Biology Commons^™

Distinct Components Of Retrograde Cav1.1-Ryr1 Coupling Revealed By A Lethal Mutation In Ryr1, David Sheridan

Biology and Earth Science Faculty Scholarship

The molecular basis for excitation-contraction coupling in skeletal muscle is generally thought to involve conformational coupling between the L-type voltage-gated Ca2+ channel (CaV1.1) and the type 1 ryanodine receptor (RyR1). This coupling is bidirectional; in addition to the orthograde signal from CaV1.1 to RyR1 that triggers Ca2+ release from the sarcoplasmic reticulum, retrograde signaling from RyR1 to CaV1.1 results in increased amplitude and slowed activation kinetics of macroscopic L-type Ca2+ current. Orthograde coupling was previously shown to be ablated by a glycine for glutamate substitution at RyR1 position 4242. In this study, we investigated whether the RyR1-E4242G mutation affects retrograde …

Cyclic Di-Gmp Phosphodiesterases Rmda And Rmdb Are Involved In Regulating Colony Morphology And Development In Streptomyces Coelicolor. Journal Of Bacteriology, Travis D. Hull, Min-Hyung Ryu, Matthew J. Sullivan, Ryan C. Johnson, Nikola T. Klena, Robert M. Gelger, Mark Gomelsky, Jennifer A. Bennett

Biology and Earth Science Faculty Scholarship

Cyclic dimeric GMP (c-di-GMP) regulates numerous processes in Gram-negative bacteria, yet little is known about its role in Gram-positive bacteria. Here we characterize two c-di-GMP phosphodiesterases from the filamentous high-GC Gram-positive actinobacterium Streptomyces coelicolor, involved in controlling colony morphology and development. A transposon mutation in one of the two phosphodiesterase genes, SCO0928, hereby designated rmdA (regulator ofmorphology and development A), resulted in decreased levels of spore-specific gray pigment and a delay in spore formation. The RmdA protein contains GGDEF-EAL domains arranged in tandem and possesses c-di-GMP phosphodiesterase activity, as is evident from in vitro enzymatic assays using the purified protein. …

A Study Of The Mussels (Mollusca: Bivalvia: Unionidae) Of Symmes Creek And Tributaries In Jackson, Gallia And Lawrence Counties, Ohio, Michael A. Hoggarth, David A. Kimberly, Benjamin G. Van Allen

Biology and Earth Science Faculty Scholarship

Freshwater mussels (family Unionidae) are among the most threatened of Ohio's aquatic fauna. Interest in their biogeography has increased as their distribution and abundance has declined. This study was performed to assess the status of the mussels of Symmes Creek and it major tributaries in southern Ohio. Of the 24 species of mussels known to have inhabited this watershed, 16 were found alive in the system in 2004 and 2005 and two others were found as freshly dead shells. These species are thought to represent the extant mussel fauna in the system today. Of the remaining six species collected prior …

Heritability Of Latent Period Estimated From Wild-Type And Selected Populations Of Puccinia Triticina, Jeffery S. Lehman, Gregory Shaner

Biology and Earth Science Faculty Scholarship

Durability of partially resistant wheat cultivars to wheat leaf rust depends on the amount of genetic variation in parasitic fitness within populations of the pathogen Puccinia triticina. To assess the durability of partial resistance, selection experiments were used to explore quantitative variation in parasitic fitness of P. triticina. Fungal populations 881-WT and 882-WT were selected for shortened latent period on partially resistant cvs. CI 13277 and Sw 72469-6 for multiple generations. Fitness components were measured for wild-type and selected fungal populations. Responses to selection and selection differentials were calculated, and broad-sense, realized heritabilities for latent period were estimated for wild-type …

Host Resistance To Monilinia Vaccinii-Corymbosi In Flowers And Fruits Of Highbush Blueberry, Jeffery S. Lehman, Suzu Igarashi, Peter V. Oudemans

Biology and Earth Science Faculty Scholarship

Monilinia vaccinii-corymbosi, the causal agent of mummy berry disease, infects blueberry flowers via the gynoecial pathway. To describe the expression of host resistance in highbush blueberry (Vaccinium corymbosum), fungal growth in the styles and colonization of the locules were compared among five blueberry cultivars in a series of controlled greenhouse experiments. Styles were harvested 1 and 4 days postinoculation, and the length colonized by hyphae was determined using fluorescence microscopy. At 8 weeks after inoculation, fruit were harvested and scored for the presence of hyphae in the locules. The infection frequency of styles ranged from 0.33 to 0.71, and only …

Host Resistance To Monilinia Vaccinii-Corymbosi In Flowers And Fruits Of Highbush Blueberry, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

