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.

Understanding seasonal weight loss tolerance in dairy goats: a transcriptomics approach.

BACKGROUND: Seasonal weight loss (SWL) is a very important limitation to the production of ruminants in the Mediterranean and Tropical regions. In these areas, long dry seasons lead to poor pastures with low nutritional value. During the dry season, ruminants, particularly those raised in extensive production systems, lose around 30% of their body weight. Seasonal weight loss has important consequences on animal productive performance and health. In this study, RNA sequencing was used to characterize feed restriction effects in dairy goat of 2 breeds with different SWL tolerance: Majorera (tolerant) and Palmera (susceptible). Nine Majorera and ten Palmera goats were randomly distributed in a control and a restricted group: Majorera Control (adequately fed; MC; n = 4), Palmera Control (adequately fed; PC; n = 6), Majorera Restricted (feed restricted; ME; n = 5) and Palmera Restricted (feed restricted; PE; n = 4). On day 22 of the trial, mammary gland biopsies were collected for transcriptomics analysis. RESULTS: From these samples, 24,260 unique transcripts were identified. From those, 82 transcripts were differentially expressed between MC and ME, 99 between PC and PE, twelve between both control groups and twenty-nine between both restricted groups. CONCLUSIONS: Feed restriction affected several biochemical pathways in both breeds such as: carbohydrate and lipid transport; intracellular trafficking, RNA processing and signal transduction. This research also highlights the importance or involvement of the genes in tolerance (ENPP1, S-LZ, MT2A and GPNB) and susceptibility (GPD1, CTPS1, ELOVL6 and NR4A1) to SWL with respectively higher expression in the Majorera restriced group and the Palmera restricted group in comparison to the control groups. In addition, results from the study may be extrapolated to other dairy ruminant species.

Patterns of homozygosity in insular and continental goat breeds.

BACKGROUND: Genetic isolation of breeds may result in a significant loss of diversity and have consequences on health and performance. In this study, we examined the effect of geographic isolation on caprine genetic diversity patterns by genotyping 480 individuals from 25 European and African breeds with the Goat SNP50 BeadChip and comparing patterns of homozygosity of insular and nearby continental breeds. RESULTS: Among the breeds analysed, number and total length of ROH varied considerably and depending on breeds, ROH could cover a substantial fraction of the genome (up to 1.6 Gb in Icelandic goats). When compared with their continental counterparts, goats from Iceland, Madagascar, La Palma and Ireland (Bilberry and Arran) displayed a significant increase in ROH coverage, ROH number and FROH values (P value < 0.05). Goats from Mediterranean islands represent a more complex case because certain populations displayed a significantly increased level of homozygosity (e.g. Girgentana) and others did not (e.g. Corse and Sarda). Correlations of number and total length of ROH for insular goat populations with the distance between islands and the nearest continental locations revealed an effect of extremely long distances on the patterns of homozygosity. CONCLUSIONS: These results indicate that the effects of insularization on the patterns of homozygosity are variable. Goats raised in Madagascar, Iceland, Ireland (Bilberry and Arran) and La Palma, show high levels of homozygosity, whereas those bred in Mediterranean islands display patterns of homozygosity that are similar to those found in continental populations. These results indicate that the diversity of insular goat populations is modulated by multiple factors such as geographic distribution, population size, demographic history, trading and breed management.

Mammary gland and milk fatty acid composition of two dairy goat breeds under feed-restriction.

