Recombinational and mutational analyses of subspecific differentiation in Oryza sativa L.

Recombinational and mutational analyses were performed in an attempt to elucidate the nature of the genic differences and the ancestral relationship between the indica and japonica subspecies of Oryza sativa L. by taking representative varieties from each group. The absence of cytological aberrations at meiosis in indica×japonica hybrids suggest that genetic differences are predominantly genic rather than chromosomal. The pattern of variation induced in the key characters, and the frequency and spectra of mutations obtained in each group, failed to support the hypothesis that indica has given rise to japonica, and suggested that the two subspecies have originated from a common ancestor.     

Microbiological characteristics of Crottin goat cheese made in different seasons

General profiles and effect of season on microbiological characteristics of Crottin goat's cheese were evaluated in different batches during storage. Microorganisms determined were: mesophilic, proteolytic, halotolerant, psychotrophs, coliforms, yeasts and Staphylococcus aureus. The presence of Escherichia coli, Salmonella spp., Yersinia enterocolitica and pH and moisture content were also analyzed. E. coli, Salmonella spp. and Y. enterocolitica were not detected in the Argentinian soft goat cheese. Cheese made during winter had significant differences in mesophilic, psychrotrophics, halotolerant microorganisms and yeast between batches. In fall cheese, there were significant differences to mesophilic, proteolytic and psychrotrophics. There were not significant differences to the microbial groups in summer cheese. The variability between batches in Crottin cheese occurred during cold months, which may be attributed to the coagulation process of the cheese at environmental temperature (without any control), creating a delay in the lactic flora activity in winter. The results showed a significant influence of the seasons in the microbial population evolution during storage, suggesting that the differences in each microbial group in different seasons could be caused by differences in the predominant strains of each group. Further studies are needed for the composition of the microorganisms, where goat's products have not specific hygienic and quality standards in Argentina.     

Taxonomic status of Pseudopleuronectes yokohamae and P. schrenki (Pleuronectidae sensu Cooper and Chapleau, 1998)

In studying the variation of the taxa group Pseudopleuronectes yokohamae and P. schrenki from various areas in the Sea of Japan, significant differences in the combination of morphometric and meristic characters were not revealed. It was found that typical characters such as fin coloration from the blind side of the body, number of rays in the fins, number of scales in the lateral line, etc. that are used by most authors to distinguish P. yokohamae and P. shrenki strongly vary and are not adequate for assigning individuals to a certain taxon. A conclusion of the absence of differences and, hence, the homogeneity of the group studied is supported by genetic-biochemical studies, as well as by analysis of the lateral line system of these two groups of flatfish. Considering the results obtained and literature data on the morphology and ecology of flatfish taxa considered in the paper, it is justifiable to consider the P. yokohamae + P. schrenki group as one polymorphic species Pseudopleuronectes yokohamae Günther, 1877. The second taxon, P. shrenki, as a later species, should be considered a synonym of the species P. yokohamae.     

Carterella (Rubiaceae), new genus from Baja California,Mexico

Carterella is described as a new genus based on Bouvardia alexanderae, endemic to Baja California Sur, Mexico. Closest relationships are to the Houstonia mucronata group, but qualitative differences in seed characters and striking quantitative differences in floral characters provide evidence for recognition of a new monotypic genus.     

Genome-wide selection and introgression of Chinese rice varieties during breeding

China is the largest rice-producing country, but the genomic landscape of rice diversity has not yet been clarified. In this study, we re-sequence 1070 rice varieties collected from China(400) and other regions in Asia(670). Among the six major rice groups(aus, indica-I, indica-II, aromatic, temperate japonica, and tropical japonica), almost all Chinese varieties belong to the indica-II or temperate japonica group. Most Chinese indica varieties belong to indica-II, which consists of two subgroup...     

<Emphasis Type="Italic">Pseudoscopelus sagamianus</Emphasis> Tanaka, 1908 (Chiasmodontidae): Designation of the neotype,morphological characteristics of the North Pacific population,and species variation within its whole area

North Pacific Pseudoscopelus sagamianus (from the Kuroshio zone) are characterized morphologically in detail. The neotype is established. The North Pacific population and the group of populations from the Atlantic and Indian oceans are compared in detail, significant differences are found between them in coloration of the orobranchial cavity and in the pattern of photophores of series trf and prcf. In the author’s opinion, these differences are of the subspecies level. Potential areas of subspecies are discussed, and the area of the whole species is verified. A possibility of validity of the name P. pierbartus Spitz et al., 2007, for the group of populations from the Atlantic and Indian oceans is considered. Additions and changes to methods of investigations of Pseudoscopelus suggested by Melo et al. (2007) are critically discussed.     

