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.     

Teratogenic effect of D-amphetamine sulphate: histodifferentiation and electrocardiogram pattern of mouse embryonic heart

Pregnant albino mice (ICR random-bred strain) received daily injections of 50 or 100 mg/kg body weight of D-amphetamine sulphate between days 9 and 11 of gestation. Parallel control animals were injected with saline solution. Treated mice were sacrificed on day 15 or 19 of gestation. The embryos were examined for gross malformations and direct embryonic ECG recordings were made; they were weighed, and their hearts were carefully dissected. Microscopic sections of the heart were stained with hematoxylin and eosin. It was found that high doses of D-amphetamine raised the incidence of mortality in the treated pregnant mice up to 40%. The resorption rate in the survivors was high (up to 58%) following the high dose of the drug. Up to 15% of the embryos from the treated groups showed gross malformations, including skeletal and eye malformations and exencephaly. The electrocardiogram (ECG) recordings in most 19-day-old embryos from both treated groups showed a pattern with prolonged Q-T interval (PQT), similar to that of control embryos in the intermediate developmental stages (days 14-16 of gestation). The ECG of control embryos (from day 17 on) resembled that of prenatal fetuses. Microscopically, the hearts of treated embryos showed a large number of undifferentiated cardiac myoblasts. It can be inferred that high doses of D-amphetamine affect embryonic development generally and delay the histodifferentiation of the myocardium, resulting in incomplete maturation of the cardiac muscles, thus leading to the immature ECG pattern, with PQT intervals.     

Comparisons of eight commercial on-farm milk progesterone tests

To evaluate eight commercial on-farm milk progesterone kits, milk samples (50 ml each of foremilk and postmilk strippings) were collected during the estrous cycle from 10 cycling Holstein cows for 24 consecutive days. Relative concentrations of progesterone were classified as low or high by comparison with standard progesterone samples supplied with each kit. The concentration of progesterone in each milk sample was determined by radioimmunoassay (RIA). Accuracy of classification into low or high levels by commercial tests was determined by the percentage of similarity with RIA values using discriminant analysis. Accuracy of the eight tests ranged from 89.0 to 98.9% for low progesterone, 74.8 to 85.6% for high progesterone, and 80.3 to 87.3% for all samples (n = 238). The percentage of fat in milk or an interaction of the percentage of milkfat by day of estrous cycle influenced commercial test results for all tests except Accufirm and Calfcheck. Progesterone levels, estimated by the test-kits, were low from 1.5 +/- 0.5 to 2.8 +/- 0.9 days before estrus (X +/- SEM) and until 4.0 +/- 0.6 to 5.9 +/- 1.3 days after estrus. These data support the principle that a single low progesterone sample cannot be used to determine proper timing of insemination. All eight commercial kits can be used to determine accurately the relative concentrations of progesterone in milk samples.     

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.      

The accuracy of enzyme-linked immunosorbent assay and latex agglutination progesterone test for the validation of estrus and early pregnancy diagnosis in dairy cattle

The accuracy of the enzyme-linked immunosorbent assay (ELISA) and the latex agglutination (LA) on-farm progesterone kit for detecting estrus and diagnosing early pregnancy was investigated in this study. Italian Friesian dairy cows (n=82) from 6 dairy herds were used for the collection of foremilk samples at the time of breeding and at 19, 21, and 23 days post insemination. Pregnancy status was ascertained by uterine palpation per rectum 40 to 60 days post insemination. Progesterone levels were affected by herd, percentage of milk fat, and the day of testing x diagnosis interaction. Validation of estrus by qualitative on-farm tests was 74.6% (LA) and 100.0% (ELISA) accurate using 0.5 ng/ml of progesterone as the RIA estimate for estrus. The accuracy rate for early pregnancy diagnosis by RIA was 68.4 to 83.8% for day 19 and day 21, respectively, while the detection rate for nonpregnancy was 84.6 to 100% on day 19 and day 21, respectively, as compared with uterine palpation per rectum. The average accuracy rate for early pregnancy diagnosis ranged from 84.7 to 92.3% for the LA and ELISA tests, respectively; the nonpregnancy rate was correctly predicted 93.9% to 68.2% for the LA and ELISA tests, respectively.     

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.      

Evaluation of an on-farm blood progesterone test for predicting the day of parturition in cattle

An on-farm blood progesterone enzymeimmunoassay (EIA) was evaluated as a diagnostic test to predict the time of calving within a 24-hour period in near-term dairy cows. Blood samples were taken daily from 45 cows beginning 5 days prior to their expected due dates until calving, and plasma was stored at -20 degrees C until all cows had calved. The EIA test was performed on frozen-thawed plasma samples, and progesterone concentrations were determined to be low (positive test for calving within 24 hours) or high (negative test for calving within 24 hours). Sensitivity, specificity and predictive value of the EIA to accurately determine parturition within 24 hours were 86.7, 90.8 and 75.0%, respectively. The EIA correctly predicted the day of parturition in 168 of 187 (89.8%) plasma samples. Ten additional cows were similarly monitored except the EIA was performed on whole blood immediately after collection, and the sensitivity, specificity and predictive value of the test were 80.0, 97.6 and 88.9%, respectively. The day of parturition was correctly predicted in 49 of 52 (94.2%) whole blood samples. More than 95% of the cows calved within 24 hours when their plasma progesterone reached < 1.3 ng/ml. When results of the EIA were compared with those of a radioimmunoassay (RIA), the EIA findings were used to correctly classify 190 of 232 (81.9%) plasma samples as having low (< 2.0 ng/ml) or high (>/= 2.0 ng/ml) concentrations of progesterone. The EIA test was found to be a quick, practical means of estimating progesterone concentrations in bovine plasma or whole blood and was a useful test for predicting the day of parturition in cows.     

Generation of RNA pseudoknot structures with topological genus filtration

In this paper we present a sampling framework for RNA structures of fixed topological genus. We introduce a novel, linear time, uniform sampling algorithm for RNA structures of fixed topological genus g  , for arbitrary g>0$g>0$. Furthermore we develop a linear time sampling algorithm for RNA structures of fixed topological genus g   that are weighted by a simplified, loop-based energy functional. For this process the partition function of the energy functional has to be computed once, which has O(n²)$O(n^2)$ time complexity.