Histological section from the base of the 5th pereiopod of a <i>P</i>. <i>fallax</i> male.

<p>Three different enlargements are presented (×4, ×10 and ×40). The exact area presented in the enlargement in the right panel is surrounded by a black frame in the left and middle panels. Sperm duct (SD), androgenic gland (AG), cuticle (Ct), and muscle (Ms). The sections were stained with H&E.</p

The gene encoding the insulin-like androgenic gland hormone in an all-female parthenogenetic crayfish - Fig 5

<p><b>Structure of <i>Pf-IAG</i> mRNA (A) and the genomic structures of <i>Pf-IAG</i> (B) and <i>Pfv-IAG</i> (C).</b> The different components of <i>Pf-IAG</i> mRNA are colored in different shades of grey, and the length of each component is indicated on the figure. Exons and introns of <i>Pf-IAG</i> DNA and their corresponding sequences in the marbled crayfish genome (<i>Pfv-IAG</i>) are indicated by the letters 'E' and 'I', respectively. The intron that was not fully sequenced (intron 1) is indicated with an asterisk. The identity (in percentage) of the exons and introns between the two genomic sequences is indicated.</p

Phylogenetic tree of deduced IAG protein sequences in 18 crustacean species.

<p>Pf-IAG is indicated with a black arrow. The bar represents the number of amino acid substitutions per site. Bootstrap values (1000 tests) are indicated on the branches.</p

Primers used for genome walking.

<p>The schematic order of the primers used for genome walking upstream (gray arrows) and downstream (black arrows) is represented.</p

Primer sequences used in this study.

<p>Primer sequences used in this study.</p

Predicted structure of Pf-IAG.

<p>The full sequence of <i>Pf-IAG</i> mRNA and its open reading frame (ORF)-deduced amino acids. The signal peptide is shown in italics. B (first) and A (second) chains are marked with a gray background, with C peptide, including its cleavage sites (underlined), flanked between them. The start codon (ATG) is underlined, and the stop codon (TGA) is underlined and indicated with an asterisk.</p

Spatial expression of <i>Pf-IAG</i> mRNA in <i>P</i>. <i>fallax</i> and in the marbled crayfish.

<p>RNA was extracted from a <i>P</i>. <i>fallax</i> male, <i>P</i>. <i>fallax</i> female and a marbled crayfish from the following tissues: right and left 5th pereiopods (R/L-5^th), gonad, hepatopancreas, abdominal muscle and cuticle. The negative control (Neg) is shown, and 12S rRNA served as the positive control.</p

Post-Embryonic Transcriptomes of the Prawn <em>Macrobrachium rosenbergii:</em> Multigenic Succession through Metamorphosis

<div><p>Like many metazoans, the freshwater prawn <em>Macrobrachium rosenbergii</em> begins its post-embryonic life with a set of morphologically distinct planktonic larval stages, followed by a benthic post-larval stage during which the maturing organism differs from the larvae both ecologically and physiologically. Understanding of the molecular basis underlying morphogenesis in crustaceans is limited to the observation that methyl farnesoate, the non-epoxidated form of the insect juvenile hormone, acts as the active crustacean juvenoid. Molt steroids were also linked to morphogenesis and several other molecular pathways, such as Hedgehog and Wnt, are known to underlie morphogenesis in all metazoans examined and, as such, are thought to do the same in crustaceans. Using next generation sequencing, we deep-sequenced the transcriptomes of several larval and post-larval stages. <em>De novo</em> assembly, followed by bioinformatics analysis, revealed that many novel transcripts are over-expressed in either larvae- or post-larvae-stage prawn, shedding light on the molecular basis underlying <em>M. rosenbergii</em> metamorphosis. Fast larval molting rates and periodic morphological changes were reflected in over-expression of transcripts annotated to the cell cycle, DNA replication and morphogenic pathways (i.e., Hedgehog and Wnt). Further characterization of transcripts assigned to morphogenic pathways by real-time RT-PCR reconfirmed their over-expression in larvae, albeit with a more complex expression pattern when examined in the individual developmental stages. The expression level of an orthologue of cytochrome P450, 15A1, known to epoxidize methyl farnesoate in insects, was increased in the late larval and early post-larval stages, in accordance with the role of methyl farnesoate in crustacean metamorphosis. This study exemplifies the applicability of a high-throughput sequencing approach for studying complex traits, including metamorphosis, providing new insight into this unexplored area of crustacean research.</p> </div

Number of KO terms assigned to differentially represented transcripts in the <i>M. rosenbergii</i> developmental transcriptomic database.

<p>Number of KO terms assigned to differentially represented transcripts in the <i>M. rosenbergii</i> developmental transcriptomic database.</p

Number of transcripts differentially represented in the <i>M. rosenbergii</i> developmental transcriptomic database.

<p>Number of transcripts differentially represented in the <i>M. rosenbergii</i> developmental transcriptomic database.</p