Monilinia vaccinii-corymbosi, the causal agent of mummy berry disease, infects blueberry flowers via the gynoecial pathway. To describe the expression of host resistance in highbush blueberry (Vaccinium corymbosum), fungal growth in the styles and colonization of the locules were compared among five blueberry cultivars in a series of controlled greenhouse experiments. Styles were harvested 1 and 4 days postinoculation, and the length colonized by hyphae was determined using fluorescence microscopy. At 8 weeks after inoculation, fruit were harvested and scored for the presence of hyphae in the locules. The infection frequency of styles ranged from 0.33 to 0.71, and only …

Heritability Of Latent Period Estimated From Wild-Type And Selected Populations Of Puccinia Triticina, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

Durability of partially resistant wheat cultivars to wheat leaf rust depends on the amount of genetic variation in parasitic fitness within populations of the pathogen Puccinia triticina. To assess the durability of partial resistance, selection experiments were used to explore quantitative variation in parasitic fitness of P. triticina. Fungal populations 881-WT and 882-WT were selected for shortened latent period on partially resistant cvs. CI 13277 and Sw 72469-6 for multiple generations. Fitness components were measured for wild-type and selected fungal populations. Responses to selection and selection differentials were calculated, and broad-sense, realized heritabilities for latent period were estimated for wild-type …

Ips Pini (Curculionidae: Scolytinae) Is A Vector Of The Fungal Pathogen, Sphaeropsis Sapinea (Coelomycetes), To Austrian Pines, Pinus Nigra (Pinaceae), Justin G.A. Whitehall, Jeffery S. Lehman, Pierluigi Bonello

Biology and Earth Science Faculty Scholarship

Sphaeropsis sapinea (Fr.:Fr.) Dyko and Sutton, is among the most common and widely distributed pathogens of conifers worldwide. S. sapinea is disseminated over short distances by rain splash and moist wind, but significant knowledge gaps regarding long-range dispersal remain. Our objective was to determine whether or not the pine engraver beetle, Ips pini Say, is a vector of the pathogen onto Austrian pines (Pinus nigra Arnold). In 2004 and 2005, individuals of I. pini were collected with pheromone traps at two locations in central Ohio (197 and 1,017 individuals for 2004 and 2005, respectively) and screened for the presence of …

First Report Of Phytophthora Insolita And P. Inflata On Rhododendron In Ohio, Antonino Testa, Mikael Schilb, Jeffery S. Lehman, Gennaro Cristinzio, Pierluigi Bonello

Biology and Earth Science Faculty Scholarship

During August 2003, we conducted a statewide survey of rhododendrons to determine if Phytophthora ramorum was present in Ohio ornamental nurseries. In total, 240 samples were randomly collected in 12 nurseries throughout Ohio from rhododendrons showing foliar necrotic lesions and twig dieback symptoms.

Relationship Among Genes Conferring Partial Resistance To Leaf Rust (Puccinia Triticina) In Wheat Lines Ci 13227 And L-574-1., Jeffery S. Lehman, Karin A. Hanson, Gregory Shaner

Biology and Earth Science Faculty Scholarship

This study describes the segregation of genes for resistance to the fungus Puccinia triticinain a cross between partially resistant wheat lines L-574-1 and CI 13227 with two and four genes for resistance, respectively. The objectives of this study were to use parental, F1, F2, and backcross populations to quantify maternal effects, degree of dominance, and transgressive segregation, and to determine whether CI 13227 and L-574-1 share any resistance genes for long latent period or small uredinia. In two experiments conducted in the greenhouse, the uppermost leaf of adult wheat plants was inoculated prior to heading with P. triticina. On days …

Relationship Among Genes Conferring Partial Resistance To Leaf Rust (Puccinia Triticina) In Wheat Lines Ci 13227 And L-574-1, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

This study describes the segregation of genes for resistance to the fungus Puccinia triticina in a cross between partially resistant wheat lines L-574-1 and CI 13227 with two and four genes for resistance, respectively. The objectives of this study were to use parental, F1, F2, and backcross populations to quantify maternal effects, degree of dominance, and transgressive segregation, and to determine whether CI 13227 and L-574- 1 share any resistance genes for long latent period or small uredinia. In two experiments conducted in the greenhouse, the uppermost leaf of adult wheat plants was inoculated prior to heading with P. triticina. …

Relationships Between Blueberry Flower Age, Pollination, And Conidial Infection By Monilinia Vaccinii-Corymbosi, Jeffery S. Lehman, Henry K. Ngugi, Harald Scherm

