Journal covers of LGD@NTU

The image of the montage picture shows how the Ap-Vas1 protein (green), a germline marker, is patterned in the parthenogenetic and viviparous ovariole. Staining of alpha-tubulin (magenta) highlights structures of the germarium (left) and adjacent embryo (right). The lower image shows a parthenogenetic mother pea aphid (left), which bears ovarioles as shown above, giving birth to an aphid nymph viviparously. The aphid nymph emerging from the mother, as well as the newly born aphid nymph (right), both carry developing ovarioles and are pregnant already.

Image credit: Chen-yo Chung, Gee-Way Lin, and Chun-che Chang.  

See also their review article on these fascinating features of aphid biology from the August 2022 journal issue:
Lin, GW., Chung, Cy., Cook, C.E. et al. Germline specification and axis determination in viviparous and oviparous pea aphids: conserved and divergent features. Dev Genes Evol 232, 51–65 (2022). https://doi.org/10.1007/s00427-022-00690-7 

Developmental expression of Aphb, an orthologue of Drosophila hunchback (hb) gene in the pea aphid, in mature embryos. Expression of Aphb can be identified in the neuroblasts and remains a conserved feature as in other insect hb orthologues. Surprisingly, transcripts of Aphb can also be identified in the germarial cells, which are derived from the germ cells, in the dorsal region of the mature embryos. This suggests that Aphb may obtain a novel role in germline develop-ment in the asexual viviparous aphids. Photo: Chen-yo Chung and Chun-che Chang, Laboratory for Genomics and Develop-ment, Department of Entomology, National Taiwan University, Taipei, Taiwan.

Aphids under the spotlight. At the 9th International Symposium on Aphids (9ISA; 2-6 June 2013, Beijing, China), scientists met to discuss recent developments in basic and applied aphid research. This special issue on 9ISA describes the current progress in aphid studies as presented at the Symposium. The cover picture represents the emergence of aphids as an insect models for ecological, evolutionary, and developmental studies. The fluorescent in situ hybridization image in the center shows that all asexual viviparous aphids are derived from the germ cells labeled with the conserved germline marker vasa (see pages 265-277). Image credit: Chen-yo Chung, Xiao-Lei Huang, Shih-Hsin Chuang, Shipher Wu, and Chun-che Chang.

This montage image shows the morphology of an asexual pea aphid ovariole. The germarium, oocyte, and early embryos were stained with a cross-reacting antibody against the Drosophila Nanos protein, which is a germline marker. Localized Nanos signals (green) were identified in presumptive germ cells in the posterior area of the blastoderm, suggesting that other localized signals in earlier stages reveal the position of germ plasm. Nuclei were stained with DAPI (blue) and F-actin was stained with phalloidin (red). For further details, see the article by Chang et al pp 413-421 in the present issue.

Cover Photo. Staining Schistocerca egg at late heart stage with a Vasa cross-reactive antibody. A Schistocerca embryonic primordium in the 15%/48 hAEL egg is stained with a Vasa cross-reactive antibody. Many cells in the embryonic primordium are unstained. Outside the embryo, there is a population of large heavily stained cells (black), which are probably the forming serosa. They are interspersed with a population of unstained nuclei which may be yolk syncytial nuclei (blue). In the yolk side, localization of Vasa protein in the margin of the embryonic primordium is first identified at this stage, which may be the potential germ-cell precursors.

See the article by Chang et al., pages 100-118, in this issue

I thank the students and others who have provided constructive feedback on

the earlier editions of this book and Ke Wu, Niklaus Hostettler, Jennifer Gillett-Kaufman, and Aaron Pomerantz, who assisted me in the preparation of this edition. I especially thank Geoffrey Attardo, Susan Brown, Lyle Buss, Chun-che Chang, Michael Clark, Cameron Currie, Marian Goldsmith, Thom Kaufman, Jason Meyer, James Newman, Jeffrey Stuart, and Yoshi Tomoyasu for their excellent photographs of the arthropod species illustrated on the cover of this book for which genome-sequence data are available. 

Preface to the Third Edition

My very best wishes for a productive and interesting read. I believe that molecular-genetic tools will help to resolve many critical issues in arthropod biology, evolution, and pest management.

Marjorie A. Hoy

Eminent Scholar and Davies,

Fischer and Eckes Professor of Biological Control,

Department of Entomology and Nematology,

University of Florida, Gainesville

September 2012