Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to impo... more Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to important changes in fatty acid composition due to feed imbalances and the consequent ruminal metabolism alteration. Milk produced in two different farming systems was compared: Holstein Friesian fed with unified in intensive production and Podolica raised on a pasture in an extensive system. Milk chemical characteristics and fatty acid composition were determined comparing milk with a normal fat level (>3.8%) to milk with a low fat level (<3.2%) in each breeding system. Holstein Friesian milk showed the decrease in trans-11 and increase in trans-10 C18:1 (shift from trans-11 to trans-10 C18:1) in low fat with respect to normal fat milk with a consequent decrease in the trans-11/trans-10 C18:1 ratio. Even conjugated linoleic acid (CLA), C18:2 cis-9, trans-11, was lower while CLA trans-10, cis-12 was higher in low fat milk than in normal fat milk from Holstein Friesian. These changes, t...
A first approach to predict nitrogen efficiency of dairy cows through milk FT-MIR spectra Clément... more A first approach to predict nitrogen efficiency of dairy cows through milk FT-MIR spectra Clément Grelet1, Eric Froidmont1, Miel Hostens2, Leslie Foldager3, Mazdak Salavati4, Amélie Vanlierde1, Martin Tang Sorensen3, Klaus Lønne Ingvartsen3, Mark A Crowe5, Conrad Ferris6, GplusE Consortium57, Frédéric Dehareng1 1CRA-W (Walloon Agricultural Research Center), Gembloux, Belgium 2Utrecht University, Utrecht, Netherlands 3Aarhus University, Tjele, Denmark 4Roslin Institute, Midlothian, United Kingdom 5UCD, Dublin, Ireland 6AFBI, Belfast, United Kingdom 7http://www.gpluse.eu/index.php/project/partners/, UCD, Ireland
The availability of panels of several thousand SNPs ordered on the genome has initiated the era o... more The availability of panels of several thousand SNPs ordered on the genome has initiated the era of population genomics, that is the application of genomic approaches to population genetics. One application of population genomics is the investigation of patterns of diversity along the chromosomes in search for signatures left by past and recent selection. These signatures are locus specific and can be identified and distinguished from the genome wide effects caused by genetic drift and demographic events. In this paper we searched for outlier behaviour within the 54,001 SNPs of the Illumina Beadchip Array assayed on 2682 bulls belonging to Italian Brown and four other Italian breeds, one dairy (Italian Friesian), one dual purpose (Italian Simmental), and two beef (Marchigiana and Piedmontese) investigated within the Italian SELMOL project on molecular genetics applied to animal breeding. Outlier values of the Fst genetic differentiation index averaged along 9 markers sliding windows ...
Cinzia Marchitelli, Federica Signorelli, Francesco Napolitano, Clément Grelet, Nicolas Gengler, F... more Cinzia Marchitelli, Federica Signorelli, Francesco Napolitano, Clément Grelet, Nicolas Gengler, Frédéric Dehareng, Hélène Soyeurt, Klaus Lønne Ingvartsen, Martin Tang Sørensen, Torben Larsen, Mark Crowe and GplusE consortium* 1 Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria, Centro di ricerca Zootecnia e Acquacoltura (CREA-ZA), Monterotondo (Roma), Italy; Centre Wallon De Recherches Agronomiques, Gembloux, Belgium; University of Liège, Gembloux, Belgium; Aarhus University,0Dept. of Animal Science, Tjele, Denmark; 5UCD School of Veterinary Medicine, Dublin, Ireland; * cinzia.marchitelli@crea.gov.it
BackgroundBovine mastitis, an inflammatory disease of the mammary gland, is classified as subclin... more BackgroundBovine mastitis, an inflammatory disease of the mammary gland, is classified as subclinical or clinical. Circulating neutrophils are recruited to the udder to combat infection. We compared the transcriptomic profiles in circulating leukocytes between healthy cows and those with naturally occurring subclinical or clinical mastitis.Methods and ResultsHolstein Friesian dairy cows from six farms in EU countries were recruited. Based on milk somatic cell count and clinical records, cows were classified as healthy (n = 144), subclinically (n = 48) or clinically mastitic (n = 22). Circulating leukocyte RNA was sequenced with Illumina NextSeq single end reads (30 M). Differentially expressed genes (DEGs) between the groups were identified using a DESeq2 package, followed by GO enrichment analysis. Both subclinical and clinical mastitis caused significant changes in the leukocyte transcriptome, with more intensive changes attributed to clinical mastitis. We detected 491 DEGs betwee...
