Genetic variation in the interleukin-8 gene promoter and vaginal concentrations of interleukin-8 are not associated with bacterial vaginosis during pregnancy.

Interleukin-8 (IL-8) may play a role in the activation of the vaginal immune system during bacterial vaginosis. However, contradictory results were obtained regarding the involvement of IL-8 in the immunological response during bacteria vaginosis. These apparently contradictory results could be due to different genetic variations of the study groups. Since some gene polymorphisms may affect the level of IL-8 production, the aim of this study was to determine whether the frequency IL-8 promoter alleles and levels of IL-8 in vaginal fluid are associated with bacterial vaginosis during pregnancy. Genotyping for IL-8 polymorphisms in the promoter region of the gene was performed in 34 pregnant women with asymptomatic bacterial vaginosis matched for gestational age with 38 pregnant women without vaginosis. Additionally, vaginal IL-8 levels were assayed by the dual monoclonal antibody sandwich enzyme-linked immunosorbent assay technique. The frequencies of the three polymorphisms were not significantly different between control women and women with bacterial vaginosis. In addition, there was no linkage disequilibrium between the polymorphisms. Furthermore, there was no statistical difference in median vaginal levels of IL-8 between both groups. Neither the frequencies of IL-8 polymorphic alleles nor levels of IL-8 in vaginal fluid were associated with bacterial vaginosis.

Biased Allele Expression and Aggression in Hybrid Honeybees may be Influenced by Inappropriate Nuclear-Cytoplasmic Signaling.

Hybrid effects are often exhibited asymmetrically between reciprocal families. One way this could happen is if silencing of one parent's allele occurs in one lineage but not the other, which could affect the phenotypes of the hybrids asymmetrically by silencing that allele in only one of the hybrid families. We have previously tested for allele-specific expression biases in hybrids of European and Africanized honeybees and we found that there was an asymmetric overabundance of genes showing a maternal bias in the family with a European mother. Here, we further analyze allelic bias in these hybrids to ascertain whether they may underlie previously described asymmetries in metabolism and aggression in similar hybrid families and we speculate on what mechanisms may produce this biased allele usage. We find that there are over 500 genes that have some form of biased allele usage and over 200 of these are biased toward the maternal allele but only in the family with European maternity, mirroring the pattern observed for aggression and metabolic rate. This asymmetrically biased set is enriched for genes in loci associated with aggressive behavior and also for mitochondrial-localizing proteins. It contains many genes that play important roles in metabolic regulation. Moreover we find genes relating to the piwi-interacting RNA (piRNA) pathway, which is involved in chromatin modifications and epigenetic regulation and may help explain the mechanism underlying this asymmetric allele use. Based on these findings and previous work investigating aggression and metabolism in bees, we propose a novel hypothesis; that the asymmetric pattern of biased allele usage in these hybrids is a result of inappropriate use of piRNA-mediated nuclear-cytoplasmic signaling that is normally used to modulate aggression in honeybees. This is the first report of widespread asymmetric effects on allelic expression in hybrids and may represent a novel mechanism for gene regulation.

A Search for Parent-of-Origin Effects on Honey Bee Gene Expression.

Parent-specific gene expression (PSGE) is little known outside of mammals and plants. PSGE occurs when the expression level of a gene depends on whether an allele was inherited from the mother or the father. Kin selection theory predicts that there should be extensive PSGE in social insects because social insect parents can gain inclusive fitness benefits by silencing parental alleles in female offspring. We searched for evidence of PSGE in honey bees using transcriptomes from reciprocal crosses between European and Africanized strains. We found 46 transcripts with significant parent-of-origin effects on gene expression, many of which overexpressed the maternal allele. Interestingly, we also found a large proportion of genes showing a bias toward maternal alleles in only one of the reciprocal crosses. These results indicate that PSGE may occur in social insects. The nonreciprocal effects could be largely driven by hybrid incompatibility between these strains. Future work will help to determine if these are indeed parent-of-origin effects that can modulate inclusive fitness benefits.

Fine-scale linkage mapping reveals a small set of candidate genes influencing honey bee grooming behavior in response to Varroa mites.

