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J H Calvo

Publications and source records attributed to J H Calvo.

13 recordsLinked to original sources

Fine mapping of genes on sheep chromosome 1 and their association with milk traits.

On the basis of comparative mapping between cattle/sheep and human for milk trait quantitative trait loci (QTL) on BTA3/OAR1, annexin A9 (ANXA9) and solute carrier family 27 (fatty acid transporter), member 3 (SLC27A3) were selected as candidate genes for fat content (FC) in sheep milk. Two other genes in the same region, cingulin (CGN) and acid phosphatase 6, lysophosphatidic (ACP6), were also considered. DNA fragments of 1931 and 2790 bp corresponding to ANXA9 and SLC27A3 respectively were isolated, and 14 and 6 single nucleotide polymorphisms (SNPs) respectively were found in each gene. ANXA9, SLC27A3, CGN and ACP6 were localized to chromosome 1 between INRA006 and AE57 by linkage mapping using the International Mapping Flock. Across-family analyses of a daughter design comprising 13 sire families revealed significant sire and SLC27A3 genotype-nested-within-sire effects for FC. Within-family analyses indicated significant regression coefficients for FC in four of six heterozygous sires. These results could reflect the existence of a QTL for FC linked to SLC27A3 in sheep.

Animals↗

Isolation, mapping and identification of SNPs for four genes (ACP6, CGN, ANXA9, SLC27A3) from a bovine QTL region on BTA3.

On the basis of fine mapping of a quantitative trait loci region of BTA3 for milk fat content, an examination of the comparative map between cattle and human indicates that the annexin 9 protein gene (ANXA9) and the fatty acid transport protein type 3 gene (SLC27A3) are two strong candidate genes. The objective of the present study is to isolate, map and characterize these genes and identify polymorphisms that could be further utilized in linkage or association studies. Furthermore, two new genes which are in the same region, cingulin protein gene (CGN) and lysophosphatidic acid phosphatase protein gene (ACP6) were studied. DNA fragments (869, 1778, 1933 and 2618 bp) corresponding to partial sequences of ACP6,CGN,ANXA9 and SLC27A3 genes were isolated. Direct sequencing of PCR products amplified from different cattle breeds revealed 1, 4, 4 and 2 SNPs for ACP6, CGN,ANXA9 and SLC27A3, respectively. For ANXA9 one SNP was located in exon 5 (A-->G 951) resulting in an amino acid change from histidine to arginine. Finally, ACP6,CGN,ANXA9 and SLC27A3 genes were located on chromosome 3 between ILSTS096 and BMS819 markers, in a region in which quantitative trait loci (QTL) for several milk traits have been described.

3' Untranslated Regions↗

Mitochondrial sequence reveals high levels of gene flow between breeds of domestic sheep from Asia and Europe.

Sequence variation present within the mitochondrial genome was used to investigate genetic diversity within sheep breeds from Asia and Europe. Comparison of 2027 bp of sequence from 121 animals revealed 44 phylogenetically informative nucleotide positions and a single insertion/deletion. A total of 57 haplotypes were observed which formed two distinct clades. Type A haplotypes were found in breeds from Asia (India, Indonesia, Mongolia, and Tibet), while type B haplotypes were observed at the highest frequency in breeds sourced from Europe (nine breeds from Austria, Aland, Finland, Spain, and northwestern Russia). The distribution of haplotypes indicates sheep appear to have the weakest population structure and the highest rate of intercontinental dispersal of any domestic animal reported to date. Only 2.7% of the sequence variation observed was partitioned between continents, which is lower than both goat (approximately 10%) and cattle (approximately 50%). Diagnostic restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) tests which distinguish type A and B haplotypes were used to test an additional 223 animals from 17 breeds of European and Asian origin. A mixture of the two lineages was found in every breed except Suffolk and the Indian Garole, indicating introgression has played a major part during breed development and subsequent selection.

Animals↗

Ovine alpha-amylase genes: isolation, linkage mapping and association analysis with milk traits.

On the basis of comparisons between cattle and sheep genome mapping information the ovine alpha-amylase gene was examined as a possible genetic marker for milk traits in sheep. The objective of the present study was to isolate, map and determine whether this gene is a candidate gene for milk traits. DNA fragments (832 and 2360 bp) corresponding to two different AMY genes were isolated, and one SNP in intron 3 and one GTG deletion in exon 3 of the 2360 bp DNA fragment were found. The 2360 bp ovine AMY DNA fragment was located on chromosome 1 by linkage mapping using the International Mapping Flock. No association was found between estimated breeding values for milk yield, protein and fat contents and AMY genotypes in a daughter design comprising 13 Manchega families with an average of 29 daughters (12-62) per sire.

