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PubMed2000

Cocaine intake by rats correlates with cocaine-induced dopamine changes in the nucleus accumbens shell.

Extracellular dopamine levels were determined by microdialysis in the core and shell of the nucleus accumbens and the frontal cortex of rats before and after an injection of cocaine (20 mg/kg, IP). After removal of the probes, these same animals were then tested for their voluntary intake of cocaine using the two-bottle, free-choice paradigm. Baseline dopamine levels and their responses to an injection of cocaine differed among the three brain areas. No significant correlations were found between baseline dopamine levels in any of the three brain regions and the voluntary cocaine consumption. A significant negative correlation was found between cocaine-induced increases in extracellular dopamine in the shell of the nucleus accumbens and the voluntary intake of cocaine (r = -0.73, p < 0.01). No such correlations were observed in the accumbens core region or the frontal cortex. These results provide further evidence of the role of the accumbal shell region in cocaine preference, and indicate that cocaine-induced increases in dopamine levels play a role in oral cocaine self-administration or preference. In addition, this relatively novel approach in using the same animals for both cocaine induced neurotransmitter responses and cocaine preference studies can also be applied for the study of other neurotransmitters and drugs of abuse.

Animals↗

PubMed2000

Food intake after diazepam, morphine or muscimol: microinjections In the nucleus accumbens shell.

This study examined the effect on food intake of bilateral microinfusions of the benzodiazepine agents, diazepam and midazolam, the opioid agonist, morphine, and the GABA(A) agonist, muscimol into the shell of the nucleus accumbens in rats. Both muscimol (at 0.075 microg, combined bilateral dose) and morphine (1.0 microg) in the nucleus accumbens shell increased feeding as expected. However, it was clear that diazepam (2.5, 5.0, 25, 50 microg) and midazolam (7.5 microg) both failed to enhance feeding even at doses that are effective when microinjected in the brain stem. We conclude that opioid and GABA(A) agents promote feeding behavior by acting on receptors in the nucleus accumbens shell, but that benzodiazepines probably act elsewhere in the brain to increase food intake.

Animals↗

PubMedDate not supplied

D1 or D2 antagonism in nucleus accumbens core or dorsomedial shell suppresses lever pressing for food but leads to compensatory increases in chow consumption.

Although interference with dopamine (DA) systems can suppress lever pressing for food reinforcement, it is not clear whether this effect occurs because of a general disruption of food motivation. One way of assessing this has been a choice procedure in which a rat responds on an fixed ratio 5 (FR5) schedule for preferred Bioserve pellets while a less preferred lab chow is concurrently available in the operant chamber. Untreated rats consume little of the chow, preferring to respond for the Bioserve pellets. Previous studies have shown that depleting DA in the accumbens substantially decreased lever pressing while increasing chow consumption. In the present study, low doses (0.0625-1.0 microg) of the D1 antagonist SCH 23390 or the D2 antagonist raclopride were injected into the either the core or shell subregions of nucleus accumbens, and rats were tested on the concurrent lever pressing/feeding task. Analysis of the dose response curves showed that injections of SCH 23390 into the core were more potent than injections into the shell for suppressing lever pressing (i.e., the ED(50) was lower in the core). Nevertheless, injections of either drug into either site suppressed lever pressing and increased intake of the concurrently available chow. Across both drugs and at both sites, the amount of chow consumed was negatively correlated with the total number of responses. Neither drug significantly increased response duration, suggesting that accumbens DA antagonism did not produce the type of motor impairment that leads to severe alterations in the form of lever pressing. In summary, the blockade of D1 or D2 receptors in nucleus accumbens core or shell decreased lever pressing for food reinforcers, but rats remained directed toward the acquisition and consumption of food. These results indicate that accumbens D1 antagonism does not decrease lever pressing because of a general reduction in food motivation. Nevertheless, interference with accumbens DA does appear to set constraints upon which responses are selected for obtaining food, and may impair the ability of animals to overcome work-related response costs in order to obtain food.

Animals↗

PubMed2002

Both the shell of the nucleus accumbens and the central nucleus of the amygdala support amphetamine self-administration in rats.

