The Glanville fritillary genome retains an ancient karyotype and reveals selective chromosomal fusions in Lepidoptera

Previous studies have reported that chromosome synteny in Lepidoptera has been well conserved, yet the number of haploid chromosomes varies widely from 5 to 223. Here we report the genome (393 Mb) of the Glanville fritillary butterfly (Melitaea cinxia; Nymphalidae), a widely recognized model species in metapopulation biology and eco-evolutionary research, which has the putative ancestral karyotype of n=31. Using a phylogenetic analyses of Nymphalidae and of other Lepidoptera, combined with orthologue-level comparisons of chromosomes, we conclude that the ancestral lepidopteran karyotype has been n=31 for at least 140 My. We show that fusion chromosomes have retained the ancestral chromosome segments and very few rearrangements have occurred across the fusion sites. The same, shortest ancestral chromosomes have independently participated in fusion events in species with smaller karyotypes. The short chromosomes have higher rearrangement rate than long ones. These characteristics highlight distinctive features of the evolutionary dynamics of butterflies and moths.

Butterflies and moths (Lepidoptera) vary in chromosome number. Here, the authors sequence the genome of the Glanville fritillary butterfly, Melitaea cinxia, show it has the ancestral lepidopteran karyotype and provide insight into how chromosomal fusions have shaped karyotype evolution in butterflies and moths.

Female behaviour drives expression and evolution of gustatory receptors in butterflies

Secondary plant compounds are strong deterrents of insect oviposition and feeding, but may also be attractants for specialist herbivores. These insect-plant interactions are mediated by insect gustatory receptors (Grs) and olfactory receptors (Ors). An analysis of the reference genome of the butterfly Heliconius melpomene, which feeds on passion-flower vines (Passiflora spp.), together with whole-genome sequencing within the species and across the Heliconius phylogeny has permitted an unprecedented opportunity to study the patterns of gene duplication and copy-number variation (CNV) among these key sensory genes. We report in silico gene predictions of 73 Gr genes in the H. melpomene reference genome, including putative CO₂, sugar, sugar alcohol, fructose, and bitter receptors. The majority of these Grs are the result of gene duplications since Heliconius shared a common ancestor with the monarch butterfly or the silkmoth. Among Grs but not Ors, CNVs are more common within species in those gene lineages that have also duplicated over this evolutionary time-scale, suggesting ongoing rapid gene family evolution. Deep sequencing (∼1 billion reads) of transcriptomes from proboscis and labial palps, antennae, and legs of adult H. melpomene males and females indicates that 67 of the predicted 73 Gr genes and 67 of the 70 predicted Or genes are expressed in these three tissues. Intriguingly, we find that one-third of all Grs show female-biased gene expression (n = 26) and nearly all of these (n = 21) are Heliconius-specific Grs. In fact, a significant excess of Grs that are expressed in female legs but not male legs are the result of recent gene duplication. This difference in Gr gene expression diversity between the sexes is accompanied by a striking sexual dimorphism in the abundance of gustatory sensilla on the forelegs of H. melpomene, suggesting that female oviposition behaviour drives the evolution of new gustatory receptors in butterfly genomes.

Insects and their chemically-defended hostplants engage in a co-evolutionary arms race but the genetic basis by which suitable host plants are identified by insects is poorly understood. Host plant specializations require specialized sensors by the insects to exploit novel ecological niches. Adult male and female Heliconius butterflies feed on nectar and, unusually for butterflies, on pollen from flowers while their larvae feed on the leaves of passion-flower vines. We have discovered–between sub-species of butterflies-fixed differences in copy-number variation among several putative sugar receptor genes that are located on different chromosomes, raising the possibility of local adaptation around the detection of sugars. We also show that the legs of adult female butterflies, which are used by females when selecting a host plant on which to lay their eggs, express more gustatory (taste) receptor genes than those of male butterflies. These female-biased taste receptors show a significantly higher level of gene duplication than a set of taste receptors expressed in both sexes. Sex-limited behaviour may therefore influence the long-term evolution of physiologically important gene families resulting in a strong genomic signature of ecological adaptation.

