Overexpression of plum auxin receptor PslTIR1 in tomato alters plant growth, fruit development and fruit shelf-life characteristics.

BACKGROUND: TIR1-like proteins are F-box auxin receptors. Auxin binding to the F-box receptor proteins promotes the formation of SCF(TIR1) ubiquitin ligase complex that targets the auxin repressors, Aux/IAAs, for degradation via the ubiquitin/26S proteasome pathway. The release of auxin response factors (ARFs) from their Aux/IAA partners allows ARFs to mediate auxin-responsive changes in downstream gene transcription. In an attempt to understand the potential role of auxin during fruit development, a plum auxin receptor, PslTIR1, has previously been characterized at the cellular, biochemical and molecular levels, but the biological significance of this protein is still lacking. In the present study, tomato (Solanum lycopersicum) was used as a model to investigate the phenotypic and molecular changes associated with the overexpression of PslTIR1. RESULTS: The findings of the present study highlighted the critical role of PslTIR1 as positive regulator of auxin-signalling in coordinating the development of leaves and fruits. This was manifested by the entire leaf morphology of transgenic tomato plants compared to the wild-type compound leaf patterning. Moreover, transgenic plants produced parthenocarpic fruits, a characteristic property of auxin hypersensitivity. The autocatalytic ethylene production associated with the ripening of climacteric fruits was not significantly altered in transgenic tomato fruits. Nevertheless, the fruit shelf-life characteristics were affected by transgene presence, mainly through enhancing fruit softening rate. The short shelf-life of transgenic tomatoes was associated with dramatic upregulation of several genes encoding proteins involved in cell-wall degradation, which determine fruit softening and subsequent fruit shelf-life. CONCLUSIONS: The present study sheds light into the involvement of PslTIR1 in regulating leaf morphology, fruit development and fruit softening-associated ripening, but not autocatalytic ethylene production. The results demonstrate that auxin accelerates fruit softening independently of ethylene action and this is probably mediated through the upregulation of many cell-wall metabolism genes.

PpERF3b, a transcriptional repressor from peach, contributes to disease susceptibility and side branching in EAR-dependent and -independent fashions.

KEY MESSAGE: Peach ERF3b is a potent transcriptional repressor for defense-related genes even in the presence of similar levels of transcriptional activators and can interfere with plant development through pathways independent of the EAR motif. Ethylene response factors (ERFs) are a major group of plant transcription factors with either activation or repression capabilities on gene transcription. Repressor-type ERFs are characterised by an intrinsic motif, namely the ERF-associated amphiphilic repression motif (EAR). Here we report the identification of three genes from peach (Prunus persica), PpERF12, PpERF3a and PpERF3b, encoding for ERF repressors. The transcription kinetics of these genes was investigated by qRT-PCR after inoculation of peach leaves with Xanthomonas campestris pv. pruni. All three genes showed higher induction in the susceptible 'BabyGold 5', than in the resistant 'Venture' peach varieties suggesting a negative role for these genes in disease resistance. The functional potency of PpERF3b has been confirmed in vivo by its ability to repress the expression of GUS-reporter gene. To better understand the functional role of PpERF3b, the full-length and the EAR-truncated (PpERF3b∆EAR) genes were overexpressed in tobacco (Nicotiana tabacum). Both transgenic plants (PpERF3b and PpERF3b∆EAR) uniformly exhibited precocious side branching, which suggests the interference of PpERF3b with auxin-mediated dormancy of lateral shoots. Consistent with that the expression of auxin-response factors (Nt-ARF1, Nt-ARF6 and Nt-ARF8) was significantly downregulated in transgenic plants compared to the wild type (WT). Although side branching was independent of EAR motif, the response of transgenic plants to inoculation by Pseudomonas syringae pv. tabaci was EAR dependent. Transgenic plants overexpressing PpERF3b∆EAR showed less disease symptoms than those overexpressing the full-length gene or WT plants. Resistance of PpERF3b∆EAR plants was associated with enhanced induction of pathogenesis-related (PR) genes. Our results indicate that repressor-type ERFs might act through pathways that are dependent or independent of the EAR motif.

Expression of auxin-binding protein1 during plum fruit ontogeny supports the potential role of auxin in initiating and enhancing climacteric ripening.