Goat dairy products are an important source of animal protein in the tropics. During the dry season, pasture scarcity leads animals to lose up to 40% of their body weight, a condition known as Seasonal Weight Loss (SWL) that is one of the major constraints in ruminant production. Breeds with high tolerance to SWL are relevant to understand the physiological responses to pasture scarcity so they could be used in programs for animal breeding. In the Canary Islands there are two dairy goat breeds with different levels of tolerance to SWL: the Palmera, susceptible to SWL; and the Majorera, tolerant to SWL. Fat is one of the milk components most affected by environmental and physiological conditions. This study hypothesises that feed-restriction affects Majorera and Palmera breeds differently, leading to different fatty acid profiles in the mammary gland and milk. An interaction between breed and feed-restriction was observed in the mammary gland. Feed-restriction was associated with an increase in oleic acid and a decrease in palmitic acid percentage in the Palmera breed whereas no differences were observed in the Majorera breed. Palmitic and oleic acids together constituted around 60% of the total fatty acids identified, which suggests that Palmera breed is more susceptible to SWL. In milk, feed-restriction affected both breeds similarly. Regarding the interaction of the breed with the treatment, we also observed similar responses in both breeds, but this influence affects only around 2% of the total fatty acids. In general, Majorera breed is more tolerant to feed-restriction.

A genome-wide perspective about the diversity and demographic history of seven Spanish goat breeds.

BACKGROUND: The main goal of the current work was to infer the demographic history of seven Spanish goat breeds (Malagueña, Murciano-Granadina, Florida, Palmera, Mallorquina, Bermeya and Blanca de Rasquera) based on genome-wide diversity data generated with the Illumina Goat SNP50 BeadChip (population size, N = 176). Five additional populations from Europe (Saanen and Carpathian) and Africa (Tunisian, Djallonké and Sahel) were also included in this analysis (N = 80) for comparative purposes. RESULTS: Our results show that the genetic background of Spanish goats traces back mainly to European breeds although signs of North African admixture were detected in two Andalusian breeds (Malagueña and Murciano-Granadina). In general, observed and expected heterozygosities were quite similar across the seven Spanish goat breeds under analysis irrespective of their population size and conservation status. For the Mallorquina and Blanca de Rasquera breeds, which have suffered strong population declines during the past decades, we observed increased frequencies of large-sized (ROH), a finding that is consistent with recent inbreeding. In contrast, a substantial part of the genome of the Palmera goat breed comprised short ROH, which suggests a strong and ancient founder effect. CONCLUSIONS: Admixture with African goats, genetic drift and inbreeding have had different effects across the seven Spanish goat breeds analysed in the current work. This has generated distinct patterns of genome-wide diversity that provide new clues about the demographic history of these populations.

Ancient DNA sheds light on the ancestry of pre-hispanic Canarian pigs.

BACKGROUND: Canarian Black (CB) pigs belong to an autochthonous and endangered breed, which is spread throughout the Canarian archipelago. It is commonly accepted that they represent a relic of the pig populations that were bred by the Berbers in North Africa over millennia. It is important to note that the geographic isolation of the Canary Islands has preserved this genetic legacy intact from foreign introgressions until the Spanish conquest of the archipelago in the 15(th) century. Ten years ago, it was demonstrated that, in CB pigs, the frequency of the Asian A2 cytochrome-b haplogroup reached 73%. The current work aimed at investigating whether this observation is explained by either a recent or an ancient introgression of CB pigs with Far Eastern pigs. RESULTS: Genetic analyses of 23 ancient samples from pre-hispanic Canarian pigs (420 to 2500 years before present) showed that Near Eastern and Far Eastern genetic signatures were totally absent in the primitive Canarian pre-hispanic pigs. Indeed, the haplotypes detected in these pigs were closely related to those of North African and European wild boars. CONCLUSIONS: Our results demonstrate that the high frequency of the Far Eastern mitochondrial cytochrome B A2 haplotype in modern Canarian Black pigs probably corresponds to a relatively recent introgression with British breeds.

Establishment of the biochemical and endocrine blood profiles in the Majorera and Palmera dairy goat breeds: the effect of feed restriction.

