A Novel Glutathione Peroxidase Mimic with Antioxidant Activity

Many diseases are associated with the overproduction of hydroperoxides that inflict cell damage. A novel cyclodextrin derivative, 6A,6B-diseleninic acid-6A',6B'-selenium bridged beta-cyclodextrin (6-diSeCD), was synthesized to be a functional mimic of glutathione peroxidase (GPX) that normally removes these hydroperoxides. The mimic had high catalytic GPX activity of 13.5 U/micromol, which is 13.6-fold higher than ebselen (PZ51), and was chemically and biologically stable in vitro. Antioxidant activity was studied by ferrous sulfate/ascorbate-induced mitochondria damage model system. These data show that the mimic has great antioxidant activity. Such mimics may result in better clinical therapies for diseases mediated by hydroperoxides.

Measurement of mRNAs for TGFss and extracellular matrix proteins in corneas of rats after PRK

PURPOSE

To assess the role of the transforming growth factor (TGF)ss system in formation of corneal haze after excimer laser photorefractive keratectomy (PRK), levels of mRNAs for three TGFss isoforms (TGFss1, TGFss2, and TGFss3), the TGFss type II receptor (TssRII), and extracellular matrix (ECM) genes including fibronectin (FN), collagen I, collagen III, and collagen IV were measured in rat corneas.

METHODS

Corneas were graded for corneal haze at 0, 1.5, 7, 21, 42, and 91 days after PRK. Total RNA was isolated from pooled corneas, and the levels of mRNAs were measured using competition-based quantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Severe corneal haze developed by day 42 and persisted to day 91. Levels of TGFss1 mRNA were high in rat corneas before PRK and remained relatively constant. In contrast, levels of TGFss2 and TGFss3 mRNAs were very low in normal corneas, increased 300-fold and 25-fold, respectively, on day 21, and remained elevated on day 91. Levels of mRNA for TssRII increased, with a peak elevation of 50-fold on day 42 after PRK. Levels of mRNAs for ECM proteins also increased. Fibronectin mRNA was nondetectable in normal corneas but rapidly increased to 675 copies/cell on day 7 and remained elevated to day 91. Collagen III mRNA levels peaked on day 21 with a 700-fold increase compared with a very low level of expression in normal cornea, and then decreased on day 91. Expression of collagen I mRNA lagged expression of collagen III mRNA and peaked at day 42 after PRK with a 1200-fold increase over normal cornea. In contrast, mRNA for collagen alpha(1)IV, a major component in basement membranes, remained relatively stable through day 21 and then increased slightly on days 42 and 91.

CONCLUSIONS

The synchronized increase in mRNA synthesis for both the TGFss system and key ECM genes supports the hypothesis that TGFss is a key growth factor promoting stromal haze formation in corneas after PRK and suggests that limiting TGFss system may reduce corneal scarring after excimer laser ablation.

[Construction and nucleotide sequence assay of human anti-HBs variable region single-chain antibody gene]

The VH and Vk gene which were acquired using phage display technology have been combined by a linker encoding a flexible peptide (Gly4 Ser)3 to form a single-chain. Its nucleotide sequence was assayed after cloning the scFv gene into middle plasmid. The successful construction of single-chain gene lays the foundations for the subsequent expression and production of double functional antibody.

Localization of myocilin to the golgi apparatus in Schlemm's canal cells

PURPOSE

Biochemical and genetic evidence suggests that overexpression of or mutations in myocilin within the cells of the aqueous humor outflow pathway play a significant role in the development of steroid-induced and several other open-angle glaucomas. As a baseline to understanding the normal and pathologic function of myocilin, we determined the subcellular localization of myocilin in steroid-treated human Schlemm's canal endothelial (SC) cells.

METHODS

SC cells were grown to confluence, treated with dexamethasone for 10 days, and then stained using antibodies against myocilin, tubulin, or beta-COP (a specific golgi protein) or vital stains for endoplasmic reticulum (ER) and golgi. Brefeldin A (BFA) and nocodazol (NZ) were used to disrupt the golgi or microtubules.

RESULTS

The authors found that myocilin staining was (a) always centered around the centrosome, (b) very similar to the pattern seen with NBD-ceramide, (c) was disrupted in characteristic ways by BFA and NZ and (d) showed extensive colocalization with beta-COP.