Auxin-binding protein1 (ABP1) is an active element involved in auxin signaling and plays critical roles in auxin-mediated plant development. Here, we report the isolation and characterization of a putative sequence from Prunus salicina L., designated PslABP1. The expected protein exhibits a similar molecular structure to that of well-characterized maize-ABP1; however, PslABP1 displays more sequence polarity in the active-binding site due to substitution of some crucial amino-acid residues predicted to be involved in auxin-binding. Further, PslABP1 expression was assessed throughout fruit ontogeny to determine its role in fruit development. Comparing the expression data with the physiological aspects that characterize fruit-development stages indicates that PslABP1 up-regulation is usually associated with the signature events that are triggered in an auxin-dependent manner such as floral induction, fruit initiation, embryogenesis, and cell division and elongation. However, the diversity in PslABP1 expression profile during the ripening process of early and late plum cultivars seems to be due to the variability of endogenous auxin levels among the two cultivars, which consequently can change the levels of autocatalytic ethylene available for the fruit to co-ordinate ripening. The effect of auxin on stimulating ethylene production and in regulating PslABP1 was investigated. Our data suggest that auxin is involved in the transition of the mature green fruit into the ripening phase and in enhancing the ripening process in both auxin- and ethylene-dependent manners thereafter.

Differential expression of peach ERF transcriptional activators in response to signaling molecules and inoculation with Xanthomonas campestris pv. pruni.

Ethylene response factors (ERFs) are a large family of transcription factors (TFs) that have diverse functions in plant development and immunity. However, very little is known about the molecular regulation of these TFs in stone fruits during disease incidence. In the present study, we describe the identification of five peach ERFs (Pp-ERFs), aiming to elucidate their potential roles in defense against Xanthomonas campestris pv. pruni (Xcp), the causal agent of bacterial spot disease. The phylogenetic analysis along with sequence comparisons indicated that all Pp-ERFs are transcriptional activators belonging to groups IX and IIV ERFs. The transactivation capacity of these proteins was verified in vivo where they all induced the expression of the GUS reporter gene and in a GCC-dependent manner. The nuclear localization was also confirmed for two of these proteins, Pp-ERF2.b and Pp-ERF2.c, after their transient expression in onion epidermal cells. The induction kinetics of Pp-ERFs after inoculation with Xcp was determined by qRT-PCR. Except for Pp-ERF2.b, transcript levels of Pp-ERFs increased strongly and rapidly in the resistant 'Venture' compared to the susceptible 'BabyGold 5' cultivar after infection with Xcp. In contrast, the expression of Pp-ERF2.b was several-fold higher in the susceptible cultivar after bacterial infection. The expression of Pp-ERFs was also monitored after treating with signaling compounds; salicylic acid (SA) (1 mM), ethephon (1 mM) and methyl jasmonate (MeJA) (50 µM). Although the results generally emphasize the role of ethylene/jasmonic acid (ET/JA) signaling pathways in regulating the expression of Pp-ERFs, there was a coordination of the timing of ET/JA responses, suggesting compensatory rather than synergistic interactions between these pathways during defense against Xcp.

Identification and genetic characterization of a gibberellin 2-oxidase gene that controls tree stature and reproductive growth in plum.

Several dwarf plum genotypes (Prunus salicina L.), due to deficiency of unknown gibberellin (GA) signalling, were identified. A cDNA encoding GA 2-oxidase (PslGA2ox), the major gibberellin catabolic enzyme in plants, was cloned and used to screen the GA-deficient hybrids. This resulted in the identification of a dwarf plum hybrid, designated as DGO24, that exhibits a markedly elevated PslGA2ox signal. Grafting 'Early Golden' (EG), a commercial plum cultivar, on DGO24 (EG/D) enhanced PslGA2ox accumulation in the scion part and generated trees of compact stature. Assessment of active GAs in such trees revealed that DGO24 and EG/D accumulated relatively much lower quantities of main bioactive GAs (GA(1) and GA(4)) than control trees (EG/M). Moreover, the physiological function of PslGA2ox was studied by determining the molecular and developmental consequences due to ectopic expression in Arabidopsis. Among several lines, two groups of homozygous transgenics that exhibited contrasting phenotypes were identified. Group-1 displayed a dwarf growth pattern typical of mutants with a GA deficiency including smaller leaves, shorter stems, and delay in the development of reproductive events. In contrast, Group-2 exhibited a 'GA overdose' phenotype as all the plants showed elongated growth, a typical response to GA application, even under limited GA conditions, potentially due to co-suppression of closely related Arabidopsis homologous. The studies reveal the possibility of utilizing PslGA2ox as a marker for developing size-controlling rootstocks in Prunus.