Feed restriction, and seasonal weight loss (SWL), are major setbacks for animal production in the tropics and the Mediterranean. They may be solved through the use of autochthonous breeds particularly well adapted to SWL. It is therefore of major importance to determine markers of tolerance to feed restriction of putative use in animal selection. Two indigenous breeds from the Canary Islands, Palmera and Majorera, are commonly used by dairy goat farmers and, interestingly, have different phenotype characteristics albeit with a common ancestry. Indeed, Majorera is well adapted to feed restriction whereas the Palmera is susceptible to feed restriction. In addition, regardless of their importance in dairy production, there are only a limited number of reports relating to these breeds and, to the best of our knowledge, there is no description of their blood metabolite standard values under control conditions or as affected by feed restriction. In this study we analysed the blood metabolite profiles in Majorera and Palmera goats aiming to establish the differential responses to feed restriction between the two breeds and to characterise their metabolite standard values under control conditions. We observed significant differences in creatinine, urea, non-esterified fatty acids (NEFAs), cholesterol, IGF-1 and T3 due to underfeeding. Furthermore, a PCA analysis, revealed that animals submitted to undernutrition could be distinguished from the control groups, with the formation of three separate clusters (Palmera individuals after 22 d of subnutrition (PE22); Majorera individuals after 22 d of subnutrition (ME22) and animals assigned to control conditions (MC0, MC22, PC0 and PC22)), highlighting different responses of the two breeds to undernutrition.

Short-term effects of milking frequency on milk yield, milk composition, somatic cell count and milk protein profile in dairy goats.

Goats in Canary Islands are milked once a day by tradition, but in most countries with high technology on farms, goats are milked twice a day, which is known to improve milk yield. Therefore it is important to know whether the increase of milking frequency can improve the production without impairing milk quality. The objective of this study was to investigate the short term effects of three milking frequencies on milk yield, milk composition, somatic cell count (SCC) and milk protein profile in dairy goats traditionally milked once a day. Twelve Majorera goats in early lactation (48±4 d in milk) were used. During a 5-week period, goats were milked once a day (X1) in weeks 1 and 5, twice a day (X2) in weeks 2 and 4, and three times a day (X3) in week 3. Milk recording and sampling were done on the last day of each experimental week. Milk yield increased by 26% from X1 to X2. No differences were obtained when goats were switched from X2 to X3, and from X3 to X2. The goats recovered the production level when they returned to X1. Different patterns of changes in the milk constituents due to the milking frequency effect were observed. Fat percentage increased when switched from X1 to X2, then decreased from X2 to X3, and from X3 to X2, whereas it did not show significant differences from X2 to X1. Milking frequency did not affect the protein and lactose percentages. SCC values were unaffected when goats were milked X1, X2 and X3, but then they increased slightly when milking frequency was returned to X2 and X1. Finally, quantitative analysis showed an increase in intensities of milk protein bands from X1 to X2, but the intensities of casein bands (α(S1)-CN, α(S2)-CN, ß-CN, κ-CN) and major whey proteins (α-La, ß-Lg) decreased from X2 to X3.

Body live weight and milk production parameters in the Majorera and Palmera goat breeds from the Canary Islands: influence of weight loss.

Seasonal weight loss (SWL), caused by poor quality pastures during the dry season, is the major limitation to animal production in the tropics. One of the ways to counter this problem is to breed animals that show tolerance to SWL. The objective of this study was to understand the effect of feed restriction in milk production and live weight (LW) evolution in two goat breeds, with different levels of adaptation to nutritional stress: the Majorera (considered to be tolerant) and the Palmera (considered to be susceptible). A total of ten animals per breed were used. Animals were divided in four groups (two for each breed): a restricted group (restricted diet) and a control group. LW and milk yield parameters were recorded through a trial that lasted 23 days in total. Overall, there were no significant differences between both restricted groups, regarding neither LW nor milk yield reductions (LW reduction 13 % and milk yield reduction of 87 % for both restricted groups). In what concerns control groups, there were no significant differences between breeds, thought there were different increments at the end of the trial for both breeds regarding LW (6 and 4 %, for Majorera and Palmera, respectively) and milk yield (28 and 8 %, respectively for Majorera and Palmera). The lack of statistically significant differences between Palmera and Majorera LW and milk yields in restricted groups may be due to the fact that the controlled trial does not replicate harsh field conditions, in which Majorera would excel, and the stress induced by those differences.

