Salt marsh harvest mouse demography and habitat use in the Suisun Marsh,California

We undertook a 2-year (2002–2004) mark–recapture study to investigate demographic performance and habitat use of salt marsh harvest mice (Reithrodontomys raviventris halicoetes) in the Suisun Marsh. We examined the effects of different wetland types and microhabitats on 3 demographic variables: density, reproductive potential, and persistence. Our results indicate that microhabitats dominated by mixed vegetation or pickleweed (Salicornia spp.) supported similar salt marsh harvest mouse densities, reproductive potential, and persistence throughout much of the year, whereas few salt marsh harvest mice inhabited upland grass-dominated microhabitats. We found that densities were higher in diked wetlands, whereas post-winter persistence was higher in tidal wetlands, and reproductive potential did not differ statistically between wetland types. Our results emphasize the importance of mixed vegetation for providing adequate salt marsh harvest mouse habitat and suggest that, despite their physiognomic and hydrological differences, both diked and tidal wetlands support salt marsh harvest mouse populations by promoting different demographic attributes. We recommend that habitat management, restoration, and enhancement efforts include areas containing mixed vegetation in addition to pickleweed in both diked and tidal wetlands. © 2011 The Wildlife Society.     

Semen cryopreservation in golden‐headed lion tamarin,Leontopithecus chrysomelas

Wild animal genetic resource banking (GRB) represents a valuable tool in conservation breeding programs, particularly in cases involving endangered species such as the golden‐headed lion tamarin (Leontopithecus chrysomelas). Thus, we aimed to assess a sperm freezing protocol for golden‐headed lion tamarins using two different exenders: BotuBOV® (BB) and Test Yolk Buffer® (TYB). Ejaculates were collected by penile vibrostimulation from animals housed at São Paulo Zoological Park Foundation, São Paulo, Brazil, and after immediate analysis, two aliquots were diluted in BB and TYB. Postthawing samples were evaluated for total and progressive motility, plasma membrane and acrosome integrities, mitochondrial activity, susceptibility to oxidative stress, and sperm–egg‐binding. No differences between BB and TYB were found for most seminal parameters, except for acrosome integrity and susceptibility to oxidative stress (in both cases BB showed higher values). However, in spite of these differences and regardless of the extender used, postthaw sperm motility and viability with the described protocol were encouraging (on average >50% and >80%, respectively), indicating that sperm cryopreservation may be a short‐term measure for the conservation of golden‐headed lion tamarins.     

The biological roots of morality

The question whether ethical behavior is biologically determined may refer either to thecapacity for ethics (e.i., the proclivity to judge human actions as either right or wrong), or to the moralnorms accepted by human beings for guiding their actions. My theses are: (1) that the capacity for ethics is a necessary attribute of human nature; and (2) that moral norms are products of cultural evolution, not of biological evolution.Humans exhibits ethical behavior by nature because their biological makeup determines the presence of the three necessary, and jointly sufficient, conditions for ethical behavior: (i) the ability to anticipate the consequences of one's own actions; (ii) the ability to make value judgements; and (iii) the ability to choose between alternative courses of action. Ethical behavior came about in evolution not because it is adaptive in itself, but as a necessary consequece of man's eminent intellectual abilities, which are an attribute directly promoted by natural selection.Since Darwin's time there have been evolutionists proposing that the norms of morality are derived from biological evolution. Sociobiologists represent the most recent and most subtle version of that proposal. The sociobiologists' argument is that human ethical norms are sociocultural correlates of behaviors fostered by biological evolution. I argue that such proposals are misguided and do not escape the naturalistic fallacy. The isomorphism between the behaviors promoted by natural selection and those sanctioned by moral norms exist only with respect to the consequences of the behaviors; the underlying causations are completely disparate.This article is based on a paper presented at the International Symposium onBiological Models of Human Action, Palma de Mallorca, Spain, 16–18 December 1985.     

Search for Drosophila genes encoding a conserved domain present in the achaete-scute complex and myc proteins

Summary Several genes of the achaete-scute complex (ASC) of Drosophila melanogaster encode a 60 amino acids long conserved domain which shares a significant homology with a region of the vertebrate myc proteins. Based on these results, the existence of a family of Drosophila genes that would share both this conserved domain and the neurogenic function of the AS-C has been postulated. To test this proposal, we have searched a D. melanogaster genomic library with a probe that encodes the conserved domain. Only under very low stringency hybridization conditions, clones not belonging to the AS-C cross-hybridized with the probe. Those that gave the strongest signals were characterized. Sequencing of the cross-hybridizing regions showed that they had no significant homology with the conserved domain, the sequence similarity extending at the most for 37 nucleotides. Although our results do not conclusively disprove the existence of a family of AS-C-like genes, they indicate that the conservation of the domain would be lower than that found for shared motifs in other families of Drosophila developmental genes.     

