G. Vonghia

Chromosome evolution and improved cytogenetic maps of the Y chromosome in cattle, zebu, river buffalo, sheep and goat.

Comparative FISH-mapping among Y chromosomes of cattle (Bos taurus, 2n = 60, BTA, submetacentric Y chromosome), zebu (Bos indicus, 2n = 60, BIN, acrocentric Y chromosome but with visible small p-arms), river buffalo (Bubalus bubalis, 2n = 50, BBU, acrocentric Y chromosome), sheep (Ovis aries, 2n = 54, OAR, small metacentric Y chromosome) and goat (Capra hircus, 2n = 60, CHI, Y-chromosome as in sheep) was performed to extend the existing cytogenetic maps and improve the understanding of karyotype evolution of these small chromosomes in bovids. C- and R-banding comparison were also performed and both bovine and caprine BAC clones containing the SRY, ZFY, UMN0504, UMN0301, UMN0304 and DYZ10 loci in cattle and DXYS3 and SLC25A6 in goat were hybridized on R-banded chromosomes by FISH. The main results were the following: (a) Y-chromosomes of all species show a typical distal positive C-band which seems to be located at the same region of the typical distal R-band positive; (b) the PAR is located at the telomeres but close to both R-band positive and ZFY in all species; (c) ZFY is located opposite SRYand on different arms of BTA, BIN, OAR/CHI Y chromosomes and distal (but centromeric to ZFY) in BBU-Y; (d) BTA-Y and BIN-Y differ as a result of a centromere transposition or pericentric inversion since they retain the same gene order along their distal chromosome regions and have chromosome arms of different size; (e) BTA-Y and BBU-Y differ in a pericentric inversion with a concomitant loss or gain of heterochromatin; (f) OAR/CHI-Y differs from BBU-Y for a pericentric inversion with a major loss of heterochromatin and from BTA and BIN for a centromere transposition followed by the loss of heterochromatin.

High resolution nuclear magnetic resonance spectroscopy (NMR) studies on meat components: potentialities and prospects

Abstract In recent years, increasing application of nuclear magnetic resonance (NMR) spectroscopy in the study of the agricultural food products has been remarked, thanks to the advantages of this technique over other conventional analytical techniques. This preliminary work presents, for the first time, the application of an innovative NMR technique, the proton high resolution magic angle spinning (1H HR-MAS), for studying meat features. It stresses that this method makes it possible to acquire qualitative and quantitative information about chemical composition, both quickly and without any particular preparation of the sample to be analysed. Finally, the study highlights the potentiality of this method in defining the origin of meat and the possibility of identifying meat adulteration.

FISH-mapping of LEP and SLC26A2 genes in sheep, goat and cattle R-banded chromosomes: comparison between bovine, ovine and caprine chromosome 4 (BTA4/OAR4/CHI4) and human chromosome 7 (HSA7)

Sheep (OAR), goat (CHI) and cattle (BTA) R-banded chromosome preparations, obtained from synchronized cell cultures, were used to FISH-map leptin (LEP) and solute carrier family 26 member 2 (SLC26A2) genes on single chromosome bands. LEP maps on OAR4q32 and CHI4q32, being the first assignment of this gene to these two species. SLC26A2 maps on BTA7q24, OAR5q24 and CHI7q24. This gene, too, was assigned for the fist time to both sheep and goat chromosomes, while it was more precisely localized on a single chromosome band in cattle. Improved cytogenetic maps of BTA4/OAR4/CHI4 were constructed and compared with HSA7 revealing five main conserved segments and complex chromosome rearrangements, including a centromere repositioning, differentiating HSA7 and BTA4/OAR4/CHI4.

