Population morphometric variation of the endemic freshwater killifish, <Emphasis Type="Italic">Fundulus lima</Emphasis> (Teleostei: Fundulidae), and its coastal relative <Emphasis Type="Italic">F. parvipinnis</Emphasis> from the Baja California Peninsula,Mexico

The population morphometric variation of the endangered freshwater killifish (Fundulus lima) was evaluated and compared with that of its euryhaline coastal relatives (F. parvipinnis parvipinnis and F. p. brevis) on the basis of 384 specimens from the Baja California peninsula, Mexico. Forty five standardized body distances were compared by means of discriminant function analysis (DFA). Sixteen body distances were significant to distinguish two groups of populations for F. lima: a first group represented by the Bebelamas and San Javier basins, and second group composed by the basins of San Ignacio, La Purísima, San Luis, San Pedro and Las Pocitas. When all freshwater and coastal populations were compared, the southernmost population of F. lima (Las Pocitas) showed a higher morphometric similarity with the southern coastal subspecies (F. p. brevis), while another southern population (San Pedro) had an intermediate position between the freshwater and coastal forms. This study suggests the presence of five evolutionary units (three freshwater and two coastal) for the genus Fundulus in the Baja California peninsula.     

Isolation and characterization of a highly polymorphic human locus (DXS455) in proximal Xq28

Human Xq28 is highly gene dense with over 27 loci. Because most of these genes have been mapped by linkage to polymorphic loci, only one of which (DXS52) is informative in most families, a search was conducted for new, highly polymorphic Xq28 markers. From a cosmid library constructed using a somatic cell hybrid containing human Xq27.3----qter as the sole human DNA, a human-insert cosmid (c346) was identified and found to reveal variation on Southern blot analyses with female DNA digested with any of several different restriction endonucleases. Two subclones of c346, p346.8 and p346.T, that respectively identify a multiallelic VNTR locus and a frequent two-allele TaqI polymorphism were isolated. Examination of 21 unrelated females showed heterozygosity of 76 and 57%, respectively. These two markers appeared to be in linkage equilibrium, and a combined analysis revealed heterozygosity in 91% of unrelated females. Families segregating the fragile X syndrome with key Xq28 crossovers position this locus (designated DXS455) between the proximal Xq28 locus DXS296 (VK21) and the more distal locus DXS374 (1A1), which is proximal to DXS52. DXS455 is therefore the most polymorphic locus identified in Xq28 and will be useful in the genetic analysis of this gene dense region, including the diagnosis of nearby genetic disease loci by linkage.     

Rhythmical timing and spatial scattering of foraging in a homer limpet {Patella rustica)

Homing to a more or less permanent scar after each foragingexcursion is a common movement pattern among intertidal gastropodsand chitons; however, details of the timing and spacing of foragingactivity have been investigated only in a few species. The presentstudy analyzes the short-term behavior of the limpet Patellarustica along the Tyrrhenian coast, Italy, using a motographictechnique to assess the fine organization of its foraging duringfavorable periods of sea roughness. P. rustica becomes activeonce the upper midlittoral is well splashed. It alternates foragingexcursions and resting at home with a periodicity slightly longerthan 12 h, suggesting a tidal-diel pattern. However, periodogramanalysis of the sea level oscillations during the study periodsrevealed no such rhythmicity because tidal oscillations werehidden by irregular variations caused by waves. As a resultof this time partitioning, limpets move, on average, less than50% of their potential activity time. Time partitioning maybe highly adaptive in reducing potential risks. Nevertheless,in the absence of clear external driving cues, the significanceof a very regular and apparently tidal pattern, fairly synchronousamong the different specimens, remains to be explained. Theactivity of P. rustica during each excursion is organized intothree parts: the outgoing journey during which grazing activityprogressively increases, a central part characterized by intensegrazing, and the return characterized by fast displacement anda more or less consistent trail following. Limpets head forrandom directions to reach foraging grounds in successive excursions,showing only a slight avoidance of the direction taken duringthe previous outward journey. This pattern produces a spatialscattering of grazing activity, allowing efficient exploitationof grazing areas distributed radially around home during subsequentexcursions.     