Populations of honey bees in North America have been experiencing high annual colony mortality for 15-20 years. Many apicultural researchers believe that introduced parasites called Varroa mites (V. destructor) are the most important factor in colony deaths. One important resistance mechanism that limits mite population growth in colonies is the ability of some lines of honey bees to groom mites from their bodies. To search for genes influencing this trait, we used an Illumina Bead Station genotyping array to determine the genotypes of several hundred worker bees at over a thousand single-nucleotide polymorphisms in a family that was apparently segregating for alleles influencing this behavior. Linkage analyses provided a genetic map with 1,313 markers anchored to genome sequence. Genotypes were analyzed for association with grooming behavior, measured as the time that individual bees took to initiate grooming after mites were placed on their thoraces. Quantitative-trait-locus interval mapping identified a single chromosomal region that was significant at the chromosome-wide level (p<0.05) on chromosome 5 with a LOD score of 2.72. The 95% confidence interval for quantitative trait locus location contained only 27 genes (honey bee official gene annotation set 2) including Atlastin, Ataxin and Neurexin-1 (AmNrx1), which have potential neurodevelopmental and behavioral effects. Atlastin and Ataxin homologs are associated with neurological diseases in humans. AmNrx1 codes for a presynaptic protein with many alternatively spliced isoforms. Neurexin-1 influences the growth, maintenance and maturation of synapses in the brain, as well as the type of receptors most prominent within synapses. Neurexin-1 has also been associated with autism spectrum disorder and schizophrenia in humans, and self-grooming behavior in mice.

Quantitative trait loci that influence the expression of guarding and stinging behaviors of individual honey bees.

This study was conducted to test for the effect of three stinging behaviors QTLs (sting-1, sting-2 and sting-3) on the expression of guarding and stinging behavior of individual honey bees, and to determine if results of defensive behavior QTLs found in studies with Africanized honey bees could be extended to other populations of bees. Samples of guards, stingers, foragers and nurse bees were taken from two backcross colonies derived from a defensive colony and a gentle colony. The genotype of each bee for both types of colonies was determined for two sequence tagged site (STS) markers linked to sting-1 and for another two STSs, one linked to sting-2 and one linked to sting-3. Results showed that sting-1 had an effect on the expression of both stinging and guarding behaviors, sting-2 and sting-3 influenced the expression of guarding behavior. These results indicate that division of labor is influenced by specific QTLs. Results also show that QTLs mapped in a population of Africanized honey bees using colony level phenotypes also influenced the expression of guarding and stinging behavior of individual bees of other populations.

Confirmation of QTL effects and evidence of genetic dominance of honeybee defensive behavior: results of colony and individual behavioral assays.

The stinging and guarding components of the defensive behavior of European, Africanized, hybrid, and backcross honeybees (Apis mellifera L.) were compared and analyzed at both colony and individual levels. Hybrid and Africanized backcross colonies stung as many times as Africanized ones. European backcross colonies stung more than European bees but not as many times as Africanized or Africanized backcross colonies. The degree of dominance for the number of times that worker bees stung a leather patch was estimated to be 84.3%, 200.8%, and 145.8% for hybrid, backcross European, and backcross Africanized colonies, respectively. Additionally, both guards at the colony entrance and fast-stinging workers of one European backcross colony had a significantly higher frequency of an Africanized DNA marker allele, located near "sting1," a QTL previously implicated in stinging behavior at the colony level. However, guards and fast-stinging bees from a backcross to the Africanized parental colony did not differ from control bees in their frequency for the Africanized and European markers, as would be expected if large genetic dominance effects for sting1 exist. These results support the hypothesis that genetic dominance influences the defensive behavior of honeybees and confirm the effect of sting1 on the defensiveness of individual worker bees.

Producción de miel de colonias de abejas (Apis mellifera L) tratadas y no tratadas con fluvalinato contra Varroajacobsoni Oudemans en Valle de Bravo, Estado de México / Honey production of treated and untreated honey bee (Apis mellifera L) colonies against the mite Varrora Jacobsoni Oudemans in valle de Bravo, Mexico

En este estudio se evaluó la producción de miel de colonias de abejas melíferas Apis mellifera L., infestadas con el ácaro Varroa jacobsoni Oud, en comparación con la de colonias tratadas con fluvalinato. Se establecieron 91 colonias de abejas, a cada una de las cuales se les introdujo una reina fecundada, joven. Las reinas provinieron de siete criaderos diferentes de varios estados de la República mexicana. Todas las colonias fueron infestadas artificialmente con un número igual de ácaros adultos y fueron manejadas de manera similar hasta la temporada de cosecha de miel. Dos meses antes de la floración y uno después de haber sido infestadas, un grupo de 33 colonias fue tratado con el acaricida fluvalinato (Apistan©), mientras que otro grupo de 58 colonias no recibió tratamiento contra la parasitosis. Al final de la floración se cuantificó la producción de miel y el nivel de parasitosis de cada una de las colonias. El grupo de colonias tratadas produjo significativamente más miel (65.5 por ciento) que el grupo de colonias donde no se aplicó acaricida; además su nivel de infestación fue significativamente más bajo que el de las colonias no tratadas (t = 3.32; gl = 89; P < 0.01, para la producción de miel; t = 6.33; gl = 89; P < 0.01, para los niveles de infestación). Se recomienda que las colonias de abejas infestadas con Varroa jacobsoni, sean tratadas con acaricidas mientras se desarrollan otros métodos de control del parásito. Este es el primer estudio que sugiere que Varroa jacobsoni daña la producción de miel en el Estado de México y en la República mexicana.