Genetic analysis of seven Italian horse breeds based on mitochondrial DNA D‐loop variation

To understand the origin and genetic diversity of Italian horses, mitochondrial DNA D‐loop sequences were generated for 163 horses from seven breeds. Sequence analysis of a 480‐bp segment revealed a total of 84 haplotypes with 57 polymorphic sites, indicating multiple maternal origins and high genetic diversity. Comparison of the haplotypes with the equine mtDNA haplotype/haplogroup nomenclature showed a haplogroup distribution in the Italian breeds more similar to that found in the Middle East breeds than in the European breeds, probably due to the economic and cultural relationship with the Middle East in the past centuries.     

A second‐generation genetic linkage map for bighead carp (Aristichthys nobilis) based on microsatellite markers

Bighead carp (Aristichthys nobilis) is an important aquaculture fish worldwide. Genetic linkage maps for the species were previously reported, but map resolution remained to be improved. In this study, a second‐generation genetic linkage map was constructed for bighead carp through a pseudo‐testcross strategy using interspecific hybrids between bighead carp and silver carp. Of the 754 microsatellites genotyped in two interspecific mapping families (with 77 progenies for each family), 659 markers were assigned to 24 linkage groups, which were equal to the chromosome numbers of the haploid genome. The consensus map spanned 1917.3 cM covering 92.8% of the estimated bighead carp genome with an average marker interval of 2.9 cM. The length of linkage groups ranged from 52.2 to 133.5 cM with an average of 79.9 cM. The number of markers per linkage group varied from 11 to 55 with an average of 27.5 per linkage group. Normality tests on interval distances of the map showed a non‐normal marker distribution; however, significant correlation was found between the length of linkage group and the number of markers below the 0.01 significance level (two‐tailed). The length of the female map was 1.12 times that of the male map, and the average recombination ratio of female to male was 1.10:1. Visual inspection showed that distorted markers gathered in some linkage groups and in certain regions of the male and female maps. This well‐defined genetic linkage map will provide a basic framework for further genome mapping of quantitative traits, comparative mapping and marker‐assisted breeding in bighead carp.     

Epilogue — Demography and anthropology

As a conclusion, this paper reviews briefly the content of the volume. The wealth of demographic data has not been adequately exploited in anthropology; this is why this publication is valuable in showing attempts to apply demographic data in a variety of anthropological problems. This symposium has explored many interesting points which we recall here. Yet it has also opened up a whole range of further questions on the material presented as well as in this broad field. Several directions of research could be developed, for instance, testing among human populations, over long periods, the ecological thoughts of ecosystems evolving as a cascade of instabilities, rather than a succession of equilibrium states. Let us also recall the pervasive nature of demographic facts in topics such as the energy cycle or the genetic structure and evolution of human populations.     

Reproduction of the rare monocarpic species Saxifraga mutata L.

The aim of the study is to investigate the impact of reproduction and genetic variation on the persistence of populations of the prealpine, monocarpic Saxifraga mutata L. The species grows on erosion slopes or rocks, and its local populations are often small and isolated. Crossing experiments resulted in better seed-set than selfing, but both yielded viable seeds. Agamospermy did not occur. In an early-successional species like S. mutata , successful selfing is important in the colonization of new habitats. Flowers of S. mutata were visited by Syrphidae and unspecialized Hymenoptera. A germination rate of 40% was reached in cultivation after 20 weeks but germination continued until the end of the experiment after 92 weeks. Seeds stored dry for 30 months at room temperature mostly lost their germinability. In natural habitats, seedlings were found almost throughout the year with a peak in spring. Suitable safe sites were small patches of open soil, bare marl on erosion slopes, and rock crevices. AU individuals investigated were diploid with 2n = 26. Allozyme electrophoresis showed a lack of segregation within the populations. Intra- and interpopulation genetic variation was low. These results were in partial disagreement with theoretical expectations in a mixed mating species. It is concluded that demographic rather than genetic processes are the main cause of extinction of populations of S. mutata , at least in the short-term.     

Genetic diversity and molecular fingerprinting of Prunus cerasus var. austera from central Italy

In central Italy, Prunus cerasus var. austera is cultivated as small stands or scattered trees in marginal areas for the production of jam and wine. Thanks to the healthy attributes of its products and its ability to grow in different environmental conditions, this variety has gained new interest in the development of marginal areas. We assessed the level of the genetic variability of P. cerasus var. austera germplasm from central Italy and identified a ‘core collection’ representative of the present genetic diversity. A total of 161 trees, morphologically identified as var. austera, and one tree, identified as var. caproniana were collected and genotyped by 14 SSRs. Two individuals provided by a commercial plant nursery, one of P. cerasus var. caproniana and one of P. cerasus var. austera, were used as control. Thirteen SSRs presented private alleles in austera. Seven individuals morphologically identified as austera revealed private alleles specific to caproniana. The PCoA and Bayesian clustering analysis showed a main genetic group including var. austera, while a second group included all the caproniana-like genotypes. A core collection of 31 trees (46% of austera genotypes) was selected. This study can be considered as a starting point for future investigations on this variety.     

Genome‐wide scans to detect positive selection in Large White and Tongcheng pigs

Due to the direction, intensity, duration and consistency of genetic selection, especially recent artificial selection, the production performance of domestic pigs has been greatly changed. Therefore, we reasoned that there must be footprints or selection signatures that had been left during domestication. In this study, with porcine 60K BeadChip genotyping data from both commercial Large White and local Chinese Tongcheng pigs, we calculated the extended haplotype homozygosity values of the two breeds using the long‐range haplotype method to detect selection signatures. We found 34 candidate regions, including 61 known genes, from Large White pigs and 25 regions comprising 57 known genes from Tongcheng pigs. Many selection signatures were found on SSC1, SSC4, SSC7 and SSC14 regions in both populations. According to quantitative trait loci and network pathway analyses, most of the regions and genes were linked to growth, reproduction and immune responses. In addition, the average genetic differentiation coefficient F_ST was 0.254, which means that there had already been a significant differentiation between the breeds. The findings from this study can contribute to further research on molecular mechanisms of pig evolution and domestication and also provide valuable references for improvement of their breeding and cultivation.     

Genetic Characteristics of Restored Elk Populations in Kentucky

Translocations are a common management practice to restore or augment populations. Understanding the genetic consequences of translocation efforts is important for the long-term health of restored populations. The restoration of elk (Cervus canadensis) to Kentucky, USA, included source stocks from 6 western states, which were released at 8 sites in southeastern Kentucky during 1997–2002. We assessed genetic diversity in restored herds and compared genetic similarity to source stocks based on 15 microsatellite DNA loci. Genetic variation in the restored populations was comparable to source stocks ( allelic richness = 3.52 and 3.50; expected heterozygosity = 0.665 and 0.661 for restored and source, respectively). Genetic differentiation among all source and restored populations ranged from 0.000 to 0.065 for pairwise F_ST and 0.034 to 0.161 for pairwise Nei's D_A. Pairwise genetic differentiation and Bayesian clustering revealed that stocks from Utah and North Dakota, USA, contributed most to restored populations. Other western stocks appeared less successful and were not detected with our data, though our sampling was not exhaustive. We also inferred natural movements of elk among release sites by the presence of multiple genetic stocks. The success of the elk restoration effort in Kentucky may be due, in part, to the large number of elk (n = 1,548), repeated releases, and use of diverse source stocks. Future restoration efforts for elk in the eastern United States should consider the use of multiple stock sources and a large number of individuals. In addition, preservation of genetic samples of founder stock will enable detailed monitoring in the future. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.