Origin and properties of non-coding ORFs in the yeast genome.

In a recent paper we have estimated the total number of protein coding open reading frames (ORFs) in the Saccharomyces cerevisiae genome, based on their properties, at about 4800. This number is much smaller than the 5800-6000 which is widely accepted. In this paper we analyse differences between the set of ORFs with known phenotypes annotated in the Munich Information Centre for Protein Sequences (MIPS) database and ORFs for which the probability of coding, counted by us, is very low. We have found that many of the latter ORFs have properties of antisense sequences of coding ORFs, which suggests that they could have been generated by duplication of coding sequences. Since coding sequences generate ORFs inside themselves, with especially high frequency in the antisense sequences, we have looked for homology between known proteins and hypothetical polypeptides generated by ORFs under consideration in all the six phases. For many ORFs we have found paralogues and orthologues in phases different than the phase which had been assumed in the MIPS database as coding.     

Acetaldehyde kinetics of enological yeast during alcoholic fermentation in grape must

Acetaldehyde strongly binds to the wine preservative SO₂ and, on average, causes 50–70 mg l^?1 of bound SO₂ in red and white wines, respectively. Therefore, a reduction of bound and total SO₂ concentrations necessitates knowledge of the factors that affect final acetaldehyde concentrations in wines. This study provides a comprehensive analysis of the acetaldehyde production and degradation kinetics of 26 yeast strains of oenological relevance during alcoholic fermentation in must under controlled anaerobic conditions. Saccharomyces cerevisiae and non-Saccharomyces strains displayed similar metabolic kinetics where acetaldehyde reached an initial peak value at the beginning of fermentations followed by partial reutilization. Quantitatively, the range of values obtained for non-Saccharomyces strains greatly exceeded the variability among the S. cerevisiae strains tested. Non-Saccharomyces strains of the species C. vini, H. anomala, H. uvarum, and M. pulcherrima led to low acetaldehyde residues (<10 mg l^?1), while C. stellata, Z. bailii, and, especially, a S. pombe strain led to large residues (24–48 mg l^?1). Acetaldehyde residues in S. cerevisiae cultures were intermediate and less dispersed (14–34 mg l^?1). Addition of SO₂ to Chardonnay must triggered significant increases in acetaldehyde formation and residual acetaldehyde. On average, 0.33 mg of residual acetaldehyde remained per mg of SO₂ added to must, corresponding to an increase of 0.47 mg of bound SO₂ per mg of SO₂ added. This research demonstrates that certain non-Saccharomyces strains display acetaldehyde kinetics that would be suitable to reduce residual acetaldehyde, and hence, bound-SO₂ levels in grape wines. The acetaldehyde formation potential may be included as strain selection argument in view of reducing preservative SO₂ concentrations.     

Brief communication: immunoglobulin (Gm and Km) allotypes in two populations of Catalonia (Spain)

Serum samples from two populations of Catalonia, Spain, 208 from Olot (Gerona) and 209 from Tortosa (Tarragona), were typed for G1m (1, 2, 3, 17), G3m (5, 10, 11, 13, 14, 15, 16, 26), and Km (1). The Gm patterns of the Catalonian populations are characterized by the presence of four haplotypes, Gm 1,17;21,26 Gm 1,2,17;21,26 Gm 1,3;5,10,11,13,14,26 and Gm 3;5,10,11,13,14,26. The homogeneity for haplotype Gm 1,17;21,26 among our data and other European populations suggests the existence of an isofrequency line which starts from the Mediterranean zone of Iberian Peninsula and continues through the northwestern part of Europe. From this line a decreasing cline towards the south can be observed. For the haplotype Gm 1,2;17,21,26, affinities are observed between Catalonian populations and other populations from central Europe. This confirms the existence of a gradient towards low values from NW to SE. The presence of the typical Mongoloid haplotype Gm 1,3;5,10,11,13,14,26 is discussed in this paper. No significant differences in the frequencies of the Km1 allele were observed among the European populations.     

Study of transferrin (TF), group specific component (GC) and alpha-1-antitrypsin (PI) subtypes in the populations of Basque country (Spain)

Genetic polymorphisms of three serum proteins Transferrin (TF), Group Specific Component (GC), and Alpha-l-Antitrypsin were investigated by isoelectric focusing (IEF) in the Basque and non Basque populations from Vizcaya and Guipuzcoa, Spain. Two of the three genetic systems (TF and PI) showed conclusive genetic heterogeneity between the Basque populations of these two provinces. In addition to the past genetic drift, the present day genetic differentiation in the Basque country seems to be contributed by the unique structure of its populations.     

