Development and validation of RP-HPLC method for the quantitative estimation of αs1-genetic variants in goat milk

A high-performance liquid chromatographic (HPLC) method was developed and validated for separation and quantification of the most common genetic variants of as1-casein in goat’s milk, to evaluate the effect of as1-casein polymorphisms on casein content. Chromatography was carried out by binary gradient technique on a reversed-phase C8 Zorbax column and the detection was made at a wavelength of 214 nm. The procedure was developed using individual raw milk samples of Girgentana goats. For calibration experiments, pure genetic variants were extracted from individual milk samples of animals with known genotypes, considering that commercial standards for goat genetic variants were not available.…

Determination of protein content and fatty acid profile in milk of Girgentana goat breed for evaluation of nutritional characteristics of dairy products

I geni delle caseine caprine mostrano un elevato polimorfismo, che influenza non solo la quantità di caseine nel latte ma anche le caratteristiche strutturali e nutrizionali e le proprietà tecnologiche del latte. Uno degli obiettivi di questa tesi è stato quello di separare e quantificare le più comuni varianti alleliche caseiniche nel latte di capra di razza Girgentana, una razza autoctona siciliana, e di valutare l’effetto dei polimorfismi caseinici sul contenuto di caseina nel latte. I genotipi e, quindi, gli alleli ai diversi geni delle caseine sono stati rilevati utilizzando protocolli di PCR, PCR-RFLP, AS-PCR e analisi di sequenziamento. I campioni di latte sono stati preparati seguen…

Influenza del suolo sulla produzione di Ocratossina A lungo la filiera vitivinicola

Population genetic structure and milk production traits in Girgentana goat breed

The aim of this work was to evaluate the genetic status of the Girgentana goat, an endangered breed from Sicily (Italy), using microsatellite markers. Furthermore, as the main purpose of the Girgentana breed is milk production, quantitative milk traits were investigated, including fatty acid profile. Molecular data from CSN1S1, CSN2, CSN1S2, and CSN3 casein genes were also used to infer haplotypes. A total of 264 individuals were collected. Samples of Maltese (n = 41) and Derivata di Siria (n = 33) goat breeds were also used to understand the genetic relationship among breeds. Test-day records for milk production were collected to determine daily milk yield, fat, protein, casein, lactose, a…

QUANTIFICATION OF GENETIC VARIANTS OF CASEINS IN MILK OF GIRGENTANA GOAT BREED

In the milk of ruminants, more than 95% of proteins are synthesized by six structural genes, four caseins (alphas1, beta, alphas2 and κ-caseins) and two whey proteins (alpha-lactalbumin and beta-lactoglobulin). Goat casein genes have been found to show high polymorphism, which influences not only the quantity of casein in milk but also the structural and nutritional characteristics and technological properties of milk. The aim of this work was to separate and quantify the most common allelic variants of caseins in milk of Girgentana goat breed, a Sicilian autochthonous breed, and to evaluate the effect of casein polymorphisms on casein content. The alleles at different casein genes were det…

Lateral habenula and hippocampus: A complex interaction raphe cells-mediated

The study has shown an excitatory influence exerted by lateral habenula (LH) on hippocampal pyramidal cells. The modulatory influence is paradoxically serotonine-mediated; in fact all LH stimulation effects were abolished by intrahippocampal iontophoretic methysergide application. The data suggest the involvement of dorsal raphe nucleus. In fact, the dorsal raphe nucleus stimulation caused on hippocampus an expected inhibitory effect antagonized by intrahippocampal iontophoretic methysergide application. In the context of this neural structure we have highlighted a disinhibitory relation between two types of cells: slow serotonergic efferent neurones and fast GABAergic interneurones. The di…

PRELIMINARY STUDY ON QUANTIFICATION OF aS1-CASEIN VARIANTS IN GIRGENTANA GOAT BREED BY DIRECT CHROMATOGRAPHIC ANALYSIS OF MILK