CONCLUSIONS

Results indicate that myocilin is localized to the golgi in SC cells. Such localization is consistent with myocilin being processed for secretion but is also consistent with sequence analysis and other data that suggest that myocilin or myocilin mutations might be targeted to the cytoplasmic face of the golgi, and under some circumstances play a role in or interfere with golgi or vesicle function. How such interference could eventually lead to open angle glaucoma is discussed.

A bis-cyclodextrin diselenide with glutathione peroxidase-like activity

A diselenide, 2,2'-diseleno-bis-beta-cyclodextrin (2-SeCD), was synthesized to imitate the antioxidant enzyme glutathione peroxidase (GPX). The GPX mimic accepts a variety of hydroperoxides as substrates. The GPX activities, reduction of H(2)O(2), tert-butyl hydroperoxide and cumenyl hydroperoxide by glutathione, are 7.4, 4.5 and 10.2 U/micromol, respectively. In contrast to ebselen (PZ51), the diselenide displays high GPX-like activity. The reduction of hydroperoxide by glutathione in the presence of a radical trap shows that the mimic catalyzes the reaction via a non-radical mechanism. A ping-pong mechanism was observed in the steady-state kinetic studies of the 2-SeCD-catalyzed reaction.

A novel selenocystine-beta-cyclodextrin conjugate that acts as a glutathione peroxidase mimic

A novel artificial glutathione peroxidase mimic consisting of a selenocystine-di-beta-cyclodextrin conjugate (selenium-bridged-6, 6'-amino-selenocystine-6,6'-deoxy-di-beta-cyclodextrin), in which selenocystine is bound to the primary side of beta-cyclodextrin through the two amino nitrogen groups of selenocystine, was synthesized. The glutathione peroxidase activities of the mimic-catalyzed reduction of H(2)O(2), tert-butylhydroperoxide, and cumene hydroperoxide by glutathione are 4.1, 2.11, and 5.82 units/micromol, respectively. The first activity was 82 and 4.2 times as much as that of selenocysteine and ebselen, respectively. Studies on the effect of substrate binding on the glutathione peroxidase activity suggest that it is important to consider substrate binding in designing glutathione peroxidase mimics. The detailed steady-state kinetic studies showed that the mimic-catalyzed reduction of H(2)O(2) by glutathione followed a ping-pong mechanism, which was similar to that of the native glutathione peroxidase.

Loss of fhit expression in invasive cervical carcinomas and intraepithelial lesions associated with invasive disease

Allelic losses involving chromosome 3p are frequently observed in cervical cancers. Deletion mapping studies of primary cervical carcinomas have localized common regions of deletion to 3p14.2 and 3p21. The candidate tumor suppressor gene FHIT has been mapped to 3p14.2, and previous studies have demonstrated reduced or aberrant FHIT transcripts and reduced or absent Fhit protein expression in a large percentage of cervical cancer-derived cell lines and primary cervical carcinomas. To expand these observations to preinvasive cervical epithelial lesions and to determine whether loss of Fhit protein expression might be associated with tumor progression, immunohistochemical methods were used to examine Fhit expression in 95 invasive cervical carcinomas, 33 high-grade squamous intraepithelial lesions (HSILs) associated with concurrent invasive cancer, 38 HSILs unassociated with invasive cancer, 24 low-grade squamous intraepithelial lesions, and 22 normal cervix samples. All normal cervical epithelia and low-grade squamous intraepithelial lesions exhibited diffuse cytoplasmic immunostaining of moderate to strong intensity. Fhit protein expression was markedly reduced or absent in 67 of 95 (71%) invasive cancers, 17 of 33 (52%) HSILs associated with invasive cancer, and 8 of 38 (21%) HSILs without associated invasive cancer. The results confirm that Fhit protein expression is reduced or absent in the majority of cervical carcinomas and suggest that loss of Fhit expression often accompanies cervical tumor progression. Moreover, absent or reduced Fhit protein is observed at a significantly higher frequency in HSILs associated with progression to invasive cancer than in HSILs with unknown risk for progression (P = 0.012). These findings suggest that loss of Fhit expression in HSILs could serve as a useful marker of high-grade preinvasive lesions that have an increased likelihood of progression to invasive carcinoma.

