Fertile Queens Research Articles

Effect of partial replacement of dimethyl sulfoxide with dextran, polyvinylpyrrolidone or polyethylene glycol on post-thaw drone semen quality and queen fertility

Effect of partial replacement of dimethyl sulfoxide with dextran, polyvinylpyrrolidone or polyethylene glycol on post-thaw drone semen quality and queen fertility

Effectiveness of using different types of nuclei and methods of replanting queen bees in bags

In Ukraine, among other industries, beekeeping occupies an important place. This fact is facilitated by the developed agricultural direction of the country and the high percentage of cultivation of entomophilic crops. However, despite the broad prospects for development and transition to an industrial basis, the beekeeping industry of Ukraine is represented, in the vast majority, by relatively small farms. One of the reasons for the low development of industrial honey production in Ukraine is the high costs of organizing an industrial apiary, which include the purchase of modern equipment for quick and efficient opening of frames, special equipment for pumping honey, the construction of separate premises for the honey pumping workshop, as well as the constant updating of equipment, such as new hives and frames, and the purchase of breeding queens. Another significant problem is the death of bee colonies due to a variety of diseases, including Varroa mite infestation. The use of pesticides to combat diseases and pests of agricultural plants and forest lands contributes to its negative share. An effective and cost-effective way to expand and increase the productivity of the apiary is the formation of bee packages using high-quality breeding queens. The use of early fertile queens makes it possible to form a strong full-fledged family and make full use of the honey collection this year. The effectiveness of the use of different types of nuclei and methods of replanting fertile queen bees in the formation of bee packages was checked. The study was carried out on bees of the Ukrainian steppe breed. The best results in terms of the percentage of fertile queens and the cost of queens per fertile were obtained using a full-size nucleus for 3 standard frames in a 16-frame bed. However, the same method required a larger number (10 times) of worker bees compared to the micronucleus. With traditional replanting using the Titov cage, the share of accepted queen bees is 90 %, and the maximum rate of reception of queen bees in packages is recorded when using the fourth method of transplantation. So, when transferring a queen with a frame of printed brood and young worker bees, the relative proportion of accepted queen bees was 98 %. Therefore, the traditional method can be considered optimal in terms of indicators: reception, manufacturability, costs.

