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A major role for zygotic hunchback in patterning the Nasonia embryo

Department of Biology, Western Washington University, Bellingham, WA 98225, USA.
Development (Impact Factor: 6.27). 09/2005; 132(16):3705-15. DOI: 10.1242/dev.01939
Source: PubMed

ABSTRACT Developmental genetic analysis has shown that embryos of the parasitoid wasp Nasonia vitripennis depend more on zygotic gene products to direct axial patterning than do Drosophila embryos. In Drosophila, anterior axial patterning is largely established by bicoid, a rapidly evolving maternal-effect gene, working with hunchback, which is expressed both maternally and zygotically. Here, we focus on a comparative analysis of Nasonia hunchback function and expression. We find that a lesion in Nasonia hunchback is responsible for the severe zygotic headless mutant phenotype, in which most head structures and the thorax are deleted, as are the three most posterior abdominal segments. This defines a major role for zygotic Nasonia hunchback in anterior patterning, more extensive than the functions described for hunchback in Drosophila or Tribolium. Despite the major zygotic role of Nasonia hunchback, we find that it is strongly expressed maternally, as well as zygotically. Nasonia Hunchback embryonic expression appears to be generally conserved; however, the mRNA expression differs from that of Drosophila hunchback in the early blastoderm. We also find that the maternal hunchback message decays at an earlier developmental stage in Nasonia than in Drosophila, which could reduce the relative influence of maternal products in Nasonia embryos. Finally, we extend the comparisons of Nasonia and Drosophila hunchback mutant phenotypes, and propose that the more severe Nasonia hunchback mutant phenotype may be a consequence of differences in functionally overlapping regulatory circuitry.

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    • "c body region , has also been detected in several insect species , includ - ing the beetle Tribolium castaneum and the cricket Gryllus bimaculatus , and the millipede Glomeris marginata , in which the hunchback domains encompass the presumptive gnathal and / or first thoracic segments ( Tautz et al . 1987 ; Wolff et al . 1995 ; Mito et al . 2005 ; Pultz et al . 2005 ; Janssen et al . 2011 ) ."
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    • "Nv otd acts in combination with Nv hunchback (hb) and localized maternal Nv giant (gt) at the anterior, and with localized maternal Nv caudal (cad) at the posterior, to specify positional identity. The domains of zygotic expression of Nv hb, Nv gt, Nv cad, Nv Krüppel (Kr), Nv tailless (tll), and Nv knirps (kni) closely resemble their Drosophila counterparts, consistent with a similar mode of blastoderm allocation (Pultz et al., 2005; Lynch et al., 2006; Olesnicky et al., 2006; Brent et al., 2007). Although these data support Drosophila-like early regulatory interactions and a long germ mode of embryogenesis, little was known about later stages of Nasonia embryonic patterning. "
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    • "To analyse Hb expression, we used a cross-reacting antibody against the Nasiona vitripennis protein (Pultz et al., 2005 "
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