Corn: Uneven Early-Season Growth Can Mean Uneven Tasseling

Uneven growth reports on Iowa corn proliferated during the early part of the 2009 growing season. As we transition into reproductive growth stages, expect to see variation within fields and hybrids as a result of various early-season stresses

Genomic Organization and Molecular Phylogenies of the Beta (β) Keratin Multigene Family in the Chicken (\u3cem\u3eGallus gallus\u3c/em\u3e) and Zebra Finch (\u3cem\u3eTaeniopygia guttata\u3c/em\u3e): Implications for Feather Evolution

Background: The epidermal appendages of reptiles and birds are constructed of beta (β) keratins. The molecularphylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian β-keratin genes are closely related to those of birds, the published genomes ofthe chicken and zebra finch provide an opportunity not only to compare the genomic organization of their β- keratins,but to study their molecular evolution in archosaurians. Results: The subfamilies (claw, feather, feather-like, and scale) of β-keratin genes are clustered in the same 5\u27 to 3\u27 orderon microchromosome 25 in chicken and zebra finch, although the number of claw and feather genes differs between the species. Molecular phylogenies show that the monophyletic scale genes are the basal group within birds and thatthe monophyletic avian claw genes form the basal group to all feather and feather-like genes. Both species have a number of feather clades on microchromosome 27 that form monophyletic groups. An additional monophyleticcluster of feather genes exist on macrochromosome 2 for each species. Expression sequence tag analysis for thechicken demonstrates that all feather β-keratin clades are expressed. Conclusions: Similarity in the overall genomic organization of β-keratins in Galliformes and Passeriformes suggestssimilar organization in all Neognathae birds, and perhaps in the ancestral lineages leading to modern birds, such as theparavian Anchiornis huxleyi. Phylogenetic analyses demonstrate that evolution of archosaurian epidermal appendagesin the lineage leading to birds was accompanied by duplication and divergence of an ancestral β-keratin gene cluster.As morphological diversification of epidermal appendages occurred and the β-keratin multigene family expanded,novel β-keratin genes were selected for novel functions within appendages such as feathers

Genomic organization and molecular phylogenies of the beta (β) keratin multigene family in the chicken (Gallus gallus) and zebra finch (Taeniopygia guttata): implications for feather evolution

Abstract Background The epidermal appendages of reptiles and birds are constructed of beta (β) keratins. The molecular phylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian β-keratin genes are closely related to those of birds, the published genomes of the chicken and zebra finch provide an opportunity not only to compare the genomic organization of their β-keratins, but to study their molecular evolution in archosaurians. Results The subfamilies (claw, feather, feather-like, and scale) of β-keratin genes are clustered in the same 5' to 3' order on microchromosome 25 in chicken and zebra finch, although the number of claw and feather genes differs between the species. Molecular phylogenies show that the monophyletic scale genes are the basal group within birds and that the monophyletic avian claw genes form the basal group to all feather and feather-like genes. Both species have a number of feather clades on microchromosome 27 that form monophyletic groups. An additional monophyletic cluster of feather genes exist on macrochromosome 2 for each species. Expression sequence tag analysis for the chicken demonstrates that all feather β-keratin clades are expressed. Conclusions Similarity in the overall genomic organization of β-keratins in Galliformes and Passeriformes suggests similar organization in all Neognathae birds, and perhaps in the ancestral lineages leading to modern birds, such as the paravian Anchiornis huxleyi. Phylogenetic analyses demonstrate that evolution of archosaurian epidermal appendages in the lineage leading to birds was accompanied by duplication and divergence of an ancestral β-keratin gene cluster. As morphological diversification of epidermal appendages occurred and the β-keratin multigene family expanded, novel β-keratin genes were selected for novel functions within appendages such as feathers.</p

Corn Era Hybrid Nutrient Concentration and Accumulation of Secondary and Micronutrients