Селекция медоносной пчелы: достижения, проблемы и перспективы

The honey bee (Apis mellifera L.) is one of the most important managed insect pollinators worldwide. In recent years, negative processes have been occurring in honey bee populations all over the world, Russia included. Of particular concern are the mass mortality of bees due to decreased adaptation of bee colonies to environmental factors and the hybridization of bees due to replacement of native populations by gentle and productive commercial lines. Nowadays, honey bee selection is a promising area of world beekeeping which is aimed at improving and breeding new lines and breeds that are highly productive, resistant to diseases, and adapted to local climate and honey flow conditions. The review is devoted to the issues of honeybee selection and includes an analysis of the problems and achievements of classical selection, and an assessment of prospects for the introduction of molecular selection into beekeeping. In most selection and breeding programs, economic and behavioral traits, primarily honey productivity, colony strength, gentle temper, and low swarming tendency have been of predominant importance. Other selective traits, such as viability, disease resistance, and local adaptation are considered less significant since their insufficient manifestation can be compensated by caring for the bees, for example, pharmaceuticals, artificial feeding, and other beekeeping methods. Latterly, due to the growing problem of Varroa infestation of bee colonies, breeding programs also consider traits such as hygienic behavior, the growth of Varroa infestation, etc. In Russia, the selection of bees is aimed at obtaining strong colonies that are highly productive in honey, winter-hardy, resistant to diseases, possessing high egg-laying queens, etc. Recently, the genotype-environment interaction and its influence on honey bee health have been of particular interest. These studies demonstrate the relevance of breeding sustainable bee populations and lines adapted to local conditions. This will preserve the diversity of bees, prevent their death, and ensure sustainable productivity and adaptation of bee colonies to environmental changes. In traditional breeding programs, animals are selected and evaluated based on their phenotypic traits and using pedigrees. Such analysis is very labor-intensive, subjective, and considerably time-consuming. Bee selection is complicated by polyandry, male parthenogenesis, free and random mating of queens, death of mated drones, etc. Although the potential of classic breeding methods has not been fully realized yet, modern breeding programs require the use of molecular genetics methods and genomic technologies. The introduction of molecular markers (SSRs, SNP, etc.), sequencing, microarray, and information technology makes it possible to incorporate genetic information into breeding programs and provides more accurate and efficient breeding results. Despite the sequencing of the Apis mellifera genome in 2006, specific genetic markers that could be used in bee selection have not yet been proposed. At the same time, 'Omics' technologies have made it possible to identify various molecular markers (QTL, SNP, RNA, and proteins), which theoretically can be used for the selection and improvement of bee breeds. Quantitative trait loci (QTL) have now been identified, which is associated with queen fertility, disease resistance, and various types of behavior, including hygienic behavior and Varroa-sensitive hygiene in bees. Considerable research interest is aimed at creating bee populations that are resistant to diseases, primarily var-roosis as the biggest threat to global beekeeping, and developing methods for assessing the complex behavior of bees and their effective selection. To assess associations with honey production, gentleness, hygienic behavior, and resistance to the Varroa mite, a high-density SNP chip was developed. It can be used in genomic selection of honeybees and for Genome-Wide Association Studies (GWAS). The successful use of Marker-Associated Selection (MAS) in beekeeping has been demonstrated, namely, DNA markers associated with royal jelly productivity (genes of the mrjp family) have been developed. In 2023, the first study was conducted to estimate the breeding value of a bee reference population based on queen genotyping and it showed that genomic selection can be successfully applied to bees. The use of bee gut microbiome data as markers of colony health and viability in breeding programs is discussed. Thus, honey bee breeding, including molecular selection, provides an increase in the genetic and adaptive potential of existing breeds and the creation of new lines and ecotypes of bees, highly productive and adapted to certain natural and climatic conditions. Selection of honeybees contributes to the development and intensification of beekeeping. Even though the development of DNA markers of productivity, adaptability and resistance to diseases will open up new prospects for genetic selection and provide a significant advantage in time, issues related to the improvement of the classical system of bee selection currently remain relevant. The article contains 4 Figures, 1 Tables, 105 References. The Author declares no conflict of interest.

Comparative Analyses of Reproductive Caste Types Reveal Vitellogenin Genes Involved in Queen Fertility in Solenopsis invicta.

The red imported fire ant (Solenopsis invicta Buren) is a social pest species with a robust reproductive ability that causes extensive damage. Identification of the genes involved in queen fertility is critical in order to better understand the reproductive biology and screening for the potential molecular targets in S. invicta. Here, we used the mRNA deep sequencing (RNA-seq) approach to identify differentially expressed genes (DEGs) in the transcriptomes of three reproductive caste types of S. invicta, including queen (QA) and winged female (FA) and male (MA) ants. The genes that were specific to and highly expressed in the queens were then screened, and the Vg2 and Vg3 genes were chosen as targets to explore their functions in oogenesis and fertility. A minimum of 6.08 giga bases (Gb) of clean reads was obtained from all samples, with a mapping rate > 89.78%. There were 7524, 7133, and 977 DEGs identified in the MA vs. QA, MA vs. FA, and FA vs. QA comparisons, respectively. qRT-PCR was used to validate 10 randomly selected DEGs, including vitellogenin 2 (Vg2) and 3 (Vg3), and their expression patterns were mostly consistent with the RNA-seq data. The S. invicta Vgs included conserved domains and motifs that are commonly found in most insect Vgs. SiVg2 and SiVg3 were highly expressed in queens and winged females and were most highly expressed in the thorax, followed by the fat body, head, and epidermis. Evaluation based on a loss-of-function-based knockdown analysis showed that the downregulation of either or both of these genes resulted in smaller ovaries, less oogenesis, and less egg production. The results of transcriptional sequencing provide a foundation for clarifying the regulators of queen fertility in S. invicta. The functions of SiVg2 and SiVg3 as regulators of oogenesis highlight their importance in queen fecundity and their potential as targets of reproductive disruption in S. invicta control.