Intracranial self-administration of drugs offers the opportunity to localize the neuronal substrates mediating the rewarding effects of drugs. The purpose of the present study was to explore whether the nucleus accumbens shell and the central nucleus of the amygdala, two components of the "extended amygdala," would support self-administration of the psychostimulant amphetamine. Male Wistar rats were trained to lever press under a Fixed Ratio 1 schedule of reinforcement for D-amphetamine injections (0, 1.0, 1.5, 2.0 and 3.0 microg/microl/inj) into either the nucleus accumbens shell or the central nucleus of the amygdala. An ascending limb dose-response function with peak responding at the 2.0 microg/microl/inj dose was obtained for self-administration at both brain sites. These results indicate that monoaminergic transmission in both the nucleus accumbens shell and the central nucleus of the amygdala mediates the rewarding effects of amphetamine. Further, the present study provides additional evidence about the functional homogeneity of the forebrain continuum called the "extended amygdala."

Amphetamine↗

PubMed2000

Protease produced by Pseudomonas aeruginosa K-187 and its application in the deproteinization of shrimp and crab shell wastes.

In addition to chitinase/lysozyme, Pseudomonas aeruginosa K-187 also produced a protease useful for the deproteinization of shrimp and crab shell wastes. The optimal culture conditions for P. aeruginosa K-187 to attain the highest protease activity were investigated and discussed. The highest protease activity was as high as 21.2 U/ml, 10-fold that (2.2 U/ml) obtained prior to optimization. The protease of P. aeruginosa K-187, produced under the optimal culture conditions, was tested for crustacean waste deproteinization. The percent of protein removal for shrimp and crab shell powder (SCSP) after 7-day incubation was 72%, while that of natural shrimp shell (NSS) and acid-treated SCSP was 78% and 45%, respectively. In contrast, with the protease produced under pre-optimization conditions, the percent of protein removal for SCSP, NSS, and acid-treated SCSP was 48%, 55%, and 40%, respectively. For comparison, three other protease-producing microbes were tested for crustacean waste deproteinization. However, they were shown to be less efficient in deproteinization than P. aeruginosa K-187. The crude protease produced by P. aeruginosa K-187 can be covalently immobilized on a reversibly soluble polymeric support (hydroxypropyl methycellulose acetate succinate). The immobilized enzyme was soluble above pH 5.5 but insoluble below pH 4.5. Immobilization efficiency was 82%. The immobilized enzyme was stable between pH 6 and 9 and at temperatures below 60 degrees C. The optimum pH and temperature for the immobilized enzyme was pH 8 and 50 degrees C. The half-life of the immobilized enzyme was 12 days, longer than that of free protease (8 days). The utilization of the immobilized enzyme for the deproteinization of SCSP has resulted in a 67% protein removal. By contrast, SCSP protein removal by using free enzymes was 72%. The protease was further purified and characterized. The purification steps included ammonium sulfate precipitation, DEAE-Sepharose CL-6B ion-exchange chromatography, and Sephacryl S-200 gel-permeation chromatography. The enzyme had a molecular weight estimated to be 58.8 kDa by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme was active from pH 7 to 9 and its optimal pH was 8.

Journal Article↗

PubMed2001

An in vitro investigation of the suitability of press-coated tablets with hydroxypropylmethylcellulose acetate succinate (HPMCAS) and hydrophobic additives in the outer shell for colon targeting.

To develop a new colon targeting formulation, which can suppress drug release completely during 12 h in the stomach and release the drug rapidly after a lag time of 3+/-1 h in the small intestine, the use of press-coated tablets with hydroxypropylmethylcellulose acetate succinate (HPMCAS) in the outer shell was investigated. The release of diltiazem hydrochloride (DIL) as a model drug contained in the core tablets in the 1st fluid (pH 1.2) was suppressed by preparing with higher compression force, but the lag time in the 2nd fluid (pH 6.8) could not exceed 1.5 h. Therefore, to improve the dissolution characteristics, the effects of addition of various hydrophobic additives to HPMCAS were examined. All of the additives examined suppressed the release rate in the 1st fluid, and prolonged the lag time in the 2nd fluid compared to HPMCAS alone. However, although none of the additives examined fulfilled all of the desired criteria, magnesium stearate (MgSt) and calcium stearate (CaSt) showed interesting effects; the former suppressed drug release completely in 1st fluid, while the latter markedly prolonged the lag time in 2nd fluid. To integrate the merits of each additive, press-coated tablets with a powder mixture of HPMCAS, MgSt and CaSt in the outer shell (HMC tablets) were prepared and in vitro tests were performed. The results indicated that HMC tablets with a mixing ratio of 80% HPMCAS, 5-15% MgSt and 15-5% CaSt in the outer shell met the desired criteria and the lag time in 2nd fluid could also be controlled from 2 to 9 h. At a mixing ratio of 80% HPMCAS, 10% MgSt and 10% CaSt, the dissolution profiles of DIL in 1st fluid and 2nd fluid were not remarkably affected by agitation intensity, and addition of bile salts, pretreatment time or anticipated higher pH except for pH 6.0, respectively. These results indicated the usefulness of HMC tablets with the desirable functions for colon-targeting formulations.