Biology and Earth Science Faculty Scholarship

Monilinia vaccinii-corymbosi infects open blueberry flowers via the gynoecial pathway, leading to mummification of the developing fruit. To determine the effect of flower age on infection, stigmata were inoculated with conidia of M. vaccinii-corymbosi between 0 and 5 days after anthesis, fungal growth rates through the stylar canal were measured in detached flowers in the laboratory, and fruit disease incidence was determined in plants grown in the greenhouse. Hyphal growth rates were greatest in flowers inoculated on the day of anthesis, declined linearly with increasing flower age at inoculation (r = 0.921; P < 0.0001; n = 12), and were unaffected by the presence or absence of pollen applied at the time of inoculation. In greenhouse-grown plants, the percentage of infected fruit decreased exponentially with increasing flower age at inoculation (R = 0.878; P = 0.0057; n = 10), with disease incidence ranging from 76.4% for flowers inoculated on the day of anthesis to 15.5% for those inoculated 4 days later. Fruit disease incidence in the greenhouse was linearly correlated with hyphal growth rates in detached flowers (r = 0.985; P < 0.0001; n = 9), justifying the use of detached flowers when investigating gynoecial infection by M. vaccinii-corymbosi. In separate experiments, the effects of timing and sequence of pollination and inoculation on hyphal growth rates through the stylar canal and on disease incidence were investigated. Application of pollen to detached flowers 1 or 2 days before inoculation reduced hyphal growth rates by between 14.0 and 42.9% compared with flowers that received pollen and conidia simultaneously. Similarly, reductions in fruit disease incidence by between 9.5 and 18.3% were observed on greenhouse-grown plants for pollination-to-inoculation intervals ranging from 1 to 4 days. These results document that newly opened flowers are most susceptible to infection by M. vaccinii-corymbosi and that fruit disease incidence is reduced if pollination occurs at least 1 day before inoculation. Strategies that lead to early pollination of newly opened flowers may be useful for managing mummy berry disease in the field.

Relationships Between Blueberry Flower Age, Pollination, And Conidial Infection By Monilinia Vaccinii-Corymbosi, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

Monilinia vaccinii-corymbosi infects open blueberry flowers via the gynoecial pathway, leading to mummification of the developing fruit. To determine the effect of flower age on infection, stigmata were inoculated with conidia of M. vaccinii-corymbosi between 0 and 5 days after anthesis, fungal growth rates through the stylar canal were measured in detached flowers in the laboratory, and fruit disease incidence was determined in plants grown in the greenhouse. Hyphal growth rates were greatest in flowers inoculated on the day of anthesis, declined linearly with increasing flower age at inoculation (r = 0.921; P < 0.0001; n = 12), and were unaffected by the presence or absence of pollen applied at the time of inoculation. In greenhouse-grown plants, the percentage of infected fruit decreased exponentially with increasing flower age at inoculation (R = 0.878; P = 0.0057; n = 10), with disease incidence ranging from 76.4% for flowers inoculated on the day of anthesis to 15.5% for those inoculated 4 days later. Fruit disease incidence in the greenhouse was linearly correlated with hyphal growth rates in detached flowers (r = 0.985; P < 0.0001; n = 9), justifying the use of detached flowers when investigating gynoecial infection by M. vaccinii-corymbosi. In separate experiments, the effects of timing and sequence of pollination and inoculation on hyphal growth rates through the stylar canal and on disease incidence were investigated. Application of pollen to detached flowers 1 or 2 days before inoculation reduced hyphal growth rates by between 14.0 and 42.9% compared with flowers that received pollen and conidia simultaneously. Similarly, reductions in fruit disease incidence by between 9.5 and 18.3% were observed on greenhouse-grown plants for pollination-to-inoculation intervals ranging from 1 to 4 days. These results document that newly opened flowers are most susceptible to infection by M. vaccinii-corymbosi and that fruit disease incidence is reduced if pollination occurs at least 1 day before inoculation. Strategies that lead to early pollination of newly opened flowers may be useful for managing mummy berry disease in the field.

Variation And Heritability Of Phenology In The Fungus Monilinia Vaccinii-Corymbosi On Blueberry, Jeffery S. Lehman, Peter V. Oudemans

Biology and Earth Science Faculty Scholarship

The germination of field-collected pseudosclerotia and the development of apothecia from eight New Jersey populations of the mummy berry fungus Monilinia vaccinii-corymbosi were evaluated under controlled conditions in the greenhouse. Development data for apothecia were used to describe the timing of apothecium formation and to estimate broad- and narrow-sense heritabilities of fungal phenology. Mean development times for the formation of apothecia ranged from 35.4 to 54.7 days. The mean development times for populations collected from early-season cv. Weymouth ranged from 35.4 to 39.6 days and were significantly shorter than the development times for three of the four populations collected from …