Theory and experiments of a three-cavity wavelength-selective photodetector

We propose a novel wavelength-selective photodetector with three subcavities, i.e., a filtering cavity, a spacer cavity, and an absorption cavity, for obtaining a narrow spectral response linewidth and a high quantum efficiency simultaneously. A theoretical prediction has been made that a less than 1-nm linewidth and a quantum efficiency as high as 90% are possible. We discuss the effects of the key factors on the performance of this type of photodetector that has been designed and fabricated. A spectral response linewidth of approximately 1.4 nm (FWHM) and an external quantum efficiency higher than 50% have been achieved experimentally. Such devices are promising for wavelength-division multiplexing applications.

[Conformity of cancerous diagnosis of serum-fluorimetry under the influence of carotenoid fluorescence]

We observed that carotenoid had sensitization for fluorescence of porphyrin as cancerous diagnostic technology was applied in clinic by serum-fluorimetry. The Forster theory was used in order to analyse sensitized fluorescence between carotenoid and porphyrin in this paper. Transfer characteristic between energy donor and energy acceptor was calculated and discussed its influence on cancerous diagnosis.

Changes in respiratory control in humans induced by 8 h of hyperoxia

In humans, 8 h of isocapnic hypoxia causes a progressive rise in ventilation associated with increases in the acute ventilatory responses to hypoxia (AHVR) and hypercapnia (AHCVR). To determine whether 8 h of hyperoxia causes the converse of these effects, three 8-h protocols were compared in 14 subjects: 1) poikilocapnic hyperoxia, with end-tidal PO(2) (PET(O(2))) = 300 Torr and end-tidal PCO(2) (PET(CO(2))) uncontrolled; 2) isocapnic hyperoxia, with PET(O(2)) = 300 Torr and PET(CO(2)) maintained at the subject's normal air-breathing level; and 3) control. Ventilation was measured hourly. AHVR and AHCVR were determined before and 0.5 h after each exposure. During isocapnic hyperoxia, after an initial increase, ventilation progressively declined (P < 0.01, ANOVA). After exposure to hyperoxia, 1) AHVR declined (P < 0.05); 2) ventilation at fixed PET(CO(2)) decreased (P < 0.05); and 3) air-breathing PET(CO(2)) increased (P < 0.05); but 4) no significant changes in AHCVR or intercept were demonstrated. In conclusion, 8 h of hyperoxia have some effects opposite to those found with 8 h of hypoxia, indicating that there may be some "acclimatization to hypoxia" at normal sea-level values of PO(2).

Discovery of a novel, paternally expressed ubiquitin-specific processing protease gene through comparative analysis of an imprinted region of mouse chromosome 7 and human chromosome 19q13.4

Using mouse BAC clones spanning an imprinted interval of proximal mouse chromosome 7 and the genomic sequence of the related interval of human chromosome 19q13.4, we have identified a novel mouse gene, Usp29 (ubiquitin-specific processing protease 29), near two known imprinted genes, Peg3 and Zim1. Gene Usp29 is located directly adjacent to Peg3 in a "head-to-head" orientation, and comprises exons distributed over a genomic distance of at least 400 kb. A similar human gene is also found in the homologous location in human chromosome 19q13.4. The mouse Usp29 gene is also imprinted and is transcribed mainly from the paternal allele with highest expression levels in adult brain, especially in the cerebral cortex and hippocampus, and in the forebrain, face, and limb buds of midgestation mouse embryos. Analysis of a full-length 7.6-kb cDNA clone revealed that Usp29 encodes an 869-amino-acid protein that displays significant homology with yeast and nematode ubiquitin carboxyl-terminal hydrolases. These data suggest that, like the candidate Angelman syndrome gene Ube3a (ubiquitin ligase), Usp29 may represent another imprinted gene involved in the ubiquitination pathway. This identification of a third imprinted gene, Usp29, from the Peg3/Zim1-region confirms the presence of a conserved imprinted domain spanning at least 500 kb in the proximal portion of mouse chromosome 7 (Mmu7).