Background Previous studies have identified many immune pathways which are consistently altered i... more Background Previous studies have identified many immune pathways which are consistently altered in humans and model organisms as they age. Dairy cows are often culled at quite young ages due to an inability to cope adequately with metabolic and infectious diseases, resulting in reduced milk production and infertility. Improved longevity is therefore a desirable trait which would benefit both farmers and their cows. This study analysed the transcriptome derived from RNA-seq data of leukocytes obtained from Holstein cows in early lactation with respect to lactation number. Results Samples were divided into three lactation groups for analysis: i) primiparous (PP, n = 53), ii) multiparous in lactations 2–3 (MP 2–3, n = 121), and iii) MP in lactations 4–7 (MP > 3, n = 55). Leukocyte expression was compared between PP vs MP > 3 cows with MP 2–3 as background using DESeq2 followed by weighted gene co-expression network analysis (WGCNA). Seven modules were significantly correlated (r ...
Background Milk sialylated oligosaccharides (SOS) play crucial roles in many biological processes... more Background Milk sialylated oligosaccharides (SOS) play crucial roles in many biological processes. The most abundant free SOS in goat’s milk are 3’sialyllactose (3′-SL), 6’sialyllactose (6′-SL) and disialyllactose (DSL). The production of these molecules is determined genetically by the expression of glycosyltransferases and by the availability of nucleotide sugar substrates, but the precise mechanisms regulating the differential patterns of milk oligosaccharides are not known. We aimed to identify the complete cDNAs of candidate genes implicated in SOS biosynthesis (B4GALT1, LALBA, ST3GAL5, ST6GAL1) and to analyse their expression during lactation in the Garganica and Maltese goat breeds. Moreover, we analysed the colostrum and milk contents of 3′-SL, 6′-SL and disialyllactose (DSL) and the possible correlations between expressed genes and SOS. Results We identified the complete coding cDNAs of B4GALT1 (HQ700335.1), ST3GAL5 (KF055858.2), and ST6GAL1 (HQ709167.1), the single nucleot...
Developmental and comparative immunology, Sep 20, 2017
Although buffaloes (Bubalus bubalis) are a major component of the livestock industry worldwide, l... more Although buffaloes (Bubalus bubalis) are a major component of the livestock industry worldwide, limited progress has been made in the study of the mechanisms regulating the immune response to pathogens and parasites affecting their health and productivity. This has been, in part, attributable to the limited availability of reagents to study immune responses in buffalo. As reported here, a set of cross-reactive monoclonal antibodies (mAbs), developed against bovine, ovine and caprine leukocyte differentiation molecules (LDM) and major histocompatibility complex (MHC) molecules, were identified and used to compare expression of LDM in Italian and Egyptian buffalo. The results show most of the epitopes identified with the mAbs are conserved on LDM and MHC I and II molecules in both lineages of buffalo. Comparison of the composition of lymphocyte subsets between buffalo and cattle revealed they are similar except for expression of CD2 and CD8 on workshop cluster one (WC1) positive γδ T ...
Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- bor... more Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- borne zoonoses worldwide, typically carried by pigs. It is well known that Salmonella has evolved a wide array of strategies enabling it to invade the host, but little information is available on the specific host responses to Salmonella infections. In the present study, we used an in vivo approach (involving piglets infected with a virulent or an attenuated S. Typhimurium strain) coupled to histological and proteomic analysis of the cecum mucosa, to highlight the host pathways activated during S. Typhimurium infection. We confirm the complex host-pathogen interaction. Our data showed that the metabolic and the cytoskeleton organization functions were the most significantly altered. In particular, the modifications of energy metabolic pathway could suggest a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;nutriprive&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; mechanism, in which the host reduce its metabolic and energetic status to limit Salmonella infection. This study could represent a preliminary approach, providing information useful to better understand the host-Salmonella interaction.