Goat mammary gland metabolism: An integrated Omics analysis to unravel seasonal weight loss tolerance.

Seasonal weight loss (SWL), is a major limitation to animal production. In the Canary Islands, there are two dairy goat breeds with different levels of tolerance to SWL: Majorera (tolerant) and Palmera (susceptible). Our team has studied the response of these breeds to SWL using different Omics tools. The objective of this study was to integrate such results in a data driven approach and using dedicated tools, namely the DIABLO method. The outputs of our analysis mainly separate unrestricted from restricted goats. Metabolites behave as "hub" molecules, grouping interactions with several genes and proteins. Unrestricted goats upregulated protein synthesis, along with arginine catabolism and adipogenesis pathways, which are related with higher anabolic rates and a larger proportion of secretory tissue, in agreement with their higher milk production. Contrarily, restricted goats seemingly increased the synthesis of acetyl-CoA through serine and acetate conversion into pyruvate. This may have occurred to increase fatty acid synthesis and/or to use them as an energy source in detriment to glucose, which was more available in the diet of unrestricted goats. Lastly, restricted Palmera upregulated the expression of PEBP4 and GPD1 genes compared to all other groups, which might support their use as putative biomarkers for SWL susceptibility. SIGNIFICANCE: Seasonal weight loss (SWL) is a major issue influencing animal production in the tropics and Mediterranean. By studying its impact on the mammary gland of tolerant and susceptible dairy goat breeds, using Omics, we aim at surveying the tissue for possible biomarkers that reflect these traits. In this study, data integration of three Omics (transcriptomics, proteomics and metabolomics) was performed using bioinformatic tools, to relate putative biomarkers and evaluate all three levels of information; in a novel approach. This information can enhance selection programs, lowering the impact of SWL on food production systems.

The effects of storage temperature on goat milk somatic cell count using the DeLaval counter.

This study investigated the influence of storage temperature and storage time on goat milk somatic cell counts (SCCs) determined using the DeLaval cell counter (DCC). SCCs were measured in 40 Majorera goat milk samples using the DCC device. Samples were grouped from high score (>2,750 x 10(3) cells/mL) to low score (<630 x 10(3) cell/mL) according to the SCC. Each milk sample was divided into four aliquots and stored at four different temperatures (4 degrees C, 21 degrees C, 36 degrees C or 45 degrees C). The SCC was recorded every hour for 12 hours. Storage of goat milk with a high SCC for 5, 5, 2 or 1 hour at 4 degrees C, 21 degrees C, 36 degrees C or 45 degrees C, respectively, decreased the SCC value compared to fresh milk. The goat milk SCC was lower after 1 hour of storage than that determined for fresh milk at any tested temperature in low-SCC samples. The data presented herein suggest that regardless of storage temperature, goat milk samples should not be stored for more than 1 hour before measurement of SCC with a DCC device.

Suitability of dual-purpose cockerels of 3 different genetic origins for fattening under free-range conditions.

The utilization of male chickens for fattening constitutes a potential advantage of the dual-purpose concept. In addition to the use of commercial hybrids, producers could introduce alternative chicken genotypes or further develop local breeds. To gain more information about the genetic effect on growth performance, carcass characteristics, physicochemical meat traits, and sensory attributes, 60 cockerels belonging to Les Bleues (developed from the French breed Bresse Gauloise), Canarian (Spanish local breed), and Dominant Red Barred D459 (DRB D459; commercial dual-purpose hybrid) genotypes were reared under free-range conditions in a warm tropical climate and slaughtered at 15 wk of age. The major findings were as follows: (i) Les Bleues chickens exhibited the best growth rate and the body weight of 2.44 kg reached by this strain at 15 wk would be gained only after 18 to 19 wk with DRB D459 and it would take even 2 wk longer for Canarian breed, according to the growth modeling using the Morgan equation, although the body weights between the latter were statistical similar at 15 wk; (ii) Les Bleues strain had a good capability in terms of meat production performance, presenting carcasses with significantly heavier commercial cuts, and higher fleshiness than the other 2 genotypes; (iii) although significant differences among genotypes appeared in the physical characteristics of the breast meat, especially those concerning the skin and meat color and water-holding capacity, which was significantly reduced for Canarian chickens, no significant differences were detected in the chemical composition and fatty acid profile of the breast meat; (iv) trained panelists (n = 8) pointed out that leg meat of none of the genotypes is better in terms of global appreciation, but untrained consumers (n = 99) perceived that the Les Bleues leg meat was significantly more palatable than the DRB D459 leg meat.