Effects of desferrioxamine on serum erythropoietin and ventilatory sensitivity to hypoxia in humans

In cell culture, hypoxia stabilizes a transcriptional complex called hypoxia-inducible factor-1 (HIF-1) that increases erythropoietin (Epo) formation. One hallmark of HIF-1 responses is that they can be induced by iron chelation. The first aim of this study was to examine whether an infusion of desferrioxamine (DFO) increased serum Epo in humans. If so, this might provide a paradigm for identifying other HIF-1 responses in humans. Consequently a second aim was to determine whether an infusion of DFO would mimic prolonged hypoxia and increase the acute hypoxic ventilatory response (AHVR). Sixteen volunteers undertook two protocols: 1) continuous infusion of DFO over 8 h and 2) control. Epo and AHVR were measured at fixed times during and after the protocols. The results show that 1) compared with control, Epo increased in most subjects at 8 h [52.8 +/- 57.7 vs. 6.9 +/- 2.5 (SD) mIU/ml, for DFO = 4 g/70 kg body wt, P < 0.05] and 12 h (63.7 +/- 76.3 vs. 7.3 +/- 2.5 mIU/ml, P < 0.001) after the start of DFO administration and 2) DFO had no significant effect on AHVR. We conclude that, whereas infusions of DFO mimic hypoxia by increasing Epo, they do not mimic prolonged hypoxia by augmenting AHVR.

Universal symmetry property of point defects in crystals

Point defects (vacancies, solute atoms, and disorder) are ubiquitous in crystalline solids. With in situ transmission electron microscopy we find clear evidence for the existence of a universal symmetry property of point defects; i.e., the symmetry of short-range order of point defects follows the crystal symmetry when in equilibrium. We further show that this symmetry-conforming property can lead to various interesting effects including "aging-induced microstructure memory" and the associated "time-dependent two-way shape memory."

Processing of cdk5 activator p35 to its truncated form (p25) by calpain in acutely injured neuronal cells

Recently, it was shown that conversion of cdk5 activator protein p35 to a C-terminal fragment p25 promotes a deregulation of cdk5 activity, which may contribute to neurodegeneration in Alzheimer's disease. In this study, we present evidence that calpain is a protease involved in the conversion of p35 to p25. To activate calpain, rat cerebellar granule neurons were treated with maitotoxin (MTX). A C-terminus-directed anti-p35 antibody detected that p35 conversion to p25 paralleled the formation of calpain-generated alpha-spectrin (alpha-fodrin) breakdown products (SBDP's) in a maitotoxin-dose-dependent manner. Two calpain inhibitors (MDl28170 and SJA6017) reduced p35 processing but were unchanged when exposed to the caspase inhibitor carbobenzoxy-Asp-CH(2)OC(=O)-2, 6-dichlorobenzene or the proteasome inhibitors (lactacystin and Z-Ile-Glu(OtBu)Ala-Leu-CHO). p35 protein was also degraded to p25 when rat brain lysate was subjected to in vitro digestion with purified mu- and m-calpains. Additionally, in a rat temporary middle cerebral artery occlusion model, p35 processing to p25 again paralleled SBDP formation in the ischemic core. Lastly, in malonate-injured rat brains, the ipsilateral side showed a striking correlation of SBDP formation with p35 to p25 conversion and tau phosphorylation (at Ser202 and Thr205) increase. These data suggest that calpain is a major neuronal protease capable of converting p35 to p25 and might play a pathological role of activating cdk5 and its phosphorylation of tau in Alzheimer's disease.

Osteomyocutaneous flap as a preclinical composite tissue allograft: swine model

Composite tissue allotransplantation (CTA) constitutes one of the last frontiers of microsurgery. Prior to its clinical application, the long-term efficacy of modern immunotherapy must be tested in a pre-clinical CTA model. Based on the concept of osteomyocutaneous forearm flap, we developed a CTA flap model in swine. After identifying the vascular territory of the flaps in six pigs (vascular casting), flaps were transplanted from mismatched donor to recipient pigs (n = 6). Rejection was assessed daily by visual inspection and histopathology of biopsy specimens. Recipient pigs were able to ambulate immediately following surgery. There were no flap failures owing to technical or surgical complications. Rejection occurred over a period of 7 days as manifested by edema, cellular infiltration, epidermalysis, and thrombosis. This pre-clinical flap model is excellent for evaluating the effectiveness of modern immunotherapy because it is anatomically and immunologically relevant and because the minimal morbidity caused to the animal permits long-term studies.

[The preparation of electric arc method and spectral analysis on long persistence luminescent chinaware of SrAl2O4:Eu2+]

Luminescent chinaware of long persistence of SrAl2O4:Eu2+ has been prepared with using are method. Fluorescence and excitation spectra were measured in order to study its luminescence and long persistence properties. Results show that both of luminescent chinaware and polycrystalline powdered phosphor are the same in luminescence decay and consist of an initial fast process and a later extremely slow process. Long persistence properties of luminescent chinaware are better more than polycrystalline powdered phosphor, and its function of environment-resistant has been improved prominently.

