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.     

Immunochemistry of the HLA class II molecules isolated from a mouse cell transfected with DQ alpha and beta genes from a DR4 haplotype

Cells from a mouse B lymphoma were transfected by DQ alpha and DQ beta genes derived from a DR4 haplotype. Quantitatively, the resulting expression of human class II molecules was similar to that of human B lymphoblastoid cell lines. Qualitatively, the transformant class II molecules differed from normal class II molecules in their carbohydrate moiety. As for their antigenic specificity, they were shown to carry two determinants previously identified on DQ molecules controlled by DR4 haplotypes, i. e., DQw3 and DCHON. The transformant molecules did not carry a third DR4-associated specificity, DC5 (equivalent to TA10), and must possess a structure allelic to DC5. However, no corresponding alloantigenic specificity was detected by a screening of relevant alloantisera.     

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.     

Electro-insertion of xeno-glycophorin into the red blood cell membrane

The electroporation technique, with field strengths slightly below the critical value Ec for electroporation of red blood cells (RBC), enables the insertion of xeno-proteins into the RBC membrane without damaging the cells. The electro-insertion has been used to insert biotinylated human glycophorin into human RBC membrane and human glycophorin into murine RBC membrane. Binding anti-human glycophorin antibody (10F7) to the murine RBC bearing human glycophorin indicates extracellular orientation of inserted glycophorin. Insertion of about 10(5) glycophorin molecule per cell has been estimated by whole cell ELISA.     

Serological recognition of HLA-DR allodeterminant corresponding to DNA sequence involved in gene conversion

HLA class 11 molecules were isolated from mouse L cells transfected with a DR gene and an allele, 52a, of locus DR III from an HLA-homozygous cell line, AVL, of the DR3 haplotype. The isolated molecules were found to possess a new allospecificity, named TR81. This specificity behaved allelic to the previously described DR III locus. The TR81 specificity was also present on the DR I gene product of the DR3 haplotype. The nucleotide sequence of the gene encoding TR81 differs from TR81-negative DR genes of the DRw52 family in only two codons, both located in the regions known to be involved in a gene conversion event. Consequently, the following conclusions can be formulated. (a) TR81 is a bi-locus specificity and allelic to TR22 only in its DR III locus localization. (b) The TR81 specificity is the phenotypic counterpart of the gene conversion event which led to the generation of the DR I gene of the DR3 haplotype. (c) One or both individual amino acid substitutions in the first domain of the DR chain are responsible for the TR81 allospecificity. (d) Since TR81 is expressed on the DR I chain of the DR3 haplotype, it is possible that TR81 and DR3 represent the same serological specificity.     

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.