Developmental changes in digestive enzyme activity in American shad, Alosa sapidissima, during early ontogeny

In order to assess the digestive physiological capacity of the American shad Alosa sapidissima and to establish feeding protocols that match larval nutritional requirements, we investigated the ontogenesis of digestive enzymes (trypsin, amylase, lipase, pepsin, alkaline phosphatase, and leucine aminopeptidase) in larvae, from hatching to 45 days after hatching (DAH). We found that all of the target enzymes were present at hatching, except pepsin, which indicated an initial ability to digest nutrients and precocious digestive system development. Trypsin rapidly increased to a maximum at 14 DAH. Amylase sharply increased until 10 DAH and exhibited a second increase at 33 DAH, which coincided with the introduction of microdiet at 30 DAH, thereby suggesting that the increase was associated with the microdiet carbohydrate content. Lipase increased until 14 DAH, decreased until 27 DAH, and then increased until 45 DAH. Pepsin was first detected at 27 DAH and then sharply increased until 45 DAH, which suggested the formation of a functional stomach. Both alkaline phosphatase and leucine aminopeptidase markedly increased until 18 DAH, which indicated intestinal maturation. According to our results, we conclude that American shad larvae possess the functional digestive system before mouth opening, and the significant increases in lipase, amylase, pepsin, and intestinal enzyme activities between 27 and 33 DAH suggest that larvae can be successfully weaned onto microdiets around this age.

Molecular characterization and expression analysis of AMPK α subunit isoform genes from Scophthalmus maximus responding to salinity stress

AMP-activated protein kinase (AMPK) is a highly conserved and multi-functional protein kinase that plays important roles in both intracellular energy balance and cellular stress response. In the present study, molecular characterization, tissue distribution and gene expression levels of the AMPK α1 and α2 genes from turbot (Scophthalmus maximus) under salinity stress are described. The complete coding regions of the AMPK α1 and α2 genes were isolated from turbot through degenerate primers in combination with RACE using muscle cDNA. The complete coding regions of AMPK α1 (1722 bp) and α2 (1674 bp) encoded 573 and 557 amino acids peptides, respectively. Multiple alignments, structural analysis and phylogenetic tree construction indicated that S. maximus AMPK α1 and α2 shared a high amino acid identity with other species, especially fish. AMPK α1 and α2 genes could be detected in all tested tissues, indicating that they are constitutively expressed. Salinity challenges significantly altered the gene expression levels of AMPK α1 and α2 mRNA in a salinity- and time-dependent manners in S. maximus gill tissues, suggesting that AMPK α1 and α2 played important roles in mediating the salinity stress in S. maximus. The expression levels of AMPK α1 and α2 mRNA were a positive correlation with gill Na⁺, K⁺-ATPase activities. These findings will aid our understanding of the molecular mechanism of juvenile turbot in response to environmental salinity changes.

Effects of stocking density on antioxidant status, metabolism and immune response in juvenile turbot (Scophthalmus maximus)

This study was designed to evaluate the physiological and immune responses of juvenile turbot to stocking density. Turbot (average weight 185.4g) were reared for 120days in a land based recirculating aquaculture system (RAS) under three stocking densities: low density (LD, ~9.3-26.1kg/m², initial to final density), medium density (MD, ~13.6-38.2kg/m²) and high density (HD, ~19.1-52.3kg/m²). Fish were sampled at days 0, 40, 80 and 120 to obtain growth parameters and liver tissues. No significant difference was detected in growth, biochemical parameters and gene expression among the three densities until at the final sampling (day 120). At the end of this trial, fish reared in HD group showed lower specific growth rate (SGR) and mean weight than those reared in LD and MD groups. Similarly, oxidative stress and metabolism analyses represented that antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione (GSH)) and metabolic enzymes (glycerol-3-phosphate dehydrogenase (G3PDH) and glucose-6-phosphate dehydrogenase (G6PDH)) clearly reduced in the liver of turbot reared in HD group. The gene expression data showed that glutathione S-transferase (GST), cytochrome P450 1A (CYP1A), heat shock protein 70 (HSP 70) and metallothionein (MT) mRNA levels were significantly up-regulated, and lysozyme (LYS) and hepcidin (HAMP) mRNA levels were significantly down-regulated in HD group on day 120. Overall, our results indicate that overly high stocking density might block the activities of metabolic and antioxidant enzymes, and cause physiological stress and immunosuppression in turbot.