A pilot trial of the alpha-1 adrenergic antagonist, prazosin, for alcohol dependence

BACKGROUND

Current medications for alcohol dependence (AD) show only modest efficacy. None target brain noradrenergic pathways. Theory and preclinical evidence suggest that noradrenergic circuits may be involved in alcohol reinforcement and relapse. We therefore tested the alpha-1 adrenergic receptor antagonist, prazosin, as a pharmacotherapy for AD.

METHODS

We randomized 24 participants with AD but without posttraumatic stress disorder to receive either prazosin or placebo in a 6-week, double-blind pilot study. Medication was titrated to a target dose of 4 mg QAM, 4 mg QPM, and 8 mg QHS by the end of week 2. Participants received 5 medical management treatment sessions. Participants were reminded 3 times each day via a text pager to take medications and to call a telephone monitoring system once daily to provide self-reports of alcohol consumption and craving, the primary outcome measures. Results were analyzed using mixed linear regression adjusted for drinking days per week at baseline and week number.

RESULTS

Twenty of the 24 (83%) subjects completed. Among the completers, the prazosin group reported fewer drinking days per week than the placebo group during the final 3 weeks of the study. Since only 1 woman was randomized to placebo and only three women completed the trial, the following results focus on the 17 male completers. The prazosin group reported fewer drinking days per week and fewer drinks per week during the final 3 weeks of the study; average total number of drinking days for the placebo group 5.7 (SEM 1.9) versus 0.9 (SEM 0.5) for the prazosin group, and average total number of drinks 20.8 (SEM 6.5) for the placebo group versus 2.6 (SEM 1.3) for the prazosin group. Rates of adverse events were equivalent across conditions.

CONCLUSIONS

Prazosin holds promise as a pharmacologic treatment for AD and deserves further evaluation in a larger controlled trial.

Admission characteristics of Indian and white alcoholic patients in a rural mental hospital

A group of 58 American Indian alcoholic admissions and a group of 211 White alcoholic admissions to a California State Mental Hospital were interviewed utilizing a 141-item interview scale. The two groups were compared as to their responses to the interview items by a series of one-way analyses of variance. Statistically significant differences were found on demographic, socioeconomic, hospitalization, drinking and friendship pattern variables. The results are discussed with reference to data reliability, and socioeconomic and cultural factors. The study's findings are also related to an apparent need for the education of police and native Americans in the area concerning treatment resources available to native American problem drinkers.

In vitro growth inhibition of mastitis-causing coliform bacteria by bovine apo-lactoferrin and reversal of inhibition by citrate and high concentrations of apo-lactoferin

Bovine apo-lactoferrin (apo-Lf) was added to in vitro cultures of eight strains of coliform bacteria associated with bovine mastitis. As little as 0.02 mg of APO-Lf per ml resulted in marked inhibition of growth of all coliforms. Growth inhibition was lost if saturated Lf or iron plus apo-Lf was added to the synthetic medium. The inhibition of growth increased as the concentration of apo-Lf increased from 0.02 to 0.2 mg/ml for Klebsiella pneumoniae (OARDC-A1), Klebsiella spp. (K1-21), and Aerobacter aerogenes (55-12222) and 2 mg/ml for A. aerogenes (76-2414-1), Escherichia coli (60-Lilly), E. coli (66-S16), and Klebsiella spp. (K6-24). As the concentration of apo-Lf was increased above 0.2 or 2 mg/ml, there was less inhibition of growth except for E. coli (33-C4). Apo-Lf at 20 mg/ml was bactericidal for E. coli (33-C4). Results are compatible with the hypothesis that coliform bacteria respond to low-iron environments by production of iron-sequestering agents that complete effectively with apo-Lf for free iron. Addition of apo-Lf plus citrate resulted in loss of growth inhibition. The molar ratio (citrate to apo-Lf) was found to be more important than the absolute concentration of either component. A ratio of 75 resulted in 50% growth inhibition, whereas ratios of 300 and greater resulted in less than 10% growth inhibition. These results suggest that the ratio of citrate to Lf would be important in evaluating Lf as a nonspecific protective factor of bovine mammary secretions.

