Systematics within Gyps vultures: a clade at risk

Background  

Populations of the Oriental White-backed Vulture (Gyps bengalensis) have declined by over 95% within the past decade. This decline is largely due to incidental consumption of the non-steroidal anti-inflammatory veterinary pharmaceutical diclofenac, commonly used to treat domestic livestock. The conservation status of other Gyps vultures in southern Asia is also of immediate concern, given the lack of knowledge regarding status of their populations and the continuing existence of taxonomic uncertainties. In this study, we assess phylogenetic relationships for all recognized species and the majority of subspecies within the genus Gyps. The continuing veterinary use of diclofenac is an unknown but potential risk to related species with similar feeding habits to Gyps bengalensis. Therefore, an accurate assessment of the phylogenetic relationships among Gyps vultures should aid in their conservation by clarifying taxonomic uncertainties, and enabling inference of their respective relatedness to susceptible G. bengalensis.     

Determination of the radioprotective effects of topical applications of MEA, WR-2721, and N-acetylcysteine on murine skin

Topical applications of MEA (beta-mercaptoethylamine or cysteamine), WR-2721 [S-2-(3-aminopropylamino)-ethylphosphorothioic acid], and N-acetylcysteine (NAC) were tested for their ability to protect the normal skin of the hind legs of mice against acute and late damage from single doses of 137Cs radiation. No significant protection was observed with either WR-2721 or NAC. MEA was shown to offer significant protection against acute skin damage in both buffered and unbuffered forms, but no significant protection against late contraction. The use of topical MEA on unanesthetized animals breathing carbogen (95% O2, 5% CO2) appears to give an enhanced level of radioprotection over that shown for anesthetized, air-breathing animals.     

Patterns of divergence during evolution of alpha 1-proteinase inhibitors in mammals

alpha 1-Proteinase inhibitor (alpha 1-PI), a member of the serine proteinase inhibitor superfamily, has a primary role in controlling neutrophil elastase activity within the mammalian circulation. Several studies have indicated that the reactive center region of alpha 1-PI, the amino acid sequence of which is critical to recognition of and binding to target proteinases, is highly divergent within and among species. This appears to be a consequence of accelerated rates of evolution that may have been driven by positive Darwinian selection. In order to examine this and other features of alpha 1-PI evolution in more detail, we have isolated and sequenced cDNAs representing alpha 1- PI mRNAs of the mouse species Mus saxicola and Mus minutoides and have compared these with a number of other mammalian alpha 1-PI mRNAs. Relative to other mammalian mRNAs, the extent of nonsynonymous substitution is generally high throughout the alpha 1-PI mRNA molecule, indicating greater overall rates of amino acid substitution. Within and among mouse species, the 5'-half of the mRNA, but not the 3'-half, has been homogenized by concerted evolution. Finally, the reactive center is under diversifying or positive Darwinian selection in murid rodents (rats, mice) and guinea pigs yet is under purifying selection in primates and artiodactyls. The significance of these findings to alpha 1-PI function and the possible selective forces driving evolution of serpins in general are discussed.      

Mitochondrial DNA polymorphisms in subterranean mole-rats of the Spalax ehrenbergi superspecies in Israel, and its peripheral isolates

Patterns of mitochondrial DNA (mtDNA) variation were examined in 133 mole-rats constituting all four chromosomal species (2n = 52, 2n = 54, 2n = 58, and 2n = 60) of the Spalax ehrenbergi superspecies in Israel, as well as the peripheral isolates of 2n = 60. In the main range of the complex, a total of 28 mtDNA haplotypes were found in 64 mole-rats, with most haplotypes being unique to either a single chromosomal species or population. mtDNA divergence increased from low to high diploid number in a north-to-south direction in Israel. Overall levels of mtDNA diversity were unexpectedly the highest in the 2n = 60, the youngest species of the complex. The mtDNA haplotypes can be separated into two major groups, 2n = 52-54 and 2n = 58-60, and a phylogenetic analysis for each group revealed evidence of a few haplotypes not sorted by diploid number. The overall patterns of mtDNA divergence seen within and among the four chromosomal species are consistent with the parapatric mode of speciation as suggested from previous studies of allozyme and DNA hybridization. In a separate data set the patterns of mtDNA variation were examined across the main geographic range and across peripheral semi-isolates and isolates of the 2n = 60 chromosomal species. Fifteen haplotypes were found in 69 mole-rats. High levels of mtDNA diversity characterized the main range, semi-isolated, and even some desert isolated populations. The peripheral isolates contain much mtDNA diversity, including novel haplotypes.      