Predicting the Fertility of Long-term Honey Bee Drone Sperm Storage through Correlation of In vitro and In vivo Data

The article describes a study on the long-term storage of honey bee drone sperm and the evaluation of its quality. The current method of evaluating sperm quality, which involves inseminating queens and waiting for progeny. It is time-consuming and limited by the seasonal nature of beekeeping. The study aims to find correlations between queen fertility rates and sperm quality indicators in the queen spermatheca versus sperm quality indicators after storage in a thawed sperm sample. The study also examines the correlation between number of sperm cells, sperm motility, sperm viability, proportion of worker bee broods, sperm quality indicators in the spermatheca of queen bees, and duration of queen laying. The goal of this study is to validate in vitro-in vivo data and to facilitate future research on sperm storage issues.

H3K4me1 Modification Functions in Caste Differentiation in Honey Bees.

Honey bees are important species for the study of epigenetics. Female honey bee larvae with the same genotype can develop into phenotypically distinct organisms (sterile workers and fertile queens) depending on conditions such as diet. Previous studies have shown that DNA methylation and histone modification can establish distinct gene expression patterns, leading to caste differentiation. It is unclear whether the histone methylation modification H3K4me1 can also impact caste differentiation. In this study, we analyzed genome-wide H3K4me1 modifications in both queen and worker larvae and found that H3K4me1 marks are more abundant in worker larvae than in queen larvae at both the second and fourth instars, and many genes associated with caste differentiation are differentially methylated. Notably, caste-specific H3K4me1 in promoter regions can direct worker development. Thus, our results suggest that H3K4me1 modification may act as an important regulatory factor in the establishment and maintenance of caste-specific transcriptional programs in honey bees; however, the potential influence of other epigenetic modifications cannot be excluded.

Review of Sustainable Cryopreservation and Above-Freezing Storage Solutions of European Honey Bee Apis mellifera Drone Semen

Abstract The European honey bee Apis mellifera is the main pollinator for most crops used for human consumption. However, a number of diseases, parasites, pesticides and other factors that generally result in the widely described colony collapse disorder weakens honey bee colonies. In order to maintain the existing honey bee germ lines and facilitate the creation of new disease-resistant lines, it is necessary to ensure consistent breeding work, which would also allow the long-term preservation of the unique germplasm lines. One of the most promising solutions for the preservation of honey bee germplasm is the storage of honey bee drone semen. In recent decades, there has been a renewed interest in the preservation of honey bee drone semen using both cryopreservation and above-freezing storage methods. This review summarizes the latest developments in novel sperm storage technologies and their assessment by sperm quality and queen fertility indicators. Additionally, this article analyses the advantages and disadvantages of the reviewed solutions and outlines directions in which additional research would be needed to develop effective, available and affordable drone semen storage solutions. To the best of the authors' knowledge this is the first review of cryopreservation and above-freezing storage solutions of European honey bee Apis mellifera drone semen in the scientific literature.

Histopathological Study of some Abnormalities of Infertility in the Queens

The present study deals with causes of infertility abnormalities in queens. The sample of the present study consists of eight of the female reproductive system of queens. The sample of this study was collected from queens of different places in Basra randomly. Then the female reproductive system of queens was completely removed by the operation of ovario- Hysterectomy in which this operation was done weekly in the laboratory of surgery in Basra Veternerary Medicine,The female reproductive system was completely grossly diagnosed in order to know the infections in it. In addition, our study confirmed the importance of the ovaries and uterus in fertility of queens, The present study showed that six of the sample were uninfected in which the percentage was (75%); while two of the sample were infected in their ovaries and uterus in which the percentage was (25%). The result of the study showed that one of them has follicular cyst (12.5%) in ovary and endometritis (12.5%) .

Age characteristics of reproducive and maternal qualities of sheep of the prekos breed

