Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae): a comparison with haploid males, queens and workers

Abstract

In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males.

Effects of ploidy and sex-locus genotype on gene expression patterns in the fire antSolenopsis invicta

“…Two recent studies [21,22] comparing whole-body haploid and diploid males in the stingless bee Melipona quadrifasciata identified fewer than 100 differentially expressed genes, but this low number may be due primarily to the small number of genes examined compared to our study. Although ploidy is associated with cell size in other organisms, such an association is not known in ants, except for sperm cells of Lasius sakagamii [16].…”

“…B 281: 20141776 bodies and thus simultaneously assayed many tissue types that may differ in their extent of development between individuals of different ploidy levels, thus magnifying any tissue-specific expression differences. Two recent studies [21,22] comparing whole-body haploid and diploid males in the stingless bee Melipona quadrifasciata identified fewer than 100 differentially expressed genes, but this low number may be due primarily to the small number of genes examined compared to our study. Although ploidy is associated with cell size in other organisms, such an association is not known in ants, except for sperm cells of Lasius sakagamii [16].…”

“…This difference is interesting because ploidy level has been shown to influence cell size and cell proliferation rate in various yeast, plants and animals. Moreover, ploidy level is associated with gene dosage regulation and endopolyploidization that would presumably affect gene expression in many tissues and thus influence overall developmental trajectories [17][18][19][20][21][22].…”

Genomics, transcriptomics and proteomics: enabling insights into social evolution and disease challenges for managed and wild bees

“…; Borges et al . ) and Dufourea novaeangliae (Eickwort et al . ) is sparse, whereas for Eufriesea mexicana it has hardly been documented at all.…”