The current extensive use of the domestic goat (Capra hircus) is the result of its medium size and high adaptability as multiple breeds. The extent to which its genetic variability was influenced by early domestication practices is largely unknown. A common standard by which to analyze maternally-inherited variability of livestock species is through complete sequencing of the entire mitogenome (mitochondrial DNA, mtDNA). We present the first extensive survey of goat mitogenomic variability based on 84 complete sequences selected from an initial collection of 758 samples that represent 60 different breeds of C. hircus, as well as its wild sister species, bezoar (Capra aegagrus) from Iran. Our phylogenetic analyses dated the most recent common ancestor of C. hircus to ~460,000 years (ka) ago and identified five distinctive domestic haplogroups (A, B1, C1a, D1 and G). More than 90 % of goats examined were in haplogroup A. These domestic lineages are predominantly nested within C. aegagrus branches, diverged concomitantly at the interface between the Epipaleolithic and early Neolithic periods, and underwent a dramatic expansion starting from ~12–10 ka ago. Domestic goat mitogenomes descended from a small number of founding haplotypes that underwent domestication after surviving the last glacial maximum in the Near Eastern refuges. All modern haplotypes A probably descended from a single (or at most a few closely related) female C. aegagrus. Zooarchaelogical data indicate that domestication first occurred in Southeastern Anatolia. Goats accompanying the first Neolithic migration waves into the Mediterranean were already characterized by two ancestral A and C variants. The ancient separation of the C branch (~130 ka ago) suggests a genetically distinct population that could have been involved in a second event of domestication. The novel diagnostic mutational motifs defined here, which distinguish wild and domestic haplogroups, could be used to understand phylogenetic relationships among modern breeds and ancient remains and to evaluate whether selection differentially affected mitochondrial genome variants during the development of economically important breeds.
The process of canine domestication represents certainly one of the most interesting questions that evolutionary biology aims to address. A “multiphase” view of this process is now accepted, with a first phase during which different groups of wolves were attracted by the anthropogenic niche and a second phase characterized by the gradual establishment of mutual relationships between wolves and humans. Here, we provide a review of dog (Canis familiaris) domestication, highlighting the ecological differences between dogs and wolves, analyzing the molecular mechanisms which seem to have influenced the affiliative behaviors first observed in Belyaev’s foxes, and describing the genetics of ancient European dogs. Then, we focus on three Mediterranean peninsulas (Balkan, Iberian and Italian), which together represent the main geographic area for studying canine domestication dynamics, as it has shaped the current genetic variability of dog populations, and where a well-defined European genetic structure was pinpointed through the analysis of uniparental genetic markers and their phylogeny.
The Maremmano horse is considered one of the most important Italian warmblood breeds which originated from an ancient population. In 1980, the National Association of Maremmano Breeders established the first Studbook that recorded 440 dams and four sire founders. In this study, we selected the most significant maternal lines in terms of offspring (for a total of 74 lineages and 92 Maremmano horses) and analyzed their mitochondrial DNA control regions. We found a high variability, reflecting the importance of this local breed as a genetic resource to be preserved. Through multiple sampling, we then verified the pedigree information for 12 dam lines by matching genealogical data with mitochondrial haplotypes. A complete concordance was demonstrated in nine lineages, while for the other we highlighted a different number of haplotypes for each line (three in Fiorella, two in Nizza I, and two in Pomposina), thus suggesting that the information recorded in the Studbook could be wrong and the samples do not descend from the same maternal founder. Our combined analysis provides the opportunity to confirm the ancestry of animals and could be employed to prevent errors in pedigree data also for other breeds and species.
28 October 2020 in Italian Journal of Animal Science
South African native chicken breeds are no exception to the declining of local domestic breeds that has long been recognised and found associated with the commercialisation of breeding in domestic animals. The aims of the study were: (i) to provide a comprehensive view of genetic variation in four KwaZulu-Natal indigenous chicken populations (Jozini, Newcastle, Pietermaritzburg, and Port Shepstone), and (ii) to estimate the extent of differentiation of the village populations from three conserved South African indigenous pure breeds (Potchefstroom koekoek, Ovambo, and Venda) by genotyping individuals at 19 autosomal microsatellite loci. Finally, (iii) new information to the history of KwaZulu-Natal indigenous chicken populations was made available by exploring their phylogenetic relationship and their possible maternal origin through the mitochondrial DNA. The results suggested noticeable genetic diversity within and between ecotypes with clear sub-structuring between them. The indigenous populations had high genetic diversity (observed heterozygosity ranging from 0.61 in Pietermaritzburg to 0.70 in Jozini) while conserved populations showed considerable within population inbreeding coefficient (from 0.01 in Potchefstroom koekoek to 0.18 in Ovambo). Median-joining network analyses indicated the dominance of haplogroup E suggesting a likely Southeast Asia and/or Indian subcontinent origin. The presence of haplogroup B and C not only emphasises multiple maternal origin but also highlights genetic introgression of local chickens with commercial genotypes. These results highlighted the importance of local breeds as a genetic reservoir; moreover, the conservation of local breeds may play an important role in the local economy as a source of high-quality products for consumers.
Nowadays, the coexistence between humans and domestic animals (especially dogs and cats) has become a common scenario of daily life. Consequently, during a forensic investigation in civil or criminal cases, the biological material from a domestic animal could be considered “evidence” by law enforcement agencies. Animal genomics offers an important contribution in attacks and episodes of property destruction or in a crime scene where the non-human biological material is linked to the victim or perpetrator. However, only a few animal genetics laboratories in the world are able to carry out a valid forensic analysis, adhering to standards and guidelines that ensure the admissibility of data before a court of law. Today, forensic sciences focus on animal genetics considering all domestic species through the analysis of STRs (short tandem repeats) and autosomal and mitochondrial DNA SNPs (single nucleotide polymorphisms). However, the application of these molecular markers to wildlife seems to have gradually gained a strong relevance, aiming to tackle illegal traffic, avoid the loss of biodiversity, and protect endangered species. The development of third-generation sequencing technologies has glimmered new possibilities by bringing “the laboratory into the field”, with a reduction of both the enormous cost management of samples and the degradation of the biological material.
The Sardinian Anglo Arab (SAA) is a famous horse breed in Italy, with a significant historical background in the island of Sardinia. The aim of the study is to perform an evaluation of genetic variability in SAA using pedigree and mitochondrial data. In the current population, pedigree completeness was observed to be close to 100%, while the inbreeding coefficient and the average relatedness were lower than 3%. The ratio of effective founders/numbers of ancestors was 3.68 for the whole pedigree. The effective population size (Ne) computed by an individual increase in inbreeding (Ne_1) was 456.86, the Ne on equivalent generations (Ne_2) was 184.75, and this value slightly increased to 209.31 when computed by log-regression on equivalent generations (Ne_3). These results suggest the presence of crossbreeding and bottleneck phenomena, and they were compared with other Italian horses (reported in bibliography) to present the SAA among the Italian horse breeds scenario. Furthermore, the noteworthy mitochondrial variability reflects the use of a considerable number of founder mares; the contribution of L lineage was very important, probably because of the re-colonization from the Iberian Peninsula after the Last Glacial Maximum.