Structure and evolution of the Cinful retrotransposon family of maize.

A maize cDNA clone was isolated by virtue of its intense hybridization to total maize genomic DNA, indicating homology to highly repetitive sequences. Genomic homologues were identified and subcloned from an adh1-bearing maize yeast artificial chromosome (YAC). Sequencing revealed that the expressed sequence was part of a Ty3-gypsy-type retrotransposon. We discovered and sequenced two complete retrotransposons of this family, and named them Cinful elements because they are members of a family of maize retrotransposons including Zeon-1 and the first plant transposable element sequenced, the solo long terminal repeat (LTR) called Cin1. All are defective, as Cinful-1 and Cinful-2 elements lack gag and Zeon-1 lacks pol homology. Despite the apparent lack of an intact "autonomous" element, the Cinful family has expanded to a copy number of about 18 000, representing just under 9% of the maize genome. Both point mutations and major rearrangements, including possible gene acquisition, differentiate members of the Cinful family. Cinful family members were found to have an unusual feature that we also observed in two other Ty3-class retrotransposons of teosinte and tobacco: related tandem repeats that separate their internal domains with a gag- or pol-containing homology from a 3' segment of unknown function. The conserved and variable features identified provide insights into the origin, mutational history, and functional components of this major constituent of the maize genome.

[Analysis Of Protein Components At Varioue Stages Of Clonorchis Sinensis]

In this study the authors examined the protein components at various stages of Clonorchis sinensis, and those of tegument and metabolite of adult Clonorchis by using SDS-polyacrylamide gel electrophoresis and immunodiffusion. The following results were obtained: 1. The protein components of C. sinensis were gradually changed during its development. A considerable change occurred during the initial 7 days after the metacercarial infection. 2. Two bands of protein of about 97,000 molecular weight (MW) and 178,000 MW were unique to excysted metacercaria of C. sinensis. Other 2 bands of protein of 23,000 and 25,000 MW which were absent in metacercariae, might be associated with the development of sex organs in adult. 3. In the metabolite, some components of tegumental proteins were detected. And this tegumental protein components in metabolite seems to be the major antigenic components reacting with infected rabbit antiserum by immunodiffusion. 4. Twenty bands of protein were detected in the isolated adult tegument. Among them 6 bands were in 97,000~65,000 MW, 3 bands in 56,000~53,000 MW and 5 bands in 37,000~30,000 MW. On the other hand, in metabolic products of adult C. sinensis, 17 bands were detected.

[A Comparative Analysis Of Various Parts Of Ascaris Suum With Respect To Their Protein Composition]

For the purpose of making a comparative study of protein compositions in Ascaris suum by sexes and body parts, extracts were prepared from whole bodies, body walls, genital organs, digestive organs and body fluid, of both sexes. And electrophoretic analysis was conducted using polyacrylamide slab gel in the presence of sodium dodecyl sulfate. The results were as follows: 1. In this study, protein bands of each part were separated in the largest number and most clearly under 8%~12 % (10 %) gradient gel condition. The number of bands by body parts was 43 in body walls, 51 in genital organs, 47 in digestive organs, and 34 in body fluid. 2. When examined in terms of sex, the number of bands of whole body was 38 in females and 35 in males. 3. The electrophoretic patterns of body wall protein were in most cases similar with those seen in digestive organs. And the band with a molecular weight of 72,900 was unique to the body wall, and the 122,000 MW band was unique to the female body wall. 4. In genital organ extracts, large molecular weight proteins (more than 80,000) were more frequently met. The molecular weights showed some differences between the two sexes. Of the bands, those having molecular weights of 119,700, 100,500, 88,500 and 86,100 were unique to the female genital organs. On the other hand, the male genital organs showed unique bands having molecular weights of 87,100, 82,800, and 15,500. An unique band common to the genital organs of both sexes was one having 49,300 MW. 5. In the digestive organs evenly distributed protein bands of molecular weights of l0,000~120,000 were observed. The band having 59,800 MW was unique to the digestive organs. The number of bands obtained from body fluid was comparatively small, and the number of bands having less than 30,000 MW was 7, accounting for 55 % of the total protein amounts. The bands having 47,600 MW and 31,400 MW were unique to body fluid.

[Lung Findings In Experimental Paragonimiasis]

A pathological study was done to elucidate sequential changes of the lungs in various time intervals following experimental paragonimiasis in 15 dogs and 15 cats. The dogs and cats were fed with 30~50 metacercariae of Paragonimus westermani, and were sacrificed at 15, 20, 30, 45, 60, 90 and 120 days after infection respecively. Autopsies were performed immediately after death. Gross and microscopic examination of the lungs showed following findings: 1. There were no qualitative difference in pathological findings between dogs and cats. 2. Pathological findings were first noticed at 20 days of infection in thoracic cavity, which consisted of fibrinous plueritis along with superficial hemorrhage. Although no worm was found in the lung parenchyma at this period, juveniles were seen in pleural cavity together with turbid effusion. 3. Paragonimus juveniles were first recognized inside the lung parenchyma by 30 days of infection. This was the period when the lungs showed multiple areas of hemorrhage and probably active penetration by smaller worms. Hemorrhagic bronchopneumonia was quite pronounced from this stage through 45 days of infection. 4. Paragonimus worm cyst was essentially composed of fibrous scar and heavy inflammatory cellular infiltrate. The lining epithelial cells were first became noticed by 2 months of infection. And these epithelial cells were thought to be probably transformed alveolar lining cells rather than bronchiolar epithelial cells. As the infection progress, the cyst wall became more stabilized and often showed squamous metaplasia. 5. Fibrinous pleuritis with pleural effusion was very prominent finding in early periods of infection. Bronchiolitis and focal vascular sclerosis were often seen in experimental paragonimiasis.