Página 1 dos resultados de 77 itens digitais encontrados em 0.003 segundos

Efeitos da quantidade de alimento larval sobre a determinação de castas da abelha sem ferrão Scaptotrigona aff. depilis (Moure, 1942) (Hymenoptera, Apidae, Meliponini) - uma análise morfométrica, de expressão gênica e de títul; The role of the quantity of larval diet in caste determination of the stingless bee Scaptotrigona aff. depilis (Moure, 1942) (Hymenoptera, Apidae, Meliponini) a morphometric, gene expression e hormone titer analysis

Cabral, Gisele de Carvalho Pinto
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/11/2009 PT
Relevância na Pesquisa
56.65%
Neste estudo, foi investigado o efeito da dieta larval no desenvolvimento de características morfológicas casta-específicas e na expressão de alguns genes durante o desenvolvimento da abelha sem ferrão Scaptotrigona aff. depilis . Nesta espécie, as castas femininas são determinadas pela quantidade de alimento consumida durante o desenvolvimento larval. Grupos experimentais larvas criadas in vitro foram feitos com duas quantidades diferentes de alimento larval, obtido de favos recém provisionados nesta espécie. As larvas do primeiro grupo receberam 32l de alimento larval, correspondente a quantidade média de alimento recebida por larvas de operárias naturalmente, já as larvas do segundo grupo receberam 130l, correspondente a quantidade média encontrada naturalmente em células reais. Todas as larvas criadas com 130l de alimento larval se desenvolveram em rainhas, como esperado; da mesma forma, a maioria das larvas criadas com 32l se desenvolveram em operárias. Interessantemente, porém, algumas larvas deste grupo se desenvolveram em rainhas miniaturas, sugerindo que outros fatores, além do trófico, estejam envolvidos na determinação de castas em S. aff. depilis. Subsequentemente, analisamos os títulos de hormônio juvenil (HJ) na hemolinfa por radioimunoensaio durante quatro estágios do último instar larval e encontramos que as larvas do grupo de 130l de dieta apresentaram maiores títulos no estágio defecante (LD) (p=0...

Ocorrência natural de sexuados, produção in vitro de rainhas e multiplicação de colônias em Tetragonisca augustula (Hymenoptera, Apidae, Meliponini); Natural occurrence of sexuals, production in vitro of queens and colony multiplication in Tetragonisca angustula (Hymenoptera, Apidae, Meliponini).

Prato, Mauro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/02/2011 PT
Relevância na Pesquisa
46.5%
Com o avanço da meliponicultura, a utilização das abelhas sem ferrão, assim como de seus subprodutos, tem abrangido novas áreas, como a polinização de culturas agrícolas. Assim, a demanda pelo aumento do número de colônias tem sido constante, porém devido ao pouco conhecimento sobre a biologia reprodutiva dessas abelhas, há dificuldade de produção de colônias em larga escala, acarretando uma séria limitação quanto à utilização comercial desses polinizadores. Buscamos com este trabalho, oferecer ferramentas que possibilitem a multiplicação de colônias de abelhas sem ferrão em grande quantidade em um curto período de tempo. Nas abelhas indígenas sem ferrão (exceto no gênero Melipona e nos casos onde ocorrem rainhas-miniatura) a quantidade de alimento ingerido pelas larvas fêmeas é o fator responsável pela diferenciação das castas, pois as larvas que se tornam rainhas ingerem mais alimento que as larvas de futuras operárias, não havendo diferença qualitativa entre o alimento fornecido às larvas que originarão ambas as castas. De acordo com este modelo de determinação de castas, buscamos estabelecer a produção in vitro de rainhas em Tetragonisca angustula oferecendo maior quantidade de alimento às larvas de operárias...

