Measuring spatial preferences at fine-scale resolution identifies known and novel cis-regulatory element candidates and functional motif-pair relationships

AbstractIn the mouse, 129 functional class I odorant receptor (OR) genes reside in a ~ 3 megabase huge gene cluster on chromosome 7. The J element, a long-range cis-regulatory element governs the singular expression of class I OR genes by exerting its effect over the whole cluster. To elucidate the molecular mechanisms underlying class I-specific enhancer activity of the J element, we analyzed the J element sequence to determine the functional region and essential motif. The 430-bp core J element, that is highly conserved in mammalian species from the platypus to humans, contains a class I-specific conserved motif of AAACTTTTC, multiple homeodomain sites, and a neighboring O/E-like site, as in class II OR-enhancers. A series of transgenic reporter assays demonstrated that the class I-specific motif is not essential, but the 330-bp core J-H/O containing the homeodomain and O/E-like sites is necessary and sufficient for class I-specific enhancer activity. Further motif analysis revealed that one of homeodomain sequence is the Greek Islands composite motif of the adjacent homeodomain and O/E-like sequences, and mutations in the composite motif abolished or severely reduced class I-enhancer activity. Our results demonstrate that class I and class II enhancers share a functional motif for their enhancer activity.

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High Resolution Stereography of Complementary Freeze-Fracture Replicas Reveals the Presence of Depressions Opposite Membrane Associated Particles of Split Membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066267 ◽

1971 ◽

Vol 29 ◽

pp. 442-443

Author(s):

Russell L. Steere

Keyword(s):

High Resolution ◽

Cardiac Muscle ◽

Electron Micrographs ◽

Chromic Acid ◽

Freeze Fracture ◽

Distilled Water ◽

Fine Scale ◽

Acid Cleaning ◽

Cleaning Solution

Complementary replicas have revealed the fact that the two common faces observed in electron micrographs of freeze-fracture and freeze-etch specimens are complementary to each other and are thus the new faces of a split membrane rather than the original inner and outer surfaces (1, 2 and personal observations). The big question raised by published electron micrographs is why do we not see depressions in the complementary face opposite membrane-associated particles? Reports have appeared indicating that some depressions do appear but complementarity on such a fine scale has yet to be shown.Dog cardiac muscle was perfused with glutaraldehyde, washed in distilled water, then transferred to 30% glycerol (material furnished by Dr. Joaquim Sommer, Duke Univ., and VA Hospital, Durham, N.C.). Small strips were freeze-fractured in a Denton Vacuum DFE-2 Freeze-Etch Unit with complementary replica tooling. Replicas were cleaned in chromic acid cleaning solution, then washed in 4 changes of distilled water and mounted on opposite sides of the center wire of a Formvar-coated grid.

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Comparison of Fine-Scale Recombination Rates in Humans and Chimpanzees

Yearbook of Obstetrics Gynecology and Women s Health ◽

10.1016/s1090-798x(08)70303-5 ◽

2006 ◽

Vol 2006 ◽

pp. 16-17

Author(s):

S.E. Bulun

Keyword(s):

Fine Scale ◽

Recombination Rates

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Fine-scale temporal study of the influence of hydrobiological conditions on the spawning of the sea urchin Strongylocentrotus intermedius

Marine Ecology Progress Series ◽

10.3354/meps11678 ◽

2016 ◽

Vol 550 ◽

pp. 147-161 ◽

Cited By ~ 6

Author(s):

PM Zhadan ◽

MA Vaschenko ◽

VB Lobanov ◽

AF Sergeev ◽

SA Kotova

Keyword(s):

Sea Urchin ◽

Strongylocentrotus Intermedius ◽

Fine Scale ◽

Temporal Study

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Fine-scale taxonomic and temporal variability in the energy density of invertebrate prey of juvenile Chinook salmon Oncorhynchus tshawytscha

Marine Ecology Progress Series ◽

10.3354/meps13513 ◽

2020 ◽

Vol 655 ◽

pp. 185-198

Author(s):

J Weil ◽

WDP Duguid ◽

F Juanes

Keyword(s):

Energy Density ◽

Chinook Salmon ◽

Temporal Variability ◽

Energy Content ◽

Single Point ◽

Single Species ◽

Fine Scale ◽

Temporal Differences ◽

Juvenile Chinook Salmon ◽

Juvenile Chinook

Variation in the energy content of prey can drive the diet choice, growth and ultimate survival of consumers. In Pacific salmon species, obtaining sufficient energy for rapid growth during early marine residence is hypothesized to reduce the risk of size-selective mortality. In order to determine the energetic benefit of feeding choices for individuals, accurate estimates of energy density (ED) across prey groups are required. Frequently, a single species is assumed to be representative of a larger taxonomic group or related species. Further, single-point estimates are often assumed to be representative of a group across seasons, despite temporal variability. To test the validity of these practices, we sampled zooplankton prey of juvenile Chinook salmon to investigate fine-scale taxonomic and temporal differences in ED. Using a recently developed model to estimate the ED of organisms using percent ash-free dry weight, we compared energy content of several groups that are typically grouped together in growth studies. Decapod megalopae were more energy rich than zoeae and showed family-level variability in ED. Amphipods showed significant species-level variability in ED. Temporal differences were observed, but patterns were not consistent among groups. Bioenergetic model simulations showed that growth rate of juvenile Chinook salmon was almost identical when prey ED values were calculated on a fine scale or on a taxon-averaged coarse scale. However, single-species representative calculations of prey ED yielded highly variable output in growth depending on the representative species used. These results suggest that the latter approach may yield significantly biased results.

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