Brian Layton Cardall

Brain Layton Cardall, Research & Publications

Brian Layton Cardall: Presentation & Question: Host-plant specificity in the saltcedar biocontrol beetle: is Diorhabda an agent of selection in Tamarix? (abstract) Oral presentation at 2009 Tamarisk and Russian Olive Research Conference, Tamarisk Coalition, Grand Sierra Resort, Reno, Nevada, February 19, 2009

Alicyn R. Gitlin, Brian L. Cardall, Steven M. Shuster, Gerard J. Allan, and Thomas G. Whitham

GENETIC DIVERSITY OF COTTONWOOD (POPULUS SP.) BEFORE, DURING, AND AFTER ESTABLISHMENT OF TAMARIX

Arizona Republic Council, Volume 22, Number 3 (December 2009)

Note: At the Arizona Riparian Council Spring 2009 Meeting, it was made known that the newsletter occasionally highlights the works of graduate students. Brian Cardall and Alicyn Gitlin are the first since that meeting to commit to this endeavor. We hope to do justice to Brian's intent and his work. Below we present a small subset of the research Brian and Alicyn discussed; he was working on so many projects that they won't all fit here!

There is evidence that Tamarix alters floodplain conditions in ways that impact native riparian trees. Tamarix inhibits cottonwood (Populus spp.) germination by altering soil chemistry through an interaction with the introduced leafhopper Opsius stactogalus, one of the most common arthropods on Tamarix (Wiesenborn 2005, Siemion 2008). In certain climatic conditions, Tamarix increases surface salinity, which can also decrease cottonwood germination (Shafroth et al. 1995, Rowland et al. 2004, Ladenburger et al. 2006, Ulery and Rosel 2006, Siemion 2008). Once established, Tamarix persists during dry periods that READ MORE

D. D. Cole, K. E. Mock, B. L. Cardall, and T. A. Crowl (2008)

Morphological and genetic structuring in the Utah Lake sucker complex

Molecular Ecology 17(24), 5189-5204.

Abstract: Population decline in the federally endangered June sucker (Chasmistes liorus), a lakesucker unique to Utah Lake, Utah, has been attributed in part to hybridization with the more widespread Utah sucker (Catostomus ardens). As a group, suckers in Utah Lake exhibit considerable external morphological variation. Meristic and morphological ambiguities, presumably the result of hybridization, create a continuum of intermediate forms between Chasmistes and Catostomus extremes and prevent definitive identification to species. Here we describe and evaluate the morphological and genetic variation in suckers in Utah Lake by comparing a morphological analysis with amplified fragment length polymorphism and microsatellite analyses. Suckers were morphologically differentiated using mouth characters associated with different feeding strategies: planktivory (June sucker) and benthivory (Utah sucker). Although we found no genetic evidence for a deep divergence between June and Utah morphs, significant, but slight population structuring accompanied the substantial morphological variation. Bayesian model-based genetic clustering analyses detected two sucker populations in Utah Lake; however, these clusters were not strongly concordant with morphological groupings or between marker systems. The suckers in Utah Lake present an interesting dilemma regarding conservation: should one conserve (breed and stock) a subset of the morphotypic variation in the Utah Lake sucker complex, focusing on the endangered June sucker morphotype, or should one conserve both June sucker and Utah sucker morphotypes in this complex, possibly maximizing evolutionary potential? We explore this question in the context of current genetic and morphological variation in the Utah Lake sucker complex as well as historical information on this complex and other lakesuckers.

B. L. Cardall, L. S. Bjerregaard, and K. E. Mock (2007)

Microsatellite markers for the June sucker (Chasmistes liorus mictus), Utah sucker (Catostomus ardens), and five other catostomid fishes of western North America.

Molecular Ecology Notes 7 (3) , 457–460.

Abstract: We developed and optimized five new microsatellite markers for the genetic management of the endangered June sucker. We report the cross-amplification of these markers, and an additional seven microsatellites previously developed for the suckers of the Klamath Basin, in seven catostomid species of western North America. No linkage disequilibrium was detected between pairs of loci. Since the majority of these loci exhibited conserved priming sites, these markers may be useful for landscape scale studies of multiple sucker lineages

K. E. Mock, R. P. Evans, M. Crawford, B. L. Cardall, S. U. Janecke, and M. P. Miller (2006)

Rangewide molecular structuring in the Utah sucker (Catostomus ardens).

Molecular Ecology 15(8), 2223-2238.

Abstract: The Utah sucker (Catostomus ardens) is endemic to the Bonneville Basin and the upper Snake River drainage in western North America, and is thought to hybridize with the federally endangered June sucker (Chasmistes liorus mictus) in Utah Lake ( Bonneville Basin ). Here we describe the discovery of a major subdivision in Utah suckers (4.5% mitochondrial sequence divergence) between the ancient Snake River drainage and the Bonneville Basin . This boundary has not previously been recognized in Utah suckers based on morphologic variation, but has been recently described in two endemic cyprinids in the region. Populations in valleys east of the Wasatch Mountains in Utah clustered with the Snake River populations, suggesting that these valleys may have had an ancient hydrologic connection to the Snake River . We also found evidence of population isolation within the Bonneville basin, corresponding to two Pleistocene subbasins of the ancient Lake Bonneville . In contrast, we found no molecular evidence for deep divergence between Utah suckers and June suckers in Utah Lake or for a history of hybridization between divergent lineages in that population, although we recognize that demographic events may have obscured this signal. These findings suggest that the morphological differences between Utah and June suckers in Utah Lake may be the result of strong, and relatively recent, ecological selection. In summary, morphological and molecular characters seem to vary along different axes in different portions of the range of this taxon, providing an interesting system for studying the contributions of neutral and adaptive variation to species diversity.

B. L. Cardall, E. D. Brodie III, E. D. Brodie Jr., and C. T. Hanifin (2004)

Tetrodotoxin in the skin secretions of the rough-skin newt (Taricha granulosa) and regeneration after secretion.

Toxicon, 44(8):933-8.

Abstract: Rough-skin newts (Taricha granulosa) released tetrodotoxin (TTX) in their skin secretions in response to mild electric stimulation. This release resulted in a large (21 % to almost 90 % of the pre-stimulation levels) reduction in the amount of TTX present in the dorsal skin of individual newts. Over the next nine months newts significantly regenerated the levels of TTX in their skin. These data, in combination with previously published results, are consistent with the hypothesis that these newts produce their own TTX.