Biochem Mol Biol Educ. 2021 Sep;49(5):729-736. doi: 10.1002/bmb.21554. Epub 2021 Jun 23.

Practicing logical reasoning through Drosophila segmentation gene mutants.

Biochemistry and molecular biology education : a bimonthly publication of the International Union of Biochemistry and Molecular Biology

Ariadna Bargiela, Ruben Artero

PMID: 34160891 DOI: 10.1002/bmb.21554

Abstract

Laboratory practical sessions are critical to scientific training in biology but usually fail to promote logical and hypothesis-driven reasoning and rely heavily on the teacher's instructions. This paper describes a 2-day laboratory practicum in which students prepare and analyze larval cuticle preparations of Drosophila segmentation gene mutant strains. Embryonic segmentation involves three major classes of genes according to their loss-of-function phenotypes: the establishment of broad regions by gap genes, the specification of the segments by the pair-rule genes, and the compartments within segments by the segment polarity genes. Students are asked to sort undefined segmentation mutants into gap, pair-rule, or segment polarity categories based on their knowledge of the Drosophila segmentation process and the microscopic anatomical traits they are capable of finding in the sample preparations. This technically simple practicum prompts students to pay attention to detailed observation to detect anatomic markers of intrasegmental compartments and thorax versus abdomen cuticle, and promote their logical reasoning in hypothesizing to which segmentation type a given mutant fits best.

© 2021 The Authors. Biochemistry and Molecular Biology Education published by Wiley Periodicals LLC on behalf of International Union of Biochemistry and Molecular Biology.

Keywords: Drosophila; development; larval cuticle; mutant phenotype; segmentation genes

References

1. Nüsslein-Volhard C, Wieschaus E. Mutations affecting segment number and polarity in drosophila. Nature. 1980;287:795-801. - PubMed
2. Anderson KV, Nüsslein-Volhard C. Information for the dorsal-ventral pattern of the drosophila embryo is stored as maternal mRNA. Nature. 1984;311:223-7. - PubMed
3. Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P. Drosophila and the molecular genetics of pattern formation: genesis of the body plan. Garland Sci. 2002. https://www.ncbi.nlm.nih.gov/books/NBK21054/. - PubMed
4. Ostrowski S, Dierick HA, Bejsovec A. Genetic control of cuticle formation during embryonic development of Drosophila melanogaster. Genetics. 2002;161:171-82. - PubMed
5. Sanson B. Generating patterns from fields of cells. EMBO Rep. 2001;2:1083-8. https://doi.org/10.1093/embo-reports/kve255 - PubMed
6. Bejsovec A, Martinez AA. Roles of wingless in patterning the larval epidermis of drosophila. Development. 1991;113:471-85. - PubMed
7. Waldrop S, Chan C-C, Cagatay T, Zhang S, Rousset R, Mack J, et al. An unconventional nuclear localization motif is crucial for function of the drosophila Wnt/wingless antagonist naked cuticle. Genetics. 2006;174:331-48. - PubMed
8. Muñoz-Descalzo S, Terol J, Paricio N. Cabut, a C2H2 zinc finger transcription factor, is required during drosophila dorsal closure downstream of JNK signaling. Dev Biol. 2005;287:168-79. - PubMed
9. Sullivan W, Ashburner M, Hawley RS, et al. Drosophila protocols. NY, USA: Cold Spring Harbor Laboratory Press; 2000. - PubMed
10. Reya T, Clevers H. Wnt signalling in stem cells and cancer. Nature. 2005;434:843-50. - PubMed
11. Clevers H, Nusse R. Wnt/β-catenin signaling and disease. Cell. 2012;149:1192-205. - PubMed

Publication Types

• Journal Article