Stress and immune responses in skin of turbot (Scophthalmus maximus) under different stocking densities

Fish skin and its mucus provide the first line of defense against chemical, physical and biological stressors, but little is known about the role of skin and its mucus in immune response to crowding stress. In the present study, we investigated the stress and immune responses in skin of turbot (Scophthalmus maximus) under different stocking densities. Turbot (average weight 185.4 g) were reared for 120 days under three densities: low density (LD), medium density (MD), and high density (HD). After 120 days, fish were weighed and sampled to obtain blood, mucus and skin tissues which were used for analyses of biochemical parameters and genes expression. The results showed HD treatment significantly suppressed growth and enhanced plasma cortisol and glucose levels (P < 0.05). In mucus, the activities of lysozyme (LZM), alkaline phosphatase (ALP) and esterase in HD treatment were lower than LD and MD treatments (P < 0.05) In skin, HD treatment resulted in up-regulation in malondialdehyde (MDA) formation and heat shock protein 70 (HSP 70) mRNA level, and down-regulation in activity of superoxide dismutase (SOD) and the transcriptions of glutathione-s-transferase (GST), interleukin-1β (IL-1β), tumor necrosis factor -α (TNF-α), insulin-like growth factor- (IGF-) and LZM (P < 0.05). Overall, the data suggested that overly high stocking density was a stressor which caused an immunosuppression in skin of turbot. Moreover, this information would help to understand the skin immunity and their relation with stress and disease in fish.

The physiological performance and immune response of juvenile turbot (Scophthalmus maximus) to nitrite exposure

Nitrite (NO(2-)) is the most common toxic nitrogenous compound in aquatic environment. The aim of the present study was to investigate the effects of nitrite physiological performance and immune response of turbot. Fish were exposed to 0, 0.02, 0.08, 0.4 and 0.8 mM nitrite for 96 h. After 0, 24, 48 and 96 h of exposure, blood were collected to measure the levels of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), alkaline phosphatase (ALP), total protein (TP), albumin (Alb), complement C3 (C3), complement C4 (C4), immunoglobulin M (IgM) and lysozyme (LYS); gill samples were taken to analyze mRNA levels of LYS, heat shock protein 70 (HSP 70), heat shock protein 90 (HSP 90), metallothionein (MT), toll-like receptor 3 (TLR-3), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and insulin-like growth factor I (IGF-I). The results showed that nitrite (0.4 and/or 0.8mM) significantly increased the levels of GPT, GOT, ALP, C3 and C4, reduced the levels of IgM and LYS, up-regulated the gene expressions of HSP 70, HSP 90, MT, TLR-3, TNF-α and IL-1β, and down-regulated the gene expressions of LYS and IGF-1 after 48 and 96 h of exposure. Based on the results, it can be concluded that high level nitrite exposure results in dysfunction of the blood physiology and immunity in turbot. Further, this study will be helpful to understand the mechanism of aquatic toxicology induced by nitrite in marine fish.

Effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus)

Nitrite (NO2(-)) is commonly present as contaminant in aquatic environment and toxic to aquatic organisms. In the present study, we investigated the effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus). Fish were exposed to various concentrations of nitrite (0, 0.02, 0.08, 0.4 and 0.8mM) for 96 h. Fish blood and gills were collected to assay haematological parameters, oxidative stress and expression of genes after 0, 24, 48 and 96 h of exposure. In blood, the data showed that the levels of methemoglobin (MetHb), triglyceride (TG), potassium (K(+)), cortisol, heat shock protein 70 (HSP70) and glucose significantly increased in treatments with higher concentrations of nitrite (0.4 and/or 0.8mM) after 48 and 96 h, while the levels of haemoglobin (Hb) and sodium (Na(+)) significantly decreased in these treatments. In gills, nitrite (0.4 and/or 0.8mM) apparently reduced the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH), increased the formation of malondialdehyde (MDA), up-regulated the mRNA levels of c-jun amino-terminal kinase (JUK1), p53, caspase-3, caspase-7 and caspase-9 after 48 and 96 h of exposure. The results suggested caspase-dependent and JUK signaling pathways played important roles in nitrite-induced apoptosis in fish. Further, this study provides new insights into how nitrite affects the physiological responses and apoptosis in a marine fish.

