<Emphasis Type="Italic">Bruguiera hainesii</Emphasis>, a critically endangered mangrove species,is a hybrid between <Emphasis Type="Italic">B. cylindrica</Emphasis> and <Emphasis Type="Italic">B. gymnorhiza</Emphasis> (Rhizophoraceae)

Bruguiera hainesii (Rhizophoraceae) is one of the two Critically Endangered mangrove species listed in the IUCN Red List of Threatened Species. Although the species is vulnerable to extinction, its genetic diversity and the evolutionary relationships with other Bruguiera species are not well understood. Also, intermediate morphological characters imply that the species might be of hybrid origin. To clarify the genetic relationship between B. hainesii and other Bruguiera species, we conducted molecular analyses including all six Bruguiera species using DNA sequences of two nuclear genes (CesA and UNK) and three chloroplast regions (intergenic spacer regions of trnL-trnF, trnS-trnG and atpB-rbcL). For nuclear DNA markers, all nine B. hainesii samples from five populations were heterozygous at both loci, with one allele was shared with B. cylindrica, and the other with B. gymnorhiza. For chloroplast DNA markers, the two haplotypes found in B. hainesii were shared only by B. cylindrica. These results suggested that B. hainesii is a hybrid between B. cylindrica as the maternal parent and B. gymnorhiza as the paternal one. Furthermore, chloroplast DNA haplotypes found in B. hainesii suggest that hybridization has occurred independently in regions where the distribution ranges of the parental species meet. As the IUCN Red List of Threatened Species currently excludes hybrids (except for apomictic plant hybrids), the conservation status of B. hainesii should be reconsidered.     

Molecular evidence for a natural diploid hybrid between <Emphasis Type="Italic">Miscanthus</Emphasis><Emphasis Type="Italic">sinensis</Emphasis> (Poaceae) and <Emphasis Type="Italic">M. sacchariflorus</Emphasis>

The hybrid origin of Miscanthus purpurascens has previously been proposed, primarily because of its intermediate morphology. In this study, phylogenies based on the DNA sequences from the internal transcribed spacer region of nuclear ribosomal DNA (nrDNA ITS), on the DNA sequences of the trnL intron and trnL-F intergenic spacer of chloroplast DNA, and on amplified fragment length polymorphism (AFLP) fingerprinting confirm that M. purpurascens originated through homoploid hybridization between M. sinensis and M. sacchariflorus. Two different types of ITS sequences were identified from almost all plants of M. purpurascens. One type was found to be closely related to M. sinensis and the other to M. sacchariflorus. Miscanthus purpurascens was found to possess many M. sinensis- and M. sacchariflorus-specific AFLP bands but no band specific to itself. Clustering with the Unweighted Pair Group Method with Arithmetic Mean and principal coordinate analysis based on the AFLP data also demonstrated that M. purpurascens is an approximate intermediate of the two species. In addition, M. purpurascens has the plastid genome of M. sinensis or M. sacchariflorus, suggesting that either species could be its maternal parent. All specimens of M. purpurascens and its coexisting parental species are identified as diploids (2n = 2x = 38). Possible mechanisms of natural hybridization, hybrid status, chloroplast DNA recombination, and evolutionary implications of this hybridization are also discussed.     

<Emphasis Type="Italic">Nibribacter flagellatus</Emphasis> sp. nov., isolated from rhizosphere of <Emphasis Type="Italic">Hibiscus syriacus</Emphasis> and emended description of the genus <Emphasis Type="Italic">Nibribacter</Emphasis>

A Gram-stain negative, aerobic, motile by flagella, rod-shaped strain (THG-T16^T) was isolated from rhizosphere of Hibiscus syriacus. Growth occurred at 10–40 °C (optimum 28–30 °C), at pH 6.0–8.0 (optimum 7.0) and at 0–1.0% NaCl (optimum 0%). Based on 16S rRNA gene sequence analysis, the near phylogenetic neighbours of strain THG-T16^T were identified as Nibribacter koreensis KACC 16450^T (98.6%), Rufibacter roseus KCTC 42217^T (94.7%), Rufibacter immobilis CCTCC AB 2013351^T (94.5%) and Rufibacter tibetensis CCTCC AB 208084^T (94.4%). The DNA G+C content of strain THG-T16^T was determined to be 46.7 mol%. DNA–DNA hybridization values between strain THG-T16^T and N. koreensis KACC 16450^T, R. roseus KCTC 42217^T, R. immobilis CCTCC AB 2013351^T, R.tibetensis CCTCC AB 208084^T were 33.5?±?0.5% (31.7?±?0.7% reciprocal analysis), 28.1?±?0.2% (25.2?±?0.2%), 17.1?±?0.9% (10.2?±?0.6%) and 8.1?±?0.3% (5.2?±?0.1%). The polar lipids were identified as phosphatidylethanolamine, two unidentified aminophospholipids, an unidentified aminolipid and three unidentified lipids. The quinone was identified as MK-7 and the polyamine as sym-homospermidine. The major fatty acids were identified as C_16:1 ω5c, C_17:1 ω6c, iso-C_15:0, summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and summed feature 4 (iso-C_17:1 I and/or anteiso-C_17:1 B). On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics, and DNA–DNA hybridization data, strain THG-T16^T represents a novel species of the genus Nibribacter, for which the name Nibribacter flagellatus sp. nov. is proposed. The type strain is THG-T16^T(=?KACC 19188^T?=?CCTCC AB 2016246^T).     