Colon↗

PubMed1997

Chronic cocaine increases neurotensin gene expression in the shell of the nucleus accumbens and in discrete regions of the striatum.

The effects of chronic cocaine administration on neurotensin (NT) mRNA expression were investigated in the rat brain using in situ hybridization. Adult Wistar rats were injected daily with cocaine (15 mg/kg i.p.) or saline for 10 days. One hour after the last injection, the brains were removed and coronal sections of the nucleus accumbens and striatum processed for in situ hybridization using a 35S-labeled NT mRNA oligonucleotide probe. Repeated administration of cocaine induced a specific increase in the expression of NT mRNA in the shell of the nucleus accumbens whereas no changes were observed in the core compartment. In addition, cocaine enhanced the expression of the NT gene in neurons confined to the posterior dorsomedial striatum, but did not alter this same region in the anterior striatum. A strong increase in NT mRNA expression was also observed in rats treated with cocaine in the ventrolateral region of the striatum, the fundus striati. No modifications were seen in the dorsolateral or ventromedial striatum, the lateral septum, or the olfactory tubercle. These findings demonstrate that cocaine affects NT mRNA expression in discrete populations of neurons confined to the shell of the nucleus accumbens and dorsomedial and ventrolateral striatum of the rat. The shell of the nucleus accumbens is a limbic area considered the locus of the reinforcing and locomotor activating properties of cocaine while the dorsal striatum is implicated in the regulation of motor output, and appears to be involved in the stereotypies induced by cocaine. The specific increases in NT gene expression induced by chronic cocaine suggest that these changes could be physiologically relevant for the behavioral effects of psychostimulant drugs.

Animals↗

PubMed2001

Organotins and imposex in the rock shell, Thais clavigera, from oyster mariculture areas in Taiwan.

The amounts of organotin compounds such as butyltins [sigma BTs: tributyl- (TBT), dibutyl- (DBT), monobutyl- (MBT)] and phenyltins [sigma PhTs: triphenyl- (TPhT), diphenyl- (DPhT) and monophenyl- (MPhT)] in rock shells, Thais clavigera, from the northern (Shiangsan), central (Lukang) and southern (Chiku) Taiwan oyster mariculture areas varied with season and location. High values of sigma BTs (mainly TBT) and low values of sigma PhTs (mainly TPhT) were found during winter (January 1999) at Shiangsan, while high amounts of sigma PhTs (mainly TPhT) and low sigma BTs (mainly TBT) were found during summer (August 1998) at Lukang. The snails were also affected by imposex. Imposex at Shiangsan, Lukang and Chiku increased from 67.1, 59.3 and 36.7% in summer to 100, 100 and 80% in winter, respectively. Relative penis size indices similar trend at Chiku site. No male displayed rock shells were found at Shiangsan and Lukang in winter. Linear correlations between pseudopenis length versus TBT (r = 0.7655, P < 0.001), DBT (r = 0.4253, P < 0.05), MBT (r = 0.5865, P < 0.01) and TPhT (r = -0.6160, P < 0.01) were obtained significant. Among 200 samples, significant positive correlations between length (pseudopenis/shell) ratio of female versus TBT (r = 0.6944, P < 0.005) and sigma BTs (r = 0.6413, r < 0.01) were also observed. The weak correlations between length (pseudopenis/shell) ratio of female versus DBT (r = 0.3085) and MBT (r = 0.4240, P < 0.1) and TPhT (-0.4917, P < 0.05; negative correlation) could indicate that DBT, MBT and TPhT have little or no effect on the development of imposex in rock shells.

Animals↗

PubMed2002

Removal of copper from aqueous solution by chitosan in prawn shell: adsorption equilibrium and kinetics.