Biochemical composition of the ovarian fluid and its effects on the fertilization capacity of turbot Scophthalmus maximus during the spawning season

This study investigated the biochemical composition of ovarian fluid and its effect on the fertilization capacity of turbot Scophthalmus maximus during the spawning season. The fertilization rate and pH of ovarian fluid varied throughout the spawning season, with the highest values recorded at the mid-season. Positive correlations were found between the fertilization rate and the ovarian fluid pH. The composition of major inorganic ions (Na(+) , K(+) , Ca(2+) and Cl(-) ) showed no significant changes during the spawning season. Alkaline phosphatase (AKP) activity was significantly higher during mid-season than other seasons. The lowest levels of protein, acid phosphatase (ACP) and aspartate aminotransferase (AAT) were in the ovarian fluid released at the mid-season. Moreover, significant relationships were observed between the fertilization rate and the levels of protein, ACP, AKP and AAT. These observations suggest that the biochemical profile of ovarian fluid affects the insemination microenvironment as well as the fertilization capacity of S. maximus eggs. Determination of such profiles may prove to be a useful strategy to improve S. maximus breeding techniques.

Genome-wide identification, classification, and analysis of heat shock transcription factor family in Chinese cabbage (Brassica rapa pekinensis)

Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetable crops grown worldwide, and various methods exist for selection, propagation, and cultivation. The entire Chinese cabbage genome has been sequenced, and the heat shock transcription factor family (Hsfs) has been found to play a central role in plant growth and development and in the response to biotic and abiotic stress conditions, particularly in acquired thermotolerance. We analyzed heat tolerance mechanisms in Chinese cabbage. In this study, 30 Hsfs were identified from the Chinese cabbage genome database. The classification, phylogenetic reconstruction, chromosome distribution, conserved motifs, expression analysis, and interaction networks of the Hsfs were predicted and analyzed. Thirty BrHsfs were classified into 3 major classes (class A, B, and C) according to their structural characteristics and phylogenetic comparisons, and class A was further subdivided into 8 subclasses. Distribution mapping results showed that Hsf genes were located on 10 Chinese cabbage chromosomes. The expression profile indicated that Hsfs play differential roles in 5 organs in Chinese cabbage, and likely participate in the development of underground parts and regulation of reproductive growth. An orthologous gene interaction network was constructed, and included MBF1C, ROF1, TBP2, CDC2, and HSP70 5 genes, which are closely related to heat stress. Our results contribute to the understanding of the complexity of Hsfs in Chinese cabbage and provide a basis for further functional gene research.

[Progress in study on the skin mucus lectin in fish]

Since water is a perfect medium for both bacteria and parasitic microbes, fish skin is constantly exposed to pathogen attacks. It is generally believed that skin mucus serves a mechanical as well as biochemical barrier. Lectins, an important part of the mucus, are carbohydrate-binding proteins that are neither antibodies nor enzymes, yet play important roles in innate and adaptive immunity. Based on the structure of the carbohydrate recognition domain (CRD) and their function, fish mucus lectins are classified as four types. Recent research has shed light on the structural diversity and functions in innate immunity of mucus lectins. Here, we reviewed recent research progress on the classification, biological properties and functions of fish mucus lectins. Analyses on other fish species are therefore important in clarifying lectin diversity and their functions in skin mucus.

Characterization of RAG1 and IgM (mu chain) marking development of the immune system in red-spotted grouper (Epinephelus akaara)

