Identification of somaclonal variants of sugarcane (Saccharum spp.) resistant to sugarcane mosaic virus via RAPD markers

Somaclonal variants resistant to sugarcane mosaic virus (SCMV) were obtained from susceptible sugarcane cv PR62258 through somatic embryogenesis by increasing the number of subcultures of the embryogenic callus tissue in MS medium with 3 mg/L 2,4-dichlorophenoxyacetic acid. Transfers were made at 30-day intervals for 1, 2 or 3 subcultures. Two somaclones, namely AT626 and BT627, were selected by their resistance to SCMV. These subclones have maintained the resistance trait over seven years of testing in the field. In this report we identified the somaclonal SCMV resistant variants from the maternal line and the nonresistant somaclones, using the RAPD technique.     

Noradrenergic and adrenergic systems in the brain of the urodele amphibian,Pleurodeles waltlii,as revealed by immunohistochemical methods

The distribution of noradrenaline and adrenaline in the brain of the urodele amphibian Pleurodeles waltlii has been studied with antibodies raised against noradrenaline and the enzymes dopamine--hydroxylase and phenylethanolamine-N-methyltransferase. Noradrenaline-containing cell bodies were found in the anterior preoptic area, the hypothalamic nucleus of the periventricular organ, the locus coeruleus and in the solitary tract/area postrema complex at the level of the obex. Noradrenergic fibers are widely distributed throughout the brain innervating particularly the ventrolateral forebrain, the medial amygdala, the lateral part of the posterior tubercle, the parabrachial region and the ventrolateral rhombencephalic tegmentum. Putative adrenergic cell bodies were found immediately rostral to the obex, ventral to the solitary tract. Whereas the cell bodies and their dendrites were Golgi-like stained, axons were more difficult to trace. Nevertheless, some weakly immunoreactive fibers could be traced to the basal forebrain. A comparison of these results with data previously obtained in anurans reveals not only several general features, but also some remarkable species differences.Abbreviations Acc Nucleus accumbens - AP area postrema - Apl amygdala, pars lateralis - Apm amygdala, pars medialis - ca commissura anterior - Cb cerebellum - cc central canal - Dp dorsal pallium - epl external plexiform layer - gl glomerular layer of the olfactory bulb - H ganglion habenulae - igl internal granular layer - Ip nucleus interpeduncularis - Lc locus coeruleus - Ll lateral line lobe - Lp lateral pallium - Ls lateral septum - ml mitral cell layer - Mp medial pallium - Ms medial septum - nPT nucleus pretectalis - NPv nucleus of the periventricular organ - nV nervus trigeminus - oc optic chiasm - Poa preoptic area - Ri nucleus reticularis inferior - SC nucleus suprachiasmaticus - sol solitary tract - Str striatum - thd thalamus dorsalis - thv thalamus ventralis - To tectum opticum - TP tuberculum posterius - V ventricle - VH ventral hypothalamic nucleus - III nucleus nervi oculomotorii - IXm nucleus motorius nervi glossopharyngei - Xm nucleus motorius nervi vagi     

The larval development of lateral musculature in gilthead sea bream Sparus aurata and sea bass Dicentrarchus labrax

Fibre-type differentiation of the lateral musculature has been studied in Sparus aurata (L.) and Dicentrarchus labrax (L.) during larval development. Histochemical and ultrastructural techniques show two presumptive muscle layers and two germinative zones of presumptive myoblasts. At hatching, myotomal muscle consists of a monolayer of thin undifferentiated cells near the skin (first germinative zone) overlying another mono-layer of small diameter fibres extending hypaxially and epaxially away from the transverse septum. Below this, there is a much thicker, deep layer of fibres, generally large in diameter and polygonal in shape. The presumptive myoblasts are located between these two layers of fibres in the second germinative zone. Initially, the superficial and deep muscle fibres show high and low myosin ATPase activity, respectively. Both layers grow by generating new fibres from the two mentioned germinative zones. At the end of larval life, the superficial layer changes its histochemical profile from high to low myosin ATPase activity and, at the same time, intermediate or pink muscle fibres can be observed by oxidative activity (the NADH-TR reaction). Morphometric analysis shows a significant increase in mean fibre diameter during successive ages, as shown by the Student's t-test (hypertrophic growth). Skewness and kurtosis values of fibre diameters point to the generation of a new fibre population from the germinative zones (hyperplastic growth).     