Mathematical properties of Fst between admixed populations and their parental source populations

We consider the properties of the F(st) measure of genetic divergence between an admixed population and its parental source populations. Among all possible populations admixed among an arbitrary set of parental populations, we show that the value of F(st) between an admixed population and a specific source population is maximized when the admixed population is simply the most distant of the other source populations. For the case with only two parental populations, as a function of the admixture fraction, we further demonstrate that this F(st) value is monotonic and convex, so that F(st) is informative about the admixture fraction. We illustrate our results using example human population-genetic data, showing how they provide a framework in which to interpret the features of F(st) in admixed populations.     

Craniometric variability in two populations of roe deer (Capreolus capreolus) from Spain

Two populations of roe deer from Spain, approximately 300 km apart from each other and currently recognized as separate subspecies. were studied to analyse the nature of the morphological differences between these populations and to assess the validity of its taxonomic division. Sixty-one skulls of roc deer from the Occidental Cantabric Mountains (OCM) and 17 from the Northern lberic Mountains (NIM) were used. No significant sexual dimorphism allowed pooling of male and female samples, on which a large set of 53 measurements was taken. Skulls from the OCM population are, on average, 1·9% larger than those from the NIM population. Twenty-five out of the 53 characters showed some degree of significant differences between means of both populations, though only four showed highly significant differences. Mandible characters were the most variable traits, showing also significant differences between populations. Eight principal factors were extracted. explaining a total of 84·7% of the sample variance. An ANOVA of factor scores from each population revealed significant differences in PF 1 and PF 3. Interpretation of these two factors suggests that morphological differences between both populations can be summarized as specimens from OCM having larger mandibles and broader neurocranium than specimens from NIM. Mandible differences might reflect morphological adaptations to favour the consumption of ligneous plants, which are more frequently eaten by the OCM roe deer population, whereas a broader neurocranium might be related to antler size. It is concluded that biometric differences observed in skulls from these two populations only reflect minor morphological adaptations to different habitats, thus. there is a lack of morphological data to support the taxonomic distinction of the OCM population as a separate subspecies.     

Spatio-temporal genetic variability in sea trout (Salmo trutta) populations from north-western Spain

1. Genetic variation at five microsatellite loci was investigated in six sea trout ( Salmo trutta ) populations to describe their spatio-temporal genetic variation in north-western Spain. We observed significant genetic variation between river basins, and isolation by distance with restricted gene flow between neighbouring rivers, which suggests an important homing behaviour.
2. Despite these populations suffering a serious demographic decline during 1998, we did not detect any reduction in their genetic variation, suggesting a reasonably high effective population size and temporal stability.
3. Genetic differences among rivers should be taken into account in future management activities. Given the high genetic variability and the temporal stability observed, we believe that no supportive breeding programmes are presently needed in these populations.     

Genetic diversity of wild grapevine populations in Spain and their genetic relationships with cultivated grapevines

The wild grapevine, Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi, considered as the ancestor of the cultivated grapevine, is native from Eurasia. In Spain, natural populations of V. vinifera ssp. sylvestris can still be found along river banks. In this work, we have performed a wide search of wild grapevine populations in Spain and characterized the amount and distribution of their genetic diversity using 25 nuclear SSR loci. We have also analysed the possible coexistence in the natural habitat of wild grapevines with naturalized grapevine cultivars and rootstocks. In this way, phenotypic and genetic analyses identified 19% of the collected samples as derived from cultivated genotypes, being either naturalized cultivars or hybrid genotypes derived from spontaneous crosses between wild and cultivated grapevines. The genetic diversity of wild grapevine populations was similar than that observed in the cultivated group. The molecular analysis showed that cultivated germplasm and wild germplasm are genetically divergent with low level of introgression. Using a model‐based approach implemented in the software structure , we identified four genetic groups, with two of them fundamentally represented among cultivated genotypes and two among wild accessions. The analyses of genetic relationships between wild and cultivated grapevines could suggest a genetic contribution of wild accessions from Spain to current Western cultivars.     

Variation in populations of Cepaea nemoralis (L.) in North Spain

In a survey of 105 populations of Cepaea nemoralis sampled in North Spain, the distribution of morph polymorphism seems to have a climatic component. The area sampled corresponds with the two main climatic regions in the Iberian Peninsula: Green and Brown Iberia, which have an Atlantic and Continental climate, respectively. Paler colour and banding phenotypes are found in the Atlantic zone, while the dark ones are commoner in Brown Iberia. This may arise from climatic selection related to behaviour patterns, which may be particularly important in limiting situations with harsh climates.     