In vertebrates, lymphoid-specific recombinase protein encoded by recombination-activating genes (RAG1/2) plays a key role in V(D)J recombination of the T-cell receptor and B-cell receptor. In this study, both RAG1 and the immunoglobulin M (IgM) mu chain were cloned to characterize their potential role in the immune defense at developmental stages of red-spotted grouper, Epinephelus akaara. The open reading frame (ORF) of E. akaara RAG1 included 2778 nucleotide residues encoding a putative protein of 925 amino acids, while the ORF of the IgM mu chain had 1734 nucleotide residues encoding 578 amino acids including variable (VH) and constant (CH1-CH2-CH3-CH4) regions. E. akaara RAG1 was composed of a zinc-binding dimerization domain (ZDD) with a RING finger and zinc finger A (ZFA) in the non-core region and a nonamer-binding region (NBR), with a zinc finger B (ZFB), the central and C-terminal domains in the core region. Tridimensional models of the ZDD and NBR of E. akaara RAG1 were constructed for the first time in fishes, while a 3D model of the E. akaara IgM mu chain was also clarified. The RAG1 mRNA was only detected in the thymus and kidney of 4-month and 1.5-year old groupers using qPCR, and the RAG1 protein was confirmed using western blotting and immunohistochemistry. The IgM mu mRNA was examined in most tissues except the gonad. RAG1 and IgM mu gene expression were observed at 15 dph (days post-hatching) and 23 dph respectively, and increased to a higher level at 37 dph. In addition, this was the first time that the morphology of the E. akaara thymus was characterized. The oval-shaped thymus of 4-month old fish was clearly seen and there were amounts of T lymphocytes present. The results suggested that the immune action of E. akaara was likely to start to develop around 15 dph to 29 dph. The transcript level of the RAG1 gene and the number of lymphocytes in the thymus between 4-month and 1.5-year old groupers indicated that age-related thymic atrophy also occurs in fishes. The similar functional structures of RAG1 and IgM protein between fish and mammals indicated that teleost species share a similar mechanism of V(D)J recombination with higher vertebrates.

[Relationship between the familial nonrandom chromosome loss (NCL) and leukomogenesis]

By using R-banding karyotypic analysis technique, the bone marrow (BM) cells were performed in 223 hematopoietic malignacies and 105 diopathic throbocytopenic purpura (ITP), which served as control. The following results were obtained: (1) Nonrandom chromosome loss (NCL), such as, -11, -14, -21, etc, which were found in the affected members of leukemia families, were found in about 30% sporadic ANLL, MDS and about 50% ALL, espedislly in 100% (5/5) CLL, but not found in ITP (P < 0.001). These results indicated that the familial nonrandom chromosome loss were associated with leukomogenesis. (2) Because most of BM cells are hypodiploed and have the same kinds of NCL in each cases of CLL, which can develop into ALL, ANLL and also cancers, ALL BM hypo- and hyper-diploid and/or polyploid cells might be origin of hypodiploid cells. (3) 28% (6/21) of pediatric patients with AL, MDS, or FA (Fanconi Anemia) have one parent, who have up to 30% BM hypodiploid cells and similar kinds of NCL and also have the rearrangement of C-erbB and abnormal proliferation of BM. The NCL were found in the three consecutive generations of a family with 5 ALL among 10 members of third generation. It indicated that the familial NCL might be inherited and be coded by a unknown gene alteration, which might be related to leukomo and carcinogenesis, because there are genes or their candidates for leukemia in the chromosomes 11, 14 and 21. (4) Based on the works of my colleages and I, the model of leukomo and carcinogenesis was proposed and the relationship between chromosome monosomy, deletion, translocations and leukomogenesis were showed elswhere. The significance of monosomy 11, 14 and 21 etc. were discussed briefly.

Physical training modifies the age-related decrease of GAP-43 and synaptophysin in the hippocampal formation in C57BL/6J mouse

We investigated the effect of a moderate amount of prolonged physical training initiated at 3 months of age on the expression of GAP-43 and synaptophysin in the hippocampal formation. C57BL/6J mice were divided into three groups which were trained (24 months old), sedentary (24 months old) and young (3 months old). From 3 months of age on, mice of trained group were treated with voluntary running wheel for 1 h each day (5 days per week) until 24 months of age (21 months running), whereas mice of sedentary group were put in immobilized wheels for the same time. Using immunohistochemistry and image analysis system, GAP-43 and synaptophysin were analysed quantitatively in the CA1, CA3 areas and the dentate gyrus of the hippocampal formation. As compared with young mice, the densities of GAP-43 and synaptophysin immunostaining showed a significant decrease in the hippocampal formation in sedentary group (P<0.01). After 21 months of running, the densities of GAP-43 and synaptophysin immunostaining significantly increased in the examined areas of the hippocampal formation in trained mice compared to their age-matched sedentary controls (P<0.05, 0.01). These results indicate that a moderate amount of prolonged physical training could modify the age-related decrease of the expression of GAP-43 and synaptophysin in the hippocampal formation, and that the increased expression of GAP-43 and synaptophysin might be associated with the anatomical sprouting and synaptogenesis.

