Phylogeography of feral Monteiro pig in the Brazilian Pantanal Ecosystem.

The Monteiro is a feral pig found in the Brazilian Pantanal ecosystem. The goal of this research is to generate data and knolewdge related to animal populations wich can be used for management and development of an in vitro conservation program for animal resourses at Pantanal ecosystem. The present study evaluated animals sampled from 10 distinct locations within the region, using 19 microsatellite markers (N = 189) and the control region of mitochondrial DNA (mtDNA) (N = 392). Low genetic differences were found between populations with the microsatellite data. The FST range was between 0.009 and 0.063 (p-value < 0.05). The Mantel test corroborated with previous results, as low correlations between genetic and geographic distances were observed (r2 = 0.2309, p = 0.06). Bayesian analysis for genetic structure identification placed the Monteiro pigs into three main clusters (MOB, Pop 1 and all others Pantanal populations). Most of the Monteiro pigs share a single European haplotype as seen by mtDNA analyses. This haplotype is not exclusive, as it is shared with other swine populations (commercial and other locally adapted breeds). Monteiro populations from different geographic locations within Pantanal are not isolated and can be considered as a large unique population. Since animals roam freely to seek food and water, or even due to seasonal flooding of their habitat, the Monteiro populations presented absence of major genetic structure and evidence of high gene flow. These results can be used to create a management plan and in situ and ex situ conservation program for conservation and use of the Monteiro breed in the Pantanal ecosystem.

The genome of Eucalyptus grandis.

Eucalypts are the world's most widely planted hardwood trees. Their outstanding diversity, adaptability and growth have made them a global renewable resource of fibre and energy. We sequenced and assembled >94% of the 640-megabase genome of Eucalyptus grandis. Of 36,376 predicted protein-coding genes, 34% occur in tandem duplications, the largest proportion thus far in plant genomes. Eucalyptus also shows the highest diversity of genes for specialized metabolites such as terpenes that act as chemical defence and provide unique pharmaceutical oils. Genome sequencing of the E. grandis sister species E. globulus and a set of inbred E. grandis tree genomes reveals dynamic genome evolution and hotspots of inbreeding depression. The E. grandis genome is the first reference for the eudicot order Myrtales and is placed here sister to the eurosids. This resource expands our understanding of the unique biology of large woody perennials and provides a powerful tool to accelerate comparative biology, breeding and biotechnology.

A flexible multi-species genome-wide 60K SNP chip developed from pooled resequencing of 240 Eucalyptus tree genomes across 12 species.

We used whole genome resequencing of pooled individuals to develop a high-density single-nucleotide polymorphism (SNP) chip for Eucalyptus. Genomes of 240 trees of 12 species were sequenced at 3.5× each, and 46 997 586 raw SNP variants were subject to multivariable filtering metrics toward a multispecies, genome-wide distributed chip content. Of the 60 904 SNPs on the chip, 59 222 were genotyped and 51 204 were polymorphic across 14 Eucalyptus species, providing a 96% genome-wide coverage with 1 SNP/12-20 kb, and 47 069 SNPs at ≤ 10 kb from 30 444 of the 33 917 genes in the Eucalyptus genome. Given the EUChip60K multi-species genotyping flexibility, we show that both the sample size and taxonomic composition of cluster files impact heterozygous call specificity and sensitivity by benchmarking against 'gold standard' genotypes derived from deeply sequenced individual tree genomes. Thousands of SNPs were shared across species, likely representing ancient variants arisen before the split of these taxa, hinting to a recent eucalypt radiation. We show that the variable SNP filtering constraints allowed coverage of the entire site frequency spectrum, mitigating SNP ascertainment bias. The EUChip60K represents an outstanding tool with which to address population genomics questions in Eucalyptus and to empower genomic selection, GWAS and the broader study of complex trait variation in eucalypts.

Fine mapping and single nucleotide polymorphism effects estimation on pig chromosomes 1, 4, 7, 8, 17 and X.

Fine mapping of quantitative trait loci (QTL) from previous linkage studies was performed on pig chromosomes 1, 4, 7, 8, 17, and X which were known to harbor QTL. Traits were divided into: growth performance, carcass, internal organs, cut yields, and meat quality. Fifty families were used of a F2 population produced by crossing local Brazilian Piau boars with commercial sows. The linkage map consisted of 237 SNP and 37 microsatellite markers covering 866 centimorgans. QTL were identified by regression interval mapping using GridQTL. Individual marker effects were estimated by Bayesian LASSO regression using R. In total, 32 QTL affecting the evaluated traits were detected along the chromosomes studied. Seven of the QTL were known from previous studies using our F2 population, and 25 novel QTL resulted from the increased marker coverage. Six of the seven QTL that were significant at the 5% genome-wide level had SNPs within their confidence interval whose effects were among the 5% largest effects. The combined use of microsatellites along with SNP markers increased the saturation of the genome map and led to smaller confidence intervals of the QTL. The results showed that the tested models yield similar improvements in QTL mapping accuracy.

