye (Secale cereale L.) cultivars was carried out in order to estimate the polymorphism and the variability degree of this highly variable enzymatic system. Analysis of the Cathodal Peroxidase System (CPX) were performed using polyacrylamide gel electrophoresis. Thirteen loci were recorded in embryo plus scutellum and endosperm. The percentage of polymorphic loci ranged from 53.84% to 92.30% when the 99% polymorphism criterion was used; these high values were possibly due to the studied system. The average heterozygosity values ranged from 0.179 to 0.378; these values fell into the expected for open-pollinated species. Genetic distance values fitted well with those expected for conspocific plants with a little of diversification.

Biochemical Systematics of North American Moles (Insectivora: Talpidae)

Genetic variation within and among five genera and seven species of North American moles of the family Talpidae was examined using starch-gel electrophoresis. All loci examined, except LAP, were found to segregate for more than one allele among species, with a maximum of eight different alleles at any single locus. Average heterozygosity values (H) ranged from 0.00 to 0.015 in fossorial genera and up to 0.050 in the semifossorial Neurotrichus gibbsii . Allozymic data suggest that the Recent North American talpid fauna comprises two separate groups. These findings support the contention of Cabrera (1925) that the North American moles are most appropriately considered as two distinct subfamilies: the Condylurinae, including only the genus Condylura ; and the Scalopinae, consisting of Scalopus, Neurotrichus, Parascalops , and Scapanus . Formal recognition of these subfamilies, however, must await Old World comparisons. Genetic similarity among genera excluding Condylura ranged from a low Roger's similarity value (S) of 0.28 between Scalopus and Parascalops to a high of 0.57 between Scapanus orarius and Neurotrichus , with the average S across genera being 0.46. These data suggest that Parascalops and Scapanus shared a common ancestor after the divergence of Scalopus . The allozymic data provided an estimated divergence time of from 25 to 38 million years BP for this dichotomy, and 49 million years for the divergence between Condylura and other North American genera.

Genic variation in the deer mouse, Peromyscus maniculatus, in a small geographic area

Genic variation was examined with starch and polyacrylamide gel electrophoresis at 14 loci in 12 populations of Peromyscus maniculatus nubiterrae from a small part of the Appalachians in eastern Tennessee and western North Carolina. Polymorphism was observed at eight loci with no significant correlations between frequency of common genotypes or alleles and altitude. Average individual heterozygosity (\-H) values were low for P. maniculatus whether using only ‘slow’ evolving loci (mean = 3.0%) or both ‘slow’ and ‘fast’ evolving loci (mean = 4.9%). No significant correlation was present between altitude and \-H. Interlocality variation of \-H was as great in this study as previously reported for P. maniculatus over larger geographic areas. Rogers' coefficients of genetic similarity of paired combinations of populations based on ‘slow’ evolving loci (range of 0.941 to 0.997) or based on ‘slow’ and ‘fast’ evolving loci (range of 0.858 to 0.974) showed all populations to be highly similar. Ranges of similarity values observed in the present study were as great as those previously reported for P. maniculatus over a larger geographic area.