The studies were carried out during 2020-2021 on ewes (515 heads) of the Kharkiv intrabreed type of the Prekos breed (KhTP) and their offspring in the conditions of the breeding plant of the State Enterprise of the Experimental Farm Gontarovka of the Institute of Animal Sciencе of the National Academy of Sciences of Ukraine.
 It was established that for 45 days during artificial insemination, the fertility of sheep (OP), calculated according to the results of their lambing, averaged 91.8 %. The highest rate was characterized by sheep that had the third lamb - 97.3 %. According to the results of 4-6 lambs, a relatively stable high fertility of queens was noted - 93.4-95.3 %. Significant downward deviations of this indicator were observed in ewes used for reproduction in the first and second years, and especially in animals with 7 and 8 or more lambing. Analysis of variance found that the age factor of ewes is highly likely (p<0.01) associated with their fertility, and the strength of its influence ŋх 2 is 0.491.
 The factor of individual rams-producers also influences (OP) ewes. The variability due to the influence of this factor varied from 87 to 95.1 %.
 Different (OP) of ewes, due to their age, had a corresponding effect on the indicators of their multiple pregnancy (P), calculated per 100 inseminated heads. This indicator in ewes for the first fifth lamb ranged from 113 to 150 lambs. At the same time, there is a clear trend of its growth due to the increase in the number of reproductive years. However, this trend is not linear and is valid for animals with 1-6 lambs. Ewes with 7 and 8 or more lambs worsen their reproductive ability rather sharply.

Wings make queens of Indian jumping ants

Families are complicated – ask any ant. Embarking on a new life, the females of many ant species take to the wing before establishing themselves as queen of their own colony populated with their worker offspring, which provide care and labour. But these hierarchical divisions are not so clear cut in all ant species. ‘The association of some behaviours with the queen and others with the worker morph is not universal’, says Benjamin Pyenson from Arizona State University, USA, explaining that Indian jumping ant (Harpegnathos saltator) queens can take on roles usually associated with workers, while the workers are also capable of producing eggs – usually the preserve of ant queens – in specific situations. Pyenson, Christopher Albin-Brooks and Jürgen Liebig, also from Arizona State University, wondered whether the loss of the queen's wings might have something to do with their ability to straddle the boundaries that usually differentiate queens from their worker offspring.However, as Indian jumping ant founding queens naturally perform many of the duties of workers – foraging and caring for brood and defending the nest – simply monitoring the caring responsibilities of the queen ants after they had lost their wings was not going to be sufficient to determine whether wingless queens transition to behaving like workers. Fortunately, winged queens never duel with workers to establish where they reside in the colony's two-tier hierarchy, whereas wingless queens do. So, Pyenson, Albin-Brooks and Corinne Burhyte (Arizona State University), set out to discover whether queen ants that had lost their wings tussled more with their colony mates than queens that still had their wings. Sure enough, after watching hours of ant interactions, the researchers saw that queens that had naturally shed their wings duelled more than winged queens and Pyenson says, ‘One clue that the queen and worker ants might not be all that different was that the stings I received from both of them seemed equally painful!’. In addition, all the colony residents duelled more when the researchers removed some queen's wings.The team also kept track of the fertility of several queens, discovering that the wingless queens produced fewer yolky eggs – which could go on to produce young. The wingless queens were becoming more like worker ants, losing their fertility. Also, some of the females whose wings had been removed by the scientists mated with males from their own colony, something that winged and naturally wingless queens never do, to avoid inbreeding and ensure that they find new nests with unrelated males. Finally, the researchers checked the oily waterproof coating covering the ants’ exterior to find out how appealing the winged and wingless queens smelled to mates, as winged females produce more alluring oily scents to attract males. However, 2 months after losing their wings, the now flightless females had lost their attractive aroma. Without wings, Indian jumping ant queen ants shift to behaving like workers and their bodies also adjust to become more worker-like.The discovery that Indian jumping ant workers and queens are equally capable of taking on each other's roles could help scientists understand how the sophisticated hierarchical colony structures favoured by other ant species have evolved. ‘Our results tell us that the ant queen's ability to fly away from the nest probably evolved before the ability to lay a lot of eggs, because in some species the workers can also lay eggs and the queens and workers are similar sizes’, Pyenson explains.