Goat αs1-casein is a highly polymorphic protein, coded by CSN1S1 gene. Nowadays, several alleles were identified and associated with different levels of αs1-casein in goat milk. Polymorphisms at αs1-casein locus have been shown to affect not only the quantity of this casein in goat milk, but also the structural and nutritional characteristics (hypoallergenic properties) and technological properties of the milk (1). The aim of this work was to separate and quantify the most common allelic variants of αs1-casein in milk of Girgentana goat breed, a Sicilian autochthonous breed, and to evaluate the effect of αs1-casein polymorphisms on casein content. The CSN1S1 A/01, B/E, F, and N alleles were…

Effect of acetylcholine and dopamine iontophoretically applied on the sensory responsive caudate unit

A putative integrative function of the striatum was evaluated through the study of the electrical activity of sensory responsive caudate neurones. Both nervous (radial nerve) and auditory stimulations were delivered in order to characterize populations of neurones affected by peripheral stimuli; the units were previously activated by iontophoretic glutamate. On these units the iontophoretic ejection of ACh and DA was tested. Experimental results demonstrated a prevalent excitatory effect of ACh, while DA appeared to exert a drastic decrease on firing rate. A comparison between peripheral stimuli and chemical substances was made. The result of such study showed a most important action of the…

ASSOCIATION BETWEEN THE POLYMORPHISM AT CASEIN LOCI AND MILK FATTY ACID COMPOSITION IN GIRGENTANA GOATS

composition is an important trait for the goat dairy industry because of its influence on cheese yield and the organoleptic properties of dairy products (Chilliard et al., 2003). Goat milk is particularly rich in saturated fatty acids (SFA) whereas monounsaturated (MUFA) and polyunsaturated (PUFA) FA are less abundant (Fontecha et al., 2000).The aim of this work was to provide new data to better understand the influence of polymorphism at casein loci on fatty acid profile in Girgentana goat milk. One hundred lactating Girgentana goats, homogeneous for milk production, days of lactation, body weight and diet were used. The procedure was developed using individual raw milk samples, collected …

Electrophysiological and Iontophoretic Aspects of the Habenular Influence on Hippocampal Neurones

In previous experimental studies, carried out on cats, we demonstrated that electrical stimulation of lateral habenula (LH) at 0.5-3.0 Hz or 5-20 Hz had a double effect (low frequency-excitation; high frequency-inhibition) on the spontaneous firing rate of single hippocampal neurones. Our results, in agreement with similar case studies, allowed us to hypothesise that in the habenular modulation of the hippocampus the raphe nucleus is probably involved. In fact, all the effects of LH stimulation were antagonised by the iontophoretic intrahippocampal application of methysergide. In the present series of experiments, performed on rats, it was possible to demonstrate that LH stimulation at 1-10…

Oxidation Processes in Sicilian Olive Oils Investigated by a Combination of Optical and EPR Spectroscopy

:  Extra virgin olive oil (EVOO) is recognized as one of the healthiest foods for its high content of antioxidants, which forestall and slow down radical formation. Free radical-initiated oxidation is considered one of the main causes of rancidity in fats and oils. As a consequence, reliable protocols for the investigation of oil oxidation based on selective, noninvasive, and fast methods are highly desirable. Here we report an experimental approach based on UV-Vis absorbance, steady-state fluorescence, and electron paramagnetic resonance (EPR) spectroscopy for studying oxidation processes induced by temperature for a period up to 35 d on Sicilian EVOO samples. We followed the decrease in β…

Quantitative determination of casein genetic variants in goat milk: Application in Girgentana dairy goat breed

The study was conducted to develop a high-performance liquid chromatographic (HPLC) method to quantify casein genetic variants (αs2-, β-, and κ-casein) in milk of homozygous individuals of Girgentana goat breed. For calibration experiments, pure genetic variants were extracted from individual milk samples of animals with known genotypes. The described HPLC approach was precise, accurate and highly suitable for quantification of goat casein genetic variants of homozygous individuals. The amount of each casein per allele was: αs2-casein A = 2.9 ± 0.8 g/L and F = 1.8 ± 0.4 g/L; β-casein C = 3.0 ± 0.8 g/L and C1 = 2.0 ± 0.7 g/L and κ-casein A = 1.6 ± 0.3 g/L and B = 1.1 ± 0.2 g/L. A good correl…

