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Age at which larvae are orphaned determines their development into typical or rebel workers in the honeybee (Apis mellifera L.).

Kuszewska K, Woyciechowski M - PLoS ONE (2015)

Bottom Line: These rebel workers are more queenlike and have greater reproductive potential than normal workers.However, it was unclear whether larvae orphaned at any time during their feeding period can develop into rebels.Our results showed that larvae orphaned during the final four or more days of their feeding life develop into rebel workers with more ovarioles in their ovaries, smaller hypopharyngeal glands, and larger mandibular and Dufour's glands compared with typical workers with low reproductive potential that were reared with a queen or orphaned at the third to last or a later day of feeding life.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland.

ABSTRACT
In the honeybee, diploid larvae fed with royal jelly develop into reproductive queens, whereas larvae fed with royal jelly for three days only and subsequently with honey and pollen develop into facultatively sterile workers. A recent study showed that worker larvae fed in a queenless colony develop into another female polyphenic form: rebel workers. These rebel workers are more queenlike and have greater reproductive potential than normal workers. However, it was unclear whether larvae orphaned at any time during their feeding period can develop into rebels. To answer this question, the anatomical features of newly emerged workers reared in queenless conditions at different ages during the larval period were evaluated. Our results showed that larvae orphaned during the final four or more days of their feeding life develop into rebel workers with more ovarioles in their ovaries, smaller hypopharyngeal glands, and larger mandibular and Dufour's glands compared with typical workers with low reproductive potential that were reared with a queen or orphaned at the third to last or a later day of feeding life.

No MeSH data available.


Related in: MedlinePlus

Results of PCA based on the average values of workers’ ontogenic parameters (body mass, ovariole number, hypopharyngeal gland size, mandibular gland size and Dufour’s gland size).Biplot (a) with loading variables showing the correlations of the environmental variables with PC1 and PC2. In the score plot (b) the different colours and numbers describe groups of workers originating from different colonies, reared for different numbers of days in the queenless condition (e.g. number 4/3 indicates workers that originated from the fourth colony and group 3, whereas number 2/0 indicates workers originating from the second colony and group 0). The dotted circles indicate two clusters of workers (rebel and non-rebel), whereas the grey circles indicate sub-clusters of workers from each colony based on their similarity in body mass.
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pone.0123404.g003: Results of PCA based on the average values of workers’ ontogenic parameters (body mass, ovariole number, hypopharyngeal gland size, mandibular gland size and Dufour’s gland size).Biplot (a) with loading variables showing the correlations of the environmental variables with PC1 and PC2. In the score plot (b) the different colours and numbers describe groups of workers originating from different colonies, reared for different numbers of days in the queenless condition (e.g. number 4/3 indicates workers that originated from the fourth colony and group 3, whereas number 2/0 indicates workers originating from the second colony and group 0). The dotted circles indicate two clusters of workers (rebel and non-rebel), whereas the grey circles indicate sub-clusters of workers from each colony based on their similarity in body mass.

Mentions: In the PCA, the two principals (PC1 and PC2) account for 94.00% of the variance between the groups of workers reared as larvae in different conditions and colonies (Table 2). The correlations of the environmental variables with the PC1 and PC2 axes are given as vectors in the biplot (Fig 3A). The first axis (PC1) accounts for 73.85% of the variance and is negatively correlated with ovariole number and the size of the mandibular and Dufour’s glands and positively correlated with hypopharyngeal gland size (Fig 3A). The second axis (PC2) accounts for 20.15% of the variance (Table 2) and is negatively correlated with the body mass of the workers (Fig 3A). The PCA reveals two very conspicuous clusters of workers, based on their similarities in anatomical parameters (PC1). The first cluster (Fig 3B) consists of workers reared as larvae in the queenright condition (group 0) and those reared for the last 1, 2 or 3 days of their feeding period in the queenless condition (groups 1–3). The second cluster, by contrast, is composed of workers reared in the queenless condition for the last 4, 5 or 6 days of the larval feeding period (Fig 3B). In each of these two clusters, we can also designate sub-clusters based on similarities in body mass (PC2). These sub-clusters consist of groups of workers originating from each colony (Fig 3B). Finally, two ANOVAs with Tukey tests were performed using factor coordinates for the 35 groups of workers (cases) that were calculated in the PCA. In the first analysis, the coordinates described by the PC1 axis were used. These results confirmed that workers from groups 0–3 developed into normal workers, whereas those from groups 4–6 developed into rebel individuals (P < 0.001). The analysis also indicated that workers from groups 4–6 differ from one another (groups 4 and 5, P = 0.004; groups 4 and 6, P < 0.001; groups 5 and 6, P = 0.001). Moreover, anatomical parameters also depend on the colony (P < 0.001). The coordinates described by the PC2 axis were used in the second analysis. Here, the results showed that body mass depends on the workers’ colony of origin (P < 0.001) and that the workers originating from the second colony had a lower body mass than those originating from other colonies. However, experimental group had no significant effect on body mass (P = 0.409).