Syntheses of methyl ethers of methyl α-D-mannopyranoside,and hydrogen bonding in diastereoisomers of methyl 4-O-(1-ethoxyethyl)-α-D-mannopyranoside

The synthesis of the 4-methyl, the 2,4-dimethyl, and the 2,3,6-trimethyl ethers of methyl α-D-mannopyranoside has been accomplished by the use of selective, benzoyl protecting groups, the 1-ethoxyethyl protecting group, and methylation with diazomethane. Considerable differences were noted in the i.r.- and n.m.r.-spectroscopic and t.l.c. properties of the diastereoisomers of methyl 4-O-[1-ethoxyethyl]-α-D-mannopyranoside. A structure, analogous to that of trans-decalin, maintained by intramolecular hydrogen-bonding is proposed for these compounds. The differences in physical properties of the two diastereoisomers are interpreted on the basis that the (R) isomer has an axially attached methyl group, and, therefore, the ring involved cannot be so stable as that of the (S) isomer.     

Differences in the pattern visual evoked potential between pregnant and non-pregnant women

It has been proposed that latencies of some components of the pattern-reversal visual evoked potential (PRVEP) are shorter in women than in men because of differences in levels of circulating sex steroids. Pregnancy is a time when serum levels of oestrogen and progestogen are considerably greater than in the non-pregnant state. Whole and half field PRVEP latencies and amplitudes have been compared in 16 pregnant and 38 healthy non-pregnant women. The mean P100 latencies for all responses were shorter in the pregnant women, with statistically significant differences for the left eye whole field latency (P < 0.05) and the left eye right and left half field latencies (P < 0.005 and P < 0.05, respectively) and the right eye right half field latency (P < 0.05). The latencies in women in the pregnant group showed a negative correlation with gestation, which reached statistical significance for the REWF (r = −0.55, P < 0.05). These observed differences in PRVEP latencies in pregnant and non-pregnant women and the association between latency and gestation are likely to be due to differences in circulating sex steroids, and this effect may be the principal reason for latency differences between the sexes.     

Orthology, Function and Evolution of Accessory Gland Proteins in the Drosophila repleta Group

The accessory gland proteins (Acps) of Drosophila have become a model for the study of reproductive protein evolution. A major step in the study of Acps is to identify biological causes and consequences of the observed patterns of molecular evolution by comparing species groups with different biology. Here we characterize the Acp complement of Drosophila mayaguana, a repleta group representative. Species of this group show important differences in ecology and reproduction as compared to other Drosophila. Our results show that the extremely high rates of Acp evolution previously found are likely to be ubiquitous among species of the repleta group. These evolutionary rates are considerably higher than the ones observed in other Drosophila groups' Acps. This disparity, however, is not accompanied by major differences in the estimated number of Acps or in the functional categories represented as previously suggested. Among the genes expressed in accessory glands of D. mayaguana almost half are likely products of recent duplications. This allowed us to test predictions of the neofunctionalization model for gene duplication and paralog evolution in a more or less constrained timescale. We found that positive selection is a strong force in the early divergence of these gene pairs.     

Studien zur Sozialisation von Pfirsichköpfchen (Agapornis fischeri) nach der Nestlingsphase – Volierenbeobachtungen

Some observations on the socialization of five young Peach-faced Lovebirds (Agapornis fischeri) within an aviary group of seven adult birds are described. Group 1 consisted of two fledglings with a parent pair, group 2 included three fledglings with an unmated mother. Socialization and behavioural development of both groups are described and compared.In comparison with the Rosy-faced Lovebirds (Agapornis roseicollis) there are only few differences. They mainly concern the territoriality of the young parrots in and around the nestbox. Otherwise the three main phases (family phase, transitional phase, mating phase) are nearly identical and show only short differences in time.     

