scholarly journals Control of reproductive dominance by the thelytoky gene in honeybees

2007 ◽  
Vol 3 (3) ◽  
pp. 292-295 ◽  
Author(s):  
H. Michael G Lattorff ◽  
Robin F.A Moritz ◽  
Robin M Crewe ◽  
Michel Solignac
Keyword(s):  
Egg Production ◽  
Early Stage ◽  
Single Gene ◽  
Queen Pheromone ◽  
Apis Mellifera Capensis ◽  
Candidate Locus ◽  
Social Bees ◽  
Eusocial Insects ◽  
Cape Honeybee ◽  
General Importance

Differentiation into castes and reproductive division of labour are a characteristics of eusocial insects. Caste determination occurs at an early stage of larval development in social bees and is achieved via differential nutrition irrespective of the genotype. Workers are usually subordinate to the queen and altruistically refrain from reproduction. Workers of the Cape honeybee ( Apis mellifera capensis ) do not necessarily refrain from reproduction. They have the unique ability to produce female offspring parthenogenetically (thelytoky) and can develop into ‘pseudoqueens’. Although these are morphologically workers, they develop a queen-like phenotype with respect to physiology and behaviour. Thelytoky is determined by a single gene ( th ) and we show that this gene also influences other traits related to the queen phenotype, including egg production and queen pheromone synthesis. Using 566 microsatellite markers, we mapped this gene to chromosome 13 and identified a candidate locus thelytoky , similar to grainy head (a transcription factor), which has been shown to be highly expressed in queens of eusocial insects. We therefore suggest that this gene is not only important for determining the pseudoqueen phenotype in A. m. capensis workers, but is also of general importance in regulating the gene cascades controlling reproduction and sterility in female social bees.

scholarly journals Correlation of Royal Jelly composition with swarming tendency in Honey Bees (Apis mellifera): A Review

2021 ◽  
Author(s):  
Ivy Neha Chander ◽  
Lovleen Marwaha
Keyword(s):  
Honey Bees ◽  
Egg Production ◽  
Royal Jelly ◽  
Review Paper ◽  
Queen Pheromone ◽  
Eusocial Insects ◽  
Warm Weather ◽  
Growth Development ◽  
The Impact ◽  
Swarming Behaviour

Honey bees are eusocial insects which respond to warm weather, abundant food source by increasing their population through swarming to ensure the survival of the colony. To maintain a superior colony a queen must have a nutrient-rich diet and high egg production. Royal jelly is a high-quality food which has numerous beneficial properties required for proper growth, development, survival of the queen. Factors like congestion, lack of adequate queen pheromone, abnormal queen pheromone, pathogenic infections, exposure to pesticides influence the queen quality which further promotes non-reproductive swarming behaviour. Worker bees analyse the queen condition to prepare for supersedure or emergency queen rearing. This review paper highlights the influence of royal jelly composition on the queen quality, the impact of queen quality on swarming tendency, correlation between royal jelly composition and swarming tendency.

scholarly journals A Single Gene Causes Thelytokous Parthenogenesis, the Defining Feature of the Cape Honeybee Apis mellifera capensis

2020 ◽  
Vol 30 (12) ◽  
pp. 2248-2259.e6
Author(s):  
Boris Yagound ◽  
Kathleen A. Dogantzis ◽  
Amro Zayed ◽  
Julianne Lim ◽  
Paul Broekhuyse ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Single Gene ◽  
Apis Mellifera Capensis ◽  
Thelytokous Parthenogenesis ◽  
Cape Honeybee

scholarly journals Fusarium graminearum Possesses Virulence Factors Common to Fusarium Head Blight of Wheat and Seedling Rot of Soybean but Differing in Their Impact on Disease Severity

2014 ◽  
Vol 104 (11) ◽  
pp. 1201-1207 ◽  
Author(s):  
Luca Sella ◽  
Katia Gazzetti ◽  
Carla Castiglioni ◽  
Wilhelm Schäfer ◽  
Francesco Favaron
Keyword(s):  
Fusarium Head Blight ◽  
Disease Severity ◽  
Fusarium Graminearum ◽  
Map Kinases ◽  
Early Stage ◽  
Single Gene ◽  
Crown Rot ◽  
Head Blight ◽  
Soybean Seedlings ◽  
Seedling Rot