The families of TGF-β (transforming growth factor-β) proteins are the most important growth facto... more The families of TGF-β (transforming growth factor-β) proteins are the most important growth factors in the ovary, and three related oocyte-derived members, namely GDF9 (growth differentiation factor 9), BMP15 (bone morphogenetic protein 15), and BMPR1B (bone morphogenetic protein receptor 1B), have been shown to be essential for follicular growth and ovulation. Although the essential role of these genes in determining litter size in sheep and mouse and in controlling folliculogenesis in human has been demonstrated, there is limited information on their action in other species, especially in bovine. Bovine is a monotocous specie, as humans, with one or sometimes two newborns per birth. The twinning is a complex trait determined by both genetic and environmental factors. This study aimed at investigating the nucleotide sequences of different fragments of GDF9, BMP15, and BMPR1B genes in Maremmana cows reared in Castelporziano Presidential Estate (Rome). In this herd, in the period between 1996 and 2008, a twinning rate of 12 % (on average) was observed. We identified nine single-nucleotide polymorphisms (SNPs), five in the coding region, and four in the noncoding region: Two polymorphisms caused non-synonymous mutations, g.6045 G>A (V202I) in the BMP15 gene, and g.231 T>C (L66S) in GDF9 gene. The mutation L66S was found only in cows with double birth. In the literature, there are different evidences that mutations in proregion of GDF9 protein could affect its correct function. A relationship between mutations in this region of protein and granulosa cells proliferation and oocyte development was hypothesized.
Understanding which are the genetic variants underlying the nutritional and sensory properties of... more Understanding which are the genetic variants underlying the nutritional and sensory properties of beef, enables improvement in meat quality. The aim of this study is to identify new molecular markers for meat quality through an association study using candidate genes included in the PPARG and PPARGC1A networks given their master role in coordinating metabolic adaptation in fat tissue, muscle and liver. Amongst the novel associations found in this study, selection of the positive marker variants of genes such as BCL3, LPL, PPARG, SCAP, and SCD will improve meat organoleptic characteristics and health by balancing the n-6 to n-3 fatty acid ratio in meat. Also previous results on GDF8 and DGAT1 were validated, and the novel ATF4, HNF4A and PPARGC1A associations, although slightly under the significance threshold, are consistent with their physiological roles. These data contribute insights into the complex gene-networks underlying economically important traits.
Abstract In this report, we describe the identification of the complete ovine gelsolin ( GSN ) is... more Abstract In this report, we describe the identification of the complete ovine gelsolin ( GSN ) isoform b cDNA. We sequenced exons 12 and 13 and parts of introns 11, 12 and 13 in 263 sheep of three breeds. We found 11 novel SNPs, of which 2 were missense mutations. GSN is a Ca 2+ -dependent actin-regulatory protein that modulates actin assembly and disassembly. Because actin is involved in the regulation of intracellular lipid metabolism, particularly in the formation of cytoplasmic fat droplets and in the transport of lipid constituents, we tested the hypothesis that different GSN genotypes might influence actin activity and, consequently, milk yield and quality. An association analysis was performed between each SNP and the following traits, which were evaluated in 464 recorded lactations of the same sheep: milk yield, fat and protein content, as well as somatic cell score. Significant associations ( P = 0.02) were found between three SNPs in intron 12 and fat content in the Altamurana breed. For two of the SNPs, the effect was also noted in the Gentile breed ( P = 0.09). Suggestive associations were also found between the SNPs and other traits, albeit not in all of the breeds. The three SNPs that affected fat content were located in the consensus sequences of binding sites for the following transcription factors: Tal-1 alpha, Evi-1 and Egr-3. Therefore, we hypothesised that the incorrect modulation of actin assembly occurs in one of the GSN genotypes, with a particularly evident effect on fat content.
Two methods have been developed for the assessment of conservation priorities on the basis of mol... more Two methods have been developed for the assessment of conservation priorities on the basis of molecular markers. According to the Weitzman approach, contributions to genetic diversity are derived from genetic distances between populations. Alternatively, diversity within and across populations is optimized by minimizing marker-estimated kinships. We have applied, for the first time, both methods to a comprehensive data set of 69 European cattle breeds, including all cosmopolitan breeds and several local breeds, for which genotypes of 30 microsatellite markers in 25-50 animals per breed have been obtained. Both methods were used to calculate the gain in diversity if a breed was added to a set of nine non-endangered breeds. Weitzman-derived diversities were confounded by genetic drift in isolated populations, which dominates the genetic distances but does not necessarily increase the conservation value of a breed. Marker-estimated kinships across populations were less disturbed by genetic drift than the Weitzman diversities and assigned high conservation values to Mediterranean breeds, which indeed have genetic histories that differ from the non-endangered breeds. Prospects and limitations of marker-assisted decisions on conservation priorities are discussed.
Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to impo... more Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to important changes in fatty acid composition due to feed imbalances and the consequent ruminal metabolism alteration. Milk produced in two different farming systems was compared: Holstein Friesian fed with unified in intensive production and Podolica raised on a pasture in an extensive system. Milk chemical characteristics and fatty acid composition were determined comparing milk with a normal fat level (>3.8%) to milk with a low fat level (<3.2%) in each breeding system. Holstein Friesian milk showed the decrease in trans-11 and increase in trans-10 C18:1 (shift from trans-11 to trans-10 C18:1) in low fat with respect to normal fat milk with a consequent decrease in the trans-11/trans-10 C18:1 ratio. Even conjugated linoleic acid (CLA), C18:2 cis-9, trans-11, was lower while CLA trans-10, cis-12 was higher in low fat milk than in normal fat milk from Holstein Friesian. These changes, t...
A first approach to predict nitrogen efficiency of dairy cows through milk FT-MIR spectra Clément... more A first approach to predict nitrogen efficiency of dairy cows through milk FT-MIR spectra Clément Grelet1, Eric Froidmont1, Miel Hostens2, Leslie Foldager3, Mazdak Salavati4, Amélie Vanlierde1, Martin Tang Sorensen3, Klaus Lønne Ingvartsen3, Mark A Crowe5, Conrad Ferris6, GplusE Consortium57, Frédéric Dehareng1 1CRA-W (Walloon Agricultural Research Center), Gembloux, Belgium 2Utrecht University, Utrecht, Netherlands 3Aarhus University, Tjele, Denmark 4Roslin Institute, Midlothian, United Kingdom 5UCD, Dublin, Ireland 6AFBI, Belfast, United Kingdom 7http://www.gpluse.eu/index.php/project/partners/, UCD, Ireland
The availability of panels of several thousand SNPs ordered on the genome has initiated the era o... more The availability of panels of several thousand SNPs ordered on the genome has initiated the era of population genomics, that is the application of genomic approaches to population genetics. One application of population genomics is the investigation of patterns of diversity along the chromosomes in search for signatures left by past and recent selection. These signatures are locus specific and can be identified and distinguished from the genome wide effects caused by genetic drift and demographic events. In this paper we searched for outlier behaviour within the 54,001 SNPs of the Illumina Beadchip Array assayed on 2682 bulls belonging to Italian Brown and four other Italian breeds, one dairy (Italian Friesian), one dual purpose (Italian Simmental), and two beef (Marchigiana and Piedmontese) investigated within the Italian SELMOL project on molecular genetics applied to animal breeding. Outlier values of the Fst genetic differentiation index averaged along 9 markers sliding windows ...
Cinzia Marchitelli, Federica Signorelli, Francesco Napolitano, Clément Grelet, Nicolas Gengler, F... more Cinzia Marchitelli, Federica Signorelli, Francesco Napolitano, Clément Grelet, Nicolas Gengler, Frédéric Dehareng, Hélène Soyeurt, Klaus Lønne Ingvartsen, Martin Tang Sørensen, Torben Larsen, Mark Crowe and GplusE consortium* 1 Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria, Centro di ricerca Zootecnia e Acquacoltura (CREA-ZA), Monterotondo (Roma), Italy; Centre Wallon De Recherches Agronomiques, Gembloux, Belgium; University of Liège, Gembloux, Belgium; Aarhus University,0Dept. of Animal Science, Tjele, Denmark; 5UCD School of Veterinary Medicine, Dublin, Ireland; * cinzia.marchitelli@crea.gov.it
BackgroundBovine mastitis, an inflammatory disease of the mammary gland, is classified as subclin... more BackgroundBovine mastitis, an inflammatory disease of the mammary gland, is classified as subclinical or clinical. Circulating neutrophils are recruited to the udder to combat infection. We compared the transcriptomic profiles in circulating leukocytes between healthy cows and those with naturally occurring subclinical or clinical mastitis.Methods and ResultsHolstein Friesian dairy cows from six farms in EU countries were recruited. Based on milk somatic cell count and clinical records, cows were classified as healthy (n = 144), subclinically (n = 48) or clinically mastitic (n = 22). Circulating leukocyte RNA was sequenced with Illumina NextSeq single end reads (30 M). Differentially expressed genes (DEGs) between the groups were identified using a DESeq2 package, followed by GO enrichment analysis. Both subclinical and clinical mastitis caused significant changes in the leukocyte transcriptome, with more intensive changes attributed to clinical mastitis. We detected 491 DEGs betwee...
