Stages of embryonic development in the amphipod crustacean,Parhyale hawaiensis

Abstract

Studying the relationship between development and evolution and its role in the generation of biological diversity has been reinvigorated by new techniques in genetics and molecular biology. However, exploiting these techniques to examine the evolution of development requires that a great deal of detail be known regarding the embryonic development of multiple species studied in a phylogenetic context. Crustaceans are an enormously successful group of arthropods and extant species demonstrate a wide diversity of morphologies and life histories. One of the most speciose orders within the Crustacea is the Amphipoda. The embryonic development of a new crustacean model system, the amphipod Parhyale hawaiensis, is described in a series of discrete stages easily identified by examination of living animals and the use of commonly available molecular markers on fixed specimens. Complete embryogenesis occurs in 250 h at 26 degrees C and has been divided into 30 stages. This staging data will facilitate comparative analyses of embryonic development among crustaceans in particular, as well as between different arthropod groups. In addition, several aspects of Parhyale embryonic development make this species particularly suitable for a broad range of experimental manipulations.

A versatile strategy for gene trapping and trap conversion in emerging model organisms

“…1). As a proof of principle, we demonstrate iTRAC in Parhyale hawaiensis, a crustacean that has emerged as an attractive model for developmental studies (Browne et al, 2005;Extavour, 2005;Gerberding et al, 2002;Liubicich et al, 2009;Ozhan-Kizil et al, 2008;Pavlopoulos and Averof, 2005;Pavlopoulos et al, 2009;Price et al, 2010;Rehm et al, 2009;Vargas-Vila et al, 2010).…”

Engrailed-like immunoreactivity in the embryonic ventral nerve cord of the Marbled Crayfish (Marmorkrebs)

“…The epitope has been localized to residues 38-58 of the homeodomain, and this epitope is conserved between invected and engrailed proteins. Immunolocalization experiments with this antibody in Drosophila, grasshoppers, crayfish and other crustaceans have provided evidence for consistent staining patterns during embryonic segmentation suggesting an evolutionary conservation of the epitope that 4D9 recognizes across the Euarthropoda (Patel et al 1989a, b;Scholtz et al 1993Scholtz et al , 1994Browne et al 2005;Alwes and Scholtz 2006). Abzhanov and Kaufman (2000) have cloned partial cDNAs of engrailed from crayfish and for this organism have reported the presence of two engrailed paralogous, en1 and en2, similar to the situation in insects.…”

“…3c, d) and that considering their position show some resemblance to ''median neuroblast progeny'' (MP) as is present in other arthropods. This type of cell has been described for grasshoppers (Condron et al 1994), the amphipod crustaceans Orchestia cavimana (Gerberding and Scholtz 1999) and Parhyale hawaiensis (Browne et al 2005), and the crayfish Procambarus clarkii (DumanScheel and Patel 1999; the median neuroblast itself is not En-li? in these species).…”

“…In crustaceans, the expression pattern and role of the Engrailed protein (En) has been intensely studied during segmentation of malacostracan embryos (Patel et al 1989a, b;Scholtz et al 1993Scholtz et al , 1994Scholtz 1995;Gerberding and Scholtz 1999;Abzhanov and Kaufman 2000;Browne et al 2005;reviews: Patel 1994, Scholtz and Dohle 1996, Dohle and Scholtz 1997, Scholtz, 2001. As for crayfish, the pattern of En expression during germ band formation has been thoroughly analyzed in Procambarus clarkii (Patel et al 1989b) using the monoclonal antibody 4D9 and has also been briefly documented in the Marbled Crayfish (Alwes and Scholtz 2006).…”

“…In addition to segmentation, several reports exist on the neuronal expression of the En protein in the ventral nerve cord of malacostracan embryos (Scholtz 1995;Harzsch et al 1998;Duman-Scheel and Patel 1999;Abzhanov and Kaufman 2000;Browne et al 2005). A detailed comparison of neuronal En expression in Malacostraca with that in Insecta has been undertaken by Duman-Scheel and Patel (1999) who suggested five distinct En-positive cell types to be homologous throughout the two groups.…”