Université de Fribourg

Circadian and genetic modulation of visually-guided navigation in Drosophila larvae

Asirim, Ece Z. ; Humberg, Tim-Henning ; Maier, G. Larisa ; Sprecher, Simon G.

In: Scientific Reports, 2020, vol. 10, no. 1, p. 2752

Organisms possess an endogenous molecular clock which enables them to adapt to environmental rhythms and to synchronize their metabolism and behavior accordingly. Circadian rhythms govern daily oscillations in numerous physiological processes, and the underlying molecular components have been extensively described from fruit flies to mammals. Drosophila larvae have relatively simple nervous...

Université de Fribourg

Multilevel regulation of the glass locus during Drosophila eye development

Fritsch, Cornelia ; Bernardo-Garcia, F. Javier ; Humberg, Tim-Henning ; Mishra, Abhishek Kumar ; Miellet, Sara ; Almeida, Silvia ; Frochaux, Michael V. ; Deplancke, Bart ; Huber, Armin ; Sprecher, Simon G.

In: PLOS Genetics, 2019, vol. 15, no. 7, p. e1008269

Development of eye tissue is initiated by a conserved set of transcription factors termed retinal determination network (RDN). In the fruit fly Drosophila melanogaster, the zinc-finger transcription factor Glass acts directly downstream of the RDN to control identity of photoreceptor as well as non-photoreceptor cells. Tight control of spatial and temporal gene expression is a critical...

Université de Fribourg

Muscarinic acetylcholine receptor signaling generates OFF selectivity in a simple visual circuit

Qin, Bo ; Humberg, Tim-Henning ; Kim, Anna ; Kim, Hyong S. ; Short, Jacob ; Diao, Fengqiu ; White, Benjamin H. ; Sprecher, Simon G. ; Yuan, Quan

In: Nature Communications, 2019, vol. 10, no. 1, p. 1–16

ON and OFF selectivity in visual processing is encoded by parallel pathways that respond to either light increments or decrements. Despite lacking the anatomical features to support split channels, Drosophila larvae effectively perform visually- guided behaviors. To understand principles guiding visual computation in this simple circuit, we focus on investigating the physiological properties...

Université de Fribourg

Two pairs of drosophila central brain neurons mediate larval navigational strategies based on temporal light information processing

Humberg, Tim-Henning ; Sprecher, Simon G.

In: Frontiers in Behavioral Neuroscience, 2018, vol. 12, p. -

Some animals are attracted by sun light, others are highly repulsed by it. Especially for slowly moving animals, such as Drosophila larvae, direct sunlight may be perceived as noxious stimulus as it increases the risk of desiccation, DNA-damaging by UV-light and exposure to predators. For several reasons, model organisms like Drosophila larvae are well-suited for investigating how light cues...

Université de Fribourg

Patterning mechanisms diversify neuroepithelial domains in the Drosophila optic placode

Mishra, Abhishek Kumar ; Bernardo-Garcia, F. Javier ; Fritsch, Cornelia ; Humberg, Tim-Henning ; Egger, Boris ; Sprecher, Simon G.

In: PLOS Genetics, 2018, vol. 14, no. 4, p. e1007353

The central nervous system develops from monolayered neuroepithelial sheets. In a first step patterning mechanisms subdivide the seemingly uniform epithelia into domains allowing an increase of neuronal diversity in a tightly controlled spatial and temporal manner. In Drosophila, neuroepithelial patterning of the embryonic optic placode gives rise to the larval eye primordium, consisting of...

Université de Fribourg

Dedicated photoreceptor pathways in Drosophila larvae mediate navigation by processing either spatial or temporal cues

Humberg, Tim-Henning ; Bruegger, Pascal ; Afonso, Bruno ; Zlatic, Marta ; Truman, James W. ; Gershow, Marc ; Samuel, Aravinthan ; Sprecher, Simon G.

In: Nature Communications, 2018, vol. 9, no. 1, p. 1260

To integrate changing environmental cues with high spatial and temporal resolution is critical for animals to orient themselves. Drosophila larvae show an effective motor program to navigate away from light sources. How the larval visual circuit processes light stimuli to control navigational decision remains unknown. The larval visual system is composed of two sensory input channels,...

Université de Fribourg

Age- and wavelength-dependency of drosophila larval phototaxis and behavioral responses to natural lighting conditions

Humberg, Tim-Henning ; Sprecher, Simon G.

In: Frontiers in Behavioral Neuroscience, 2017, vol. 11, p. -

Animals use various environmental cues as key determinant for their behavioral decisions. Visual systems are hereby responsible to translate light-dependent stimuli into neuronal encoded information. Even though the larval eyes of the fruit fly Drosophila melanogaster are comparably simple, they comprise two types of photoreceptor neurons (PRs), defined by different Rhodopsin genes expressed....

Université de Fribourg

Successive requirement of Glass and Hazy for photoreceptor specification and maintenance in Drosophila

Bernardo-Garcia, F. Javier ; Humberg, Tim-Henning ; Fritsch, Cornelia ; Sprecher, Simon G.

In: Fly, 2017, vol. 11, no. 2, p. 112–120

Development of the insect compound eye requires a highly controlled interplay between transcription factors. However, the genetic mechanisms that link early eye field specification to photoreceptor terminal differentiation and fate maintenance remain largely unknown. Here, we decipher the function of 2 transcription factors, Glass and Hazy, which play a central role during photoreceptor...