YREE determination in seawater. Standardization and validation of a new method based on preconcentration techniques

The most interesting attraction of using rare-earth elements and yttrium (YREE) to address geochemical and marine chemical problems consists of their chemical coherence as group of trace elements. These characters allow YREE compositions of rocks and minerals to be extensively used in studies of provenance, petrogenesis and chemical evolution of the geological materials (1). Similarly, YREE compositions in the hydrosphere were used in studies of coagulation, particle-solution reactions and oceanic circulation of water masses (2-4). Unfortunately, very low concentrations of YREE (ng l-1 or sub-ng l-1) associated to high ionic strength of seawater always represented the main difficulty to ana…

Lateral habenula and hippocampal units: electrophysiological and iontophoretic study

In previous works we studied, on cats, the effects of lateral habenula (LH) stimulation on hippocampal units. In particular, the results showed an excitation or an inhibition in relation to the stimulation frequency (0.5-3.0 Hz or 5.0-20 Hz, respectively). All the LH stimulation effects were antagonised by iontophoretic intrahippocampal application of methysergide (MS). In this series of experiments it was possible to demonstrate, on rats, that LH stimulation causes an excitatory effect in a major number of hippocampal units in relation to the frequency increase. The inhibitory effect by iontophoretic serotonine application and the reversible blockade of habenular modulation after iontophor…

Effects of diet on casein and fatty acid profiles of milk from goats differing in genotype for αS1-casein synthesis

This study investigated the interactions between nutrition and the genotype at αS1-CN loci (CSN1S1) in goats, evaluating the impact of fresh forage-based diets and an energy supplement on the casein and fatty acid (FA) profiles of milk from Girgentana goats. Twelve goats were selected for having the same genotype at the αS2-CN, β- CN, and κ-CN loci and differing in the CSN1S1 genotype: homozygous for strong alleles (AA) or heterozygous for strong and weak alleles (AF). Goats of each genotype were divided into three groups and, according to a 3 × 3 Latin square design, fed ad libitum three diets: sulla fresh forage (SFF), SFF plus 800 g/day of barley (SFB), and mixed hay plus 800 g/day of ba…

Nitric oxide and glutamate interaction in the control of cortical and hippocampal excitability.

Summary: Purpose: We investigated the role of nitric oxide (NO) as a new neurotransmitter in the control of excitability of the hippocampus and the cerebral cortex, as well as the possible functional interaction between NO and the glutamate systems. Methods: The experiments were performed on anesthetized rats. The bioelectrical activities of the somatosensory cortex and the CA1 region of the hippocampus of these rats were recorded. Pharmacologic inhibition of NO synthase (NOS) through the nonselective and brain-selective inhibitors, N-nitro-L-arginine methyl ester (l-NAME) and 7-nitroindazole (7-NI), was performed. Results: The treatments caused the appearance of an interictal discharge act…

Habenular effect on hippocampal excitability is not cholinergically-mediated.

Electrophysiological and microiontophoretic analysis of the habenulo-hippocampal circuit.

In the cat, the effects of lateral habenula stimulation, at different ranges of frequency, on hippocampal units were studied. Habenular stimulation at low frequency excited, while at high frequency inhibited the greater part of hippocampal units. Moreover, in order to clarify the possible pathway involved in the habenulo-hippocampal circuit, the effects of iontophoretic acetylcholine and serotonin on hippocampal units were compared with those of habenular stimulation. Iontophoretic acetylcholine induced both excitatory and inhibitory responses while serotonin induced only inhibitory responses. Iontophoretic atropine blocked the effects of acetylcholine ejection but did not antagonize stimul…