Genomic selection for growth and wood quality in Eucalyptus: capturing the missing heritability and accelerating breeding for complex traits in forest trees.

• Genomic selection (GS) is expected to cause a paradigm shift in tree breeding by improving its speed and efficiency. By fitting all the genome-wide markers concurrently, GS can capture most of the 'missing heritability' of complex traits that quantitative trait locus (QTL) and association mapping classically fail to explain. Experimental support of GS is now required. • The effectiveness of GS was assessed in two unrelated Eucalyptus breeding populations with contrasting effective population sizes (N(e) = 11 and 51) genotyped with > 3000 DArT markers. Prediction models were developed for tree circumference and height growth, wood specific gravity and pulp yield using random regression best linear unbiased predictor (BLUP). • Accuracies of GS varied between 0.55 and 0.88, matching the accuracies achieved by conventional phenotypic selection. Substantial proportions (74-97%) of trait heritability were captured by fitting all genome-wide markers simultaneously. Genomic regions explaining trait variation largely coincided between populations, although GS models predicted poorly across populations, likely as a result of variable patterns of linkage disequilibrium, inconsistent allelic effects and genotype × environment interaction. • GS brings a new perspective to the understanding of quantitative trait variation in forest trees and provides a revolutionary tool for applied tree improvement. Nevertheless population-specific predictive models will likely drive the initial applications of GS in forest tree breeding.

High-throughput SNP genotyping in the highly heterozygous genome of Eucalyptus: assay success, polymorphism and transferability across species.

BACKGROUND: High-throughput SNP genotyping has become an essential requirement for molecular breeding and population genomics studies in plant species. Large scale SNP developments have been reported for several mainstream crops. A growing interest now exists to expand the speed and resolution of genetic analysis to outbred species with highly heterozygous genomes. When nucleotide diversity is high, a refined diagnosis of the target SNP sequence context is needed to convert queried SNPs into high-quality genotypes using the Golden Gate Genotyping Technology (GGGT). This issue becomes exacerbated when attempting to transfer SNPs across species, a scarcely explored topic in plants, and likely to become significant for population genomics and inter specific breeding applications in less domesticated and less funded plant genera. RESULTS: We have successfully developed the first set of 768 SNPs assayed by the GGGT for the highly heterozygous genome of Eucalyptus from a mixed Sanger/454 database with 1,164,695 ESTs and the preliminary 4.5X draft genome sequence for E. grandis. A systematic assessment of in silico SNP filtering requirements showed that stringent constraints on the SNP surrounding sequences have a significant impact on SNP genotyping performance and polymorphism. SNP assay success was high for the 288 SNPs selected with more rigorous in silico constraints; 93% of them provided high quality genotype calls and 71% of them were polymorphic in a diverse panel of 96 individuals of five different species.SNP reliability was high across nine Eucalyptus species belonging to three sections within subgenus Symphomyrtus and still satisfactory across species of two additional subgenera, although polymorphism declined as phylogenetic distance increased. CONCLUSIONS: This study indicates that the GGGT performs well both within and across species of Eucalyptus notwithstanding its nucleotide diversity ≥ 2%. The development of a much larger array of informative SNPs across multiple Eucalyptus species is feasible, although strongly dependent on having a representative and sufficiently deep collection of sequences from many individuals of each target species. A higher density SNP platform will be instrumental to undertake genome-wide phylogenetic and population genomics studies and to implement molecular breeding by Genomic Selection in Eucalyptus.

Molecular and pedigree analysis applied to conservation of animal genetic resources: the case of Brazilian Somali hair sheep.

