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Virus-specific or group-specific antibody probes to potyviruses can be produced by targeting the immune response to the virus-specific, N-terminal region of the capsid protein (29-95 amino acids depending on the virus) or to the conserved core region (216 amino acids) of the capsid protein, respectively. Immunochemical analysis of overlapping, synthetic octapeptides covering the capsid protein of the Johnsongrass strain of Johnsongrass mosaic virus (JGMV-JG) has delineated the peptide sequences recognized by five polyclonal rabbit antisera and two mouse monoclonal antibodies (mAbs). The antibodies characterized were (i) three virus-specific rabbit polyclonal antisera and one virus-specific mouse mAb (1/25) raised against native virus particles, (ii) one polyclonal antiserum raised against trypsin-derived core particles of JGMV-JG, (iii) one group-specific polyclonal antiserum raised against the denatured, truncated coat protein from trypsinderived core particles of JGMV-JG, and (iv) one group-specific mouse mAb (1/16) raised against native virus particles. The two epitopes seen by mAb 1/25 occurred at residues 18-27 and 43-52 and overlapped with the two major epitopes seen by the virus-specific polyclonal antiserum. The group-specifilc epitope seen in JGMV-JG by mAb 1/16 was also recognized strongly in potato virus Y. the type member of the potyvirus group. The multiple epitopes seen by the cross-reactive polyclonal antisera were distributed across the entire core region of the coat protein and their relative antibody binding responses varied between JGMV-JG, potato virus Y, and six other distinct potyviruses.Plant diseases are estimated to be responsible for economic losses worldwide of $60 billion per annum (1). The most important pathogens are fungi, with plant viruses the second most important group of infectious agents. Of the 28 plant virus groups or families the potyvirus group is the largest. It contains at least 175 independent members and accounts for about 30% of all viruses known to infect plant species around the world (2, 3). Potyvirus particles are flexuous rods, 729-900 nm long and -11 nm in diameter, and consist of up to 2000 subunits of a single protein species (4).Successful control and eradication of plant virus infections is dependent on the availability of simple, reliable methods for plant virus detection and identification. To date, this has been difficult to achieve for potyviruses due to the large size of the group, the vast variation between members, and the lack of satisfactory taxonomic parameters to distinguish independent viruses from related strains (2-4). Thus, there is a real need to evaluate new criteria for the identification and classification of potyviruses.During investigations on the structural characterization of the coat proteins of potyviruses we made the following observations that have implications for potyvirus detection and classification: (i) distinct potyviruses exhibit coat protein sequence homology of 38-71% with major differences in the length (29-95 re...

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Synthesis and secretion of calcitonin and calcitonin gene-related peptide (CGRP) were studied in medullary thyroid carcinomas (MTC) by hybridization histochemistry on tissue sections and by Northern gel analysis of mRNA. Five patients with MTC and elevated serum levels of calcitonin and CGRP were studied. Surgically obtained tumor samples (four primary and three lymph node metastases) were extracted after freezing, and the RNA was fractionated on Northern gels. Hybridization was carried out with 32P-labeled synthetic oligodeoxyribonucleotides coding specifically for calcitonin and CGRP. Calcitonin- and CGRP-specific mRNAs approximately 1000 nucleotides in length were demonstrated in all 7 tumor samples. However, neither calcitonin nor CGRP mRNA was detected in a pheochromocytoma from 1 of the patients who had multiple endocrine neoplasia type II. A series of unselected lung carcinomas yielded the same result. Hybridization histochemistry was carried out on sections from the same tumors using the same probes. The mRNAs for calcitonin and CGRP were located in all cells of neoplastic MTC appearance, with CGRP mRNA at significantly lower levels. This demonstrated that both calcitonin and CGRP mRNA were present within the same tumor cells. The lung tumors and pheochromocytoma were negative with both probes. Hybridization histochemistry is likely to be of use in diagnosis of medullary thyroid cancer and in studying the calcitonin-CGRP mRNA processing mechanism in whole cells.

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