Padrões Diferenciais de Expressão Gênica no Desenvolvimento das Castas de Apis mellifera, com Ênfase na Diferenciação das Operárias; Gene Expression Patterns Governing Caste Determination in the Honey Bee (Apis mellifera) with an Emphasis on Worker Differentiation

Silva, Aline Carolina Aleixo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/08/2012 PT
Relevância na Pesquisa
46.74%
Nas abelhas sociais Apis mellifera a determinação de castas está relacionada à nutrição diferencial durante o desenvolvimento larval. Os indivíduos são alimentados com geléia real até o terceiro estágio larval, quando aqueles que são destinados a se tornarem operárias passam a receber uma mistura de secreções glandulares, mel e pólen. O conteúdo da dieta recebida após o terceiro estágio larval ativará respostas endócrinas diferenciais que resultarão no estímulo de vias distintas de expressão gênica que culminarão no desenvolvimento de rainhas e operárias. Vários modelos de determinação de castas foram propostos envolvendo diferentes fatores que atuam sobre o desenvolvimento de cada uma, em especial o Hormônio Juvenil (HJ), as vias de sinalização por insulina/IGF e TOR (target of rapamycin) a metilação diferencial e a proteína recentemente descoberta, royalactin, que favorecem o desenvolvimento de rainhas. Para o desenvolvimento de operárias foi sugerido estímulo de outras vias de sinalização, que possivelmente envolveria a participação dos genes ultraspiracle (usp), cryptocephal (crc) e retinoid- and fatty acid-binding protein (RfaBp). Utilizando diferentes abordagens avaliamos a participação destes genes no processo que culmina no desenvolvimento das castas. Através da análise de expressão gênica em larga escala utilizando microarrays...

Caste Asymmetries in the Neotropical Swarm-Founding Wasp Polybia (Trychothorax) ignobilis (Hymenoptera, Vespidae, Epiponini)

Desuo, Ivan Cesar; Shima, Sulene Noriko; Lima Oliveira, Alexandre Capelete; Gomes, Bruno; Santos Dias, Carlos Tadeu
Fonte: California State University Publicador: California State University
Tipo: Artigo de Revista Científica Formato: 51-70
ENG
Relevância na Pesquisa
46.54%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Epiponini wasps are dominant in Neotropical regions and represent, in several ways, exceptions for general theories regarding social insects. They are highly eusocial and most species build large and complex nests. These wasps form large populations, and colony reproductive fission occurs by swarming. on the other hand, differently from other highly social insects, in several species morphological differences among castes are slight or absent, suggesting that caste determination in the Epiponini differs from better known systems. In fact, the mechanisms that lead to caste differentiation in this tribe still remain obscure. The aim of this study is to investigate the pattern of caste differentiation during the colonial cycle of the Neotropical Epiponini wasp Polybia (T) ignobilis. Measurements were taken from 13 morphometric variables regarding the head, metassoma, messosoma, and wing. Ovarian development, relative age, and fat bodies were also examined. Four patterns of ovarian development were found and varied from filamentous ovarioles with no visible oocytes to well-developeded ovaries with mature oocytes. ANOVA showed that queens were significantly larger than workers in all colony phases...

Caste Differences in Polybia emaciata, a Mud-Nesting Eusocial Wasp (Hymenoptera: Vespidae), that Bear on Pre-Imaginal Determination but not Size Differences

Noll, Fernando Barbosa; Taverna, Luis Gustavo; Oliveira Lima, Alexandre Capelete de; Mateus, Sidnei
Fonte: California State University Publicador: California State University
Tipo: Artigo de Revista Científica Formato: 189-204
ENG
Relevância na Pesquisa
46.7%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 05/03569-8; Processo FAPESP: 07/08633-1; The Epiponini is a group of social wasps living in polygynic societies. The caste dimorphism varies from incipient to well distinct. Morphometric analyses on twelve body parts and ovarian development of Polybia emaciata Lucas 1879, were used to estimate the level of caste differentiation in seven colonies. Physiologic differences were found. Among queens the ovaries were inseminated and presented as highly developed; in intermediate females, ovaries were slightly developed and uninseminated, and for the workers the ovaries were not developed or inseminated. In addition, the coloration of the mesosoma and metasoma were darker in workers and intermediates. Morphometric analysis evidenced slight morphological differences. Even though body proportions were not enough to discriminate castes, the fifth sternite of the gaster had important characters that were able to differentiate queens from workers and intermediates. We propose that P. emaciata presents a case of pre-imaginal caste determination, which is not strictly based on size.