Comparative mapping of twenty-eight bovine loci in sheep (Ovis aries, 2n = 54) and river buffalo (Bubalus bubalis, 2n = 50) by FISH

Peripheral blood cell cultures were treated for late incorporation of both BrdU and Hoechst-33258 to obtain R-banding pattern preparations. Twenty-eight bovine cosmids from 19 bovine syntenic groups (U), three of which contain type I loci and 25 which contain microsatellite loci and have previously been assigned to cattle chromosomes, were comparatively FISH-mapped to sheep and river buffalo chromosomes according to the standard karyotypes (13 loci for the first time in the latter species). The results enrich the physical maps of both species with information relative to the following loci and to the corresponding syntenic groups: IDVGA35 and IDVGA53 (U6), IDVGA61 and IDVGA84 (U13), JAB10 (U5), IDVGA41 and IDVGA57 (U27), IDVGA87 (U11), IDVGA32 and IDVGA10 (U19), IDVGA49, IDVGA66 and IDVGA68 (U1), ZNF164 (U23), IDVGA74 and IDVGA70 (U9), IDVGA47, IDVGA46 and IDVGA58 (U21), MAP1B (U14), IDVGA79 (U4), CATHL (U12), IDVGA71 (U8), IDVGA59 (U26), IDVGA29 (U29), IDVGA7 (U7), IDVGA82 (X), IDVGA50 (Y). All mapped loci were localized on homoeologous chromosomes and chromosome regions of the two species, confirming the high degree of chromosome homoeologies between the subfamilies Bovinae and Caprinae.

Dietary supplementation of garlic and rosemary: effects on colour stability and lipid oxidation in lamb meat

Riassunto Integrazione alimentare con aglio e rosmarino: effetti sul colore e sull’ossidazione lipidica della carne di agnello. Agnelli di razza Gentile di Puglia sono stati alimentati con un mangime di base (Controllo) o integrato con aglio fresco (3,5 g kg-1), estratto di aglio (500 mg kg-1), estratto di rosmarino (500 o 1000 mg kg-1) o con vitamina E (500 mg kg-1 α-tocoferolo acetato). Sono stati costituiti due sottogruppi di agnelli macellati rispettivamente a 80 o 110 giorni. Nei giorni 1, 3, 5 e 7 successivi alla macellazione sono stati valutati il colore e l’ossidazione lipidica mediante TBARS test sul muscolo Longissimus lumborum. Il colore della carne è stato migliorato dagli antiossidanti naturali, ma soprattutto dalla vit. E (P<0,05). Il TBARS test ha evidenziato una diminuzione dell’ossidazione lipidica nei gruppi vit. E e aglio estratto (P<0,01), seguiti dal gruppo rosmarino 1000 (P<0,05). A 110 giorni si sono attenuate le differenze tra i trattamenti alimentari, ma la vit. E e l’aglio estratto hanno confermato il loro effetto antiossidante (P<0,05).

Fatty acid chain elongation synthesis in eel (Anguilla anguilla) liver mitochondria

The properties of fatty acid chain elongation synthesis have been investigated in liver mitochondria of the European eel (Anguilla anguilla). The incorporation of [1-(14)C]acetyl-CoA into fatty acids shows a specific activity of 0.43+/-0.05 nmol/min x mg protein (n=6), which is more than twice higher than that previously reported in rat liver mitochondria. Label incorporation into fatty acids was, in mitochondria disrupted by freezing and thawing, much higher than in intact organelles thus suggesting a probable localization of this pathway inside mitochondria. Only a negligible acetyl-CoA incorporation into fatty acids occurs in the absence of ATP, Mg2+ or reduced pyridine nucleotides; NADH alone seems to be as effective as NADH + NADPH as a hydrogen donor for the reducing steps. CoASH, without effect up to 10 microM, showed a strong inhibition at higher concentrations. From the ratio of total radioactivity and radioactivity in carboxyl carbon it can be inferred that in eel-liver mitochondria only chain elongation of preexisting fatty acids occurs. A significant fatty acid chain elongation activity is also present when, instead of acetyl-CoA, [2-(14)C]malonyl-CoA is used as a carbon unit donor. Moreover, the synthesized fatty acids were actively incorporated into phopholipids, mainly phosphatidylcholine, phosphatidylethanolamine and sphyngomyelin.