Animals↗

Association of the heart fatty acid-binding protein (FABP3) gene with milk traits in Manchega breed sheep.

The ovine fatty acid-binding protein type 3 gene has been chosen as a functional candidate gene for milk traits. Two different single nucleotide polymorphisms (SNPs) of ovine FABP3 gene have been tested in a daughter design comprising 13 families. No association was found between estimated breeding values for milk yield, protein and fat contents (FC) and genotypes across families using anova and transmission disequilibrium test (TDT). In within-family analysis, one family showed a significant effect for FC. These results could indicate linkage disequilibrium between the FABP3 gene and a quantitative trait loci (QTL) for FC, with the heterozygous genotype associated with a positive effect in this trait.

Analysis of Variance↗

Characterization, genetic variation and chromosomal assignment to sheep chromosome 2 of the ovine heart fatty acid-binding protein gene (FABP3).

The purpose of this study was to locate and detect genetic variation in the sheep FABP3 gene, a candidate gene for milk and meat quality traits in sheep. We have obtained an almost complete sequence (4,689 bp, excluding a part of intron 1) of the sheep FABP3 gene using PCR-based comparative genome walking. Sheep FABP3 has been located to chromosome 2 by sheep sequence-specific PCR on DNA from a sheep/rodent cell hybrid panel, and confirmed by linkage mapping using the International Mapping Flock. Direct sequencing of PCR products amplified from different DNA samples of Manchega breed sheep over the complete sheep FABP3 gene revealed 13 SNPs, one CTC insertion/deletion and a variable polyA tract. This poly A tract was found in association with a SINE/artiodactyls repeat. In addition, two SNPs were screened in different sheep breeds.

Animals↗

Random amplified polymorphic DNA fingerprints for identification of species in poultry pâté.

Because some fraudulent or unintentional mislabeling occurs that can be undetected, resulting in lower quality pâté, and because some population groups, for philosophical or religious reasons, do not wish to eat meat from certain species, a new procedure was developed and evaluated to detect pâté species composition by randomly amplified polymorphic DNA (RAPD). The RAPD method was used to generate fingerprint patterns for pork, chicken, duck, turkey, and goose meats. Ten DNA samples from pork, chicken, turkey, and duck meats were tested to confirm the effectiveness and specificity. Specific results for each species were obtained by the RAPD method. Sensitivity of the method was studied by DNA dilution in each species, detecting as little as 250 pg of DNA. Isolations of DNA from 30 pâtés (tinned and untinned) were carried out, and an optimal DNA was obtained for using as template DNA in polymerase chain reaction (PCR). The RAPD-PCR pattern was useful to identify species composition of pork, duck, duck-pork, goose, and poultry pâtés. This study demonstrates the usefulness of RAPD fingerprinting to distinguish between species in pâtés.

Animals↗

Technical note: A quick and more sensitive method to identify pork in processed and unprocessed food by PCR amplification of a new specific DNA fragment.

We developed and evaluated a PCR procedure to detect pork in heated and unheated meat, sausages, canned food, cured products, and pâtés using a faster, more specific, and more sensitive method than others previously described. Isolation of a new DNA-specific porcine repetitive element was performed by nonspecific PCR amplification. After analyzing this repetitive sequence, a pair of primers were synthesized. To confirm the effectiveness and specificity of this fragment, 55 pig blood DNA samples (from differents breeds) were tested and positive results were obtained. With 200 samples tested from other species, the specific pork amplification was not detected. Using this method, we can partially quantify degree of contamination, depending on the PCR amplification cycles, detecting up to 0.005% pork in beef and 1% pork in duck pâté using 30 and 20 PCR amplification cycles, respectively. The amount of porcine DNA detected in cattle DNA was 1.25 and 250 pg when using 30 and 20 amplification cycles, respectively. Pork has been identified in both heated and unheated meat products, sausages, canned food, hamburgers, and pâtés. In conclusion, specific PCR amplification of a repetitive DNA element seems to be a powerful technique for the identification of pork in processed and unprocessed food, because of its simplicity, specificity, and sensitivity (with 30 amplification cycles we can detect 0.005% pork). Furthermore, it is a very fast method, because 1% pork contamination can be detected with 20 PCR cycles. The procedure is also much cheaper than other methods based on RFLP-PCR, immunodiffusion, or other techniques that need expensive equipment.

Animals↗