Caste differences in Polybia ematiata, a mud-nesting eusocial wasp (hymenoptera: Vespidae), that bear on pre-imaginal determination but not size differences

Noll, Fernando B.; Taverna, Luis Gustave; De Oliveira Lima, Alexandre Capelete; Mateus, Sidnei
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 189-204
ENG
Relevância na Pesquisa
46.7%
The Epiponini is a group of social wasps living in polygynic societies. The caste dimorphism varies from incipient to well distinct. Morphometric analyses on twelve body parts and ovarian development of Polybia emaciata Lucas 1879, were used to estimate the level of caste differentiation in seven colonies. Physiologic differences were found. Among queens the ovaries were inseminated and presented as highly developed; in intermediate females, ovaries were slightly developed and uninseminated, and for the workers the ovaries were not developed or inseminated. In addition, the coloration of the mesosoma and metasoma were darker in workers and intermediates. Morphometric analysis evidenced slight morphological differences. Even though body proportions were not enough to discriminate castes, the fifth sternite of the gaster had important characters that were able to differentiate queens from workers and intermediates. We propose that P. emaciata presents a case of pre-imaginal caste determination, which is not strictly based on size.

Caste determination in a polyembryonic wasp involves inheritance of germ cells

Donnell, David M.; Corley, Laura S.; Chen, Gang; Strand, Michael R.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.58%
Social insects are characterized by the development of castes in which some colony members reproduce whereas others function as altruistic helpers. The conditional switch controlling caste formation usually involves environmental stimuli that act on processes that regulate development of individuals. Unlike other social species, embryos of polyembryonic wasps develop clonally to produce large numbers of genetically identical offspring and two morphologically distinct castes. All embryos in a clone exist in an identical environment, the host, yet develop into either reproductive larvae that mature into adult wasps or soldier larvae whose function is defense. Here, we report that caste determination in Copidosoma floridanum involves inheritance of germ cells. Expression of a C. floridanum homolog (Cf-vas) of the germ cell marker Vasa indicated that the B4 blastomere in four cell-stage embryos is specified as a primordial germ cell. Vas expression later in development further indicated that embryos developing into reproductive larvae possess primordial germ cells whereas embryos developing into soldier larvae do not. Ablation of the B4 blastomere resulted in most broods containing only soldiers whereas ablation of other blastomeres produced broods containing both castes. These results indicate that soldier larvae are obligately sterile and reveal a previously unknown role for germ cells in caste formation.

Differential gene expression in queen–worker caste determination in bumble-bees

Pereboom, Jeffrey J. M; Jordan, William C; Sumner, Seirian; Hammond, Robert L; Bourke, Andrew F. G
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.81%
Investigating how differential gene expression underlies caste determination in the social Hymenoptera is central to understanding how variation in gene expression underlies adaptive phenotypic diversity. We investigated for the first time the association between differential gene expression and queen–worker caste determination in the bumble-bee Bombus terrestris. Using suppression subtractive hybridization we isolated 12 genes that were differentially expressed in queen- and worker-destined larvae. We found that the sets of genes underlying caste differences in larvae and adults failed to overlap greatly. We also found that B. terrestris shares some of the genes whose differential expression is associated with caste determination in the honeybee, Apis mellifera, but their expression patterns were not identical. Instead, we found B. terrestris to exhibit a novel pattern, whereby most genes upregulated (i.e. showing relatively higher levels of expression) in queen-destined larvae early in development were upregulated in worker-destined larvae late in development. Overall, our results suggest that caste determination in B. terrestris involves a difference not so much in the identity of genes expressed by queen- and worker-destined larvae...

