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SICB 2014 Annual Meeting Abstracts
S10.2−4 PRAKASH, M*; MUKUNDARAJAN, H; Stanford
University; [email protected]
Insect Flight on a Fluid Interfaces and Chaotic Oscillators
Here we present the discovery of a novel mode of interfacial "2D
flight" in water lily beetles (Galerucella nymphaeae), that are capable
of multiple modes of flapping−wing locomotion along a fluid
interface, as well as fully−fledged airborne flight. 2D flight is
characterized by a novel set of physical constraints because of it's
coupling to a fluid interface (say, surface of a pond) and the role of of
capillary−gravity wave trains behind the moving insect. Here, we
analyze the kinematics of 2D flight, highlight key differences in this
unique mode of flight and develop a dynamic model to explain flight
characteristics. Finally, we present an analysis of the vertical
oscillations in the flight trajectory due to the non−linear forced
oscillator created by vertical wing lift and surface tension. Utilizing
this technique, we further outline a method for tether−free
measurement of flight forces in insects.
99.8 PRESNELL, JS*; SCHNITZLER, CE; BROWNE, WE;
University of Miami, FL, National Human Genome Research
Institute, NIH, Bethesda, MD; [email protected]
Klf/Sp transcription factor family expansion, diversification, and
innovation in the Unikonta
The Krüppel−like factor (Klf) gene family consists of two groups of
transcription factors, Klf and Specificity protein (Sp) factors. KLF/SP
proteins bind GT box and GC−rich DNA sequences associated with
gene regulatory regions through a highly conserved DNA binding
domain (DBD) composed of three C−terminal C2H2 zinc fingers
(KLF−DBD). Members of the Klf gene family influence transcription
via interactions with other transcription factors, cofactors, chromatin
remodeling factors, and transcriptional machinery components.
These protein−protein interactions are mediated by an array of
transactivation domains typically found N−terminal of the
KLF−DBD. Collectively the Klf/Sp genes play key roles in a variety
of critical biological processes including cell proliferation, stem cell
maintenance, embryonic development, and tissue differentiation and
they have been implicated in a number of human diseases and
cancers. Many Klf/Sp genes have been characterized in a handful of
bilaterian lineages, however very little is known about the Klf gene
family in non−bilaterians and virtually nothing is known outside of
the metazoans. We identified and characterized the complete Klf/Sp
gene complement from the genomes of 14 lineages spanning the
Unikonta. We also examined the phylogenetic distribution of
transactivation domains associated with the Klf gene family. Within
the Metazoa, the expansion of the Klf gene family transactivation
repertoire is strongly associated with the expansion of cell type
complexity. Our results indicate that expansion of the Klf gene family
is paralleled by transactivation domain diversification via both the
acquisition of pre−existing ancient domains as well as by the
appearance of novel domains exclusive to the Klf gene family.
98.3 PRICE, E.R.*; CAVIEDES−VIDAL, E.; KARASOV, W.H.;
University of Wisconsin−Madison, Universidad Nacional de San
Luis; [email protected]
Mechanistic correlates of paracellular nutrient absorption in
protein specialists
Water−soluble nutrients (e.g., glucose and amino acids) can be
absorbed across enterocytes via protein−mediated transport, or
paracellularly through the tight junctions between enterocytes.
Previously we demonstrated that absorption of arabinose (a
nutrient−sized paracellular probe) was higher in intact insectivorous
bats (Tadarida brasiliensis and Myotis lucifugus) when compared to
insectivorous rodents (Onychomys leucogaster and Peromyscus
leucopus). This phenomenon can also be observed in isolated
intestines: in intestinal perfusions, arabinose clearance was higher in
insectivorous bats compared to insectivorous rodents when compared
on a nominal surface area basis. This implies that bats have either
more tight junctions per nominal surface area (for example via longer
villi) and/or bats have leakier tight junctions (perhaps achieved via
differential expression of the proteins that form the tight junctions).
We investigated these mechanistic correlates using histological
examination of intestines and by measuring gene expression of
several claudin proteins. Supported by NSF Award 1025886.
January 3−7, 2014, Austin, TX
Downloaded from http://icb.oxfordjournals.org/ at Biomedical Library Gent on June 5, 2014
14.2 PRAET, T; ADRIAENS, D*; NEUTENS, C; MAIA, A; DE
BEULE, M; VERHEGGHE, B; Ghent University, IBiTech −
bioMMeda, Ghent University, Evolutionary Morphology of
Vertebrates, Eastern Illinois University, Dept. of Biological Sciences;
[email protected]
Understanding the mechanics of tail grasping in seahorses using a
parametrized computer model
Seahorses are intriguing fishes for several reasons, one being their
prehensile tail. Syngnathid fishes, to which seahorses, pipefish,
seadragons and pipehorses belong, are characterised by a body
armour of bony plates. They form a serially articulated system that
encloses the vertebral column and its musculature. In the ancestral
condition, as in pipefish, the tail is straight with limited flexibility,
and mainly used for steering (pectorals and dorsal used for
swimming). During evolution, the tail became modified into a
grasping apparatus multiple times independently within the
syngnathid family. Less known than the seahorse prehensile
capabilities, pipehorses also show different morphologies related to
grasping performance. To better understand the structural basis of tail
grasping mechanics, a parameterized model of the seahorse tail was
developed. By combining multibody dynamics analysis with finite
element analysis, we analysed the implication of partial contribution
of epaxial and hypaxial muscles, versus ventral median muscle, as
well as that of the bony plate geometry. Natural bending postures, as
observed in living seahorses, can be obtained up to some degree. The
analyses showed particular relations between morphology and
bending kinematics. Using this seahorse model, functional
implications of evolutionary changes in in syngnathid tails can be
further analysed, as well as to develop biomimetic designs of serially
articulated systems that meet particular application demands.