Reproductive pattern in agrarian and immigrant receptor populations: a survey of El Ejido (SE Spain)

This paper deals with the fertility pattern of the El Ejido population, an agricultural Spanish community characterised by the rapid development of its modern agrarian economy. Consequently, the arrival of immigrants has sharply increased throughout the second half of the twentieth century, with important demographic consequences as well as reproductive changes. The analyses of the age-specific fertility rate (fx) and the total fertility rate (TFR) were used in order to describe the reproductive pattern of this population in 2000. The main characteristics were the following: a) Regarding the temporal change, an important decrease of fx has been observed in all age groups for the last twenty years, as a consequence of progressive birth control. However, the reproductive pattern has kept almost invariable and has been characterised by a maximum fertility at age group of 25-29 years old. b) Regarding the general Spanish fertility, the comparison of fx in both populations suggests a younger maternity in the agricultural population than in the national, the maximum fertility delayed to the 30-34 age group. c) Moreover, the El Ejido population showed a clear higher offspring per woman (TFR = 1.42) than the national (TFR = 1.24), according to the agrarian character of the El Ejido population. d) Finally, this greater reproductive level of El Ejido is also due to the arrival of women at fertile age, who come mainly from Africa, and above all from Morocco.     

Assimilation of grape phytosterols by Saccharomyces cerevisiae and their impact on enological fermentations

Although yeasts are known to be able to incorporate a wide variety of exogenous sterols under strict anaerobiosis, no data are available on the assimilation of grapevine phytosterols under enological conditions and the eventual impact on fermentation kinetics. We used therefore a mixture of pure phytosterols, in a proportion representative of the different grape skins phytosterols, to supplement a synthetic fermentation medium simulating a grape must. Under anaerobiosis, normal biomass formation was achieved with 5 mg phytosterols l^–1. Similar results were obtained in comparison with the observed maximal fermentation rates. These results clearly indicated that grape phytosterols may efficiently act as a substitute for ergosterol in the yeast membrane for promoting yeast growth and initial fermentative activity. Analysis of total yeast sterols indicated that phytosterols are accumulated without further modification, mainly in their esterified form. However, all the fermentations performed with synthetic media supplemented with phytosterols led to stuck fermentations, linked to a correlative strong decrease in cell viability during the stationary phase. Therefore, grape phytosterols are easily incorporated by yeast cells under enological conditions for promoting initial growth and fermentative activity, but rapidly perturb the yeast membrane properties by being the predominant sterols.     

Mutant allele frequencies in domestic cat populations in Catalonia,Spain, and their genetic relationships with Spanish and English colonial cat populations

Two Catalan cat populations (Spain) were analyzed. The genetic profiles of these Catalan populations are very homogeneous. The low q (t ^b) values are the most outstanding factor. These populations and two British cat populations were compared with different colonial settlement cat populations. A close genetic relationship was found between Catalan populations and those of California, Texas, Colorado, Mexico and the North of South America (Caracas and Willemstad (Curaçao)).     

Spatial and temporal variations of Chondrus crispus (Gigartinaceae, Rhodophyta) carrageenan content in natural populations from Galicia (NW Spain)

Qualitative and quantitative differences in carrageenan composition of gametophytes and tetrasporophytes of Chondrus crispus were observed in this study. Carrageenans in gametophytes belong to the kappa family (κ-, ι-, ν- and μ-carrageenan). The dominant fractions were κ- and ι-carrageenan (more than 50% of the total carrageenans). In tetrasporophytes, the presence of λ-carrageenan was confirmed. Carrageenan content in gametophytes (37.4?±?1.68% DW) was higher than in tetrasporophytes (29.13?±?0.76% DW). Spatial and temporal variation in carrageenan content in both life cycle phases appears to be related mainly to seawater and air temperatures, insolation, water movement and desiccation. The highest values of carrageenan content were recorded in those localities where higher values of precipitation, wind speed or water movement occurred. A bimodal temporal pattern on carrageenan content was observed. Fronds showed a high carrageenan content in spring and autumn. During these seasons, the content was over 40% in gametophytes and 30% in the tetrasporophytes. In summer and winter, these values down in both life cycle phases below 30%. In general the highest carrageenan contents were related to highest seawater temperatures. On the contrary, high air temperature and high insolation appeared to be unfavourable for carrageenan production. GLM models were obtained to predict carrageenan production from natural C. crispus populations, along Galician coast.     

