dissection-immunohistochemistry-larval-pupal-adult-drosophila

Dissection and Immunohistochemistry of Larval, Pupal and Adult <em>Drosophila</em> Retinas

The compound eye of Drosophila melanogaster consists of about 750 ommatidia (unit eyes). Each ommatidium is composed of about 20 cells, including ...

The mammalian vomeronasal organ (VNO), a part of the olfactory system, detects pheromones--chemical signals that modulate social and reproductive behaviours. But the molecular receptors in the VNO that detect these chemosensory stimuli remain undefined. Candidate pheromone receptors are encoded by two distinct and complex superfamilies of genes, V1r and V2r (refs 3 and 4), which code for receptors with seven transmembrane domains. These genes are selectively expressed in sensory neurons of the VNO. However, there is at present no functional evidence for a role of these genes in pheromone responses. Here, using chromosome engineering technology, we delete in the germ line of mice an approximately 600-kilobase genomic region that contains a cluster of 16 intact V1r genes. These genes comprise two of the 12 described V1r gene families, and represent approximately 12% of the V1r repertoire. The mutant mice display deficits in a subset of VNO-dependent behaviours: the expression of male sexual behaviour and maternal aggression is substantially altered. Electrophysiologically, the epithelium of the VNO of such mice does not respond detectably to specific pheromonal ligands. The behavioural impairment and chemosensory deficit support a role of V1r receptors as pheromone receptors.

Deficient pheromone responses in mice lacking a cluster of vomeronasal receptor genes.

Mangelhafte Pheromon-Antworten in M&#xE4;usen, denen ein Cluster von vomeronasalen Rezeptor-Gene.

Neural cell fate programs must generate an enormous number of neurons with distinct adult functions. The decision to choose one neuronal subtype from two alternatives--a binary fate decision--is one way to diversify neuronal subtypes during nervous system development. Recent progress has been made in describing the genetic programs that define late-stage neuronal identity. Here, we review mechanisms that control how such fate decisions generate two different postmitotic, terminally differentiated neuronal subtypes. We survey examples from Caenorhabditis elegans and Drosophila that demonstrate different modes of binary neuronal fate specification that depend on cell division, lineage, stochastic gene expression, or extracellular signals. Comparison of these strategies reveals that, although organisms use diverse approaches to generate neural diversity, some common themes do exist.

Binary fate decisions in differentiating neurons.

Neuronale Zelle muss Schicksal eine enorme Anzahl von Neuronen mit getrennte Erwachsenen Funktionen erzeugen. Die Entscheidung f&uuml;r eine neuronale Untertyp aus zwei Alternativen--eine bin&auml;re Schicksal Entscheidung--ist eine M&ouml;glichkeit, neuronale Subtypen w&auml;hrend der Entwicklung des Nervensystems zu diversifizieren. J&uuml;ngste Fortschritte erzielt worden bei der Beschreibung der genetischen Programme, die Sp&auml;tstadium neuronale Identit&auml;t definieren. Hier &uuml;berpr&uuml;fen wir die Mechanismen, die kontrollieren, wie solche Entscheidungen Schicksal zwei postmitotischen, unheilbar differenzierte neuronale Subtypen generieren. Wir inspizieren Beispiele von Caenorhabditis Elegans und Drosophila zur Veranschaulichung verschiedene Modi der bin&auml;ren neuronale Schicksal-Spezifikation, die Zellteilung, Abstammung, stochastische Genexpression oder extrazellul&auml;re Signale abh&auml;ngen. Diese Strategien im Vergleich zeigt, dass zwar Organismen vielf&auml;ltige Ans&auml;tze, zum Generieren von neuronalen Vielfalt verwenden, gemeinsamen Themen vorhanden sind.

Bin&auml;re Schicksal Entscheidungen in Neuronen zu unterscheiden.

Patterning the Drosophila retina for color vision relies on postmitotic specification of photoreceptor subtypes. R8 photoreceptors express one of two light-sensing Rhodopsins, Rh5 or Rh6. This fate decision involves a bistable feedback loop between Melted, a PH-domain protein, and Warts, a kinase in the Hippo growth pathway. Here, we show that a subset of the Hippo pathway-Merlin, Kibra, and Lethal(2)giant larvae (Lgl), but not Expanded or Fat-is required for Warts expression and activity in R8 to specify Rh6 fate. Melted represses warts transcription to disrupt Hippo pathway activity and specify Rh5 fate. Therefore, R8 Hippo signaling exhibits ON-or-OFF regulation, promoting mutually exclusive fates. Furthermore, Merlin and Lgl are continuously required to maintain R8 neuronal subtypes. These results reveal roles for Merlin, Kibra, and Lgl in neuronal specification and maintenance and show that the Hippo pathway is reimplemented for sensory neuron fate by combining canonical and noncanonical regulatory steps.

Binary regulation of Hippo pathway by Merlin/NF2, Kibra, Lgl, and Melted specifies and maintains postmitotic neuronal fate.

Musterung der Drosophila-Netzhaut f&uuml;r Farbensehen basiert auf postmitotischen Spezifikation der Photorezeptoren Subtypen. R8 Photorezeptoren schnelles zwei Licht-Sensorik Rhodopsin, Rh5 oder Rh6. Dieses Schicksal Entscheidung beinhaltet eine bistabile R&uuml;ckkopplung zwischen Melted, ein Protein, das PH-Dom&auml;ne und Warzen, eine Kinase in die Hippo-Wachstum-Pathway. Hier zeigen, dass eine Teilmenge der Hippo Weg-Merlin, Kibra und t&ouml;dliche (2) Riesen Larven (Lgl), aber nicht erweitert oder Fett-f&uuml;r Warzen Expression und Aktivit&auml;t im R8 Rh6 Schicksal angeben ist erforderlich. Geschmolzene Represses Warzen Transkription Hippo Stoffwechselweg Aktivit&auml;t zu st&ouml;ren und angeben Rh5 Schicksal. Daher weist die R8 Hippo Signalisierung an-oder aus Verordnung, gegenseitig Schicksale zu f&ouml;rdern. Dar&uuml;ber hinaus sind Merlin und Lgl kontinuierlich verpflichtet R8 neuronale Untertypen. Diese Ergebnisse lassen sich mit Rollen f&uuml;r Merlin, Kibra und Lgl in neuronale Spezifikation und Verwaltung und zeigen, dass die Hippo-Pathway f&uuml;r sensorische Neuron Schicksal erneut implementiert wird durch die Kombination von kanonischen und Mitgliedattribut rechtliche Schritte.

Article	Year
Deficient pheromone responses in mice lacking a cluster of vomeronasal receptor genes. Nature\| PubMed ID: 12214233	2002
Binary fate decisions in differentiating neurons. Current opinion in neurobiology\| PubMed ID: 20022236	2010
Binary regulation of Hippo pathway by Merlin/NF2, Kibra, Lgl, and Melted specifies and maintains postmitotic neuronal fate. Developmental cell\| PubMed ID: 22055343	2011

David Jukam

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