Phenology Of Apothecium Production In Populations Of Monilinia Vaccinii-Corymbosi From Early- And Late-Maturing Blueberry Cultivars, Jeffery S. Lehman, Peter V. Oudemans

Biology and Earth Science Faculty Scholarship

Pseudosclerotia were evaluated for differences in timing of apothecium development in four controlled experiments conducted over a 2-year period. In a separate experiment, conidia from 10 randomly selected isolates from both of the fungal populations were used to inoculate open flowers. Germination of pseudosclerotia produced from these artificial inoculations also was evaluated. The timing and rate of shoot elongation for cvs. Weymouth and Jersey were assessed in one greenhouse and two field experiments. Average development times for the fungal population from cv. Weymouth were 8 to 15 days earlier or 33 to 42% less than those for the population from …

Selection Of Populations Of Puccinia Recondita F. Sp. Tritici For Shortened Latent Period On A Partially Resistant Wheat Cultivar, Jeffery S. Lehman, Gregory Shaner

Biology and Earth Science Faculty Scholarship

Wild-type fungal population 851-WT was selected for shortened latent period on cv. CI 13227 for five uredinial generations to study the adaptation of Puccinia recondita f. sp. tritici to partially resistant wheat cultivars. Differences among wild-type and selected populations for traits contributing to parasitic fitness (i.e., latent period, infection frequency, and uredinium area and growth rate) were assessed in monocyclic infection experiments on susceptible cv. Monon and partially resistant cvs. Suwon 85, Sw 72469-6, L-574-1, and CI 13227. Differences were greatest among fungal populations on cv. CI 13227. The mean latent period of selected population 851-C5 was 2 days shorter …

Selection Of Populations Of Puccinia Recondita F. Sp. Tritici For Shortened Latent Period On A Partially Resistant Wheat Cultivar, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

Wild-type fungal population 851-WT was selected for shortened latent period on cv. CI 13227 for five uredinial generations to study the adaptation of Puccinia recondita f. sp. tritici to partially resistant wheat cultivars. Differences among wild-type and selected populations for traits contributing to parasitic fitness (i.e., latent period, infection frequency, and uredinium area and growth rate) were assessed in monocyclic infection experiments on susceptible cv. Monon and partially resistant cvs. Suwon 85, Sw 72469-6, L-574-1, and CI 13227. Differences were greatest among fungal populations on cv. CI 13227. The mean latent period of selected population 851-C5 was 2 days shorter …

Phenology Of Apothecium Production In Populations Of Monilinia Vaccinii-Corymbosi From Early- And Late-Maturing Blueberry Cultivars, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

Pseudosclerotia were evaluated for differences in timing of apothecium development in four controlled experiments conducted over a 2-year period. In a separate experiment, conidia from 10 randomly selected isolates from both of the fungal populations were used to inoculate open flowers. Germination of pseudosclerotia produced from these artificial inoculations also was evaluated. The timing and rate of shoot elongation for cvs. Weymouth and Jersey were assessed in one greenhouse and two field experiments. Average development times for the fungal population from cv. Weymouth were 8 to 15 days earlier or 33 to 42% less than those for the population from …

Genetic Variation In Latent Period Among Isolates Of Puccinia Recondita F. Sp. Tritici On Partially Resistant Wheat Cultivars, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

The durability of partially resistant wheat cultivars to wheat leaf rust depends on the amount of genetic variation in parasitic fitness within populations of the pathogen Pucciniareconditaf. sp.tritici. To assess the durability ofpanialresistance, phenotypic variation inlatentperiod (a major component of parasitic fitness) was quantified and partitioned into genetic and nongenetic components for isolates of P.reconditaf. sp.triticion susceptible and partially resistant cultivars. Latent periods among isolates differed by 24 to 27% on individual partially resistant cultivars. In simulated epidemics, isolates with short latent periods caused 2 to 2.5 times more disease and overcame 13 to 35% of the

resistance of four …

Discovery Of The Federally Endangered Freshwater Mussel, Epioblasma Obliquata Obliquata (Rafinesque, 1820) (Unionidae), In Ohio, Michael A. Hoggarth, Daniel L. Rice, Diana M. Lee

Biology and Earth Science Faculty Scholarship

Discovery of the purple catspaw, Epioblasma obliquata obliquata, in Killbuck Creek, Coshocton County, OH, is reported. This subspecies of unionid mollusc was thought to have been extirpated from the state in the mid to late 1800s and was known only from two nonreproductive populations in Kentucky and Tennessee. The mussel was thought to be on the verge of extinction. Fifteen living and 23 dead specimens of this subspecies were collected in September 1994 from Killbuck Creek. This is the largest known population of this rare subspecies and it is the only known population to currently support breeding individuals. It is …