[Mobilization of autologous peripheral blood stem cells by chemotherapy and recombinant granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF)]

OBJECTIVE

To observe the efficacy of chemotherapy and recombinant granulocyte colony-stimulating factor (G-CSF, Glycosylated) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in autologous peripheral blood stem cells (APBSC) mobilization.

METHODS

The mobilization regimen: CBP 350 mg/m(2) intravenously injected at day 1, Vp16 350 mg/m(2) intravenously injected from day 1 to day 3. G-CSF and GM-CSF 5 microg x kg(-1) x d(-1) each, subcutaneously injected and DXM 5 mg/d intramuscularly injected, from the day of white blood cell (WBC) recovery to (2.4 - 6.4) x 10(9)/L from nadir to the day before the end of APBSC harvesting. APBSC harvesting started when WBC > 20.0 x 10(9)/L and ended when accumulated mononuclear cells (MNC) > 5 x 10(8)/kg. CFU-GM assay and CD(34)(+) cells counting of the APBSC were performed.

RESULTS

Twenty cases underwent APBSC mobilization. APBSC harvest began at day 22.15 +/- 3.66 for two successive days. Accumulated MNC was (5.93 +/- 1.62) x 10(8)/kg, CD(34)(+) cells (23.10 +/- 11.53) x 10(6)/kg and CFU-GM (3.44 +/- 2.85) x 10(5)/kg. No severe toxicity was observed. Hematopoiesis was well reconstituted in 8 patients received single and in 1 patient received double APBSC transplantations.

CONCLUSION

Chemotherapy combined with G-CSF + GM-CSF was a safe and highly effective method for APBSC mobilization.

Distinctions between bovine herpesvirus 1 and herpes simplex virus type 1 VP22 tegument protein subcellular associations

The alphaherpesvirus tegument protein VP22 has been characterized with multiple traits including microtubule reorganization, nuclear localization, and nonclassical intercellular trafficking. However, all these data were derived from studies using herpes simplex virus type 1 (HSV-1) and may not apply to VP22 homologs of other alphaherpesviruses. We compared subcellular attributes of HSV-1 VP22 (HVP22) with bovine herpesvirus 1 (BHV-1) VP22 (BVP22) using green fluorescent protein (GFP)-fused VP22 expression vectors. Fluorescence microscopy of cell lines transfected with these constructs revealed differences as well as similarities between the two VP22 homologs. Compared to that of HVP22, the BVP22 microtubule interaction was much less pronounced. The VP22 nuclear interaction varied, with a marbled or halo appearance for BVP22 and a speckled or nucleolus-bound appearance for HVP22. Both VP22 homologs associated with chromatin at various stages of mitosis and could traffic from expressing cells to the nuclei of nonexpressing cells. However, distinct qualitative differences in microtubule, nuclear, and chromatin association as well as trafficking were observed. The differences in VP22 homolog characteristics revealed in this study will help define VP22 function within HSV-1 and BHV-1 infection.

[Comparative study of three common G6PD gene mutations in Yao and Han People in Guangxi]

OBJECTIVE

To study G6PD gene mutation diversity in Yao and Han people in Guangxi and compare the genotypic frequencies.

METHODS

The three common G6PD gene mutations in Chinese were investigated in 34 G6PD deficient individuals from Yao and 37 from Han people by using an amplification refractory mutation system (ARMS).

RESULTS

Among 34 cases of G6PD deficiency of Yao people, the genotypic frequencies of G1376T, G1388A and A95G were 41.2%, 26.5% and 14.7%, respectively. A case of C1311T was detected. As compared with that in Han people, the respective frequencies were 16.2%, 40.6% and 5.4%.

CONCLUSION

The main G6PD mutations in Yao people were the same with Han people in Guangxi, but G1376T mutation was higher than that in Han people. The C1311T mutation in Yao people in Guangxi was reported for the first time.