Effect of physical training on the age-related changes of acetylcholinesterase-positive fibers in the hippocampal formation and parietal cortex in the C57BL/6J mouse

We investigated the effect of a moderate amount of prolonged physical training initiated at 3 months of age on the age-related changes of the hippocampal and cortical cholinergic fibers. A total of 80 male C57BL/6J mice were divided into five groups which were trained (including adult and old trained, AT and OT), sedentary (adult and old sedentary, AS and OS) and young (Y). From 3 months old, the mice of the trained groups were treated with a voluntary running wheel for 1 h each day, 5 days per week. AT had been trained up to 13-month-old whereas OT up to 24 months old. At the same time, the mice of the sedentary groups were put in immobilized wheels. We set the criterion for effective training in the trained mice such that the heart-to-body weight ratio should be at least 2 S.D. above the mean in the age-matched groups. Using AChE histochemistry and stereology, the AChE-positive fibers were analyzed quantitatively in the molecular layers in CA1, CA3 and the dentate gyrus of the hippocampal formation, and in III, V layers in the motor and somatosensory cortex. Comparison of Y, AS and OS (3, 13 and 24 months of age) showed minimum AChE-positive fiber density in the hippocampal formation and the cortex in OS (P < 0.01). After 10 and 21 months of running, the AChE-positive fibers in all regions examined in the trained groups were significantly increased compared to their age-matched controls (P < 0.05 or 0.01). In the hippocampal formation, the increase was about 17% in AT and 23% in OT, whereas, in the cortex, it was 13% in AT and 22% in OT. These results indicated that a moderate amount of prolonged physical training could modify the age-related loss of cholinergic fibers in the hippocampal formation and cortex, furthermore the modified loss of cholinergic fibers might be associated with the regeneration of hippocampal and cortical cholinergic fibers stimulated by chronic running.

[Relationship between the occurrences of AL, MDS and AA and abnormal BM proliferation of patient's parents]

After studying of familial leukemias, Myelodysplastic Syndrome (MDS) and aplastic anemia (AA), we observed and analysed bone marrow (BM) cells hematologically and molecular-cytogenetically in 36 persons who are first degree relatives (FDRs) of patients with acute leukemias (AL), MDS and AA. The peripheral blood (PB) lymphocyte chromosome fragility sensitive to folic acid and unstability was also analysed in 18 FDRs. The abnormal BM megakaryocystic/erythroid cellularity and the rearrangement of c-erbB were found in 66%-86.1% of parents and siblings of patients. The associations of dysplastic megakaryopoiesis, including the presence of lymphoid small megakaryocytes, with the chromosomal monosomy or/and the rearrangement/amplification of C-erbB, were found in a few parents and siblings. These results were consistent with those of MDS, Fanconi Anemia (FA) and AL. The normal karyotype and SCD positive of BM cells and PB lymphocytes, and PB lymphocyte chromosomal fragility and unstability were found in most of patients' parents, while familial chromosomal monosomy of BM cells and PB lymphocyte chromosomal fragility were found in parents and siblings of familial leukemia patients. Based on the studies of a large family with 7 cases of acute erythroleukamia and relative myeloleukemias in three consecutive generations and a family with 3 CAA and 1 AML, the rearrangement of c-erbB might be inherited. The rearrangement/amplification of c-erbB and its PCR detected results could be the indicators of gene diagnosis of preleukemia and might be useful in genetic conselling of leukemias. The common origin of AL, MDS and AA was discussed.

Morphological plasticity of axotomized retinal ganglion cells following intravitreal transplantation of a peripheral nerve segment

During normal development of retinal ganglion cells when the axons are growing, transient dendritic spines have been observed. Similar dendritic spine-like processes are also exhibited by retinal ganglion cells undergoing axonal regeneration into a peripheral nerve grafted to the damaged optic axons. Here we show, using the intracellular injection of Lucifer Yellow, that when a segment of peripheral nerve is transplanted to the vitreous body, a procedure which induces ectopic sprouting of axon-like processes from the cell bodies and dendrites of some retinal ganglion cells, similar spine-like processes appear on the dendrites of cells with ectopic sprouts. Quantitative analysis indicated that there were significant changes with posttransplantation survival time in the distributions of spine-like processes and axon-like processes on these sprouting retinal ganglion cells following the intravitreal transplantation of a piece of peripheral nerve. The remodelling of the spine-like processes and axon-like processes correlated with one another suggesting that plastic changes can occur in certain dendritic subcompartments independent of the growth activity of the other dendritic subcompartments.