Immunotherapy of neoplastic diseases with neuraminidase: Contradictions,new aspects,and revised concepts

Summary The divergent experimental results in immunotherapy of spontaneous, chemically induced or virus-induced solid tumors or leukemias with neuraminidase are reviewed and analyzed under the various aspects of the possible modes and conditions of action of the enzyme: Immunocompetence of the host, animal residual tumor volume, enzymatic activity of the neuraminidase, and identity of the antigenic specificity within the tumor system are well-known prerequisites for an effective tumor immunotherapy. In addition, there seems to be evidence that the number of tumor cells used for vaccination and the dose of enzymatically active VCN, whether bound to VCN-treated tumor cells or injected intratumorally, may be decisive in the negative or positive outcome. Moreover, there are indications that a preexistent sensitization against the so-called Thomsen-Friedenreich antigen, which seems to be unmasked after VCN treatment of cells, may influence the tumor therapeutic success. The effect of nonspecific immunostimulators given in addition to neuraminidase or to neuraminidase-treated cells is controversial. Thus, this combination cannot be recommended unless it is fully explored. To overcome the problem of the dependence of the tumor therapeutic effect on the dose of cells and the amount of neuraminidase with respect to different tumors and different adjuvant treatments, a new immunization concept, named chessboard vaccination, has been proposed. The data obtained so far in vitro and in vivo with this chessboard vaccination are briefly reviewed. They show that chessboard vaccination might be of diagnostic as well as of therapeutic interest.     

Pentobarbital anesthesia and the response of tumor and normal tissue in the C3Hf/sed mouse to radiation

Studies of the effect of pentobarbital anesthesia on the radiation response have been performed using early generation isotransplants of three spontaneous tumors of the C3H mouse: a mammary carcinoma (MCaIV), a fibrosarcoma (FSaII), and a squamous cell carcinoma (SCCVII). The enhancement ratio of pentobarbital [ER(PB)] for TCD50 as the end point was greater than or equal to 1 for all conditions tested. The ER(PB) for O2 3 ATA conditions and two equal doses was 1.46, 1.72, and 2.21 for MCaIV, FSaII, and SCCVII, respectively. The ER(PB) using MCaIV was the same for O2 and carbogen at 1 or 3 ATA. Also, tumor size of MCaIV did not significantly affect the ER(PB) for O2 3 ATA conditions. Further, with the two-dose protocol the anesthesia and the hyperbaric oxygen needed to be used at the second dose; condition at the first dose was not critical. For fractionated irradiation of MCaIV (10 and 15 equal doses) the ER(PB) was smaller than for two-dose treatment; also the effect was less for intratumor temperature of 35 degrees C than 26-27 degrees C. There was no effect of the anesthesia on the acute response of normal skin of the leg. Lung damage by hyperbaric oxygen was not an important factor in these results. Additionally, ERs were computed for O2 at 3 ATA. This ER(O2 3 ATA) was larger for anesthesized than conscious mice. The ER(O2 3 ATA) for MCaIV was high (greater than 1.5) even for radiation given in 10 or 15 equal doses.     

Life history attributes of Indian meal moth (Lepidoptera: Pyralidae) and Angoumois grain moth (Lepidoptera: Gelechiidae) reared on transgenic corn kernels

The Indian meal moth, Plodia interpunctella (Hübner), and Angoumois grain moth, Sitotroga cerealella (Olivier), are two globally distributed stored-grain pests. Laboratory experiments were conducted to examine the impact that corn (Zea mays L.) kernels (i.e., grain) of some Bacillus thuringiensis Berliner (Bt) corn hybrids containing CrylAb Bt delta-endotoxin have on life history attributes of Indian meal moth and Angoumois grain moth. Stored grain is at risk to damage from Indian meal moth and Angoumois grain moth; therefore, Bt corn may provide a means of protecting this commodity from damage. Thus, the objective of this research was to quantify the effects of transgenic corn seed containing CrylAb delta-endotoxin on Indian meal moth and Angoumois grain moth survival, fecundity, and duration of development. Experiments with Bt grain, non-Bt isolines, and non-Bt grain were conducted in environmental chambers at 27 +/- 1 degrees C and > or = 60% RH in continuous dark. Fifty eggs were placed in ventilated pint jars containing 170 g of cracked or whole corn for the Indian meal moth and Angoumois grain moth, respectively. Emergence and fecundity were observed for 5 wk. Emergence and fecundity of Indian meal moth and emergence of Angoumois grain moth were significantly lower for individuals reared on P33V08 and N6800Bt, MON 810 and Bt-11 transformed hybrids, respectively, than on their non-Bt transformed isolines. Longer developmental times were observed for Indian meal moth reared on P33V08 and N6800Bt than their non-Bt-transformed isolines. These results indicate that MON 810 and Bt-11 CrylAb delta-endotoxin-containing kernels reduce laboratory populations of Indian meal moth and Angoumois grain moth. Thus, storing Bt-transformed grain is a management tactic that warrants bin scale testing and may effectively reduce Indian meal moth and Angoumois grain moth populations in grain without application of synthetic chemicals or pesticides.