Catalytic activity of cytochrome oxidase and cytochrome c in apolar solvents containing phospholipids and low amounts of water

Cytochrome c and cytochrome oxidase, in bovine heart submitochondrial particles and in their purified forms, were transferred to a ternary system that contained phospholipids (10 mg/ml toluene), the apolar solvent toluene, and water at concentrations of 13-15 microliters (high water) and 3 microliters (low water) per milliliter of toluene. When the enzymes were transferred back to an all water system, they exhibited full catalytic capacity. In the low water ternary system, cytochrome c could be reduced by ascorbate introduced via inverted micelles. Also in this system, cytochrome oxidase was reduced by ascorbate and cytochrome c but its oxidation was highly impaired. Data on the kinetics of reduction by ascorbate of cytochrome c and cytochrome oxidase under these conditions are presented. Cytochrome oxidase reduced in the organic solvent by ascorbate failed to form a complex with CO, but formed a complex with cyanide introduced via inverted micelles. The oxidized and the ascorbate-reduced cytochrome oxidase-cyanide complex exhibited a trough at 415 nm and a peak at 433 nm. The extent and rate of formation of the cyanide complex were higher with the reduced form of cytochrome oxidase. To achieve protein-protein interactions (cytochrome c-cytochrome oxidase) in the ternary system, it was necessary to extract the two proteins together. There was no functional interaction when they were extracted separately and mixed. In the high water ternary system reduced cytochrome oxidase was not detected, and it oxidized ascorbate at a higher rate than in the low water system; however, this rate was several orders of magnitude lower than in aqueous media.     

Complexity and tissue specificity of the mitochondrial respiratory chain

There is a renewed interest in the structure and functioning of the mitochondrial respiratory chain with the realization that a number of genetic disorders result from defects in mitochondrial electron transfer. These so-called mitochondrial myopathies include diseases of muscle, heart, and brain. The respiratory chain can be fractionated into four large multipeptide complexes, an NADH ubiquinone reductase (complex I), succinate ubiquinone reductase (complex II), ubiquinol oxidoreductase (complex III), and cytochromec oxidase (complex IV). Mitochondrial myopathies involving each of these complexes have been described. This review summarizes compositional and structural data on the respiratory chain proteins and describes the arrangement of these complexes in the mitochondrial inner membrane. This biochemical information is provided as a framework for the diagnosis and molecular characterization of mitochondrial diseases.     

Tricyclic Imipramine Modification of the Circadian Rhythms of Hypothalamic Serotonin, its Precursors and Acid Catabolite in Individually Housed Rats

Circadian rhythms of serotonin (5HT), its precursors tryptophan (TP) and 5-hydroxy-tryptophan (5HTP) and its acid catabolite 5-hydroxy-indoleacetic acid (5HIAA), were determined in the hypothalamus of control rats and rats which had been treated continuously with subcutaneous imipramine (10 mg/kg/day) for 2 weeks.

Rats were individually housed and entrained to LD12:12. Controls showed the 5HT and TP peaks in the light and dark periods respectively, as reported in the literature, but no inverted correlation (antiphase) between SHT and 5HIAA rhythms.

Imipramine significantly modified circadian rhythm characteristics: the 5HT acrophase was advanced, that of TP and 5HIAA was delayed. Imipramine also significantly increased hypothalamic SHT and TP concentrations.     

Effect of Zeitgeber Intensity Reduction on a Simulated Dual-Oscillator Human Circadian System: Classical and Dynamic Analysis

The two-oscillator model of human circadian rhythmicity was analyzed when a zeitgeber relative intensity of 1, 0.5, or 0.1 was introduced into the equations. Fourier analysis was compared with dynamic analysis such as attractor reconstruction or Liapunov exponent calculation. After a 50 or 90% reduction in zeitgeber intensity, the dynamics of the system became equivalent and differed significantly from those of a system with maximal zeitgeber intensity. When 10% aleatory noise was added to the data, the analysis was still applicable, and the results obtained were essentially the same as in the absence of noise. Dynamic analysis could thus provide a distinct classification for periodic data, based on the type of analysis.