Cloning and characterization of PR5 gene from Curcuma amada and Zingiber officinale in response to Ralstonia solanacearum infection.

Ginger (Zingiber officinale Roscoe), is an important spice crop that is badly affected by Ralstonia solanacearum wilt. Ginger does not set seed and sexual recombination has never been reported. In spite of extensive search in its habitats, no resistance source to Ralstonia induced bacterial wilt, could be located in ginger. Curcuma amada Roxb. is a potential donor for bacterial wilt resistance to Z. officinale, if the exact mechanism of resistance is understood. Pathogenesis-related (PR)-5 proteins are a family of proteins that are induced by different phytopathogens in many plants and share significant sequence similarity with thaumatin. Two putative PR5 genes, CaPR5 and ZoPR5, were amplified from C. amada and ginger, which encode precursor proteins of 227 and 224 amino acid residues, respectively, and share high homology with a number of other PR5 genes. The secondary and three-dimensional structure comparison did not reveal any striking differences between these two proteins. The expression of Ca and ZoPR5s under R. solanacearum inoculation was analyzed at different time points using quantitative real-time PCR (qRT-PCR). Our results reveal that CaPR5 is readily induced by the bacterium in C. amada, while ZoPR5 induction was very weak and slow in ginger. These results suggest that the CaPR5 could play a role in the molecular defense response of C. amada to pathogen attack. This is the first report of the isolation of PR5 gene from the C. amada and Z. officinale. Promoter analysis indicates the presence of a silencing element binding factor in ZoPR5-promoter, but not in CaPR5. Prospective promoter elements, such as GT-1 box and TGTCA, implicated as being positive regulatory elements for expression of PR proteins, occur in the 5'-flanking sequences of the CaPR5. Transient GUS expression study confirms its action with a weaker GUS expression in ginger, indicating that the PR5 expression may be controlled in the promoter.

Regulation of two germin-like protein genes during plum fruit development.

Germin-like proteins (GLPs) have several proposed roles in plant development and defence. Two novel genes (Ps-GLP1 and 2) encoding germin-like protein were isolated from plum (Prunus salicina). Their regulation was studied throughout fruit development and during ripening of early and late cultivars. These two genes exhibited similar expression patterns throughout the various stages of fruit development excluding two important stages, pit hardening (S2) and fruit ripening (S4). During fruit development until the ripening phase, the accumulation of both Ps-GLPs is related to the evolution of auxin. However, during the S2 stage only Ps-GLP1 is induced and this could putatively be in a H(2)O(2)-dependent manner. On the other hand, the diversity in the Ps-GLPs accumulation profile during the ripening process seems to be putatively due to the variability of endogenous auxin levels among the two plum cultivars, which consequently change the levels of autocatalytic ethylene available for the fruit to co-ordinate ripening. The effect of auxin on stimulating ethylene production and in regulating Ps-GLPs transcripts was also investigated. These data, supported by their localization in the extracellular matrix, suggest that auxin is somehow involved in the regulation of both transcripts throughout fruit development and ripening.

Molecular characterization of seven genes encoding ethylene-responsive transcriptional factors during plum fruit development and ripening.

Seven ERF cDNAs were cloned from two Japanese plum (Prunus salicina L.) cultivars, 'Early Golden' (EG) and 'Shiro' (SH). Based on the sequence characterization, these Ps-ERFs could be classified into three of the four known ERF families. Their predicted amino acid sequences exhibited similarities to ERFs from other plant species. Functional nuclear localization signal analyses of two Ps-ERF proteins (Ps-ERF1a and -1b) were carried out using confocal microscopy. Expression analyses of Ps-ERF mRNAs were studied in the two plum cultivars in order to determine the role of this gene family in fruit development and ripening. The seven Ps-ERFs displayed differential expression pattern and levels throughout the various stages of flower and fruit development. The diversity in Ps-ERFs accumulation was largely due to the differences in their responses to the levels of ethylene production. However, other plant hormones such as cytokinin and auxin, which accumulate strongly throughout the various developmental stages, also influence the Ps-ERFs expression. The effect of the plant hormones, gibberellin, cytokinin, auxin, and ethylene in regulating the different Ps-ERF transcripts was investigated. A model was proposed in which the role played by the plant hormone auxin is as important as that of ethylene in initiating and determining the date and rate of ripening in Japanese plums.

