In situ Protocol for Butterfly Pupal Wings Using Riboprobes

Summary

In order to examine gene expression in the pupal wing tissue of Bicyclus anynana, we present an optimized protocol for in situ hybridizations using riboprobes. We also provide guidelines for the further optimization of this protocol for use in pupal wings of other Lepidopteran species.

Abstract

Here we present, in video format, a protocol for in situ hybridizations in pupal wings of the butterfly Bicyclus anynana using riboprobes. In situ hybridizations, a mainstay of developmental biology, are useful to study the spatial and temporal patterns of gene expression in developing tissues at the level of transcription. If antibodies that target the protein products of gene transcription have not yet been developed, and/or there are multiple gene copies of a particular protein in the genome that cannot be differentiated using available antibodies, in situs can be used instead. While an in situ technique for larval wing discs has been available to the butterfly community for several years, the current protocol has been optimized for the larger and more fragile pupal wings.

Protocol

DAY 1 Prepare the following solutions: 10x PBS 1x PBS 1x PBT ddH2O Add DEPC for 0.1% total volume and shake solutions vigorously.  Autoclave. 4% Paraformaldehyde Fix – using PBS-DEPC Proteinase K solution – if precipitate is present, vortex vigorously before removing aliquot Digestion Stop Buffer Prehybridization Buffer 50:50 PBT:Prehybridization Buffer Hybridizatio…

Discussion

Optimization of existing protocols

In situ hybridizations on larval wing discs have been successfully performed using discs from Precis coenia butterflies (Carroll et al. 1994; Keys et al. 1999; Weatherbee et al. 1999). The current protocol has been adapted from a detailed written protocol available upon request from the Carroll Lab for larval wing stainings. The changes we made serve to accommodate differences between larval and pupal wing tissues. During pupal hindwing dissections, the p…

Materials

Material Name	Type	Company	Catalogue Number	Comment
Fix Buffer				4% Paraformaldehyde in PBS
PBT				0.1% Tween 20 in PBS
Proteinase K solution				2.5g/ml Proteinase K in PBT
Digestion Stop Buffer				2 mg/ml glycine in PBT
Pre-Hybridization Buffer				For 50 ml PHB: 12 ml DEPC treated water + 25 ml Formamide + 12.5 ml 20 x SSC + 50 ul Tween 20 + 500 ul 10 mg/ml salmon sperm (Rnase free, heat denatured prior to addition to solution).
Hybridization Buffer				Add 1 mg/ml glycogen to prehybridization buffer
Block Buffer				50 mM Tris pH 6.8, 150 mM NaCl, 0.5% IGEPAL (NP40), 5 mg/ml BSA
Anti-DIG	Ab	Roche Applied Science	11 093 274 910	Alkaline Phosphatase conjugated
DIG Wash and Block Buffer Set		Roche Applied Science	11 585 762 001
Crystal Mount Aqueous Mounting Medium		Sigma	C0612	Mounting Medium