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.

Differential distribution of Y-chromosome haplotypes in Swiss and Southern European goat breeds.

The analysis of Y-chromosome variation has provided valuable clues about the paternal history of domestic animal populations. The main goal of the current work was to characterize Y-chromosome diversity in 31 goat populations from Central Eastern (Switzerland and Romania) and Southern Europe (Spain and Italy) as well as in reference populations from Africa and the Near East. Towards this end, we have genotyped seven single nucleotide polymorphisms (SNPs), mapping to the SRY, ZFY, AMELY and DDX3Y Y-linked loci, in 275 bucks from 31 populations. We have observed a low level of variability in the goat Y-chromosome, with just five haplotypes segregating in the whole set of populations. We have also found that Swiss bucks carry exclusively Y1 haplotypes (Y1A: 24%, Y1B1: 15%, Y1B2: 43% and Y1C: 18%), while in Italian and Spanish bucks Y2A is the most abundant haplotype (77%). Interestingly, in Carpathian goats from Romania the Y2A haplotype is also frequent (42%). The high Y-chromosome differentiation between Swiss and Italian/Spanish breeds might be due to the post-domestication spread of two different Near Eastern genetic stocks through the Danubian and Mediterranean corridors. Historical gene flow between Southern European and Northern African goats might have also contributed to generate such pattern of genetic differentiation.

The goat (Capra hircus) mammary gland secretory tissue proteome as influenced by weight loss: A study using label free proteomics.

UNLABELLED: Seasonal weight loss (SWL) is a significant limitation to animal production. Breeds that have evolved in harsh climates have acquired tolerance to SWL through selection. Herein, label free proteomics was used to characterize the effects of SWL in two goat breeds with different levels of adaptation to nutritional stress: Majorera (tolerant) and Palmera (susceptible). Nine Majorera and 10 Palmera dairy goats were used, divided in 4 sets, 2 for each breed: underfed and a control group: Majorera Control (MC), Palmera Control (PC), Majorera Restricted (ME) and Palmera Restricted (PE). At day 22, mammary gland biopsy samples were obtained. Label free proteomic analysis enabled the identification of over 1000 proteins, of which 96 showed differential expression between two of the groups within studied comparisons. Majorera breed showed higher expression of immune system related proteins. In contrast, Palmera breed showed higher expression of proteins related to apoptosis. Results indicate that the two goat breeds have a distinct metabolism reaction to SWL, and that proteins related to the immune system and apoptosis such as cadherin-13, collagen alpha-1, nidogen-2, clusterin and protein s100-A8 could be considered putative candidates as markers of tolerance to SWL. BIOLOGICAL SIGNIFICANCE: Seasonal weight loss (SWL) is one of the major constraints to animal production in the tropics. We compared the proteomics profiles of two dairy goat breeds with different levels of tolerance to SWL under control and feed restriction conditions using label free proteomics. We have identified over 1000 proteins in the goat mammary gland, of which 96 showed differential expression. Despite the fact that both breeds showed a decrease in the number of proteins related to protein, carbohydrates and fat biosynthesis, the tolerant breed showed higher expression of immune system related proteins compared to the susceptible breed. On the contrary, the susceptible breed had higher expression of apoptosis related proteins indicating that both breeds reacted differently to weight loss and that proteins related to the immune system and apoptosis such as cadherin-13, collagen alpha 1, nidogen-2 or clusterin may be suggested as markers of tolerance to SWL.

