CRICKETS IN SPACE-2 (CRISP-2)
Research Area: Animal Biology-Invertebrates
Expedition(s): 10 and 11
Principal Investigator(s): ● Eberhard R. Horn, University of Ulm, Ulm, Germany
RESEARCH OBJECTIVES
The Crickets in Space-2 (CRISP-2) experiment follows on from a previous experiment,
Development of an Insect Gravity Sensory System in Space, performed on the Neurolab STS-90
mission in 1998. Results revealed that the development of gravity-related behavior in crickets
was not affected by weightlessness while the physiology of a specific neuron linked to posture
sensitivity was modified.
RESULTS
Successful in-flight fertilization was obtained; high-quality
neuroanatomical stainings from embryonal nervous systems
were obtained; and after landing, embryos could be reared
until hatching to test consequences of in-flight fertilization
even on the behavioral level. A total number of 112
embryos and 1st larvae from in-flight fertilization were
available for the studies. The number of ground controls
was 103. Interestingly, the μg-exposed larvae hatched
earlier than larvae from the 1-g ground controls.
The results coming from the Eneide (Soyuz 10S/Soyuz 9S
exchange) flight revealed that after in-microgravity
fertilization, the AST-ir- , PSK-ir- , and CCAP-ir- neurones
developed as after on-ground fertilization. This holds not
only for neurons with only short neurites located either only
within the cerebrum, the thoracic, or the abdominal ganglia
chain, but also for those neurons such as PSK-ir neurons
that project throughout the whole nervous system, with cell
somata lying in the protocerebrum and dendritic
arborizations within the cerebral, thoracic, and abdominal
ganglia.
Lack of significant differences between 1 g- and altered gravity-larvae does not exclude an
altered-gravity sensitivity during early development. Compensatory mechanisms might be
activated during ongoing altered gravity conditions to overcome transient deviations from
normal neuronal development. The earlier hatching of the 1st instar larvae after in-flight
fertilization as demonstrated for the spaceflight experiment CRISP-2 makes this hypothesis very
likely.
Top: 1 of the 2 Cricket Containers (CC),
showing the adult compartment (CC-AC),
the egg collectors (CC-EC), and hatching
larvae compartments (CC-LC). Bottom:
Egg collectors in open and closed
configuration. ESA image.