Sensorimotor control of Drosophila copulation
<p>Dipteran insects show a wide range of species-specific mating postures, and interspecific differences in the postures they adopt may reflect sexual selection acting on these traits. As with most sequences of motor action, mechanosensory inputs have long been thought to be important for the...
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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2020
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| _version_ | 1824458936324980736 |
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| author | Herbert, MR |
| author2 | Goodwin, S |
| author_facet | Goodwin, S Herbert, MR |
| author_sort | Herbert, MR |
| collection | OXFORD |
| description | <p>Dipteran insects show a wide range of species-specific mating postures, and interspecific differences in the postures they adopt may reflect sexual selection acting on these traits. As with most sequences of motor action, mechanosensory inputs have long been thought to be important for the male to achieve and maintain this position,although until now we have understood very little about the function or properties ofthe sensory neurons involved.</p>
<p>In Drosophila, the conserved transcription factor doublesex (dsx) is required for the specification of both male and female sexual identity. One of the key roles played by dsx is regulating the development of a sexually dimorphic nervous system and recent work has shown that dsx is expressed in external mechanoreceptor neurons that adorn the male genitalia (herein termed male terminal sensilla; MTS). Targeted manipulation of these MTS neurons may help to elicit a deeper understanding of the functional organisation of sensorimotor circuits that aid in the maintenance of body posture, but so far these manipulations have proved difficult to achieve with a reasonable level of specificity due to the broad expression domain of developmental genes such as dsx. </p>
<p>To address this issue, in this thesis I have screened a number of both publicly available and novel genetic driver lines with the aim of establishing spatially restricted genetic access to MTS neurons. By identifying those lines labelling our cells of interest, not only can we develop a genetic toolkit for manipulating their function, but we can also gain insights into their properties by identifying, for example, the expression of mechanosensitive ion channels such as nompC or the excitatory neurotransmitter ChAT. After identifying a sufficient number of useful lines, I then developed a series of novel split-GAL4 hemidriver lines that when combined with another driver - for example dsx<sup>DBD</sup> - reveal expression that is closely restricted to MTS neurons.</p>
<p>Following on from this, using the most suitable drivers that I have identified, I haveperformed a series of manipulations on MTS function in freely behaving male flies to quantify the effects on courtship and copulation. These results show clearly how sensory feedback from MTS neurons is important for mating posture, as even animals with only a small subset of MTS neurons being manipulated exhibit marked changesin mating posture. Effects on the likelihood and duration of copulation were also a common phenotype we identified in these manipulations, but we could not howeveridentify any obvious effect of the aberrant mating posture on reproductive success. </p>
<p>Lastly, taking insight from our behavioural experiments, we have leveraged genetically encoded calcium indicators and the transsynaptic labelling technology; trans-Tango,to identify and visualize connections between sensory MTS neurons and upstream circuits in an attempt to establish a view of how body movement can be coordinated via communication between many independent proprioceptive organs. Altogether, the data presented herein represents the characterisation of a relatively simple circuit for the control of body posture that shows some remarkable capabilities to receive input from other regions of the body and ultimately feed into centres for higher order processing in the brain.</p> |
| first_indexed | 2025-02-19T04:33:48Z |
| format | Thesis |
| id | oxford-uuid:d4ce84e0-f245-48e8-9b81-b6eb16e22102 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2025-02-19T04:33:48Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | oxford-uuid:d4ce84e0-f245-48e8-9b81-b6eb16e221022025-01-22T10:25:26ZSensorimotor control of Drosophila copulationThesishttp://purl.org/coar/resource_type/c_db06uuid:d4ce84e0-f245-48e8-9b81-b6eb16e22102NeurogeneticsEnglishHyrax Deposit2020Herbert, MRGoodwin, S<p>Dipteran insects show a wide range of species-specific mating postures, and interspecific differences in the postures they adopt may reflect sexual selection acting on these traits. As with most sequences of motor action, mechanosensory inputs have long been thought to be important for the male to achieve and maintain this position,although until now we have understood very little about the function or properties ofthe sensory neurons involved.</p> <p>In Drosophila, the conserved transcription factor doublesex (dsx) is required for the specification of both male and female sexual identity. One of the key roles played by dsx is regulating the development of a sexually dimorphic nervous system and recent work has shown that dsx is expressed in external mechanoreceptor neurons that adorn the male genitalia (herein termed male terminal sensilla; MTS). Targeted manipulation of these MTS neurons may help to elicit a deeper understanding of the functional organisation of sensorimotor circuits that aid in the maintenance of body posture, but so far these manipulations have proved difficult to achieve with a reasonable level of specificity due to the broad expression domain of developmental genes such as dsx. </p> <p>To address this issue, in this thesis I have screened a number of both publicly available and novel genetic driver lines with the aim of establishing spatially restricted genetic access to MTS neurons. By identifying those lines labelling our cells of interest, not only can we develop a genetic toolkit for manipulating their function, but we can also gain insights into their properties by identifying, for example, the expression of mechanosensitive ion channels such as nompC or the excitatory neurotransmitter ChAT. After identifying a sufficient number of useful lines, I then developed a series of novel split-GAL4 hemidriver lines that when combined with another driver - for example dsx<sup>DBD</sup> - reveal expression that is closely restricted to MTS neurons.</p> <p>Following on from this, using the most suitable drivers that I have identified, I haveperformed a series of manipulations on MTS function in freely behaving male flies to quantify the effects on courtship and copulation. These results show clearly how sensory feedback from MTS neurons is important for mating posture, as even animals with only a small subset of MTS neurons being manipulated exhibit marked changesin mating posture. Effects on the likelihood and duration of copulation were also a common phenotype we identified in these manipulations, but we could not howeveridentify any obvious effect of the aberrant mating posture on reproductive success. </p> <p>Lastly, taking insight from our behavioural experiments, we have leveraged genetically encoded calcium indicators and the transsynaptic labelling technology; trans-Tango,to identify and visualize connections between sensory MTS neurons and upstream circuits in an attempt to establish a view of how body movement can be coordinated via communication between many independent proprioceptive organs. Altogether, the data presented herein represents the characterisation of a relatively simple circuit for the control of body posture that shows some remarkable capabilities to receive input from other regions of the body and ultimately feed into centres for higher order processing in the brain.</p> |
| spellingShingle | Neurogenetics Herbert, MR Sensorimotor control of Drosophila copulation |
| title | Sensorimotor control of Drosophila copulation |
| title_full | Sensorimotor control of Drosophila copulation |
| title_fullStr | Sensorimotor control of Drosophila copulation |
| title_full_unstemmed | Sensorimotor control of Drosophila copulation |
| title_short | Sensorimotor control of Drosophila copulation |
| title_sort | sensorimotor control of drosophila copulation |
| topic | Neurogenetics |
| work_keys_str_mv | AT herbertmr sensorimotorcontrolofdrosophilacopulation |