Fusarium graminearum is a toxigenic fungal pathogen that causes Fusarium head blight (FHB) and crown rot on cereal crops worldwide. This fungus also causes damping-off and crown and root rots at the early stage of crop development in soybean cultivated in North and South America. Several F. graminearum genes were investigated for their contribution to FHB in cereals but no inherent study is reported for the dicotyledonous soybean host. In this study we determined the disease severity on soybean seedlings of five single gene disrupted mutants of F. graminearum, previously characterized in wheat spike infection. Three of these mutants are impaired on a specific function as the production of deoxynivalenol (DON, Δtri5), lipase (ΔFgl1), and xylanase (Δxyl03624), while the remaining two are MAP kinase mutants (ΔFgOS-2, Δgpmk1), which are altered in signaling pathways. The mutants that were reduced in virulence (Δtri5, ΔFgl1, and ΔFgOS-2) or are avirulent (Δgpmk1) on wheat were correspondently less virulent or avirulent in soybean seedlings, as shown by the extension of lesions and seedling lengths. The Δxyl03624 mutant was as virulent as the wild type mirroring the behavior observed in wheat. However, a different ranking of symptom severity occurred in the two hosts: the ΔFgOS-2 mutant, that infects wheat spikelets similarly to Δtri5 and ΔFgl1 mutants, provided much reduced symptoms in soybean. Differently from the other mutants, we observed that the ΔFgOS-2 mutant was several fold more sensitive to the glyceollin phytoalexin suggesting that its reduced virulence may be due to its hypersensitivity to this phytoalexin. In conclusion, lipase and DON seem important for full disease symptom development in soybean seedlings, OS-2 and Gpmk1 MAP kinases are essential for virulence, and OS-2 is involved in conferring resistance to the soybean phytoalexin.

scholarly journals Insecticide exposure during brood or early-adult development reduces brain growth and impairs adult learning in bumblebees

2020 ◽  
Vol 287 (1922) ◽  
pp. 20192442 ◽  
Author(s):  
Dylan B. Smith ◽  
Andres N. Arce ◽  
Ana Ramos Rodrigues ◽  
Philipp H. Bischoff ◽  
Daisy Burris ◽  
...  
Keyword(s):  
Adult Development ◽  
Early Stage ◽  
Nervous System Development ◽  
Learning Performance ◽  
Lower Probability ◽  
Similar Degree ◽  
Micro Computed Tomography ◽  
Olfactory Conditioning ◽  
Social Bees ◽  
Computed Tomography Scanning

For social bees, an understudied step in evaluating pesticide risk is how contaminated food entering colonies affects residing offspring development and maturation. For instance, neurotoxic insecticide compounds in food could affect central nervous system development predisposing individuals to become poorer task performers later-in-life. Studying bumblebee colonies provisioned with neonicotinoid spiked nectar substitute, we measured brain volume and learning behaviour of 3 or 12-day old adults that had experienced in-hive exposure during brood and/or early-stage adult development. Micro-computed tomography scanning and segmentation of multiple brain neuropils showed exposure during either of the developmental stages caused reduced mushroom body calycal growth relative to unexposed workers. Associated with this was a lower probability of responding to a sucrose reward and lower learning performance in an olfactory conditioning test. While calycal volume of control workers positively correlated with learning score, this relationship was absent for exposed workers indicating neuropil functional impairment. Comparison of 3- and 12-day adults exposed during brood development showed a similar degree of reduced calycal volume and impaired behaviour highlighting lasting and irrecoverable effects from exposure despite no adult exposure. Our findings help explain how the onset of pesticide exposure to whole colonies can lead to lag-effects on growth and resultant dysfunction.

scholarly journals HypermethylatedFAM5CandMYLKin Serum as Diagnosis and Pre-Warning Markers for Gastric Cancer

