The demographic history and adaptation of Canarian goat breeds to environmental conditions through the use of genome-wide SNP data.

BACKGROUND: The presence of goats in the Canary Islands dates back to the late 1st millennium BC, which coincides with the colonization by the Amazigh settlers. However, the exact geographic origin of Canarian goats is uncertain since the Amazigh peoples were distributed over a wide spatial range. Nowadays, three Canarian breeds (Palmera, Majorera and Tinerfeña) are officially recognized, along with two distinct South and North Tinerfeña ecotypes, with the South Tinerfeña and Majorera goats thriving in arid and dry semi-desertic environments and the Palmera and North Tinerfeña goats are adapted to humid and temperate areas that are influenced by trade winds. Genotypes for 224 Canarian goats were generated using the Illumina Goat single nucleotide polymorphism (SNP)50 BeadChip. By merging these data with the genotypes from 1007 individuals of African and Southern European ancestry, our aim was to ascertain the geographic origin of the Canarian goats and identify genes associated with adaptation to diverse environmental conditions. RESULTS: The diversity indices of the Canarian breeds align with most of those of the analyzed local breeds from Africa and Europe, except for the Palmera goats that showed lower levels of genetic variation. The Canarian breeds demonstrate a significant genetic differentiation compared to other populations, which indicates a history of prolonged geographic isolation. Moreover, the phylogenetic reconstruction indicated that the ancestry of the Canarian goats is fundamentally North African rather than West African. The ADMIXTURE and the TreeMix analyses showed no evidence of gene flow between Canarian goats and other continental breeds. The analysis of runs of homozygosity (ROH) identified 13 ROH islands while the window-based FST method detected 25 genomic regions under selection. Major signals of selection were found on Capra hircus (CHI) chromosomes 6, 7, and 10 using various comparisons and methods. CONCLUSIONS: This genome-wide analysis sheds new light on the evolutionary history of the four breeds that inhabit the Canary Islands. Our findings suggest a North African origin of the Canarian goats. In addition, within the genomic regions highlighted by the ROH and FST approaches, several genes related to body size and heat tolerance were identified.

Exposure to Metals from Artisanal Cheeses Made with Goat's Milk.

Cheeses are an important source of essential elements. Nevertheless, the level of some metals could pose a health risk. Therefore, the concentration of trace elements and toxic metals (Cr, Cu, Li, Ni, Sr, Pb, Cd, and Al) has been determined in artisanal cheeses from different geographical locations, and the intake of these metals from cheese consumption has been evaluated. The metal concentration was determined in a total of 90 cheese samples from different locations by using inductively coupled plasma atomic emission spectroscopy. The highest concentration of Al (35.1 ± 4.42 mg/kg, wet weight) was found in artisanal cheeses from Zamora (Spain), followed by Sr (6.85 ± 0.35 mg/kg, wet weight) in artisanal cheeses from Cadiz (Spain). A daily consumption of 23.2 g of cheese provides a significant dietary contribution for Al of 0.82% of its tolerable weekly intake of 1 mg/kg of body weight per week. Canary Islands cheeses have a higher metal content than the non-Canary cheese, which could be because of the volcanic characteristics of the island soils. The intake of toxic metals and trace elements poses no risk to the health of adults.