Differential regulation of four members of the ACC synthase gene family in plum.

The regulation of ACC synthase (ACS) genes was studied in early ('Early Golden') and late ('Shiro') Japanese plum cultivars (Prunus salicina L.) in order to determine the role of this gene family in fruit ripening. Of the four Ps-ACS cDNAs isolated, two (Ps-ACS1 and -3) showed differential expression between the two cultivars. Ps-ACS1 accumulated during fruit ripening of 'Early Golden' ('EG') and 'Shiro' ('SH') in ethylene-dependent and -independent manners, respectively. Ps-ACS3a transcripts accumulated throughout fruit development and during 'EG' fruit ripening. Ps-ACS3b was detected only during ripening of 'SH' fruit. Furthermore, Ps-ACS3a transcript accumulation was negatively regulated by ethylene, whereas Ps-ACS3b was positively induced by the hormone. In both cultivars, the expression of Ps-ACS4 and -5 is under positive and negative feedback control by ethylene, respectively. Genetic analyses of 'EG' and 'SH' cultivars demonstrated that 'EG' is homozygous for Ps-ACS3a whereas 'SH' is heterozygous for Ps-ACS3 (a/b). The role of ethylene-overproducer 1-like in delaying fruit ripening by interacting with Ps-ACS proteins was also studied. The effect of the plant hormones, auxin, gibberellin, and cytokinin, in regulating ethylene production by promoting the induction of the different Ps-ACS mRNAs in plum was investigated. A model is presented in which differences in Ps-ACS alleles and gene expression between early and late plums are critical in determining the ripening behaviour of the cultivars.

Isolation and characterization of four ethylene signal transduction elements in plums (Prunus salicina L.).

Plums are climacteric fruits: their ripening is associated with a burst of ethylene production and respiration rate. Stone fruits, including plum, have a distinct pattern of growth and development, described as a double sigmoid pattern. In order to understand the developmental control of ethylene perception in plum, four ethylene perception and signal transduction components (EPSTCs) were characterized, including two ETR1-like proteins (Ps-ETR1 and Ps-ERS1), a CTR1-like protein, and an ethylene-responsive element-binding factor (ERF). Their regulation was studied throughout fruit development and ripening in early and late cultivars. Analysis of transcript levels revealed that only Ps-ERF1 and Ps-ERS1 accumulated immediately after fertilization. Increases in Ps-ETR1 and Ps-CTR1 transcript levels could not be detected before S3 of fruit development. Marked differences associated with the ripening behaviour of early ('Early Golden') and late ('Shiro') Japanese plum cultivars were observed. The early cultivar showed ripening patterns typical of climacteric fruits accompanied by sharp increases of the four transcript levels in an ethylene-dependent manner. However, the late cultivar exhibited a suppressed-climacteric pattern, with a slight increase in ethylene production related to ripening. The accumulation of the Ps-ETR1 (and not Ps-CTR1) mRNA in the late cultivar was ethylene independent. Ps-ERS1 mRNA was expressed at low, constant levels, while, Ps-ERF1 remained undetectable. The differences between the two plum cultivars in the date and rate of ripening in relation to the differences in the accumulation patterns of the four mRNAs are discussed.

Serum levels of endothelin-1 (ET-1), interleukin-2 (IL-2) and amino-terminal propeptide type III procollagen (PIII NP) in patients with acute and chronic filariasis.

Filariasis, a mosquito-borne parasitic disease, is a worldwide health problem. There is still, some controversial concerning the diagnosis of acute and chronic infections. The serum levels of endothelin-1 (ET-1), interleukin-2 (IL-2) and amino-terminal propeptide Type III (PIII NP) was measured in patients with acute and chronic filariasis as compared with controls. The ET-1, IL-2 and PIII NP levels were significantly high in chronic cases than in acute. On the other hand, the serum levels of IL-2 and PIII NP were significantly high in acute cases than in the controls. These three immuno-mediators play role in the pathogenesis of filariasis particularly. The chronic cases. So, these mediators can be used as markers for diagnosis of human cases infected with chronic and acute filariasis.

Correlation between trichomoniasis vaginalis and female infertility.