Lipidomic specializations of honeybee (Apis mellifera) castes and ethotypes

Honeybees of the same colony combine a near-homogeneous genetic background with a high level of phenotypic plasticity, making them ideal models for functional lipidomics. The only external lipid source of the colony is pollen, a diet rich in polyunsaturated fatty acids (PUFA). It has been suggested that differences in exposure to pollen-derived PUFA could partly explain differences in longevity between honeybee castes. We here investigated whether the membrane composition of honeybees plays roles in the physiological adaptation to tasks of individuals within the colony. Membranes of cell heaters, a group of workers producing heat from their flight muscles to uphold brood nest temperature, were compared to those of different types of non-heaters. We found that the lipidomic profiles of these groups fall into clearly different “lipotypes”, characterized by chain length and saturation of phospholipid-bound fatty acyl residues. The nutritional exposure to PUFA during early adult life and pupal development at the lower edge of the natural range of brood nest temperature both suppressed the expression of the cell heater-“lipotype”. Because cardiolipins (CL) are the lipid class most clearly differentiating honeybee phenotypes, and CL plays central roles in mitochondrial function, dysfunction and aging, our findings could help to understand these processes in other animals and humans.Taken together, the lipidome analysis of different life stages of workers, fertile queens, and drones lead to the hypothesis that honeybee “lipotypes” might represent adaptations to different energetic profiles and the likelihood of exposure to low temperatures.

Evolution and functionalization of vitellogenin genes in the termite Reticulitermes speratus.

Eusociality has been commonly observed in distinct animal lineages. The reproductive division of labor is a particular feature, achieved by the coordination between fertile and sterile castes within the same nest. The sociogenomic approach in social hymenopteran insects indicates that vitellogenin (Vg) has undergone neo-functionalization in sterile castes. Here, to know whether Vgs have distinct roles in nonreproductive castes in termites, we investigated the unique characteristics of Vgs in the rhinotermitid termite Reticulitermes speratus. The four Vgs were identified from R. speratus (RsVg1-4), and RsVg3 sequences were newly identified using the RACE method. Molecular phylogenetic analysis supported the monophyly of the four termite Vgs. Moreover, the termites Vg1-3 and Vg4 were positioned in two different clades. The dN/dSratios indicated that the branch leading to the common ancestor of termite Vg4 was under weak purifying selection. Expression analyses among castes (reproductives, workers, and soldiers) and females (nymphs, winged alates, and queens) showed that RsVg1-3 was highly expressed in fertile queens. In contrast, RsVg4 was highly expressed in workers and female nonreproductives (nymphs and winged adults). Localization of RsVg4messenger RNAwas confirmed in the fat body of worker heads and abdomens. These results suggest that Vg genes are functionalized after gene duplication during termite eusocial transition and that Vg4 is involved in nonreproductive roles in termites.

Influence of conditions of keeping bee families in wintering on their productivity

Creating favorable conditions for the development of bee colonies, adherence to technological techniques and processes are of great importance in increasing productivity. The article highlights the results of research on the impact of increased subframe space during the wintering of bee colonies on their further development and productivity. In the course of the research, bee colonies were evaluated on the basis of a set of economically useful traits. For research, 2 groups of bee colonies were identified, 10 in each, equivalent in strength and food security, with young fertile queens bred in the same year. The formation of experimental groups took into account the strength of bee colonies, the number of closed brood, the age of the queens, the availability of feed (honey and perga), and the quality of nest cells. These indicators in the experimental groups were almost the same. When preparing bee colonies for winter, the frames in the families of the control group were in the center of the hive, removed the top insulation and unscrewed the sheets by 5–7 sm in the experimental group performed the same actions as in the control winters substituted empty store extensions, thus increasing the subframe space. During the research, honey and wax productivity, strength of families in different periods of the active season and winter hardiness were determined. It was found that bees kept in the hives with increased subframe space, in which 76.1 % less plague was detected, compared with the control group, tolerate wintering well. These families are developing more intensively in the spring and summer period – the advantage in strength was 25.8 % in April, 31.4 % in May, and 31.6 % in June. And further they show higher honey and wax productivity by 24.9 and 32.1 %, respectively.