Heme methyl 1H chemical shifts as structural parameters in some low-spin ferriheme proteins

 The different paramagnetic shifts of the four methyl groups in ferriheme proteins have been described as being due to the effect of the axial ligand nodal plane orientation. An equation, heuristically found and theoretically explained, describing the relation between contact and pseudocontact shifts and the position of the axial ligand(s) has been derived for bis-histidine ferriheme proteins and for cyanide-histidine ferriheme proteins. The values of the heuristic parameters contained in the equations were found by fitting the shifts of bovine cytochrome b ₅ and several bis-histidine cytochromes c ₃ and histidine-cyanide systems. The agreement between the observed and the calculated shifts was found to be good. Therefore, by taking advantage of this study, information on the position of the axial ligands, that can be used as a constraint for structure determination, can be obtained from the shifts of the methyl protons. Received: 13 April 1999 / Accepted: 4 June 1999     

Comparative neurochemical features of the innervation patterns of the gut of the basal actinopterygian,Lepisosteus oculatus,and the euteleost,Clarias batrachus

The structure and physiology of enteric system are very similar in all classes of vertebrates, although they have been investigated only occasionally in non‐mammalian vertebrates. Very little is known about the distribution of the neurotransmitters in the gut of actinopterygian fishes. Anatomical and physiological studies of enteric nervous systems in the spotted gar (Lepisosteus oculatus) and airbreathing catfish (Clarias batrachus), a non‐teleost and teleost actinopterygian, respectively, have not been undertaken. This study provides the first comprehensive characterization of the range of neurochemical coding in the enteric nervous system of these two species, including the chemical diversity of the mucosal endocrine cells in the pyloric stomach of Clarias. Autonomic innervation of the secretory glands is also described and reported herein for the first time for fishes. We also report splanchnic (spinal) innervation of the stomach, submucosal ganglia (that also colocalize with nNOS) and caudal intestine of Clarias. In both fish species, numerous 5HT, ChAT, nNOS and TH‐positive nerve fibres have been observed. These discoveries demonstrate that much more physiological and pharmacological data are needed before a comprehensive model of enteric nervous system control in vertebrates can be developed.     

Comparative analysis of the human dystrophin and utrophin gene structures

We present analysis of intronic sequences in the human DMD and UTRN genes. In both genes accumulation of repeated elements could account for intron expansion. Out-of-frame rod-domain exons have stronger splice sites and are separated by significantly longer introns as compared to in-frame exons. These features are unique for the two homologs and not shared by other spectrin superfamily genes.     

Host Genetic Background Influences the Response to the Opportunistic Pseudomonas aeruginosa Infection Altering Cell-Mediated Immunity and Bacterial Replication

Pseudomonas aeruginosa is a common cause of healthcare-associated infections including pneumonia, bloodstream, urinary tract, and surgical site infections. The clinical outcome of P. aeruginosa infections may be extremely variable among individuals at risk and patients affected by cystic fibrosis. However, risk factors for P. aeruginosa infection remain largely unknown. To identify and track the host factors influencing P. aeruginosa lung infections, inbred immunocompetent mouse strains were screened in a pneumonia model system. A/J, BALB/cJ, BALB/cAnNCrl, BALB/cByJ, C3H/HeOuJ, C57BL/6J, C57BL/6NCrl, DBA/2J, and 129S2/SvPasCRL mice were infected with P. aeruginosa clinical strain and monitored for body weight and mortality up to seven days. The most deviant survival phenotypes were observed for A/J, 129S2/SvPasCRL and DBA/2J showing high susceptibility while BALB/cAnNCrl and C3H/HeOuJ showing more resistance to P. aeruginosa infection. Next, one of the most susceptible and resistant mouse strains were characterized for their deviant clinical and immunological phenotype by scoring bacterial count, cell-mediated immunity, cytokines and chemokines profile and lung pathology in an early time course. Susceptible A/J mice showed significantly higher bacterial burden, higher cytokines and chemokines levels but lower leukocyte recruitment, particularly neutrophils, when compared to C3H/HeOuJ resistant mice. Pathologic scores showed lower inflammatory severity, reduced intraluminal and interstitial inflammation extent, bronchial and parenchymal involvement and diminished alveolar damage in the lungs of A/J when compared to C3H/HeOuJ. Our findings indicate that during an early phase of infection a prompt inflammatory response in the airways set the conditions for a non-permissive environment to P. aeruginosa replication and lock the spread to other organs. Host gene(s) may have a role in the reduction of cell-mediated immunity playing a critical role in the control of P. aeruginosa infection. These results now provide a basis for mapping genomic regions underlying host susceptibility to P. aeruginosa infection.     