The metal removal capability of prawn shell is evaluated in this study using copper as a model sorbate. A mild deacetylation method was used to convert chitin on the periphery of the shell to chitosan. The equilibrium and kinetic characteristics of copper adsorption on partially deacetylated prawn shell are studied in batch stirred-tank experiments. The extent of copper removal increases with an increase in pH. Both the Langmuir model with pH-dependent parameters and the extended Langmuir-Freundlich model with pH-independent parameters account very well for the measured equilibrium data. Modeling studies using two different second order surface reaction models demonstrate that transient profiles obtained experimentally for a range of initial metal concentrations (C0) and adsorbent dosage are in good agreement with calculated curves of both models. The two rate models can be used for an accurate description of measured kinetic data so long as their rate constants are properly correlated with the two system variables. In contrast, deviation exists between experimental data and theoretical curves calculated from a diffusion-based model.

Adsorption↗

PubMed2003

Dynorphinergic GABA neurons are a target of both typical and atypical antipsychotic drugs in the nucleus accumbens shell, central amygdaloid nucleus and thalamic central medial nucleus.

Administration of typical and atypical antipsychotic drugs leads to activation of cells in the nucleus accumbens shell, central amygdaloid nucleus, and midline thalamic central medial nucleus, implicating important shared effects of these drugs. However, the exact cell types responding to antipsychotic drugs in the nucleus accumbens shell, central amygdaloid nucleus, and midline thalamic central medial nucleus are unclear. We report here that, in a rat model, the results of studies using double immunofluorescence labeling with antibodies directed against markers specific to candidate cell types suggest that the cells responding to haloperidol and clozapine in all three sites are: 1) neurons, rather than astrocytes; 2) inhibitory GABA neurons, but not acetylcholinergic neurons; and 3) dynorphin-containing GABA neurons, but not M-enkephalin-containing GABA neurons. The present study provides pharmacological evidence, at the cellular level in vivo, that the shared effects of antipsychotic drugs, whether typical and atypical, is activation of dynorphinergic GABA neurons in the nucleus accumbens shell, central amygdaloid nucleus, and midline thalamic central medial nucleus. Alternative ways to modulate dynorphinergic GABA neuronal activity or its target receptors might present an important new avenue for the treatment of schizophrenia and other psychotic disorders.

Acetylcholine↗

PubMed1997

Transient increases in catecholaminergic activity in medial prefrontal cortex and nucleus accumbens shell during novelty.

Voltammetric recordings with electrochemically modified carbon-fiber electrodes were obtained from specific regions of the forebrain in rats given free-choice access to a novel environment. Entry into novelty increased the catechol signal in the medial prefrontal cortex and shell of the nucleus accumbens by more than 100%, but had no consistent effect in either the neostriatum or accumbal core. In both the medial prefrontal cortex and accumbal shell, moreover, the novelty-induced increase in catecholaminergic activity was detectable only during the initial entry into the novel compartment and did not reappear when animals returned to the familiar environment. These results support increasing evidence for a functional distinction between the accumbal core and shell, with the latter having been linked to brain reward mechanisms. The results also indicate that novelty activates, albeit very transiently, some of the same neurochemical systems believed to play a critical role in the reinforcing effects of certain drugs of abuse.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1999

Reciprocal changes in dopamine responsiveness in the nucleus accumbens shell and core and in the dorsal caudate-putamen in rats sensitized to morphine.

In this study, we describe a model of opiate sensitization characterized by a brief schedule of treatment with repeated morphine administrations. In this model, we investigated the changes produced by repeated morphine treatment on dopamine transmission at the level of the two major terminal dopaminergic areas, the dorsolateral caudate-putamen and the nucleus accumbens in its two subdivisions, the shell and the core. Rats were treated twice a day for three days with increasing doses of morphine (10, 20 and 40 mg/kg, s.c.) or with saline. After 15 days of withdrawal, rats were challenged with 1 and 5 mg/kg (s.c.) of morphine, and dopamine transmission was monitored by microdialysis. In this model, we show that repeated morphine produces a strong behavioral sensitization accompanied by increased stimulation of dopamine transmission in the core of the nucleus accumbens and in the caudate-putamen, and by a decreased stimulation of dopamine transmission in the shell of the nucleus accumbens, as compared to control rats. Moreover, we administered to these animals amphetamine (0.5 mg/kg, s.c.) and cocaine (10 mg/kg, i.p.) to assess whether cross-sensitization occurs between opiates and psychostimulants in conditions independent of the context. In the present study, we did not observe either behavioral or biochemical sensitization to amphetamine and to cocaine in rats sensitized to morphine. These results suggest that rats behaviorally sensitized to morphine show opposite changes in the stimulant effect of morphine in the nucleus accumbens shell and core and in the dorsal caudate-putamen. Moreover, this study suggests that sensitization of the dopamine system to a given agent does not necessarily extend to drugs of abuse of different pharmacological classes.