Functional Deficits in Pak5, Pak6 and Pak5/Pak6 Knockout Mice

The p21-activated kinases are effector proteins for Rho-family GTPases. PAK4, PAK5, and PAK6 are the group II PAKs associated with neurite outgrowth, filopodia formation, and cell survival. Pak4 knockout mice are embryonic lethal, while Pak5, Pak6, and Pak5/Pak6 double knockout mice are viable and fertile. Our previous work found that the double knockout mice exhibit locomotor changes and learning and memory deficits. We also found some differences with Pak5 and Pak6 single knockout mice and the present work further explores the potential differences of the Pak5 knockout and Pak6 knockout mice in comparison with wild type mice. The Pak6 knockout mice were found to weigh significantly more than the other genotypes. The double knockout mice were found to be less active than the other genotypes. The Pak5 knockout mice and the double knockout mice performed worse on the rotorod test. All the knockout genotypes were found to be less aggressive in the resident intruder paradigm. The double knockout mice were, once again, found to perform worse in the active avoidance assay. These results indicate, that although some behavioral differences are seen in the Pak5 and Pak6 single knockout mice, the double knockout mice exhibit the greatest changes in locomotion and learning and memory.     

The metabolism of 3,5-di-tert.-butyl-4-hydroxytoluene in the rat and in man

1. The major metabolites of 3,5-di-tert.-butyl-4-hydroxytoluene (BHT) in the rat are 3,5-di-tert.-butyl-4-hydroxybenzoic acid (BHT-acid), both free (9% of the dose) and as a glucuronide (15%), and S-(3,5-di-tert.-butyl-4-hydroxybenzyl)-N-acetylcysteine. 2. The mercapturic acid does not appear to derive from the usually accepted enzyme mechanism, and may involve a non-enzymic reaction between BHT free radical and cysteine. 3. The ester glucuronide and mercapturic acid found in rat urine are also the major metabolites in rat bile and must be responsible for the enterohepatic circulation. 4. Free BHT-acid is the main component in rat faeces. 5. In man, BHT-acid, free and conjugated, is a minor component in urine, and the mercapturic acid is virtually absent. The bulk of the radioactivity is excreted as the ether-insoluble glucuronide of a metabolite in which the ring methyl group and one tert.-butyl methyl group are oxidized to carboxyl groups, and a methyl group on the other tert.-butyl group is also oxidized, probably to an aldehyde group. 6. These differences in metabolism by the rat and by man are sufficient to account for the difference in excretion by the two species.     

Differentiation among five Spanish Pinus pinaster provenances based on its oleoresin terpenic composition

The aim of this work is to establish the difference among several Spanish Pinus pinaster provenances, on the basis of its oleoresin chemical composition.Oleoresin of five P. pinaster provenances in three experimental plantation areas has been studied. Monoterpenes, sesquiterpenes, neutral diterpenes and resin acids are the main components. The compounds allowing the establishment of differences between provenances are isopimaric acid and α-pinene, whereas the differentiation between plots is established by pimaric acid and noracid 2. Provenances best differentiated are Ponteareas (Atlantic group) and Cómpeta (Maghrebian group).     

Description of new taxa of Halenia Borkh. (Gentianaceae) from Colombia and Venezuela with significance for testing a key innovation hypothesis

As a result of an ongoing complete taxonomic revision of Halenia (Gentianaceae), the new taxa Halenia perijana K.B. Hagen and H. major subsp. meridensis K.B. Hagen are described from Colombia and Venezuela, respectively. Flower morphology suggests that both taxa belong to the Halenia viridis group. H. perijana is vegetatively well separated from its probable closest relatives, and the only member of Halenia from a small and rather isolated mountain range. The new subspecies meridensis has small remnants of nectary spurs, and probably links the unspurred viridis group to its prominently spurred Central American sister group. Previous molecular clock approaches showed that the viridis group arrived in South America approximately at the same time as the weddelliana group, the distantly related second major South American group, which contains species with prominent spurs. Based on the new extensive knowledge of all species, the distribution patterns of both groups in Colombia and Venezuela are compared. The existence of marked differences—weddelliana group species grow in sympatry more often than species of the viridis group—is consistent with a key innovation effect of the presence/absence of nectary spurs, i.e., the reduction of pollinator overlap mediated by the presence of nectary spurs may allow sympatric speciation or remigration after a shorter phase of allopatric differentiation. However, this new evidence is relatively weak due to lack of statistical support and several other unresolved problems.     