Changes in lactoferrin, immunoglobulin G, bovine serum albumin, and alpha-lactalbumin during acute experimental and natural coliform mastitis in cows

An experimentally induced Escherichia coli infection of a bovine mammary gland resulted in a 30-fold increase in lactoferrin (Lf) concentration in the mammary secretion by 90 h postinoculation and a 4-fold increase in total daily production of Lf by 264 h postinoculation in the infected quarter. A simultaneous rise and fall of bovine serum albumin (BSA) and immunoglobulin G (IgG) concentrations occurred during the acute phase of the infection. Peak BSA and IgG levels were reached 36 h before peak Lf levels. BSA concentrations declined rapidly after the acute phase, whereas IgG and Lf levels remained elevated and decreased slowly as the infection subsided. A decline in alpha-lactalbumin concentration by 48 h postinoculation indicated decreased synthetic capability. The increased Lf production may be a result of a specific response of secretory tissue to inflammatory agents and thus the infectious process. Analogous changes in Lf, IgG, and BSA were observed during a natural coliform infection. Sephadex G-200 chromatography of mastitis skim milk showed that Lf approximated the monomer (molecular weight 77,100) early in infections progressed and abated, the apparent molecular weight of Lf increased to approximately that of the trimer and subsequently decreased to about 1.5 times that of the monomer.

Concentration of lactoferrin in milk of normal lactating cows and changes occurring during mastitis

The mean lactoferrin (Lf) concentration determined by electroimmunodiffusion (EID) assay of whey preparations from 80 quarters of 20 normal lactating cows was 0.35 mg/ml. The mean alpha-lactalbumin (alpha-LAC) and bovine serum albumin (BSA) concentrations were 2.01 mg/ml and 0.29 mg/ml, respectively. The mean was significantly related to cell count (P smaller than 0.01), BSA (P smaller than 0.05), stage of lactation (P smaller than 0.05), and milk production (P smaller than 0.05). The Lf-milk production relationship was the only negative correlation. In 11 cows with mastitis, there was a significant (P smaller than 0.01) increase in mean Lf concentration in infected quarters from 0.55 mg/ml on day 1 of the infection to 1.89 mg/ml by day 3. By day 15 clinical signs had subsided and mean Lf concentrations had decreased to near day 1 values. On day 3 quarters infected with coliform bacteria (clinical mastitis generally more severe) had mean Lf values more than twofold greater than those quarters infected with species of Staphylococcus or Streptococcus (milder clinical signs). Noninfected (control) quarters of cows having coliform bacteria-infected quarters had slightly increased mean Lf concentrations, where Lf concentration in contral quarters of cows having quarters infected with gram-positive organisms remained unchanged.

Porcine parvovirus: natural and experimental infections of the porcine fetus and prevalence in mature swine

Antibodies against porcine parvovirus were detected in 17 of 116 prenursing pig sera. Antibodies against transmissible gastroenteritis or ECPO-6 (an enterovirus) were not detected in prenursing sera of the pigs tested. Seventy-seven percent of 129 serum samples from 23 Ohio farms and 82% of 96 samples from slaughter plants in Ohio were serologically positive for porcine parvovirus. Mummies or other abnormalities were not observed in newly born pigs exposed to porcine parvovirus by the transuterine route 101 days after gestation. Indirect evidence suggested that the virus had not spread to other fet uses following exposure after 101 days at least not in a sufficient amount of time to stimulate detectable antibody. Direct intrafetal exposure to porcine parvovirus (i.m. injection, transutero) after 62 days of gestation resulted in dealth and mummification of the two fetuses, and apparently in the subsequent spread of the virus, as five of nine live pigs born were serologically positive for porcine parvovirus and these five pigs had not been injected with the virus. Immunoglobulin G was detected in all newborn pigs irregardless of known antigenic stimulation or the presence of specific antibody. In general, the presence of immunoglobulin M or immunoglobulin A in fetal serum was correlated with a history of antigenic stimulation or the presence of detectable antibody.