Clonal reproduction and genetic caste differences in a queen-polymorphic ant, Vollenhovia emeryi

Ohkawara, Kyohsuke; Nakayama, Megumi; Satoh, Atsumi; Trindl, Andreas; Heinze, Jürgen
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.65%
Most social Hymenoptera are characterized by simple haploid sex determination and environment-based caste differentiation. This appears to be strikingly different in the queen-polymorphic ant Vollenhovia emeryi. Almost all long- and short-winged queens from a population in Central Japan were homozygous at three microsatellite loci, whereas workers were mostly heterozygous, suggesting either a complex system of genetic caste determination or, more likely, the production of female sexuals from unfertilized eggs by thelytokous parthenogenesis and of workers from fertilized eggs. Furthermore, male genotypes were not compatible with those of the queens and had exclusively the paternal allele found in the sterile, heterozygous workers, probably because males are produced from fertilized eggs after the exclusion of maternal nuclear DNA as recently reported for Wasmannia auropunctata. The genus Vollenhovia might provide an interesting model system to trace the evolution of unusual caste and sex determination systems.

Caste totipotency and conflict in a large-colony social insect.

Strassmann, Joan E; Sullender, Barry W; Queller, David C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 07/02/2002 EN
Relevância na Pesquisa
36.63%
In most social insects with large, complex colonies workers and queens are morphologically quite distinct. This means that caste determination must occur prior to adulthood. However workers and queens in the swarm-founding epiponine wasps are often morphologically indistinguishable, or nearly so, suggesting that caste determination in these wasps could be quite different. To determine the extent of caste lability in the epiponine, Parachartergus colobopterus, we removed all the queens from one colony and all but one from another colony. Worker aggression diminished after queen removal. A week later the colony with no queens had a new, young cohort of mated queens. These must have been either adults or pupae at the time of queen removal, and so could not have been fed any differently from workers. Relatedness patterns confirmed that these new queens would normally have been workers and not queens. A model of inclusive fitness interests shows that workers ought to suppress new queen production, except at low queen numbers, a prediction supported by our empirical results. The patterns of social conflict over queenship resulting from swarm founding in a many-queen society may help to explain the unusually weak caste differentiation in the epiponines.

Expression of insulin pathway genes during the period of caste determination in the honey bee, Apis mellifera

Wheeler, D E; Buck, N; Evans, J D
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em /10/2006 EN
Relevância na Pesquisa
46.57%
Female honeybees have two castes, queens and workers. Developmental fate is determined by larval diet. Coding sequences made available through the Honey Bee Genome Sequencing Consortium allow for a pathway-based approach to understanding caste determination. We examined the expression of several genes of the insulin signalling pathway, which is central to regulation of growth based on nutrition. We found one insulin-like peptide expressed at very high levels in queen but not worker larvae. Also, the gene for an insulin receptor was expressed at higher levels in queen larvae during the 2nd larval instar. These results demonstrate that the insulin pathway is a compelling candidate for pursing the relationship between diet and downstream signals involved in caste determination and differentiation.

Worker caste determination in the army ant Eciton burchellii

Jaffé, Rodolfo; Kronauer, Daniel J.C; Bernhard Kraus, F; Boomsma, Jacobus J; Moritz, Robin F.A
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.85%
Elaborate division of labour has contributed significantly to the ecological success of social insects. Division of labour is achieved either by behavioural task specialization or by morphological specialization of colony members. In physical caste systems, the diet and rearing environment of developing larvae is known to determine the phenotype of adult individuals, but recent studies have shown that genetic components also contribute to the determination of worker caste. One of the most extreme cases of worker caste differentiation occurs in the army ant genus Eciton, where queens mate with many males and colonies are therefore composed of numerous full-sister subfamilies. This high intracolonial genetic diversity, in combination with the extreme caste polymorphism, provides an excellent test system for studying the extent to which caste determination is genetically controlled. Here we show that genetic effects contribute significantly to worker caste fate in Eciton burchellii. We conclude that the combination of polyandry and genetic variation for caste determination may have facilitated the evolution of worker caste diversity in some lineages of social insects.