Background Previous studies have identified many immune pathways which are consistently altered i... more Background Previous studies have identified many immune pathways which are consistently altered in humans and model organisms as they age. Dairy cows are often culled at quite young ages due to an inability to cope adequately with metabolic and infectious diseases, resulting in reduced milk production and infertility. Improved longevity is therefore a desirable trait which would benefit both farmers and their cows. This study analysed the transcriptome derived from RNA-seq data of leukocytes obtained from Holstein cows in early lactation with respect to lactation number. Results Samples were divided into three lactation groups for analysis: i) primiparous (PP, n = 53), ii) multiparous in lactations 2–3 (MP 2–3, n = 121), and iii) MP in lactations 4–7 (MP > 3, n = 55). Leukocyte expression was compared between PP vs MP > 3 cows with MP 2–3 as background using DESeq2 followed by weighted gene co-expression network analysis (WGCNA). Seven modules were significantly correlated (r ...
Background Milk sialylated oligosaccharides (SOS) play crucial roles in many biological processes... more Background Milk sialylated oligosaccharides (SOS) play crucial roles in many biological processes. The most abundant free SOS in goat’s milk are 3’sialyllactose (3′-SL), 6’sialyllactose (6′-SL) and disialyllactose (DSL). The production of these molecules is determined genetically by the expression of glycosyltransferases and by the availability of nucleotide sugar substrates, but the precise mechanisms regulating the differential patterns of milk oligosaccharides are not known. We aimed to identify the complete cDNAs of candidate genes implicated in SOS biosynthesis (B4GALT1, LALBA, ST3GAL5, ST6GAL1) and to analyse their expression during lactation in the Garganica and Maltese goat breeds. Moreover, we analysed the colostrum and milk contents of 3′-SL, 6′-SL and disialyllactose (DSL) and the possible correlations between expressed genes and SOS. Results We identified the complete coding cDNAs of B4GALT1 (HQ700335.1), ST3GAL5 (KF055858.2), and ST6GAL1 (HQ709167.1), the single nucleot...
Developmental and comparative immunology, Sep 20, 2017
Although buffaloes (Bubalus bubalis) are a major component of the livestock industry worldwide, l... more Although buffaloes (Bubalus bubalis) are a major component of the livestock industry worldwide, limited progress has been made in the study of the mechanisms regulating the immune response to pathogens and parasites affecting their health and productivity. This has been, in part, attributable to the limited availability of reagents to study immune responses in buffalo. As reported here, a set of cross-reactive monoclonal antibodies (mAbs), developed against bovine, ovine and caprine leukocyte differentiation molecules (LDM) and major histocompatibility complex (MHC) molecules, were identified and used to compare expression of LDM in Italian and Egyptian buffalo. The results show most of the epitopes identified with the mAbs are conserved on LDM and MHC I and II molecules in both lineages of buffalo. Comparison of the composition of lymphocyte subsets between buffalo and cattle revealed they are similar except for expression of CD2 and CD8 on workshop cluster one (WC1) positive γδ T ...
Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- bor... more Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- borne zoonoses worldwide, typically carried by pigs. It is well known that Salmonella has evolved a wide array of strategies enabling it to invade the host, but little information is available on the specific host responses to Salmonella infections. In the present study, we used an in vivo approach (involving piglets infected with a virulent or an attenuated S. Typhimurium strain) coupled to histological and proteomic analysis of the cecum mucosa, to highlight the host pathways activated during S. Typhimurium infection. We confirm the complex host-pathogen interaction. Our data showed that the metabolic and the cytoskeleton organization functions were the most significantly altered. In particular, the modifications of energy metabolic pathway could suggest a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;nutriprive&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; mechanism, in which the host reduce its metabolic and energetic status to limit Salmonella infection. This study could represent a preliminary approach, providing information useful to better understand the host-Salmonella interaction.