Studies are limited that focus on change in concentration and accumulation of secondary and micronutrients in corn (Zea mays L.) plant fractions and across corn hybrid development periods. This research was conducted in 2007 and 2008 to evaluate the partitioning of secondary and micronutrients across vegetative and reproductive stages at the plant-fraction level for 1960- and 2000-era hybrids. Two popular hybrids for each era were grown, with measurement of nutrient concentration and content in several plant and grain fractions. Secondary and micronutrient concentrations in plant fractions were lower in 2000- than 1960-era hybrids with most nutrients, except ear shoots and tassels for certain nutrients. However, nutrient content was consistently greater in 2000- compared to 1960-era hybrids in the whole plant and fractions at most development stages, except tassels and ear shoots. In tassels, nutrient content was mostly smaller in 2000-era hybrids, but in ear shoots content was similar. The accumulation rates of most nutrients per growing degree day (GDD) were greater in the reproductive period for 2000-era hybrids, but similar among eras in the vegetative period. Remobilized nutrients from vegetative to reproductive components were similar between era hybrids, except Ca and Fe, and positive except Fe, Mn, and B. It is apparent that greater nutrient content in newer hybrids was driven mainly by associated nutrient uptake rates and greater dry matter (DM). Despite the greater nutrient content with the modern hybrids, removal with grain or stover harvest would still be small for S and micronutrients

Effects of Extracellular Matrix on Cytoskeletal and Myofibrillar Organization in vitro

The distribution and three-dimensional relationship of myofibrillar and cytoskeletal components during myofibrillogenesis were examined in preparations of neonatal rat cardiac myocytes processed in parallel for scanning electron microscopy (SEM), intermediate voltage transmission electron microscopy (IVEM) and immunofluorescence (IF). Of the various methods used for processing, optimal results were achieved by pre-extraction with Triton X-100 in an actin-stabilizing buffer. This procedure effectively removed the surface membrane, as viewed by SEM images, while preserving myofibrillar and cytoskeletal structure, as evidenced by IF for actin, -actinin and vinculin. Cytoskeletons in SEM images consisted of a cortex of anastomosing filaments through which ran parallel filament bundles oriented in the long axis of the cell and attached aiong their length to the substrate by numerous fine filaments. In IVEM images, myofibrils were laterally connected at the level of the Z bands. Myocytes grown on different extracellular matrices showed different patterns and distributions of both striated myofibrils and focal adhesions, as determined by IF for -actinin and vinculin, respectively. Cells on collagen I and III contained striated myofibrils which extended to the cell perimeters where focal adhesions were predominately located. Cells on laminin and fibronectin matrices exhibited myofibrils and focal adhesions more centrally located. In addition, cells on laminin contained circumferential arcs of filaments near the cell periphery

Rearrangement of the Keratin Cytoskeleton after Combined Treatment with Microtubule and Microfilament Inhibitors

In addition to containing microtubule and microfilament systems, vertebrate epithelial cells contain an elaborate keratin intermediate-filament cytoskeleton. Little is known about its structural organization or function. Using indirect immunofluorescence microscopy with an antikeratin antiserum probe, we found that destabilization of microtubules and microfilaments with cytostatic drugs induces significant alterations in the cytoskeletal organizationof keratin filaments in HeLa and fetal mouse epidermal cells. Keratin filament organizationwas observed to undergo a rapid (1-2 h) transition from a uniform distribution to an open lattice of keratin fibers stabilized by membrane-associated focal centers . Since addition of any one drug alone did not elicit significant organizational change in the keratin cytoskeleton,we suggest that microfilaments and microtubules have a combined role in maintaining the arrangement of keratin in these cells. Vimentin filaments, the only other intermediate sized filaments found in HeLa cells, did not co-distribute with keratin in untreated or drug treated cells. These findings offer a new way to approach the study of the dynamics and functional roles of the keratin cytoskeleton in epithelial cells

Corn Following Corn in 2008

Corn following corn is in rough shape in areas across Iowa. Many wonder what is happening. The crop’s condition in general is not normal for this time of year. For example, last Sunday the USDA rated this year’s Iowa corn crop as 54 percent in ‘Good’ to ‘Excellent’ condition and 15 percent is ‘Poor’ or ‘Very Poor.’ Last year 72 percent was rated ‘Good’ to ‘Excellent’ and 5 percent was in ‘Poor’ or ‘Very Poor’ condition during the same week. Average plant height as of Sunday was 24 inches compared to 40 inches at end of the same week last year.Growing Degree Days continue to lag behind normal all over the state