Taxonomic affinities ofPhysena (Physenaceae) andAsteropeia (Theaceae)

Asteropeia andPhysena are both enigmatic woody dicotyledons from Madagascar. Various taxonomic affinities have been suggested for both genera, but no consensus has been reached. An analysis of rbcL sequence data strongly supports recognition of the sister-group relationship ofAsteropeia andPhysena and their placement as the sister group to Caryophyllales. Many similarities were noted betweenAsteropeia andPhysena for stem, wood, leaf, flower, pollen, and fruit characters. The most notable differences are found in the morphology of the flowers and the anatomy of the wood rays.     

Biological mechanisms related to differences in residual feed intake in dairy cows

Residual feed intake (RFI), defined as the difference between an animal’s actual feed intake and expected feed intake over a specific period, is an inheritable character of feed conversion efficiency in dairy cows. Research has shown that a lower RFI could improve the profitability of milk production. This study explored variation in RFI by comparing the differences in body size, milk performance, feeding behavior, and serum metabolites in 29 Holstein cows in mid lactation. The cows were selected from a total of 84 animals based on their RFI following feedlot tests. Selected cows were ranked into high RFI (RFI >1 SD above the mean, n=14) and low RFI (RFI<1 SD below the mean, n=15). The low RFI cows (more efficient) consumed 1.59 kg/day less dry matter than the high RFI group (P<0.01), while they produced nearly equal 4% fat-corrected milk. The milk : feed ratio was higher for the low RFI group than for the high RFI group (P<0.05). The levels of milk protein (P<0.01), total solids (P<0.05), and nonfat solids (P<0.05) were also higher for the low RFI group, whereas milk urea nitrogen was lower (P<0.01). The daily feeding duration was shorter for the low RFI group than for the high RFI group (P<0.01). No significant differences were found in levels of glucose, β-hydroxybutyrate, prolactin, insulin, IGF-1, growth hormone or ghrelin, but the level of neuropeptide Y was higher (P<0.01) and levels of leptin and non-esterified fatty acid (P<0.05) were lower for the low RFI group than for the high RFI group. There were substantial differences between cows with different RFI, which might affect the efficiency of milk protein metabolism and fat mobilization.     

Extrinsic and intrinsic influences on the phylogeography of the Austrocochlea constricta species group

Although extrinsic factors, such as oceanic currents and isolation induced by sea level maxima during Plio-Pleistocene glacial cycles, are often suggested as principal determinants of marine phylogeography, they are not always complete explanations. The counterexamples to predominant phylogeographic patterns in southeastern Australia suggest for example, that intrinsic factors such a habitat preference or reproductive mode can have significant influence.We collected DNA sequences from mitochondrial cytochrome c oxidase I (COI) and two nuclear gene introns from the Austrocochlea constricta species group to determine whether its porcata and constricta phenotypes are genetically distinguishable, to examine the phylogeographic effects of the Bassian Isthmus landbridge formed between Tasmania and Victoria during glacial maxima, and to investigate the importance of intrinsic factors in structuring its genetic variability.No fixed genetic differences between the porcata and constricta phenotypes were identified in any gene so the number of species comprised by the group cannot yet be determined. The two major clades recovered in COI analyses were respectively found principally east or west of the Bassian Isthmus. A. constricta is the first lecithotrophic or estuarine invertebrate known to show this pattern. There were no fixed differences, for any of the three genes, between specimens from estuarine and marine populations within either the eastern or western COI clades. Other intrinsic factors such as breeding period (possibly) and larval type (probably) may play roles in modulating phylogeographic patterns.     

Group differences in the heritability of items and test scores

It is important to understand potential sources of group differences in the heritability of intelligence test scores. On the basis of a basic item response model we argue that heritabilities which are based on dichotomous item scores normally do not generalize from one sample to the next. If groups differ in mean ability, the functioning of items at different ability levels may result in group differences in the heritability of items, even when these items function equivalently across groups and the heritability of the underlying ability is equal across groups. We illustrate this graphically, by computer simulation, and by focusing on several problems associated with a recent study by Rushton et al. who argued that the heritability estimates of items of Raven''s Progressive Matrices test in North-American twin samples generalized to other population groups, and hence that the population group differences on this test of general mental ability (or intelligence) had a substantial genetic component. Our results show that item heritabilities are strongly dependent on the group on which the heritabilities were based. Rushton et al.''s results were artefactual and do not speak to the nature of population group differences in intelligence test performance.