The families of TGF-β (transforming growth factor-β) proteins are the most important growth facto... more The families of TGF-β (transforming growth factor-β) proteins are the most important growth factors in the ovary, and three related oocyte-derived members, namely GDF9 (growth differentiation factor 9), BMP15 (bone morphogenetic protein 15), and BMPR1B (bone morphogenetic protein receptor 1B), have been shown to be essential for follicular growth and ovulation. Although the essential role of these genes in determining litter size in sheep and mouse and in controlling folliculogenesis in human has been demonstrated, there is limited information on their action in other species, especially in bovine. Bovine is a monotocous specie, as humans, with one or sometimes two newborns per birth. The twinning is a complex trait determined by both genetic and environmental factors. This study aimed at investigating the nucleotide sequences of different fragments of GDF9, BMP15, and BMPR1B genes in Maremmana cows reared in Castelporziano Presidential Estate (Rome). In this herd, in the period between 1996 and 2008, a twinning rate of 12 % (on average) was observed. We identified nine single-nucleotide polymorphisms (SNPs), five in the coding region, and four in the noncoding region: Two polymorphisms caused non-synonymous mutations, g.6045 G>A (V202I) in the BMP15 gene, and g.231 T>C (L66S) in GDF9 gene. The mutation L66S was found only in cows with double birth. In the literature, there are different evidences that mutations in proregion of GDF9 protein could affect its correct function. A relationship between mutations in this region of protein and granulosa cells proliferation and oocyte development was hypothesized.
Understanding which are the genetic variants underlying the nutritional and sensory properties of... more Understanding which are the genetic variants underlying the nutritional and sensory properties of beef, enables improvement in meat quality. The aim of this study is to identify new molecular markers for meat quality through an association study using candidate genes included in the PPARG and PPARGC1A networks given their master role in coordinating metabolic adaptation in fat tissue, muscle and liver. Amongst the novel associations found in this study, selection of the positive marker variants of genes such as BCL3, LPL, PPARG, SCAP, and SCD will improve meat organoleptic characteristics and health by balancing the n-6 to n-3 fatty acid ratio in meat. Also previous results on GDF8 and DGAT1 were validated, and the novel ATF4, HNF4A and PPARGC1A associations, although slightly under the significance threshold, are consistent with their physiological roles. These data contribute insights into the complex gene-networks underlying economically important traits.
Abstract In this report, we describe the identification of the complete ovine gelsolin ( GSN ) is... more Abstract In this report, we describe the identification of the complete ovine gelsolin ( GSN ) isoform b cDNA. We sequenced exons 12 and 13 and parts of introns 11, 12 and 13 in 263 sheep of three breeds. We found 11 novel SNPs, of which 2 were missense mutations. GSN is a Ca 2+ -dependent actin-regulatory protein that modulates actin assembly and disassembly. Because actin is involved in the regulation of intracellular lipid metabolism, particularly in the formation of cytoplasmic fat droplets and in the transport of lipid constituents, we tested the hypothesis that different GSN genotypes might influence actin activity and, consequently, milk yield and quality. An association analysis was performed between each SNP and the following traits, which were evaluated in 464 recorded lactations of the same sheep: milk yield, fat and protein content, as well as somatic cell score. Significant associations ( P = 0.02) were found between three SNPs in intron 12 and fat content in the Altamurana breed. For two of the SNPs, the effect was also noted in the Gentile breed ( P = 0.09). Suggestive associations were also found between the SNPs and other traits, albeit not in all of the breeds. The three SNPs that affected fat content were located in the consensus sequences of binding sites for the following transcription factors: Tal-1 alpha, Evi-1 and Egr-3. Therefore, we hypothesised that the incorrect modulation of actin assembly occurs in one of the GSN genotypes, with a particularly evident effect on fat content.
Two methods have been developed for the assessment of conservation priorities on the basis of mol... more Two methods have been developed for the assessment of conservation priorities on the basis of molecular markers. According to the Weitzman approach, contributions to genetic diversity are derived from genetic distances between populations. Alternatively, diversity within and across populations is optimized by minimizing marker-estimated kinships. We have applied, for the first time, both methods to a comprehensive data set of 69 European cattle breeds, including all cosmopolitan breeds and several local breeds, for which genotypes of 30 microsatellite markers in 25-50 animals per breed have been obtained. Both methods were used to calculate the gain in diversity if a breed was added to a set of nine non-endangered breeds. Weitzman-derived diversities were confounded by genetic drift in isolated populations, which dominates the genetic distances but does not necessarily increase the conservation value of a breed. Marker-estimated kinships across populations were less disturbed by genetic drift than the Weitzman diversities and assigned high conservation values to Mediterranean breeds, which indeed have genetic histories that differ from the non-endangered breeds. Prospects and limitations of marker-assisted decisions on conservation priorities are discussed.
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Papers by Cinzia Marchitelli