NMR-metabolomics profiling of mammary gland secretory tissue and milk serum in two goat breeds with different levels of tolerance to seasonal weight loss.

Goats are of special importance in the Mediterranean and tropical regions for producing a variety of dairy products. The scarcity of pastures during the dry season leads to seasonal weight loss (SWL), which affects milk production. In this work, we studied the effect of feed-restriction on two dairy goat breeds, with different tolerance levels to SWL: the Majorera breed (tolerant) and the Palmera breed (susceptible). Nuclear magnetic resonance (NMR) was used to compare the metabolome of an aqueous fraction of the mammary gland and milk serum from both breeds. Goats in mid-lactation were divided by breed, and each in two feed-regime groups: the control group and the restricted-fed group (to achieve 15-20% reduction of body weight at the end of the experiment). Milk and mammary gland samples were collected at the end of the experimental period (23rd day). (1)H NMR spectra were collected from the aqueous extract of the mammary gland biopsies and the milk serum. Profiling analysis has led to the identification of 46 metabolites in the aqueous extract of the mammary gland. Lactose, glutamate, glycine and lactate were found to be the most abundant. Analysis of milk serum allowed the identification of 50 metabolites, the most abundant being lactose, citrate and creatine. Significant differences were observed, in mammary gland biopsies and milk serum, between control and restricted-fed groups in both breeds, albeit with no differences between the breeds. Variations seem to be related to metabolism adaptation to the low-energy diet and are indicative of breed-specific microflora. Milk serum showed more metabolites varying between control and restricted groups, than the mammary gland. The Majorera breed also showed more variations than the Palmera breed in milk samples, which could be an indication of a prompt adaptation to SWL by the Majorera breed.

The Goat (Capra hircus) Mammary Gland Mitochondrial Proteome: A Study on the Effect of Weight Loss Using Blue-Native PAGE and Two-Dimensional Gel Electrophoresis.

Seasonal weight loss (SWL) is the most important limitation to animal production in the Tropical and Mediterranean regions, conditioning producer's incomes and the nutritional status of rural communities. It is of importance to produce strategies to oppose adverse effects of SWL. Breeds that have evolved in harsh climates have acquired tolerance to SWL through selection. Most of the factors determining such ability are related to changes in biochemical pathways as affected by SWL. In this study, a gel based proteomics strategy (BN: Blue-Native Page and 2DE: Two-dimensional gel electrophoresis) was used to characterize the mitochondrial proteome of the secretory tissue of the goat mammary gland. In addition, we have conducted an investigation of the effects of weight loss in two goat breeds with different levels of adaptation to nutritional stress: Majorera (tolerant) and Palmera (susceptible). The study used Majorera and Palmera dairy goats, divided in 4 sets, 2 for each breed: underfed group fed on wheat straw (restricted diet, so their body weight would be 15-20% reduced by the end of experiment), and a control group fed with an energy-balanced diet. At the end of the experimental period (22 days), mammary gland biopsies were obtained for all experimental groups. The proteomic analysis of the mitochondria enabled the resolution of a total of 277 proteins, and 148 (53%) were identified by MALDI-TOF/TOF mass spectrometry. Some of the proteins were identified as subunits of the glutamate dehydrogenase complex and the respiratory complexes I, II, IV, V from mitochondria, as well as numerous other proteins with functions in: metabolism, development, localization, cellular organization and biogenesis, biological regulation, response to stimulus, among others, that were mapped in both BN and 2DE gels. The comparative proteomics analysis enabled the identification of several proteins: NADH-ubiquinone oxidoreductase 75 kDa subunit and lamin B1 mitochondrial (up-regulated in the Palmera breed), Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-2 (up-regulated in the Majorera breed) and cytochrome b-c1 complex subunit 1, mitochondrial and Chain D, Bovine F1-C8 Sub-Complex Of Atp Synthase (down-regulated in the Majorera breed) as a consequence of weight loss.