[Cytogenetic studies on 334 myelodysplastic syndrome (MDS), aplastic anemia (AA) and other hematological diseases]

In order to distinguish various types of MDS, such as RA/AA, RA/ITP or RA/HA, from AA, ITP or HA, bone marrow (BM) cells were studied by using cytogenetic techniques including R-banding karyotypic analysis and sister chromatid differentiation (SCD) assay in 334 cases of hematological diseases (160 MDS, 54 RA/AA, RA/ITP or RA/HA; 60 AA, 3 other known anemias, 38 PNH and 19 ITP). The results showed: (1) karyotypes and SCD values were both normal in more than 90% of AA, PNH, ITP and other known anemias, but they were both abnormal in about 35.6% of MDS and only 13.0% of RA/AA, RA/ITP or RA/HA. These results indicated that cytogenetic techniques were useful in hematological clinic and that RA/AA, or RA/ITP or RA/HA might be pre-RA or atypic RA. This was supported by the results of following up on some RA/AA, RA/ITP or RA/HA cases, (2) clonal abnormal karyotypes were found in 64.4% of MDS. The recurrent chromosomal alterations were +8, 20q-, -5/5q-, -7/7q-, similar to those reported in literatures. (3) 16 MDS cases were followed up and 15 MDS with SCD negative, but one with SCD positive developed leukemia in our hospital. It is suggested that change from SCD positive to negative was indicative of malignant transformation of BM cells. This was supported by the results of cytogenetic analysis in RA/AA, RA/ITP, RA, RAEB, RAEBT and leukemias. (4) Because more structural chromosome alterations occur in SCD negative than SCD positive MDS, the numerous chromosome alterations (monosomy) might occur in earliest development of MDS into leukemias.

[Gene diagnosis and successful reversion in a patient with preleukemia]

According to the FAB classification, a patient (case 1) could not be diagnosed as MDS-RA, although she had clinical features of MDS, as compared with another patient (case 2) who was diagnosed as RAS and had abnormal karyotype (20q- and 5q-) of bone marrow (BM) cells. BM cells of the two patients were SCD (sister chromatid differentiation) negative. Rearrangement of c-erbB and c-erbA was found in the genome of the BM cells in both patients, when southern blot hybridization was performed with probe v-erbB+A. Therefore, case 1 could be diagnosed as preleukemia. During a period about 3 years of treatment with the drug stanozolol in case 1 there was good effect and successful reversion was obtained. She had then normal hematologic and cytogenetic patterns of BM and PB and the rearrangement of c-erbB of BM cells also disappeared. She has worked for two years since then. The mechanism of effective treatment and successful reversion was discussed briefly. Probe v-erbB was shown to be useful in investigation of gene diagnosis of preleukemia or MDS (shown elsewhere).

[Gene diagnosis of familial erythroleukemia at the early stage of leukomogenesis]

Southern blot hybridization was performed with probe v-erbB + A in 4 subjects. Two of them were patients with similar erythroid alterations of bone marrow: one of them was diagnosed as erythroleukemia (EL). The other two were members of a same family (husband and wife). The husband had normal erythroid cellularity of bone marrow but the wife and their 7 living sons and daughters had erythroid hypercellularity. In the second generation of this family 4 hematological patients (1 with AML and 3 with CAA) were found in the past decade. Rearrangement of cerbB and c-erbA genes was found in 3 of the 4 subjects (2 with EL and the wife mentioned above). They had 4 new hybridization bands besides 3 germlines, but the husband had only 3 germlines. The result suggests that using Southern blot hybridization technique with probe v-erbB + A, the rearrangement of c-erbB/c-erbA genes might be a diagnostic indicator of erythroleukemia at early stage of leukomogenesis in familial and sporadic patients. The etiological significance of the rearrangement of c-erbB/c-erbA in leukomogenesis was discussed.