Amphetamine↗

PubMed1997

Rapid and simple determination of oxolinic acid and oxytetracycline in the shell of the blue mussel (Mytilus edulis) by high-performance liquid chromatography.

A simple procedure for the determination of oxolinic acid (OA) and oxytetracycline (OTC), two antibacterial agents, in the shell of the blue mussel (Mytilus edulis), using reversed-phase high-performance liquid chromatography is described. Liquid chromatography was performed on a 5-microm LiChroSpher 100 RP-18E column using acetonitrile and a 0.02 M orthophosphoric acid solution as the mobile phase, with ultraviolet detection. After roughly grinding the shell, drugs were extracted using a methanolic oxalic acid solution. Linearity and precision were checked over the concentration range 0.04-0.32 microg/g. Limits of detection of OA and OTC were 0.012 and 0.008 microg/g, respectively. Mean extraction recoveries of OA and OTC from mussel shell were 72.9 and 65.4%, respectively. To demonstrate the usefulness of the analytical procedure, an experimental study was performed in blue mussels exposed to the drugs for eight days.

Animals↗

PubMed2001

Drug release from and mechanical properties of press-coated tablets with hydroxypropylmethylcellulose acetate succinate and plasticizers in the outer shell.

Dissolution profiles of diltiazem hydrochloride (DIL) contained in core tablets from press-coated (PC) tablets with hydroxypropylmethylcellulose acetate succinate (HPMCAS) and plasticizers-adsorbent in the outer shell were investigated. Although, on the addition of triethyl citrate (TEC), triacetin (TA), and acetyltriethy citrate (ATEC) as plasticizers, DIL release was suppressed completely in first fluid (pH 1.2) for 10 h, it was not suppressed in HPMCAS on the addition of dibutyl sebacate (DBS) and acetylated monoglyceride. On the other hand, DIL in second fluid (pH 6.8) was released rapidly after a lag time in all the PC tablets. Water-soluble plasticizers such as TEC, TA, and ATEC showed greater compatibility to HPMCAS, and the results were consistent with suppression of DIL release in first fluid. Furthermore, as to PC tablets with HPMCAS and TEC-adsorbent, the DIL release in second fluid did not change after pretreatment in first fluid by the paddle-beads methods. To evaluate the resistance of the outer shell against such a mechanical impact, tablets with HPMCAS, HPMCAS and TEC- or DBS-adsorbent (H, HT, or HD tablets, respectively) were prepared. In compressive load-strain curves after immersion in first fluid, wet crushing strength was lower in the order of HT > H > HD tablets. Also, the curves of HT tablets at 3 and 21 h after immersion were quite different from those of other tablets, and it was hard to find crushing points. These results suggested that the resistance of the outer shell was due to plastic deformation properties involving some interaction between HPMCAS and TEC.

Cardiovascular Agents↗

PubMed1998

Enhancement of varicella-zoster virus detection in A-549 shell vials by use of freeze-thawed specimens, extended incubation, and "a centrifuged, not incubated" direct detection method.

A total of 95 clinical samples were cultured for periods of 2 and 7 days in centrifuged A-549 shell vials before and after freezing and thawing of specimens. In addition, centrifuged A-549 shell vials were tested directly for varicella-zoster virus without incubation using a direct fluorescent antibody (DFA) technique. Twenty-seven specimens were positive by at least one method. The sensitivity for DFA on unincubated A-549 shell vials was 85.2%; for unfrozen 2-day cultures, 88.9%; for unfrozen 7-day cultures, 92.6%; for freeze-thaw 2-day cultures, 92.6%; and for freeze-thaw 7-day cultures, 96.3%. Freeze-thawed specimens cultured for 7 days yielded the highest number of positive results with conspicuous cell-to-cell spread as a sign of viral replication.