2012 ◽  
Vol 32 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Lu Chen ◽  
Liping Su ◽  
Jianfang Li ◽  
Yanan Zheng ◽  
Beiqin Yu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Candidate Genes ◽  
Early Stage ◽  
Precancerous Lesions ◽  
Single Gene ◽  
High Specificity ◽  
Serum Samples ◽  
Promoter Regions ◽  
Gastric Cancer Cell Lines ◽  
Combined Detection

Most cases of gastric cancer (GC) are not diagnosed at early stage which can be curable, so it is necessary to identify effective biomarkers for its diagnosis and pre-warning. We have used methylated DNA immunoprecipitation (MeDIP) to identify genes that are frequently methylated in gastric cancer cell lines. Promoter regions hypermethylation of candidate genes were tested by methylation-specific polymerase chain reaction (MSP) in serum samples, including GC (n= 58), gastric precancerous lesions (GPL,n= 46), and normal controls (NC,n= 30). Eighty two hypermethylated genes were acquired by array analysis and 5 genes (BCAS4, CHRM2, FAM5C, PRACandMYLK) were selected as the candidate genes. Three genes (CHRM2, FAM5CandMYLK) were further confirmed to show methylation rates increased with progression from NC to GPL, then to GC. There was obvious decrease in detection ofFAM5CandMYLKhypermethylation, but notCHRM2, from preoperative to postoperative evaluation (P< 0.001). Combined detection of FAM5C and MYLK hypermethylation had a higher sensitivity in GC diagnosis (77.6%,45/58) and pre-warning (30.4%,14/46) than one single gene detection and also had a high specificity of 90%. The combined hypermethylated status ofFAM5CandMYLKcorrelated with tumor size (P< 0.001), tumor invasion depth (P= 0.001) and tumor-node-metastasis (TNM) stage (P= 0.003). HypermethylatedFAM5CandMYLKcan be used as potential biomarkers for diagnosis and pre-warning of GC.

Ribosomal Protein S19 and Diamond Blackfan Anemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2839-2839
Author(s):  
Steven R. Ellis ◽  
Carlos Arce-Lara ◽  
Jacqueline M. Caffrey ◽  
Diana A. Alvarez-Arias
Keyword(s):  
Ribosomal Protein ◽  
Single Gene ◽  
Yeast Cells ◽  
Functional Testing ◽  
Missense Mutations ◽  
Candidate Locus ◽  
Yeast Saccharomyces Cerevisiae ◽  
Growth Defects ◽  
Diamond Blackfan Anemia ◽  
Ribosomal Protein S19

Abstract Diamond Blackfan Anemia (DBA) is one of several bone marrow failures that have been linked to defects in ribosome synthesis. 25% of DBA cases are linked to mutations in ribosomal protein S19 (Rps19). The etiology of the remaining cases is unknown. To gain a better understanding of the function of the Rps19 family of proteins we have characterized members of this protein family in the yeast, Saccharomyces cerevisiae. In yeast, Rps19 is encoded by duplicated genes, RPS19A and RPS19B. Yeast cells lacking both RPS19 genes are not viable, whereas those lacking a single gene are viable but have growth defects. These latter strains are defective in a specific step in rRNA processing that preferentially affects the maturation of 40S ribosomal subunits. We scanned other yeast strains with mutations in genes for 40S subunit proteins for processing phenotypes similar to RPS19 mutants. Several have phenotypes that overlap with RPS19 mutants, but only RPS18 stands out as being virtually identical to RPS19 mutants. The human RPS18 gene is therefore a candidate locus for pathogenic mutations in DBA patients with normal RPS19. We are currently developing strategies to sequence RPS18 genes from DBA patients with normal RPS19 to determine if mutations in RPS18 are associated with DBA. We have also developed a yeast system for the functional testing of mutant alleles of RPS19 found in DBA patients. In general, a mutation is considered pathogenic if it is not found in unaffected family members and in the general population. We have found, however, that several missense mutations classified as pathogenic in DBA patients do not affect Rps19 function in the yeast system. The failure of these mutations to affect Rps19 function in yeast points to a need for functional testing of RPS19 mutant alleles in human cells.

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