Differential expression of mitochondrial genes between queens and workers during caste determination in the honeybeeApis mellifera

Abstract

The nourishment received by female honeybee larvae determines their differentiation into queens or workers. In this study, we report the first molecular analysis of differences that occur between queens and workers during the caste-determination process. RNA-differential display experiments identified a clone that encodes for a gene that is homologous to the nuclear-encoded mitochondrial translation initiation factor (AmIF-2mt). Semi-quantitative analysis by reverse transcriptase/polymerase chain reaction (RT-PCR) throughout honeybee development detected a higher level of expression of this gene in queen larvae than in worker larvae. Analysis of two other genes encoding mitochondrial proteins, cytochrome oxidase subunit 1 (COX-1; mitochondrial-encoded) and cytochrome c (cyt c; nuclear-encoded) also showed differential expression of these two genes between queens and workers. In particular, the cyt c transcript is more abundant in queen larvae and throughout the metamorphosis of the queen. These results indicate that the higher respiratory rate previously documented in queen larvae is accomplished through a higher level of expression of both nuclear- and mitochondrial-encoded genes for mitochondrial proteins.

Mitochondrial Proteins Differential Expression during Honeybee (Apis mellifera L.) Queen and Worker Larvae Caste Determination

“…53 Mitochondrial protein synthesis is one of the ways to increase higher mitochondrial activity. 15 The overexpression of all biosynthesis proteins by the queen-intended larvae at 72 and 96 h suggests high metabolic rates of the queen-intended larvae that require more protein biosynthesis to increase either mitochondrial organelles or mitochondrial numbers to produce ATP. In particular, the up-regulation of a relatively high number of ribosomal proteins in the early age is associated with the queen larvae high metabolism and fast development and is in line with our previous finding for hypopharyngeal gland development of high royal jelly bees at early stages of development.…”

“…14 Stimulated by food intake, high concentration of juvenile hormone (JH) in honeybee is associated with the time of highest respiratory rate and acts in the transcription of mitochondrial genes. 15 To this reality, the 72 h queen larvae upregulated many more amino acid metabolism proteins than the worker-destined larvae. This agrees with previous studies.…”

“…3,6,14 The investigations on the causes of honeybee caste polymorphism have been also treated through total or global protein differential expressions, 14À18 but information at the subcellular level however remains scarce, with the exception of a RNA-differential display set of expression analyses that isolated 3 mitochondrial genes differences between 4.5-day-old queens and workers larvae. 15 Nevertheless, a protein situated in a particular subcellular site is an important principle of the functional organization of the cell, and the knowledge of the proteins provides a clue to their possible roles in manipulating the life of an organism. Particularly, the mitochondrion is one of the most complex and multifunctional organelles in eukaryotic subcellular cells that carries out a wide variety of biochemical processes such as energy production and is a place where transcription and translation take place.…”

Differential Expressions of Nuclear Proteomes between Honeybee (Apis mellifera L.) Queen and Worker Larvae: A Deep Insight into Caste Pathway Decisions

“…Recently, the influence of cell size on the larva caste development has been reported, which is also linked to the quantity of the feed provided to the larvae. Therefore, in response to environmental stimuli (quality and quantity of feed); one genome gives rise to two or more phenotypes that lead to the creations of polyphenisms in the honeybee . On the other hands, these changes in metabolic pathways in response to environmental stimuli are organized by enzymes .…”

Genetic Drift and Purifying Selection Shaped Mitochondrial Genome Variation in the High Royal Jelly-Producing Honeybee Strain (Apis mellifera ligustica)

“…Similar findings have been reported from other studies. For example, queen larvae accomplish higher metabolic activity relative to worker larvae by significantly increasing mtDNA expression level but not copy number ( Corona et al, 1999 ). It is likely that mitochondrial gene expression is upregulated at the transcriptional and/or translational level, thereby ensuring sufficient energy provision in RJBs.…”