The relationships between brain, serum, and whole blood ChE activity in the wood mouse (Apodemus sylvaticus) and the common shrew (Sorex araneus) after acute sublethal exposure to dimethoate

Inhibition of cholinesterase (ChE) activity produced by a single acute intraperitoneal administration of dimethoate was studied in the wood mouse, Apodemus sylvaticus, and the common shrew, Sorex araneus, under laboratory conditions. ChE values from serum and whole blood were compared with those obtained from brain in order to obtain a non-destructive tool for predicting the severity of brain acetylcholinesterase (AChE) inhibition. In addition, serum and brain inhibition following oral exposure to dimethoate was also measured in the wood mouse. Normal ChE activity was higher in the brain and whole blood of the shrews than in wood mice. There was no difference between species in serum ChE activity. Exposure to dimethoate caused a dose-dependent reduction in ChE activity and there was a significant recovery in activity with increasing time after administration. In both species, serum and whole blood were more sensitive than brain for revealing organophosphate-induced ChE inhibition and serum was more sensitive than whole blood. Statistically significant relationships were defined between whole blood and brain ChE activity and between serum and brain ChE activity. Compared with serum, whole blood ChE activity was the more accurate predictor of brain AChE levels. The relationships between brain and serum ChE activity did not appear to be affected by the route of administration of the pesticide.     

Characterisation of yeast microbiota,chemical and sensory properties of organic and biodynamic Sangiovese red wines

Wine quality is closely linked to the fermentation step, which is driven by the microbial ecology of grape and the use of selected microbial strains as well. The microbial species developing during fermentation determines the type and concentration of many substances, which contribute to the sensory properties of wine and its safety. In this view, the present work aims to characterise the yeast microbiota, chemical and sensory properties of Sangiovese red wines obtained from both biodynamic and organic agriculture. The natural yeast populations of grape musts and their evolution during spontaneous were monitored and investigated. In addition, the volatile composition, physico-chemical and safety features (ethyl-carbamate) and sensory properties of wines were evaluated. The results showed that the yeast population was mostly related to the grape management, i.e. organic or biodynamic, while the wine composition was mainly affected by the winemaking process, and then by the grape management.     

Toward a general mixed quantum/classical method for the calculation of the vibronic ECD of a flexible dye molecule with different stable conformers: Revisiting the case of 2,2,2‐trifluoro‐anthrylethanol

We extend a recently proposed mixed quantum/classical method for computing the vibronic electronic circular dichroism (ECD) spectrum of molecules with different conformers, to cases where more than one hindered rotation is present. The method generalizes the standard procedure, based on the simple Boltzmann average of the vibronic spectra of the stable conformers, and includes the contribution of structures that sample all the accessible conformational space. It is applied to the simulation of the ECD spectrum of (S)‐2,2,2‐trifluoroanthrylethanol, a molecule with easily interconvertible conformers, whose spectrum exhibits a pattern of alternating positive and negative vibronic peaks. Results are in very good agreement with experiment and show that spectra averaged over all the sampled conformational space can deviate significantly from the simple average of the contributions of the stable conformers. The present mixed quantum/classical method is able to capture the effect of the nonlinear dependence of the rotatory strength on the molecular structure and of the anharmonic couplings among the modes responsible for molecular flexibility. Despite its computational cost, the procedure is still affordable and promises to be useful in all cases where the ECD shape arises from a subtle balance between vibronic effects and conformational variety.