Isodicentric Y chromosome: cytogenetic,molecular and clinical studies and review of the literature

Dicentrics are among the most common structural abnormalities of the human Y chromosome. Predicting the phenotypic consequences of different duplications and deletions of dicentric Y chromosomes is usually complicated by varying degrees of mosaicism (45,X cell lines), which may, in some cases, remain undetected. Molecular studies in patients with dicentric Y chromosomes have been few, and only two studies have attempted to determine the presence of SRY (the putative testis-determining factor gene). We report an 18-year-old female with short stature, amenorrhea, hirsutism, hypoplastic labia minora, and clitoromegaly who has a 45,X/46,X,idic(Y)(p11.32)/47,X,idic(Y)(p11.32),idic(Y) (p11.32) karyotype. Southern analysis using Y-specific probes (Y97, 2D6, 1F5, pY3.4) and polymerase chain reaction (PCR) analysis using primers for ZFY and SRY were positive for all loci tested, indicating that almost all of the Y chromosome was present. Our findings and an extensive review of the literature emphasize the importance of molecular analyses of abnormal Y chromosomes before any general conclusions can be reached concerning the relative effects of the Y-chromosome abnormality and mosaicism on sexual differentiation.     

XY gonadal dysgenesis and gonadoblastoma: a study in two sisters with a cryptic deletion of the Y chromosome involving the SRY gene

This paper reports a case of XY gonadal dysgenesis in two sisters. Both patients presented an eunochoid female phenotype with normal external genitalia. At laparotomy, the elder sister was found to have bilateral gonadoblastoma. Cytogenetic studies, which included G and C banding and in situ hybridization, showed that the patients had an apparently normal 46, XY karyotype. PCR analyses revealed absence of the conserved portion (HMG box) of the SRY gene and of the Y chromosome pseudoautosomal boundary region sequence in both patients. The presence of the ZFY sequence was detected by Southern hybridization in the two affected sisters. The patients' father (46, XY, no mosaicism detected in peripheral blood lymphocytes) was positive for SRY and ZFY sequences. The occurrence of gonadoblastoma is discussed in terms of the genetic factors that may lead to tumor development.     

Dinucleotide repeat polymorphism at the D4S2458 locus close to the PKD2 locus on human chromosome 4q

A new polymorphic CA repeat sequence was identified within the candidate region fot the autosomal dominant polycystic kidney disease type 2 (PKD2) locus. It should be a useful marker in the localization of this gene.     

An autosomal dominant retinitis pigmentosa family with close linkage to D7S480 on 7q

Retinitis pigmentosa is the most prevalent inherited disorder of the retina. It can be autosomal dominant (adRP), autosomal recessive (arRP) or X-linked (XLRP). A form of adRP mapping to chromosome 7q was reported in a large Spanish pedigree. We have typed DNA from the members of another Spanish family for polymorphic markers from the known candidate genes. Positive lod scores were obtained only for the markers located on 7q31-35, giving a maximum lod score of 2.98 (3.01 by multipoint analysis) at = 0.00 for D7S480. A brief clinical evaluation is given.     

Influence of the culture medium on the expression of surface polypeptides of Yersinia enterocolitica

Three polypeptides (200, 46, and 25 kDal) encoded by the virulence plasmid were detected by SDS-PAGE in the outer membrane of Yersinia enterocolitica 09 grown at 37°C in brain-heart infusion medium. Bacteria grown at the same temperature in the tissue culture medium RPMI 1640 expressed five additional polypeptides (170, 135, 118, 100, and 98 kDal), but the 25-kDal band was not seen. The protein profile in RPMI 1640 resembles the expression pattern displayed by yersiniae when grown in vivo. The immunoblot of total membrane proteins of bacteria grown in brain-heart infusion medium revealed eight plasmid-encoded polypeptides, four of which were also in the outer membrane preparations, including a 28-kDal polypeptide. These peptides do not coincide with known plasmid-encoded outer membrane proteins.     

Some significant differences in wall chemistry among four commercial Agaricus bisporus strains

Significant differences in gross wall chemical composition were detected in four commercial Agaricus bisporus strains. All were grown under the same conditions and their walls prepared by a mild method of breakage. A more detailed analysis of the wall fractions, isolated by means of their distinct solubilities, also showed striking structural differences among the four strains studied. The detected differences, not only in the overall composition of the wall but also in the polysaccharide structure, could assist in the characterization of strains and/or varieties of the commercial basidiomycete A. bisporus.     

Production of hydrogen peroxide by Lactobacillus hilgardii and its effect on Leuconostoc oenos growth

In mixed culture of Lactobacillus hilgardii X₁B and Leuconostoc oenos X₂L, isolated from Argentinian wines, an amensalistic growth response was observed: Leuconostoc oenos did not grow, and after 24 h of incubation at 30°C no viable cells were detected. In pure and mixed cultures, Lactobacillus hilgardii produced hydrogen peroxide early in the growth cycle, reaching the maximum at 24 h. The values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the action of hydrogen peroxide on the growth of Leuconostoc oenos were: 4.08g ml^-1 and 17.00 g ml^-1 respectively.