Detecting the existence of gene flow between Spanish and North African goats through a coalescent approach.

Human-driven migrations are one of the main processes shaping the genetic diversity and population structure of domestic species. However, their magnitude and direction have been rarely analysed in a statistical framework. We aimed to estimate the impact of migration on the population structure of Spanish and African goats. To achieve this goal, we analysed a dataset of 1,472 individuals typed with 23 microsatellites. Population structure of African and Spanish goats was moderate (mean FST = 0.07), with the exception of the Canarian and South African breeds that displayed a significant differentiation when compared to goats from North Africa and Nigeria. Measurement of gene flow with Migrate-n and IMa coalescent genealogy samplers supported the existence of a bidirectional gene flow between African and Spanish goats. Moreover, IMa estimates of the effective number of migrants were remarkably lower than those calculated with Migrate-n and classical approaches. Such discrepancies suggest that recent divergence, rather than extensive gene flow, is the main cause of the weak population structure observed in caprine breeds.

Strong phylogeographic relationships among three goat breeds from the Canary Islands.

We partially sequenced the mitochondrial D-loop region in 47 individuals from eleven Spanish and foreign goat breeds. Phylogenetic analysis of these sequences allowed us to identify a particular D-loop haplotype shared by individuals from the Palmera, Majorera and Tinerfeña Canarian breeds. Genotyping of 281 goats from 17 different breeds by PCR-Hpall RFLP evidenced that the geographical distribution of this haplotype is restricted to the Canary Islands. This ancestral mitochondrial haplotype might originate in the domestic goat herds brought by the native Canarian inhabitants approximately 3000 years ago. Although we observed other miscellaneous D-loop haplotypes in the Palmera, Majorera and Tinerfeña breeds, any of them allowed us to group individuals from these three populations in a single cluster, a feature that suggests that these haplotypes might have diverse origins. The remarkable degree of phylogeographic structure of the Canary goat breeds with regard to other Spanish and foreign populations might be attributed to the isolation of these breeds in the Canary Islands for approximately 2500 years, without exposure to the migratory movements and commercial trading events that probably affected the genesis of most domestic goat breeds worldwide. The Canarian D-loop haplotype can be efficiently genotyped by using DNA isolated from milk and cheese samples, which paves the way for the future establishment of a Canary breed identity test for these dairy products.

Estimating the frequency of Asian cytochrome B haplotypes in standard European and local Spanish pig breeds.

Mitochondrial DNA has been widely used to perform phylogenetic studies in different animal species. In pigs, genetic variability at the cytochrome B gene and the D-loop region has been used as a tool to dissect the genetic relationships between different breeds and populations. In this work, we analysed four SNP at the cytochrome B gene to infer the Asian (A1 and A2 haplotypes) or European (E1 and E2 haplotypes) origins of several European standard and local pig breeds. We found a mixture of Asian and European haplotypes in the Canarian Black pig (E1, A1 and A2), German Piétrain (E1, A1 and A2), Belgian Piétrain (E1, A1), Large White (E1 and A1) and Landrace (E1 and A1) breeds. In contrast, the Iberian (Guadyerbas, Ervideira, Caldeira, Campanario, Puebla and Torbiscal strains) and the Majorcan Black pig breeds only displayed the E1 haplotype. Our results show that the introgression of Chinese pig breeds affected most of the major European standard breeds, which harbour Asian haplotypes at diverse frequencies (15-56%). In contrast, isolated local Spanish breeds, such as the Iberian and Majorcan Black pig, only display European cytochrome B haplotypes, a feature that evidences that they were not crossed with other Chinese or European commercial populations. These findings illustrate how geographical confinement spared several local Spanish breeds from the extensive introgression event that took place during the 18th and 19th centuries in Europe.