Morphogenesis and Malformations of the Skin NICHD/NIADDK Research Workshop

Developmentally caused skin malformations constitute a spectrum of birth defects, some of which can be recognized prenatally by morphologic or biochemical means. The number of prenatally diagnosable skin diseases could be greatly expanded with an increased understanding of the molecular and cellular bases of skin development and the mechanisms that result in the generation of skin defects. The National Institute of Child Health and Human Development and the National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases, therefore, sponsored a workshop that recommended basic biologic studies combined with clinical investigations of normal and abnormal cutaneous development set forth in this article. Investigations resulting from these research recommendations are intended to contribute to the knowledge that should aid in the prevention of developmentally caused skin deformities

Effects of Volitional Preemptive Abdominal Contraction on Shoulder Proprioception Following Shoulder Muscle Fatigue

The abdominal bracing maneuver, a volitional preemptive abdominal contraction (VPAC) strategy, is potentially beneficial to shoulder exercise performance. It is unclear how VPAC use affects shoulder function, including proprioception and shoulder muscle function following shoulder muscle fatigue caused by upper extremity dominant sports movements. Discovering methods that reduce its effects on shoulder proprioception and shoulder muscle function is important for clinical practice in orthopedic rehabilitation. PURPOSE: To identify VPAC effects on shoulder proprioception abilities and to identify VPAC effects on shoulder muscle electromyographic amplitudes, during seated proprioception trials, both with and without muscle fatigue present. METHODS: Thirty-nine participants (26 women, 13 men) participated in this study. Shoulder proprioception was measured by shoulder flexion reproduction angles. Kinematic data were collected during the shoulder flexion trials to determine the accuracy in the subjects’ ability to reproduce a reference angle. All data were collected before and after a shoulder muscle fatigue protocol. Electromyographic data from the anterior deltoid (AD), posterior deltoid (PD), upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and infraspinatus (IF) muscles were used to observe muscle contraction amplitudes during the angle reproduction trials. RESULTS: Shoulder reproduction angles were not significantly affected by VPAC or muscle fatigue. Individually, shoulder muscle fatigue significantly increased UT muscle amplitudes (Mdn = 0.059(0.135), p\u3c.008) and LT muscle amplitudes (Mdn = 0.023(0.059), p\u3c.008). VPAC significantly increased shoulder IF muscle amplitudes (Mdn = 0.019(0.038), p\u3c.008). CONCLUSION: The VPAC did not affect shoulder proprioception in this study, showing that the strategy may not be beneficial to improving proprioception in the shoulder joint. The affects of muscle fatigue on the selected shoulder muscles supported the observations in previous literature concerning muscle fatigue effects on selected shoulder muscle. Clinicians can use this information to assist with the creation of therapeutic exercise for the shoulder joint

Complex Gene Loss and Duplication Events Have Facilitated the Evolution of Multiple Loricrin Genes in Diverse Bird Species

The evolution of a mechanically resilient epidermis was a key adaptation in the transition of amniotes to a fully terrestrial lifestyle. Skin appendages usually form via a specialized type of programmed cell death known as cornification which is characterized by the formation of an insoluble cornified envelope (CE). Many of the substrates of cornification are encoded by linked genes located at a conserved genetic locus known as the epidermal differentiation complex (EDC). Loricrin is the main protein component of the mammalian CE and is encoded for by a gene located within the EDC. Recently, genes resembling mammalian loricrin, along with several other proteins most likely involved in CE formation, have been identified within the EDC of birds and several reptiles. To better understand the evolution and function of loricrin in birds, we screened the genomes of 50 avian species and 3 crocodilians to characterize their EDC regions. We found that loricrin is present within the EDC of all species investigated, and that three loricrin genes were present in birds. Phylogenetic and molecular evolution analyses found evidence that gene deletions and duplications as well as concerted evolution has shaped the evolution of avian loricrins. Our results suggest a complex evolutionary history of avian loricrins which has accompanied the evolution of bird species with diverse morphologies and lifestyles