Methylated cycloamyloses (cyclodextrins) and their inclusion properties

2,3,6-Tri-O-methyl and 2,6-di-O-methyl derivatives of cyclohexa- and cyclo-hepta-amylose (2,3,6-tri-O-methyl- and 2,6-di-O-methyl-α- and -β-cyclodextrin) have been prepared and shown to be versatile complexing agents. Their complexes in aqueous solution are usually more stable than the corresponding complexes of un-substituted cycloamyloses. The methylated cycloamyloses also form crystalline complexes, the stability of which depends on the size and shape of the guest molecule. The decomposition temperature of the crystalline complexes with homologous n-alkanes, which is relatively high increases with increasing chain-length of the hydro-carbon. The shift of the i.r. carbonyl band of oleic acid in its solid complex with methylated α-cyclodextrin probably reflects inclusion of the fatty acid in the mono-meric form. The methylated cycloamyloses, when used as the stationary phases for g.l.c. or dissolved in a conventional stationary phase, affect the retention times of organic compounds in a manner which suggests that inclusion phenomena are operative.     

Toxin profiles of natural populations and cultures ofAlexandrium minutum Halim from Galician (Spain) coastal waters

The toxin profiles of three isolates and natural populations of the PSP agentAlexandrium minutum from several Galician rías (NW Spain) was obtained by HPLC. The toxin content of cultures ofA. minutum is dominated by GTX4 (80–90%) and GTX4 (10–15%) with small amounts of GTX3 and GTX2 (less than 3% of each); similar results were obtained for natural populations ofAlexandrium from three different Galician rías, where a mixture ofA. lusitanicum Balech andA. minutum can occur. Important quantitative differences were found between the three isolates, one being highly and two weakly toxic. The results obtained from these isolates and natural populations ofAlexandrium were very similar to those obtained from HPLC analyses of mussels intoxicated during a PSP outbreak in Ría de Ares (Rías Altas) in 1984, confirming thatA. minutum (previously identified asGonyaulax tamarensis Lebour andAlexandrium lusitanicum) was the PSP agent during the toxic outbreak in May 1984. Toxin profiles obtained from natural populations during different PSP outbreaks in different rías and from cultures are fairly consistent and suggest that at least from the toxin point of view,A. lusitanicum andA. minutum are identical, and that the toxin profile ofA. minutum from Galicia can be used as a biochemical marker.     

Ribonuclease isolated from yeast (Saccharomyces carlsbergensis): Characterization and properties

The homogeneity of a purified ribonuclease from brewers' yeast was determined by velocity sedimentation and polyacrylamide gel electrophoresis techniques. The velocity sedimentation pattern gave a single peak with a S_app 3.46 and polyacrylamide gel electrophoresis showed one major band. The absorption spectrum of the enzyme showed maximum absorption at 277–278 nm and minimum at 252 nm. The enzyme was relatively stable to extreme pH values and high temperature. Both NaCl and KCl increased the enzyme activity whereas enzyme was inhibited by divalent metal ions. The inhibition of the enzyme was increased in the order of Ca²⁺ > Mg²⁺ > Fe²⁺Cu²⁺. Chemical modification studies of the enzyme showed that tryptophan residues and disulfide bonds were required for enzyme activity.     

Origin and migration of woodcock Scolopax rusticola wintering in Spain

Woodcock Scolopax rusticola is an important game species in Northern Spain, where it is mainly a wintering species. Knowledge about the migration and origin of the woodcock wintering in Spain is relatively sparse, existing to date only qualitative analyses dating more than a decade. From the analyses of ringing recoveries of woodcock wintering in Spain, we evaluate the relative importance of various countries or regions as sources of the woodcock wintering in Spain, an estimate of their migratory route. Our analyses show the Circum-Baltic Region to be the most important breeding area of the woodcock wintering in Spain. Within that area, both Sweden and Western Russia appear to be particularly important. Analyses of the ringing locations of woodcock ringed during migration and recovered in Spain in winter suggest that woodcock wintering in Spain migrate primarily through the South of the Baltic Sea, Germany and France. The proportion of woodcock ringed in different French regions during the postnuptial migration months (October and November) that was subsequently recovered in Spain (mainly through hunting) declined with the proportion of those birds that was recovered in France (also mainly through hunting). We discuss the management implications of these results.