Cell Line↗

PubMed1999

Tetrahydropapaveroline injected in the ventral tegmental area shifts dopamine efflux differentially in the shell and core of nucleus accumbens in high-ethanol-preferring (HEP) rats.

Since the 1970s tetrahydropapaveroline (THP) and other tetrahydroisoquinoline alkaloids have been implicated in the etiology of alcoholism. When injected into the cerebral ventricle or at specific sites in the mesolimbic system such as the ventral tegmental area (VTA), THP evokes spontaneous and intense intake of alcohol in the nondrinking animal. Further, THP evokes the extracellular efflux of dopamine in the nucleus accumbens (NAC), which comprises, in part, the postulated alcohol drinking "circuit" of neurons. The purpose of this study was to characterize the action of a THP reactive structure, the VTA, on the activity of dopamine and its metabolism in the NAC. In the anesthetized high-ethanol-preferring (HEP) rat, artificial CSF was perfused for 10 min at a rate of 10 microl per min specifically in either the core or shell of the NAC. A microbore push-pull cannula system was selected over a microdialysis probe because of its superior recovery of neurotransmitters and tip exposure of less than 1.0 mm. After a series of 5-min perfusions, a single microinjection of 5.0 microg/microl of THP was made in the ipsilateral VTA while the NAC was perfused simultaneously. Sequential samples of the NAC perfusate were assayed by an HPLC coulometric system to quantitate the concentrations of dopamine and its metabolites, DOPAC and HVA, as well as the 5-HT metabolite, 5-HIAA. The results showed that THP injected in the VTA caused a significant increase by 94 +/- 23% in the efflux of dopamine from the core of the NAC. Conversely, the THP injected identically in the VTA suppressed the efflux of dopamine within the shell of the NAC by 51 +/- 10%. The levels of DOPAC, HVA and 5-HIAA within the core and shell of the NAC generally paralleled the increase and decrease in efflux, respectively, of dopamine. CSF control injections in the VTA as well as injections outside of the VTA failed to alter dopamine or metabolite activity in the NAC. These results demonstrate that the presence of THP in the VTA alters directly the function of the pathway of mesolimbic neurons generally and the dopaminergic system specifically. That such a perturbation could account for the induction of alcohol preference is proposed in relation to a reinforcing mechanism involving opioidergic and dopaminergic elements.

Alcoholism↗

PubMed2000

The magnetic field effect affecting on the metallic chemical components of egg shell as demonstrated for breeding chicken.

The chickens were raised under fixation of the permanent magnet (80 mT) and the effect of extra magnetic field, which affects on the content of the several inorganic chemical elements of egg shell, was investigated by X-ray fluorescence spectroscopy. From 3 days after fixing the magnet, the relative concentration of Ca begun to increase. After 10 days, the relative contents of Ca were decreased, while conversely the contents of K were increased. Though there was a linear relationship between Ca content and P content in inner layer of chicken egg shell, the relationship was greatly hindered by applying the static magnetic field. The experimental result suggests that both Ca and K ion transport can be perturbed by addition of extra magnetic field in the incubation processes of chicken egg, and that Ca, P and K ions play the important role in egg shell formation.

Journal Article↗

PubMed2003

Screening molluscan cDNA expression libraries with anti-shell matrix antibodies.

In a previous paper [Marin et al., Protein Expr. Purif. 23 (2001) 175], we showed that polyclonal antibodies raised against molluscan shell matrices could be useful tools for visualizing shell proteins after a preparative fractionation of the shell matrix. In this paper, we have used the same antibodies for screening a cDNA library constructed from mantle tissues of the nacro-prismatic bivalve Pinna nobilis. The immunoscreening led to the identification of a new protein, mucoperlin [Marin et al., J. Biol. Chem. 275 (2000) 20667], which was subsequently overexpressed. A polyclonal antibody was obtained from the recombinant mucoperlin. In a control assay, we unambiguously demonstrated that this antibody and one of the sera used for the initial screening hybridize with the same clones. We assess that screening cDNA libraries with antibodies elicited against unfractionated calcifying matrices is a good alternative to oligonucleotide screening techniques, particularly in the field of molluscan biomineralization where only few gene sequences are known.

Animals↗