Sign In

A subscription to JoVE is required to view this content. Sign in or start your free trial.

In This Article

  • Summary
  • Abstract
  • Introduction
  • Protocol
  • Representative Results
  • Discussion
  • Acknowledgements
  • Materials
  • References
  • Reprints and Permissions

Summary

In this protocol, methods for conducting inbreeding crosses, and for evaluating the success of those crosses, are described for the ant Vollenhovia emeryi. These protocols are important for experiments aimed at understanding the genetic basis of sex determination systems in Hymenoptera.

Abstract

The genetic and molecular components of the sex-determination cascade have been extensively studied in the honeybee, Apis mellifera, a hymenopteran model organism. However, little is known about the sex-determination mechanisms found in other non-model hymenopteran taxa, such as ants. Because of the complex nature of the life cycles that have evolved in hymenopteran species, it is difficult to maintain and conduct experimental crosses between these organisms in the laboratory. Here, we describe the methods for conducting inbreeding crosses and for evaluating the success of those crosses in ant Vollenhovia emeryi. Inducing inbreeding in the laboratory using V. emeryi, is relatively simple because of the unique biology of the species. Specifically, this species produces androgenetic males, and female reproductives exhibit wing polymorphism, which simplifies identification of the phenotypes in genetic crosses. In addition, evaluating the success of inbreeding is straightforward as males can be produced continuously by inbreeding crosses, while normal males only appear during a well-defined reproductive season in the field. Our protocol allow for using V. emeryi as a model to investigate the genetic and molecular basis of the sex determination system in ant species.

Introduction

Eusocial Hymenopteran taxa, such as ants and bees, have evolved a haplodiploid sex-determination system in which individuals that are heterozygous at one or more complementary sex determination (CSD) loci become females, while those that are homo- or hemizygous become males (Figure 1A)1.

Genetic and molecular components involved in the sex determination cascade have been well studied in the honeybee, Apis mellifera, a hymenopteran model organism2,3,4. Recent comparative....

Protocol

1. Field Collection and Maintenance of V. Emeryi Colonies in the Laboratory

NOTE: Nests of V. emeryi are found in rotting logs and fallen decaying tree branchesin secondary forests throughout Japan. This species shows two types of colonies, i.e., (1) colonies producing only long-winged queens and (2) colonies mainly producing short-winged queens in addition to small number of long-winged queens8,14. In this pro.......

Representative Results

Results of microsatellite analysis using F0 and F1 generations showed that inbreeding crosses were produced successfully (Figure 4)6. As a result of inbreeding crosses, mated queens were obtained within one month of establishing the experimental crossing colonies. A quarter (27.1 ± 8.91% SD) of all offspring (F2) from the inbreeding crosses was male, while the remainder was female (workers and a qu.......

Discussion

This article demonstrates protocols that can be used to induce inbreeding crosses and evaluate the occurrence of inbreeding in the ant V. emeryi. In the experiments, genotyping of the individuals used for crosses is necessary to ensure that inbreeding crosses were successful. However, the effectiveness of these crossing tests is clearly apparent as diploid males can be produced throughout the year, while haploid males can only be produced in autumn in both the field and the laboratory6. S.......

Acknowledgements

We thank Mr. Taku Shimada, the delegate of AntRoom, Tokyo, Japan, for providing us with his photograph of V. emeryi reproductives. This project was funded by the Japan Society for the Promotion of Science (JSPS) Research Fellowship for Young Scientists (16J00011), and Grant in Aid for Young Scientists (B)(16K18626).

....

Materials

NameCompanyCatalog NumberComments
Plaster powderN/AN/AAny brand can be used
Charcoal, Activated, PowderWako033-02117,037-02115
Slide glassN/AN/AAny brand can be used
Dry Cricket dietN/AN/AAny brand can be used
Brown shuger N/AN/AAny brand can be used
Styrene Square-Shaped CaseAS ONEAny sizeSize varies by number of ants
IncbatorAny brand can be used
Aluminum block bath Dry thermo unit DTU-1BTAITEC0014035-000
1.5mL Hyper Microtube,Clear, Round bottomWATSON131-715CS
Ethanol (99.5)Wako054-07225
Stereoscopic microscopeN/AN/AAny brand can be used
ForsepsDUMONT0108-5-PO
Chelex 100 sodium formSIGMA11139-85-8
Phosphate Buffer Saline (PBS) Tablets, pH7.4TaKaRaT9181
ParaformaldehydeWako162-16065
-Cellstain- DAPI solutionDojindo Molecular TechnologiesD523
VECTASHIELD Hard・Set Mounting Medium with TRITC-PhalloidinVector LaboratoriesH-1600
ABI 3100xl Genetic AnalyzerApplied BiosystemsDirectly contact the constructor formore informations.
Confocal laser scanning microscope Leica TCS SP8LeicaDirectly contact the constructor formore informations.
HC PL APO CS2 20x/0.75 IMMLeicaDirectly contact the constructor formore informations.
HC PL APO CS2 63x/1.20 WATERLeicaDirectly contact the constructor formore informations.
Leica HyDTMLeicaDirectly contact the constructor formore informations.
Leica Application Suite X (LAS X)LeicaDirectly contact the constructor formore informations.

References

  1. Mable, B. K., Otto, S. P. The evolution of life cycles with haploid and diploid phases. BioEssays. 20 (6), 453-462 (1998).
  2. Beye, M., Hasselmann, M., Fondrk, M. K., Page, R. E., Omholt, S. W.

Explore More Articles

InbreedingVollenhovia EmeryiAntSex DeterminationGenetic MappingMolecular BiologyHymenopteraColony MaintenanceEnvironmental ConditionsExperimental CrossingEgg Observation

This article has been published

Video Coming Soon

JoVE Logo

Privacy

Terms of Use

Policies

Research

Education

ABOUT JoVE

Copyright © 2024 MyJoVE Corporation. All rights reserved