Effect of goat production systems on meat quality and Conjugated Linoleic Acid (CLA) content in suckling kids

Abstract The effect of goat production systems was evaluated on the concentration of conjugated linoleic acid (CLA) in meat obtained from suckling kids. Twenty male Ionica suckling kids fed only on maternal milk were subdivided into two groups of 10 subjects each according to their dams’ feeding treatment: kids in Group I were raised under dams reared by an intensive production system, while those of Group E were raised under dams grazing on pasture. Kids were slaughtered when 45 days old. The goat production system had no effect on kids’ growth rates, slaughtering yield and on the percentages of lean, fat and bone of the lumbar region and pelvic limb cuts. The pH value of the Longissimus lumborum (Ll) muscle 45 min after slaughter was higher in Group I (6.73 vs 6.54; P<0.05). Meat colour of Group E kids was lighter (50.63 vs 48.86) and showed greater (P<0.05) yellowness (13.42 vs 11.93) and Chroma values (14.92 vs 13.45). Cooking loss was higher in Group E (31.51 vs 26.98%; P<0.05), but meat tenderness of the Ll muscle was better (peak force of 2.86 vs 3.58 kg/cm2; P<0.05). Meat chemical composition did not differ between the two groups for either raw or cooked samples. On the whole, suckling kids raised under grazing goats showed a higher total CLA concentration in both raw (2.57 vs 2.25% on total fatty acids) and cooked meat (1.85 vs 1.44%), although the differences were not significant.

Effect of dietary rosemary oil on growth performance and flesh quality of farmed seabass (Dicentrarchus labrax)

Abstract In order to assess the effect of a diet integrated with rosemary oil on growth performance and flesh quality of farmed Dicentrarchus labrax, a feeding trial was carried out. Seabass were fed with two different diets for 200 days, after that they were caught and stored in ice in a refrigerator cell (0-2°C) for 17 days. Then they were examinated on 1, 3, 10 and 17 day for sensory evaluation (fresh whole fish and cooked fillet) according to QIM and Torry Scheme. Specific growth rate (SGR) and feed conversion rate (FCR) were calculated, fillets were subjected to proximate analysis. No statistical differences were found in the final average body weight for both diets as well as SGR and FCR means. The sensory score (QIM) increased linearly with storage time. No significant difference was noticed between two diets. As for cooked fillet, Torry Scheme score decreased with storage time. At day 10 significant differences were displayed between the diets (7.44 vs. 8.67; P<0.05). Overall sensory acceptability for consuming farmed seabass stored in ice was set in corrispondence of day 13 for control diet and day 14 for experimental diet. No difference was showed in the chemical composition.

Frequency and distribution of rob(1;29) in eight Portuguese cattle breeds.

Cytogenetic investigations performed in eight Portuguese cattle breeds revealed the presence of rob(1;29) in both heterozygous and homozygous conditions in all, and five breeds, respectively, with variable percentages of carriers as follows: 41.0% in Arouquesa, 69.9% in Barrosa, 39.4% in Maronesa, 2.8% in Mirandesa, 8.5% in Marinhoa, 1.8% in Mertolenga, 21.3% in Raca Brava and 21.5% in Alentejana. CBA- and RBA-banding were performed to ascertain the chromosomes involved in the chromosome abnormality. A total of 1,626 animals were investigated. Reproductive parameters (number of calves per 100 cows) were higher in Mirandesa (80%) when compared with both Maronesa (75%) and Barrosa (70%) breeds, underlining that rob(1;29) reduces fertility in the carriers.

Fatty acid chain elongation synthesis in eel-liver Microsomes

Abstract 1. 1. Fatty acid chain elongation synthesis, which is remarkably active in eel-liver microsomes, requires [2- 14 C] malonyl-CoA as the two-carbon donor. NADPH is much more effective than NADH as reducing agent. 2. 2. Maximum elongation activity was obtained at an ATP concentration of 0.5 mM, although in its absence a noticeable incorporation of malony-CoA into fatty acids was observed. Coenzyme A had no effect up to concentration of 1μM, but strongly inhibited lipogenesis at higher concentrations. 3. 3. Thin layer chromatography (TLC) analysis showed that most radioactivity was associated with free fatty acids while nearly 30% of the labelled products were esterified into phospatidylcholine, phosphatidylethanolamine and neutral lipids.