Trichomoniasis vaginalis is one of the common parasitic infection in females. The present results showed that infertile women with T. vaginalis with or without pathogenic microorganisms have decreased C3 & C4, increased IgA level in vaginal discharge and increased serum prolactin. So. T. vaginalis is incriminated as one of the causes of their infertility.

Fascioliasis an increasing zoonotic disease in Egypt.

Fascioliasis is now imposing itself as a zoonotic disease in sheep and cattle raising countries. In Egypt, human fascioliasis is increasing. During the years 1994 to 1997 the overall slaughtered animals in Egyptian abattoirs was 2,003,200 sheep and goats, 2,624,239 cattle and 3,536,744 buffaloes. The overall rates of fascioliasis were 2.02% for sheep and goats, 3.54% for cattle and 1.58% for buffaloes. Macroscopic examination of sheep liver showed up to 100 flukes per liver inside a largely dilated thick walled bile ducts. Cattle liver showed up to 275 flukes per liver inside thickened dilated and calcareous bile ducts with offensive yellowish brown bile. Buffaloes liver showed up to 330 flukes per liver. Microscopic examination showed mainly thickened wall, hyperplasia and marked fibrosis. The discussion focused on the zoonotic importance of fascioliasis in Egypt, diagnosis, treatment and prevention. No doubt, adequate control of fascioliasis is more or less a problem, since it requires the control of snail intermediate host(s) and control of infection in all affected animals and man.

Human nasopharyngeal linguatuliasis (Pentasomida) caused by Linguatula serrata.

A human nasopharyngeal linguatuliasis was reported for the second time in Egypt. The patient (20 years old male) was presented with main conspicuous complaints, fever, urticaria (face and neck), coughing, vomiting and passage of small (less than 1 cm. in length) worm-like structures in his nasal discharge and vomitus. Symptomatic treatment was given followed by a single dose of praziquantel after identification of the causative parasite. Human linguatuliasis (pentastomiasis) was discussed.

The histopathology of the intestine in hamsters infected with Leishmania D. infantum on top of pre-existing schistosomiasis mansoni.

In general, both Schistosoma mansoni and Leishmania, d. infantum affect more or less the same human organs. While the liver is the main organ affected, the intestine follows in importance. In the present study, L.d. infantum on tip of pre-existing S. mansoni in Syrian golden hamsters had delayed the appearance of both schistosomal and leishmanial granulomas in the intestine the positive control with either parasite alone. However, the leishmanial infection suppressed the schistosomal infection. Nevertheless, both types of granulomas caused shortening and broadening of the intestinal villi. The concomitant infection with leishmaniasis infantum and schistosomiasis mansoni promote the development of many pathological changes (liver, kidneys, intestine, blood picture etc.). No doubt, these changes lead to marked changes in the typical clinical picture of both parasites. Consequently, parasitological diagnosis of visceral leishmaniasis in concomitant infection is a must as in a case of VL. and HIV.

The larvicidal activity of solvent extracts of three medicinal plants against third instar larvae of Chrysomyia albiceps.

Four solvent extracts of each of Lemongrass (Symbopogon citratus), Santonica (Artemisia cinae) and Pomegranate (Punica granatum) were tested against the 3rd instar larvae of Chrysomyia albiceps. The pomegranate extracts showed the larvicidal activity with LC50 ranging between 25 ppm (acetone extract) and 280 ppm (chloroform extract). The Santonica showed larvicidal activity with LC50 ranging between 48 ppm (ethanol extract) and 380 ppm (acetone extract). The Lemongrass showed activity with LC50 ranging between 135 ppm (ethanol extract) and 570 ppm (chloroform extract). So, the most effective action in accordance to LC50 were the acetone extract of pomegranate, followed by ethanol extract of Santonica and lastly ethanol extract of Lemongrass. The slope functions of these three extracts were 4.6, 2.8 and 8.22 respectively. The shift to insect control by plant extracts pave the way to a somewhat healthy environment.

Effect of two single doses of ivermectin in treatment of asymptomatic bancroftian filariasis in two villages in the Nile Delta, Egypt.