Characterization of Queen Supergene Pheromone in the Red Imported Fire Ant Using Worker Discrimination Assays

Ants use chemical signals to communicate for various purposes related to colony function. Social organization in the red imported fire ant, Solenopsis invicta, is determined by the Sb supergene, with colonies of the monogyne (single-queen) form lacking the element and colonies of the polygyne (multiple-queen) form possessing it. Polygyne workers accept new reproductive queens in their nest, but only those carrying Sb; young winged queens lacking this genetic element are executed as they mature sexually in their natal nest or as they attempt to enter a foreign nest to initiate reproduction after mating and shedding their wings. It has been suggested that queen supergene genotype status is signaled to workers by unsaturated cuticular hydrocarbons, while queen reproductive status is signaled by piperidines (venom alkaloids). We used high-throughput behavioral assays to study worker acceptance of paper dummies dosed with fractions of extracts of polygyne queens, or blends of synthetic counterparts of queen cuticular compounds. We show that the queen supergene pheromone comprises a blend of monoene and diene unsaturated hydrocarbons. Our assays also reveal that unsaturated hydrocarbons elicit discrimination by polygyne workers only when associated with additional compounds that signal queen fertility. This synergistic effect was obtained with a polar fraction of queen extracts, but not by the piperidine alkaloids, suggesting that the chemical(s) indicating queen reproductive status are compounds more polar than cuticular hydrocarbons but are not the piperidine alkaloids. Our results advance understanding of the role of chemical signaling that is central to the regulation of social organization in an important invasive pest and model ant species.

Effects of juvenile hormone in fertility and fertility-signaling in workers of the common wasp Vespula vulgaris.

In the highly eusocial wasp, Vespula vulgaris, queens produce honest signals to alert their subordinate workers of their fertility status, and therefore they are reproductively suppressed and help in the colony. The honesty of the queen signals is likely maintained due to hormonal regulation, which affects fertility and fertility cue expression. Here, we tested if hormonal pleiotropy could support the hypothesis that juvenile hormone controls fertility and fertility signaling in workers. In addition, we aimed to check oocyte size as a proxy of fertility. To do that, we treated V. vulgaris workers with synthetic versions of juvenile hormone (JH) analogue and a JH inhibitor, methoprene and precocene, respectively. We dissected the treated females to check ovary activation and analyzed their chemical profile. Our results showed that juvenile hormone has an influence on the abundance of fertility linked compounds produced by workers, and it also showed to increase oocyte size in workers. Our results corroborate the hypothesis that juvenile hormone controls fertility and fertility signaling in workers, whereby workers are unable to reproduce without alerting other colony members of their fertility. This provides supports the hypothesis that hormonal pleiotropy contributes to keeping the queen fertility signals honest.

Eusociality through conflict dissolution.

Eusociality, where largely unreproductive offspring help their mothers reproduce, is a major form of social organization. An increasingly documented feature of eusociality is that mothers induce their offspring to help by means of hormones, pheromones or behavioural displays, with evidence often indicating that offspring help voluntarily. The co-occurrence of maternal influence and offspring voluntary help may be explained by what we call the converted helping hypothesis, whereby maternally manipulated helping subsequently becomes voluntary. Such hypothesis requires that parent-offspring conflict is eventually dissolved—for instance, if the benefit of helping increases sufficiently over evolutionary time. We show that help provided by maternally manipulated offspring can enable the mother to sufficiently increase her fertility to transform parent-offspring conflict into parent-offspring agreement. This conflict-dissolution mechanism requires that helpers alleviate maternal life-history trade-offs, and results in reproductive division of labour, high queen fertility and honest queen signalling suppressing worker reproduction—thus exceptionally recovering diverse features of eusociality. As such trade-off alleviation seemingly holds widely across eusocial taxa, this mechanism offers a potentially general explanation for the origin of eusociality, the prevalence of maternal influence, and the offspring’s willingness to help. Overall, our results explain how a major evolutionary transition can happen from ancestral conflict.

RNA m6A Modification Functions in Larval Development and Caste Differentiation in Honeybee (Apis mellifera)

Genetically identical female honeybee larvae with different diets develop into sterile workers or fertile queens. It remains unknown whether the reversible RNA N6-methyladenosine (m6A) mark functionally impact this "caste differentiation." Here, we profile the transcriptome-wide m6A methylome of honeybee queen and worker larvae at three instar stages and discover that m6A methylation dynamics are altered by differential feeding. Multiple methylome comparisons show an obvious increase in m6A marks during larval development and reveal a negative correlation between gene expression and m6A methylation. Notably, we find that worker larvae contain more hypermethylated m6A peaks than do queen larvae, and many caste-differentiation-related transcripts are differentially methylated. Chemical suppression of m6A methylation in worker larvae by 3-deazaadenosine (DAA) reduces overall m6A methylation levels and triggers worker larvae to develop queen caste features. Thus, our study demonstrates that m6A functionally impacts caste differentiation and larval development, yet it does not exclude potential contributions from other factors.