Patriline shifting leads to apparent genetic caste determination in harvester ants

Wiernasz, Diane C.; Cole, Blaine J.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.57%
The harvester ant, Pogonomyrmex occidentalis, is characterized by high levels of intracolonial genetic diversity resulting from multiple mating by the queen. Within reproductively mature colonies, the relative frequency of different male genotypes (patrilines) is not stable. The difference between samples increases with time, nearing an asymptote after a year. Patriline distributions in gynes and workers display similar patterns of change. A consequence of changing patriline distributions is that workers and gynes appear to have different fathers. However, apparent genetic differences between castes are caused by changing paternity among all females. Temporal variation in the relative frequency of patrilines may be a consequence of processes that reflect sexual conflict, such as sperm clumping. Recent work documenting genotype differences between physical castes (workers and gynes; major and minor workers) in several species of ants has been interpreted as evidence of genetic caste determination. Reanalysis of these studies found little support for this hypothesis. Apparent caste determination may result from temporal variation in sperm use, rather than from fertilization bias among male ejaculates.

Evidence for genetically influenced caste determination in phylogenetically diverse species of the termite genus Reticulitermes

Kitade, Osamu; Hoshi, Masahiro; Odaira, Shiori; Asano, Akiko; Shimizu, Manami; Hayashi, Yoshinobu; Lo, Nathan
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.65%
A number of social insect species have recently been shown to have genetically influenced caste determination (GCD), challenging the conventional view that caste determination should be strictly environmental. To date, GCD has been found in phylogenetically isolated species; examples of GCD being present in multiple species of a genus are lacking. Through crossing experiments of neotenic (juvenile) reproductives, we have recently provided the first evidence for a royal versus worker GCD in the termite Reticulitermes speratus. To elucidate whether this system is more widespread, we performed crossing experiments using three additional Reticulitermes species. Offspring caste and sex ratios were found to be highly similar to those found previously in R. speratus, raising the possibility that GCD was present in an ancestral lineage of Reticulitermes, and subsequently maintained throughout several episodes of speciation.

Recipe for a Busy Bee: MicroRNAs in Honey Bee Caste Determination

Guo, Xiangqian; Su, Songkun; Skogerboe, Geir; Dai, Shuanjin; Li, Wenfeng; Li, Zhiguo; Liu, Fang; Ni, Ruifeng; Guo, Yu; Chen, Shenglu; Zhang, Shaowu; Chen, Runsheng
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 11/12/2013 EN
Relevância na Pesquisa
46.57%
Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed Illumina/Solexa sequencing to examine the small RNA content in the bee larval food, and show that worker jelly is enriched in miRNA complexity and abundance relative to royal jelly. The miRNA levels in worker jelly were 7–215 fold higher than in royal jelly, and both jellies showed dynamic changes in miRNA content during the 4th to 6th day of larval development. Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.

Phylogeography of Pogonomyrmex barbatus and P. rugosus harvester ants with genetic and environmental caste determination

Mott, Brendon M; Gadau, Jürgen; Anderson, Kirk E
Fonte: John Wiley & Sons, Ltd Publicador: John Wiley & Sons, Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.37%
We present a phylogeographic study of at least six reproductively isolated lineages of new world harvester ants within the Pogonomyrmex barbatus and P. rugosus species group. The genetic and geographic relationships within this clade are complex: Four of the identified lineages show genetic caste determination (GCD) and are divided into two pairs. Each pair has evolved under a mutualistic system that necessitates sympatry. These paired lineages are dependent upon one another because their GCD requires interlineage matings for the production of F1 hybrid workers, and intralineage matings are required to produce queens. This GCD system maintains genetic isolation among these interdependent lineages, while simultaneously requiring co-expansion and emigration as their distributions have changed over time. It has also been demonstrated that three of these four GCD lineages have undergone historical hybridization, but the narrower sampling range of previous studies has left questions on the hybrid parentage, breadth, and age of these groups. Thus, reconstructing the phylogenetic and geographic history of this group allows us to evaluate past insights and hypotheses and to plan future inquiries in a more complete historical biogeographic context. Using mitochondrial DNA sequences sampled across most of the morphospecies’ ranges in the U.S.A. and Mexico...