The first registers of Somali sheep in Brazil are from the beginning of the 1900s. This breed, adapted to the dry climate and scarce food supply, is restricted in the northeast region of the country. Molecular marker technologies, especially those based on genotyping microsatellite and mtDNA loci, can be used in conjunction with breeding (pedigree analysis) and consequently the maintenance of genetic variation in herds. Animals from the Brazilian Somali Conservation Nuclei from Embrapa Sheep and Goats in Ceará State were used to validate genetic monitoring by traditional pedigree methods and molecular markers. Nineteen microsatellite markers and 404 base pairs from the control region of mtDNA were used. For total herd diversity, an average 5.32 alleles were found, with expected heterozygosity of 0.5896, observed heterozygosity of 0.6451, 0.4126 for molecular coancestrality, and coefficient of inbreeding (F (IS)) was -0.095. Comparing molecular coancestrality means over the years, there was a consistent increase in this parameter within the herd, increasing from 0.4157 to 0.4769 in 2 years (approx. 12% variation). Sixteen mtDNA haplotypes were identified. Inbreeding and other estimates from genealogical analyses confirm the results from molecular markers. From these results, it is possible to state that microsatellites are useful tools in genetic management of herds, especially when routine herd recording is not carried out, or there were gaps in recent generations. As well as pedigree control, genetic diversity can be optimized. Based on the results, and despite herd recording in the herd of Brazilian Somali of Embrapa Sheep and Goats, additional management measures need to be carried out in this herd to reduce inbreeding and optimize genetic variation.

A selected set of EST-derived microsatellites, polymorphic and transferable across 6 species of eucalyptus.

Species of Eucalyptus are keystone species for ecological studies in their natural ranges and are extensively planted in the tropical and subtropical regions of the world to supply high-quality woody biomass for various applications. We report the development of a selected set of 20 dinucleotide and trinucleotide repeat microsatellites derived from Eucalyptus expressed sequence tags (ESTs). These microsatellites were selected for full transferability and homogeneous rate of polymorphism across species. They were evaluated for individual fingerprinting, parentage testing, and intraspecific population structure analyses in 6 of the most extensively studied and planted species worldwide, representing key phylogenetic sections of the largest subgenus Symphyomyrtus. This set of markers provides exceptional resolution for population genetics and molecular breeding applications in the genus Eucalyptus. As they were developed from conserved transcribed regions, the transferability and polymorphism of these microsatellites will most likely extend to the other 300 or more species within the same subgenus.

Heat stress effects on sheep: Are hair sheep more heat resistant?

Climatic variables can trigger physiological, biochemical, haematological and hormonal alterations that influence the maintenance of homeothermy and can affect production and productivity in sheep. Different mechanisms are responsible for tolerance to heat stress (HS) including coat and skin colour, body size, fat distribution, physiological reactions and not just coat type (hair/wool). This review looks at physical, physiological, molecular and genetic aspects of heat tolerance in sheep and how they affect hair and wool sheep. We propose that it is the adaptation to hot environments and not the type of coat (wool/hair) itself that determines the capacity of the resistance of the animal to HS, due to modifications in essential pathways such as energy metabolism, physiological responses and body size. When studied in similar environments, commercial wool breeds tend to show higher heat stress, but hair breeds tend not to differ from wool breeds that are adapted to hot environments.

A novel genome-wide microsatellite resource for species of Eucalyptus with linkage-to-physical correspondence on the reference genome sequence.

Keystone species in their native ranges, eucalypts, are ecologically and genetically very diverse, growing naturally along extensive latitudinal and altitudinal ranges and variable environments. Besides their ecological importance, eucalypts are also the most widely planted trees for sustainable forestry in the world. We report the development of a novel collection of 535 microsatellites for species of Eucalyptus, 494 designed from ESTs and 41 from genomic libraries. A selected subset of 223 was evaluated for individual identification, parentage testing, and ancestral information content in the two most extensively studied species, Eucalyptus grandis and Eucalyptus globulus. Microsatellites showed high transferability and overlapping allele size range, suggesting they have arisen still in their common ancestor and confirming the extensive genome conservation between these two species. A consensus linkage map with 437 microsatellites, the most comprehensive microsatellite-only genetic map for Eucalyptus, was built by assembling segregation data from three mapping populations and anchored to the Eucalyptus genome. An overall colinearity between recombination-based and physical positioning of 84% of the mapped microsatellites was observed, with some ordering discrepancies and sporadic locus duplications, consistent with the recently described whole genome duplication events in Eucalyptus. The linkage map covered 95.2% of the 605.8-Mbp assembled genome sequence, placing one microsatellite every 1.55 Mbp on average, and an overall estimate of physical to recombination distance of 618 kbp/cM. The genetic parameters estimates together with linkage and physical position data for this large set of microsatellites should assist marker choice for genome-wide population genetics and comparative mapping in Eucalyptus.