Search

Abstract Congenital hypotrichosis in mammalian species consists of partial or complete absence of hair at birth. The hairless gene is often responsible for this disorder in men, mice and rats. Recent experimental data on Valle del Belice sheep reared in Sicily for milk production, support the genetic control of the ovine hypotrichosis as a Mendelian recessive trait. The ovine hairless gene was chosen as the candidate gene involved in this disorder. Blood samples were collected from Valle del Belice sheep with the normal and hypotrichotic phenotypes. Almost the entire hairless gene was successfully amplified using the long PCR technique. Unrelated sheep with differing phenotypes were randomly chosen for sequencing the amplified products. Different mutations related to the hypotrichotic phenotype were found in exon 3. In fact, sequencing revealed an A/T transversion at position 739, a G/A transition at position 823, and a C/T transition at position 1312. From these nucleotide exchanges, three substitutions of the processed mature protein were deduced at the amino acid positions 247 (Thr/Ser), 275 (Ala/Thr), and 438 (Gln/Stop). A PCR-SSCP based test was developed in order to detect the last mutation, which is responsible for the hypotrichotic phenotype.

The water buffalo is a fundamental resource, especially in developing countries, however, differently from other species, its genetic potential is still poorly investigated. In this work, we performed a candidate gene association study for milk composition in 491 female buffaloes. Animals were from four farms located in Southern Italy, where the Out-of-Breeding-Season-Mating technique is usually performed. We analysed three genes: (1) the signal transducer and activator of transcription 5A (STAT5A), (2) the tumour necrosis factor alpha (TNFα) and (3) the melatonin receptor 1A (MTNR1A). We confirmed the mutation at theMTNR1Agene and we found five novel single nucleotide polymorphisms (SNPs): one in theTNFαand four in theSTAT5A. No associations were found for the SNPs in theMTNR1AandTNFαgenes, while we identified a marked association with milk protein % for a C > T substitution at theSTAT5Agene. At thislocus, the TT buffaloes showed significantly higher protein percentage in milk. Conversely, this genotype class was the less frequent in the population. Moreover, an A > G substitution at theSTAT5Ashowed an influence on reproductive seasonality, with the advantageous allele most frequent in the population, suggesting a possible effect of selection for this trait. The C > T substitution onSTAT5Adetected in present study could be used in marker assisted selection of Mediterranean Italian buffalo, and should be monitored to understand the reasons behind the low frequency of the favourable genotype at thislocusand to stop this unfavourable trend in the population. [ABSTRACT FROM PUBLISHER]

Mycobacterium avium subsp. paratuberculosis: (MAP) causes a contagious chronic infection results in Johne's disease in a wide range of animal species, including cattle. Several genome-wide association studies (GWAS) have been carried out to identify loci putatively associated with MAP susceptibility by testing each marker separately and identifying SNPs that show a significant association with the phenotype, while SNP with modest effects are usually ignored. The objective of this study was to identify modest-effect genes associated with MAP susceptibility using a pathway-based approach. The Illumina BovineSNP50 BeadChip was used to genotype 966 Holstein cows, 483 positive and 483 negative for antibody response to MAP, data were then analyzed using novel SNP-based Gene Set Enrichment Analysis (GSEA-SNP) and validated with Adaptive Rank Truncated Product methodology. An allele-based test was carried out to estimate the statistical association for each marker with the phenotype, subsequently SNPs were mapped to the closest genes, considering for each gene the single variant with the highest value within a window of 50 kb, then pathway-statistics were tested using the GSEA-SNP method. The GO biological process 'embryogenesis and morphogenesis' was most highly associated with antibody response to MAP. Within this pathway, five genes code for proteins which play a role in the immune defense relevant to response to bacterial infection. The immune response genes identified would not have been considered using a standard GWAS, thus demonstrating that the pathway approach can extend the interpretation of genome-wide association analyses and identify additional candidate genes for target traits. [ABSTRACT FROM AUTHOR]

Abscesses are a common problem in goat farms worldwide. In most cases, the disease is caused byCorynebacterium pseudotuberculosisthat is the aetiological agent of caseous lymphadenitis (CLA). CLA causes considerable economic losses, due to reduced milk production, and to carcase damage. At present, no effective therapy for CLA is available and vaccine use is limited. The current study presents evidence for loci associated to CLA susceptibility identified using the 50K Goat SNP panel in a case-control genome wide association study. The analysis of the genotype data identified four chromosomal regions associated with disease status: on chromosomes 5, 7, 8 and 11. These results provide the first evidence for genetic loci involved in the immunological response to CLA in goat. Knowledge of genetic variations related to susceptibility will facilitate the incorporation of this information for the improvement of health status in the goat species. [ABSTRACT FROM PUBLISHER]

Background: Among the European countries, Italy counts the largest number of local goat breeds. Thanks to the recent availability of a medium-density SNP (single nucleotide polymorphism) chip for goat, the genetic diversity of Italian goat populations was characterized by genotyping samples from 14 Italian goat breeds that originate from different geographical areas with more than 50 000 SNPs evenly distributed on the genome. Results: Analysis of the genotyping data revealed high levels of genetic polymorphism and an underlying North-south geographic pattern of genetic diversity that was highlighted by both the first dimension of the multi-dimensional scaling plot and the Neighbour network reconstruction. We observed a moderate and weak population structure in Northern and Central-Southern breeds, respectively, with pairwise FST values between breeds ranging from 0.013 to 0.164 and 7.49 % of the total variance assigned to the between-breed level. Only 2.11 % of the variance explained the clustering of breeds into geographical groups (Northern, Central and Southern Italy and Islands). Conclusions: Our results indicate that the present-day genetic diversity of Italian goat populations was shaped by the combined effects of drift, presence or lack of gene flow and, to some extent, by the consequences of traditional management systems and recent demographic history. Our findings may constitute the starting point for the development of marker-assisted approaches, to better address future breeding and management policies in a species that is particularly relevant for the medium- and long-term sustainability of marginal regions. [ABSTRACT FROM AUTHOR]

Selection and breeding practices in goats have led to the fixation of several traits. This is probably due to the standardization of several peculiar morphological characteristics that have always been one of the major exclusion criteria of individuals from selection. Among these, ear carriage is one of the most ancient and considered a signature of domestication in several species, such as the dog, pig, sheep and goat (Boyko et al., 2010). The availability of improved genomic analyses tools for goats may provide useful information on genes involved in this trait. By studying, for example, the homozygosity decay of haplotypes (contiguous length of alleles) such information can be detected. In the current study, we focused on the Maltese goat, a breed showing floppy ears, in comparison with other Italian breeds using a goat medium density SNP chip (Nicoloso et al., 2015). A total 48,767 SNP markers for 369 animals belonging to 16 breeds or populations were analyzed. Genotypes were imputed within population excluding markers without known position on the current genome assembly (ARS1, Bickhart et al., 2017). Population analysis using MDS, ADMIXTURE and fastSTRUCTURE confirmed the good differentiation among the populations. Integrated Haplotype Score (iHS, Sabeti et al., 2007) was performed for each population, comparing the regions detected on the Maltese breed with the others considered to detect genes that may be involved into shaping ear morphology. These results may provide new insights into ear carriage phenotype by detecting genes that play a pivotal role in shaping the goat phenotypic diversity. [ABSTRACT FROM AUTHOR]