Caste determination in bees and termites

Hinton, H.E.
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
EN
Relevância na Pesquisa
46.57%

Development and evolution of caste dimorphism in honeybees - a modeling approach

Leimar, Olof; Hartfelder, Klaus; Laubichler, Manfred D.; Page, Robert E., Jr.
Fonte: WILEY-BLACKWELL; HOBOKEN Publicador: WILEY-BLACKWELL; HOBOKEN
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.51%
The difference in phenotypes of queens and workers is a hallmark of the highly eusocial insects. The caste dimorphism is often described as a switch-controlled polyphenism, in which environmental conditions decide an individual's caste. Using theoretical modeling and empirical data from honeybees, we show that there is no discrete larval developmental switch. Instead, a combination of larval developmental plasticity and nurse worker feeding behavior make up a colony-level social and physiological system that regulates development and produces the caste dimorphism. Discrete queen and worker phenotypes are the result of discrete feeding regimes imposed by nurses, whereas a range of experimental feeding regimes produces a continuous range of phenotypes. Worker ovariole numbers are reduced through feeding-regime-mediated reduction in juvenile hormone titers, involving reduced sugar in the larval food. Based on the mechanisms identified in our analysis, we propose a scenario of the evolutionary history of honeybee development and feeding regimes.; Swedish Research Council [621-2010-5437]; Swedish Research Council

Evolution of social parasitism in ants: size of sexuals, sex ratio and mechanisms of caste determination

Aron, S.; Passera, L.; Keller, L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 22/01/1999 EN
Relevância na Pesquisa
46.58%
Social parasitism, one of the most intriguing phenomena in ants, has evolved to various levels, the most extreme form being parasites that have lost the worker caste and rely completely on the host's worker force to raise their brood. A remarkable feature of workerless social parasites is the small size of sexuals. It has been suggested that reduced size evolved as a means to take advantage of the host's caste-determination system, so that parasite larvae develop into sexuals with less food than is required to produce host workers. An important consequence of size reduction is that it might restrict the host workers' ability to discriminate between the brood of the social parasite and their own brood and might protect parasite sexuals from elimination. We found that sexuals of the workerless inquiline ant Plagiolepis xene were significantly smaller than the sexuals of their host Plagiolepis pygmaea, but remarkably similar to the host workers. The size variance of parasite sexuals was much lower than that of their host; this result possibly suggests that there is very stabilizing selection acting on size of the parasite sexuals. Comparison of the primary (egg) and secondary (adult) sex ratios of the parasite and host showed that miniaturization of P. xene sexuals has been accompanied by their ability to develop into sexuals even when the host P. pygmaea actively prevents production of its own sexuals. These results suggest that the inquiline's size and caste threshold have been reduced such that all individuals in a parasite brood will develop into sexuals. We also found that the adult sex ratio of P. xene was heavily female-biased. This bias probably stems from local mate competition that arises from sexuals mating within the nest. There was no significant difference between the proportion of haploid eggs and adult males produced; this observation indicates that a female-biased sex ratio is achieved by queens producing a higher proportion of diploid eggs rather than by a higher mortality of haploid males.

Recipe for a Busy Bee: MicroRNAs in Honey Bee Caste Determination

Guo, Xiangqian; Su, Songkun; Skogerboe, Geir; Dai, Shuanjin; Li, Wenfeng; Li, Zhiguo; Liu, Fang; Ni, Ruifeng; Guo, Yu; Chen, Shenglu; Zhang, Shaowu; Chen, Runsheng
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
46.57%
Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed Illumina/Solexa sequencing to examine the small RNA content in the bee larval food, and show that worker jelly is enriched in miRNA complexity and abundance relative to royal jelly. The miRNA levels in worker jelly were 7-215 fold higher than in royal jelly, and both jellies showed dynamic changes in miRNA content during the 4(th) to 6(th) day of larval development. Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.; The research was supported by National Sciences Foundation of China Grant No.30630040; National Key Basic Research & Development Program 973 under Grant Nos. 2009CB825401 and 2007CB946901 to RSC, the earmarked fund for Modern Agro-industry Technology Research System (No. CARS-45-KXJ3), and a grant of the National Natural Science Foundation of China (NSFC 30571409) to SKS...