Isolation of a marker for head-specific cell differentiation in hydra

Hermans‐Borgmeyer, Irm; Schinke, Birgitta; Schaller, Heinz; Hoffmeister-Ullerich, Sabine

doi:10.1046/j.1432-0436.1996.6120095.x

Cited by 15 publications

(7 citation statements)

References 18 publications

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“…The time course of events is in agreement with early reports that showed an increase of the head-forming potential between 3 and 7 h after sectioning (MacWilliams 1983 and references therein), and fits with results obtained by investigating lithium-sensitive phases during regeneration, which showed that the fate of tissue its determined by about that time (Hassel et al 1993). Whilst components of important signal transduction cascades are upregulated or activated irrespective of the structure formed, there are also examples of early upregulation of structure-specific genes, like ks1 and hyp1, the functions of which are unknown (Weinziger et al 1994;Hermans-Borgmeyer et al 1996). Therefore, it seems reasonable to postulate a mechanism for Hydra patterning, in which (part of) the important signal transduction cascades like HvPKC2 and CREB are used without specificity for the structure, but are activated and their responses modulated by regio-specific signalling molecules.…”

Section: Hvpkc2 and Patterning In Hydrasupporting

confidence: 59%

The level of expression of a protein kinase C gene may be an important component of the patterning process in Hydra

Hassel

Bridge

Stover

et al. 1998

Development Genes and Evolution

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Several studies have provided strong, but indirect evidence that signalling through pathways involving protein kinase C (PKC) plays an important role in morphogenesis and patterning in Hydra. We have cloned a gene (HvPKC2) from Hydra vulgaris which encodes a member of the nPKC subfamily. In adult polyps, HvPKC2 is expressed at high levels in two locations, the endoderm of the foot and the endoderm of the hypostomal tip. Increased expression of HvPKC2 is an early event during head and foot regeneration, with the rise in expression being restricted to the endodermal cells underlying the regenerating ends. No upregulation is observed if regenerates are cut too close to the head to form a foot. Elevated expression of HvPKC2 is also observed in the endoderm underlying lithium-induced ectopic feet. A dynamic and complex pattern of expression is seen in developing buds. Regeneration of either head or foot is accompanied by an increase in the amount of PKC in both soluble and particulate fractions. An increase in the fraction of PKC activity which is membrane-bound is specifically associated with head regeneration. Taken together these data suggest that patterning of the head and foot in Hydra is controlled in part by the level of HvPKC2 expression, whilst head formation is accompanied by an in vivo activation of both calcium-dependent and independent PKC isoforms.

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Section: Hvpkc2 and Patterning In Hydrasupporting

confidence: 59%

The level of expression of a protein kinase C gene may be an important component of the patterning process in Hydra

Hassel

Bridge

Stover

et al. 1998

Development Genes and Evolution

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“…Expression of the peptide Hym-301 and polypeptide Hyp-1 is observed from the cuticle stage on. In adult polyps, expression of both peptide genes is sensitive to changes in positional signals along the body column (Takahashi et al 1997;Hermans-Borgmeyer et al 1996). Overall, the RT-PCR analysis in Fig.…”

Section: Spatial and Temporal Expression Analysis Of Developmental Gementioning

confidence: 83%

Expression of developmental genes during early embryogenesis of Hydra

Fröbius

Genikhovich

Kürn

et al. 2003

Development Genes and Evolution

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Hydra is a classical model to study key features of embryogenesis such as axial patterning and stem cell differentiation. In contrast to other organisms where these mechanisms are active only during embryonic development, in Hydra they can be studied in adults. The underlying assumption is that the machinery governing adult patterning mimics regulatory mechanisms which are also active during early embryogenesis. Whether, however, Hydra embryogenesis is governed by the same mechanisms which are controlling adult patterning, remains to be shown. In this paper, in precisely staged Hydra embryos, we examined the expression pattern of 15 regulatory genes shown previously to play a role in adult patterning and cell differentiation. RT-PCR revealed that most of the genes examined were expressed in rather late embryonic stages. In situ hybridization, nuclear run-on experiments, and staining of nucleolar organizer region-associated proteins indicated that genes expressed in early embryos are transcribed in the engulfed "nurse cells" (endocytes). This is the first direct evidence that endocytes in Hydra not only provide nutrients to the developing oocyte but also produce maternal factors critical for embryogenesis. Our findings are an initial step towards understanding the molecular machinery controlling embryogenesis of a key group of basal metazoans and raise the possibility that in Hydra there are differences in the mechanisms controlling embryogenesis and adult patterning.

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“…4). Hyp 1, encoding a product with no significant similarity to any known protein (34), is expressed in a pattern antithetical to that of Cn-ems. Specifically, hyp-1 expression is high at the mouth, where Cn-ems is not expressed, and attenuates aborally, with expression restricted to inter-taeniolar furrows to a limit at the tentacle zone.…”

Section: Discussionmentioning

confidence: 99%

“…This correlation, coupled with Cn-ems expression restricted to the heads in adult polyps, suggests that Cn-ems also may play a role in developmental patterning of the head. Budhead (35) and hyp 1 (34) both are expressed in regenerating heads, suggesting that these genes may be expressed together with Cn-ems in developing heads. Thus, hyp 1, budhead, and Cn-ems are good candidates for genes responsible for establishing and͞or maintaining the axial and radial organization of the hydrozoan head.…”

Section: Discussionmentioning

confidence: 99%

Over one-half billion years of head conservation? Expression of an ems class gene in Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa)

Mokady

Dick

Lackschewitz

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

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We report the isolation of an empty spiracles class homeodomain-containing gene, Cn-ems, from the hydrozoan Hydractinia symbiolongicarpus, the first gene of this class characterized in a lower metazoan. Cn-ems was found to be expressed in the head of gastrozooids, specifically in endodermal epithelial cells of the taeniolae of the hypostome. Cn-ems is not expressed in gonozooids, which lack taeniolae. Experimental conversion of the posterior region of the planula larva into head structures up-regulates expression of the gene. These findings establish that the association of ems-class genes with head structures preceded the evolution of bilateral symmetry.

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Isolation of a marker for head-specific cell differentiation in hydra

Cited by 15 publications

References 18 publications

The level of expression of a protein kinase C gene may be an important component of the patterning process in Hydra

The level of expression of a protein kinase C gene may be an important component of the patterning process in Hydra

Expression of developmental genes during early embryogenesis of Hydra

Over one-half billion years of head conservation? Expression of an ems class gene in Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa)

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