[Influence of the administrators of family planning on the spread of norplant in countryside of Sichuan]

The purpose of the study was to understand the family planning administrators' knowledge of Norplant and their fluence on the spread of Norplant in countryside of Sichuan. 156 administratoras were surveyed. It was found that most of the administrators worked hard on education, propagation, organization and management of using Norplant, and they recognized the contraceptive efficacy of Norplant. However, the educational level of the administrators was generally low. They were short of the training on Norplant related knowledge(training rate was only 36.5%). The degree of the users' satisfaction and the administrators' knowledge on Norplant varied between areas. The result indicated that the basic quality of the administrators and their knowledge of Norplant were influences on the spread of Norplant in the countryside of Sichuan. Soit is very important to improve the basic quality and knowledge of the administrators of family planning.

Somatic mutations of the PPP2R1B candidate tumor suppressor gene at chromosome 11q23 are infrequent in ovarian carcinomas

Previous studies have demonstrated frequent allelic losses of distal chromosome 11q in ovarian carcinomas. The tumor suppressor gene(s) presumably targeted by these losses have not yet been identified. PPP2R1B is a candidate tumor suppressor gene at 11q23 that has recently been shown to be mutated in a subset of colorectal and lung cancers. We evaluated 5 ovarian carcinoma cell lines and 27 primary ovarian carcinomas for allelic losses of 11q23 and for mutations in the open reading frame of PPP2R1B. We also evaluated the primary tumors for allelic losses at 17p13, another chromosomal region frequently affected by losses of heterozygosity (LOH) in ovarian cancers. 11q23 and 17p13 allelic losses were identified in 25% and 74% of the carcinomas, respectively. No mutations within PPP2R1B coding sequences were found. These findings indicate that mutations of the PPP2R1B gene are infrequent in ovarian cancer and that deletions affecting the distal portion of chromosome 11q in ovarian cancer likely target inactivation of other genes.

[Epstein-Barr virus infection and expression of T-cell intracellular antigen-1 (TIA-1) in intestinal T-cell lymphoma]

OBJECTIVE

To study the status of Epstein-Barr virus (EBV) infection and the expression of TIA-1 antigen in 24 cases of intestinal T-cell lymphomas.

METHODS

In situ hybridization for EBER1/2; immunohistochemical staining by three step ABC technique for TIA-1, LMP-1, CD30, CD45RO, CD3 AND CD20. 19 cases of intestinal B-cell lymphomas were used for comparison.

RESULTS

(1) Of the 24 intestinal T-cell lymphoma cases, 23 were pleomorphic, medium to large cell type, and one cases was small cell type; in 20 of the 24 cases EBER1/2 signals were detected in the tumor cells; in 4 of the 20 EBER1/2 positive cases, tumor cells expressed LMP-1; EBER1/2 was not detected in 19 cases of intestinal B-cell lymphomas. (2) in 23 of the 24 cases, TIA-1 was expressed in most tumor cells, but not in the only case of small cell type; TIA-1 was negative in tumor cells of all 19 cases of intestinal B-cell lymphomas.

CONCLUSIONS

A high level of EBV infection was present in this group of intestinal T-cell lymphomas, the expression of TIA-1 may be related to its cell origin. Intestinal T-cell lymphoma may be an EBV-associated extranodal NK/T cell lymphoma.

Molecular characterization of radiation- and chemically induced mutations associated with neuromuscular tremors, runting, juvenile lethality, and sperm defects in jdf2 mice

The juvenile development and fertility-2 (jdf2) locus, also called runty-jerky-sterile (rjs), was originally identified through complementation studies of radiation-induced p-locus mutations. Studies with a series of ethylnitrosourea (ENU)-induced jdf2 alleles later indicated that the pleiotropic effects of these mutations were probably caused by disruption of a single gene. Recent work has demonstrated that the jdf2 phenotype is associated with deletions and point mutations in Herc2, a gene encoding an exceptionally large guanine nucleotide exchange factor protein thought to play a role in vesicular trafficking. Here we describe the molecular characterization of a collection of radiation- and chemically induced jdf2/Herc2 alleles. Ten of the 13 radiation-induced jdf2 alleles we studied are deletions that remove specific portions of the Herc2 coding sequence; DNA rearrangements were also detected in two additional mutations. Our studies also revealed that Herc2 transcripts are rearranged, not expressed, or are present in significantly altered quantities in animals carrying most of the jdf2 mutations we analyzed, including six independent ENU-induced alleles. These data provide new molecular clues regarding the wide range of jdf2 and p phenotypes that are expressed by this collection of recently generated and classical p-region mutations.