To evaluate the efficacy and longitudinal effect of two single (100 micrograms/kg) doses of ivermectin, 3 months apart, 240 asymptomatic male subjects from 2 endemic Egyptian villages were enrolled in a one-year double-blind study. Subjects aged 15-55 years were randomly assigned placebo (40) or ivermectin (200). Microfilaria (MF) density in 1 ml blood was measured by membrane filtration before and every 3 months after treatment. Initial mean MF density was 462 (range 14-2869/ml). Clinical examination performed daily for 3 days after each treatment revealed brief, mild side effects: fever, headache, weakness, nausea, and epigastric pain, with no adverse physical or laboratory findings. Three months after initial dose, 31% of MF counts had completely cleared; in the remainder, mean MF density was 11.0 (2.4% of pretreatment level). At 3, 6 and 9 months after the second dose there was complete MF clearance in 60%, 45% and 47%; in those still infected, MF densities were 1.7, 4.6 and 6.1% of the pretreatment level. Therefore, treatment with two doses of ivermectin reduced microfilaremia, without inducing severe side effects. Prolonged suppression of microfilaremia may indicate an effect of ivermectin on the adult worms and may reduce the potential for MF acquisition by mosquitoes, reducing transmission of lymphatic filariasis. It was concluded that ivermectin is a useful drug for public health measure, including asymptomatic filariasis patients.

Prevalence of intestinal parasites in filariasis endemic areas in Egypt.

Stool and blood specimens were collected from 230 individuals of both sexes at 2 villages (Qualyubia Governorate) where filariasis is endemic. The overall prevalence of parasites was 81%, while it was higher (92.4%) among filariasis patients than non infected individuals (50%). On the other hand, the level of microfilaria (MF) in the blood apparently showed an influence on the prevalence of parasitic infection in the infected individuals. However, in all groups, E. histolytica was the commonest protozoal parasite followed by G. lamblia. As regard helminthic infections, S. mansoni was the commonest followed by E. vermicularis. These data suggest that filariasis as an endemic disease may suppress the immune response of the host and under such circumstances, the susceptibility for other infections become higher.

Studies on the sacculant portion of the kidney of Biomphalaria glabrata Say (1818) as a haemopoietic organ.

The term immunity signifies all those properties of the host which confer resistance to a specific infectious agent. This resistance may be of all degrees ranging from complete to incomplete susceptibility. The defensive functions is performed by various cellular and humoral components which interact with each other producing a co-ordinated immune response directed towards eliminating the pathogen or minimizing its danger. Snails as other members of the Animal Kingdom have their own immune system. The present study concentrated on the sacculant portion of the kidney of B. glabrata as a haemopoietic stem cell. The histological picture of this portion in the kidney as well as in-vitro culture was studied. (I) The histological studies showed that (a) the sacculant portion constituted the last fifth of the kidney highly folded with primitive epithelial tissue, (b) amoebocytes (10.7 +/- 0.98m) rounded, oval or amoeboid, showing flattening and spreading when encapsulated around foreign particles, when doing so, both the cytoplasm and nucleus were more basophilic, (c) the haemocytes in the sacculant portion were distributed either as clustering forming amoebocytic plugs or dense aggregation or being normal in distribution (d) there was a significant correlation between haemocytic diameter and shell weight and between shell weight and shell diameter but no significant correlation between haemocytic diameter and shell diameter. (II) The in-vitro studies showed that (a) The medium 199 and fetal calf serum (3:1) produced higher number of granulocytes, (b) the cells differed in shape and size from those shown in histological studies of the kidney itself (c) the majority of the cells were large sized granulocytes and very few small sized hyalinocytes, (d) granulation of cytoplasm took place in the culture medium used more than in the sacculant portion, (e) only the smaller granulocytes showed greater ability for mitotic division. The results were photographed and discussed.

Abnormal distribution of the histocompatibility antigens (HLA) in lousy patients.

The histocompatibility antigens have important functions in the development of the immune response, in the development of immunologic tolerance and in the resistance and susceptibility to diseases. In the present study, the frequency of the human leucocytic antigens (HLA) were studied in 31 lousy children with Pediculus h. capitis (head lice) and 14 adults with Phthirus pubis (pubic lice) to evaluate the immune response in their pathogenesis. The patients (children and adults) were parasite-free as indicated by urine, stool and blood analysis and clinical examination. A significant increase was found between HLA-A11 and, -B5 and lousy children with P. h. capitis and between HLA,-A11, -B5 and -B27 and lousy adults with P. pubis. The association between HLA antigens and parasitic infection was discussed.