Age at which larvae are orphaned determines their development into typical or rebel workers in the honeybee (Apis mellifera L.).

Kuszewska K, Woyciechowski M - PLoS ONE (2015)

Results of PCA based on the average values of workers’ ontogenic parameters (body mass, ovariole number, hypopharyngeal gland size, mandibular gland size and Dufour’s gland size).Biplot (a) with loading variables showing the correlations of the environmental variables with PC1 and PC2. In the score plot (b) the different colours and numbers describe groups of workers originating from different colonies, reared for different numbers of days in the queenless condition (e.g. number 4/3 indicates workers that originated from the fourth colony and group 3, whereas number 2/0 indicates workers originating from the second colony and group 0). The dotted circles indicate two clusters of workers (rebel and non-rebel), whereas the grey circles indicate sub-clusters of workers from each colony based on their similarity in body mass.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400021&req=5

pone.0123404.g003: Results of PCA based on the average values of workers’ ontogenic parameters (body mass, ovariole number, hypopharyngeal gland size, mandibular gland size and Dufour’s gland size).Biplot (a) with loading variables showing the correlations of the environmental variables with PC1 and PC2. In the score plot (b) the different colours and numbers describe groups of workers originating from different colonies, reared for different numbers of days in the queenless condition (e.g. number 4/3 indicates workers that originated from the fourth colony and group 3, whereas number 2/0 indicates workers originating from the second colony and group 0). The dotted circles indicate two clusters of workers (rebel and non-rebel), whereas the grey circles indicate sub-clusters of workers from each colony based on their similarity in body mass.
Mentions: In the PCA, the two principals (PC1 and PC2) account for 94.00% of the variance between the groups of workers reared as larvae in different conditions and colonies (Table 2). The correlations of the environmental variables with the PC1 and PC2 axes are given as vectors in the biplot (Fig 3A). The first axis (PC1) accounts for 73.85% of the variance and is negatively correlated with ovariole number and the size of the mandibular and Dufour’s glands and positively correlated with hypopharyngeal gland size (Fig 3A). The second axis (PC2) accounts for 20.15% of the variance (Table 2) and is negatively correlated with the body mass of the workers (Fig 3A). The PCA reveals two very conspicuous clusters of workers, based on their similarities in anatomical parameters (PC1). The first cluster (Fig 3B) consists of workers reared as larvae in the queenright condition (group 0) and those reared for the last 1, 2 or 3 days of their feeding period in the queenless condition (groups 1–3). The second cluster, by contrast, is composed of workers reared in the queenless condition for the last 4, 5 or 6 days of the larval feeding period (Fig 3B). In each of these two clusters, we can also designate sub-clusters based on similarities in body mass (PC2). These sub-clusters consist of groups of workers originating from each colony (Fig 3B). Finally, two ANOVAs with Tukey tests were performed using factor coordinates for the 35 groups of workers (cases) that were calculated in the PCA. In the first analysis, the coordinates described by the PC1 axis were used. These results confirmed that workers from groups 0–3 developed into normal workers, whereas those from groups 4–6 developed into rebel individuals (P < 0.001). The analysis also indicated that workers from groups 4–6 differ from one another (groups 4 and 5, P = 0.004; groups 4 and 6, P < 0.001; groups 5 and 6, P = 0.001). Moreover, anatomical parameters also depend on the colony (P < 0.001). The coordinates described by the PC2 axis were used in the second analysis. Here, the results showed that body mass depends on the workers’ colony of origin (P < 0.001) and that the workers originating from the second colony had a lower body mass than those originating from other colonies. However, experimental group had no significant effect on body mass (P = 0.409).

Bottom Line: These rebel workers are more queenlike and have greater reproductive potential than normal workers.However, it was unclear whether larvae orphaned at any time during their feeding period can develop into rebels.Our results showed that larvae orphaned during the final four or more days of their feeding life develop into rebel workers with more ovarioles in their ovaries, smaller hypopharyngeal glands, and larger mandibular and Dufour's glands compared with typical workers with low reproductive potential that were reared with a queen or orphaned at the third to last or a later day of feeding life.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland.

ABSTRACT
In the honeybee, diploid larvae fed with royal jelly develop into reproductive queens, whereas larvae fed with royal jelly for three days only and subsequently with honey and pollen develop into facultatively sterile workers. A recent study showed that worker larvae fed in a queenless colony develop into another female polyphenic form: rebel workers. These rebel workers are more queenlike and have greater reproductive potential than normal workers. However, it was unclear whether larvae orphaned at any time during their feeding period can develop into rebels. To answer this question, the anatomical features of newly emerged workers reared in queenless conditions at different ages during the larval period were evaluated. Our results showed that larvae orphaned during the final four or more days of their feeding life develop into rebel workers with more ovarioles in their ovaries, smaller hypopharyngeal glands, and larger mandibular and Dufour's glands compared with typical workers with low reproductive potential that were reared with a queen or orphaned at the third to last or a later day of feeding life.

No MeSH data available.


Related in: MedlinePlus