Structure of the Midgut of the Queen Bee <i>Apis mellifera</i> <I>L.</I> Naturally Infected with <i>Sacbrood virus</i> (SBV)

Bees and their larvae are susceptible to various viral diseases, which leads to disruption of the bee family, and sometimes to its death. The <i>Sacbrood virus </i>is especially dangerous for the bee family. Sick families differ sharply in their condition and productivity from healthy ones, develop slowly in the spring, and grow little brood. Therefore, the aim of the study was to identify physiological changes in the intestines of mature uteruses affected by <i>Sacbrood virus</i> or SBV disease. Histological examinations supplemented the data on the pathogenesis of honey bees affected by <i>Sacbrood virus</i>. Data on physiological and morphological changes in the middle part of the intestine of fertile queens are presented. Histological examinations were performed in different parts of the midgut. In patients of queens, in comparison with clinically healthy ones, changes in the function of the pertrophic membrane were revealed. An increase in the length of the midgut fold in the anterior part of the intestine by 23% (p<0.001) was detected. Under the influence of pathogenicity of the virus there is an intensive proliferation of enterocytes in the middle part of the intestine. The defeat of the structural components of the mucosa is evidenced by the absence of a peretrophic membrane in the caudal direction of the midgut of diseased queens where necrotic lesions of the mucous membrane up to the basement membrane were detected.

ФАКТОРЫ, ВЛИЯЮЩИЕ НА ВОСПРОИЗВОДИТЕЛЬНЫЕ КАЧЕСТВА СВИНОМАТОК В УСЛОВИЯХ ООО «БАШКИРСКАЯ МЯСНАЯ КОМПАНИЯ»

The article provides material on determining the influence of some technological factors and the genotype of pigs in the main herd on the reproductive qualities of sows. Analysis of the breeding campaign in IC 2 "Mirny" LLC "Bashkir Meat Company" for 2017-2019. showed that the number of cases during the analyzed period increased by 1.6%, incl. for the main queens - by 10.3%, and for the checked ones, on the contrary, decreased by 21.3%. In general, analyzing the productivity of the broodstock of SK 2 "Mirny" LLC "Bashkir Meat Company", it can be noted that in 2019 12256 farrows were received, of which 79.7% - from the main queens and 20.3% - from the checked sows. The average fertility of queens for the breeds raised was 15.0 heads, incl. in the main queens - 15.4 heads, in the tested queens - 13.4 heads. The greatest multiple (16.1 heads) was revealed in purebred breeding of the Yorkshire breed. The average large-sized piglets in the complex is 1.38 kg, the survival rate for weaning is 93.1%, and the yield of business piglets is 13.6 heads. It has been established that the reproductive qualities of sows are relatively stable throughout the year, which is associated with the maintenance of an optimal microclimate in the livestock premises of the pig complex. When receiving marketable fattening young stock, preference should be given to parental genotypes YxJ, YxL.

Reproduction and signals regulating worker policing under identical hormonal control in social wasps

In social Hymenoptera, fertility and fertility signalling are often under identical hormonal control, and it has been suggested that such hormonal pleiotropies can help to maintain signal honesty. In the common wasp Vespula vulgaris, for example, fertile queens have much higher juvenile hormone (JH) titers than workers, and JH also controls the production of chemical fertility cues present on the females’ cuticle. To regulate reproductive division of labour, queens use these fertility cues in two distinct ways: as queen pheromones that directly suppress the workers’ reproduction as well as to mark queen eggs and enable the workers to recognize and police eggs laid by other workers. Here, we investigated the hormonal pleiotropy hypothesis by testing if experimental treatment with the JH analogue methoprene could enable the workers to lay eggs that evade policing. In support of this hypothesis, we find that methoprene-treated workers laid more eggs, and that the chemical profiles of their eggs were more queen-like, thereby causing fewer of their eggs to be policed compared to in the control. Overall, our results identify JH as a key regulator of both reproduction and the production of egg marking pheromones that mediate policing behaviour in eusocial wasps.