<Emphasis Type="Italic">Cytisus aeolicus</Emphasis> Guss. ex Lindl. <Emphasis Type="Italic">in vitro</Emphasis> cultures and genistin production

Cytisus aeolicus Guss. ex Lindl. (Fabaceae family, subfamily Faboideae) is an endangered endemic species of the Aeolian Islands, Sicily. In vitro multiplication of C. aeolicus shoots was described in this work and cell cultures were established from cotyledons and hypocotyls to investigate their potential production of isoflavones. Aseptically germinated seeds, cultivated on LS modified basal medium, gave the initial explants used both to induce axillary propagation and callus cultures. The LS (Linsmaier and Skoog) basal medium, supplemented with 0.1 mg L^?1 of 6-benzylaminopurine were used to induce axillary propagation. The callus induction was performed using the basal medium added with 5 mg L^?1 2,4-dichlorophenoxy acetic acid and 5 mg L^?1 kinetin (control medium). Basal medium was also added with 2000 mg L^?1 casein hydrolysate (CH) or 900 mg L^?1myo-inositol (MI). C. aeolicus callus cultures on CH and MI media produced an unique compound, the isoflavone genistein 7-O-ß-D-glucopyranoside (genistin), which has not previously been isolated from wild plants. Callus cultures grown on the medium containing myo-inositol produced the greatest amount of genistin. C. aeolicus tissue culture procedures could provide suitable plant material both for germplasm preservation (by micropropagation) and for biotechnological selective isoflavone production (by callus culture).     

<Emphasis Type="Italic">Zunongwangia flava</Emphasis> sp. nov., belonging to the family <Emphasis Type="Italic">Flavobacteriaceae</Emphasis>, isolated from <Emphasis Type="Italic">Salicornia europaea</Emphasis>

A yellow pigmented bacterium designated strain MBLN094^T within the family Flavobacteriaceae was isolated from a halophyte Salicornia europaea on the coast of the Yellow Sea. This strain was a Gram-stain negative, aerobic, non-spore forming, rod-shaped bacterium. Phylogenetic analysis of the 16S rRNA gene sequence of strain MBLN094^T was found to be related to the genus Zunongwangia, exhibiting 16S rRNA gene sequence similarity values of 97.0, 96.8, 96.4, and 96.3% to Zunongwangia mangrovi P2E16^T, Z. profunda SM-A87^T, Z. atlantica 22II14-10F7^T, and Z. endophytica CPA58^T, respectively. Strain MBLN094^T grew at 20?37°C (optimum, 25?30°C), at pH 6.0?10.0 (optimum, 7.0?8.0), and with 0.5?15.0% (w/v) NaCl (optimum, 2.0?5.0%). Menaquinone MK-6 was the sole respiratory quinone. The polar lipids were phosphatidylethanolamine, two unidentified aminolipids, and four unidentified lipids. Major fatty acids were iso-C_17:0 3-OH, summed feature 3 (C_16:1ω6c and/or C16:1 ω7c), and iso-C_15:0. The genomic DNA G + C content was 37.4 mol%. Based on these polyphasic taxonomic data, strain MBLN094^T is considered to represent a novel species of the genus Zunongwangia, for which the name Zunongwangia flava sp. nov. is proposed. The type strain is MBLN094^T (= KCTC 62279^T = JCM 32262^T).     

Anatomical abnormalities of the intertribal cybrid between <Emphasis Type="Italic">Brassica napus</Emphasis> and <Emphasis Type="Italic">Lesquerella fendleri</Emphasis> chloroplasts

The anatomical research of the vegetative organs of the cytoplasmatic hybrid grown in vitro and containing the Brassica napus nucleus and the Lesquerella fendleri chloroplasts was carried out and compared to the parental forms. It was found that the anatomical structure of the cybrid is similar to rapeseed. Anomalous changes in the epithelial, parenchymal, and connective tissue of the leaf, stalk, stem, and root of the cybrid were detected. The appearance of the anatomical defects can be explained by nuclear-cytoplasmatic incompatibility, which is the cause of low adaptability of the cybrid to in vivo conditions and takes place due to alien chloroplast gene expression in the remote species.     

Development of an <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation method for <Emphasis Type="Italic">Taxus</Emphasis> suspension cultures

The FDA-approved anti-cancer compound paclitaxel is currently produced commercially by Taxus plant cell suspension cultures. One major limitation to the use of plant cell culture as a production platform is the low and variable product yields. Therefore, methods to increase and stabilize paclitaxel production are necessary to ensure product security, especially as the demand for paclitaxel continues to rise. Although a stable transformation method for Taxus suspension cultures has been developed, stable transformant yields are low (around 1% of experiments) and the method does not translate to the Taxus cuspidata Siebold and Zucc. and Taxus canadensis Marshall cell lines utilized in this study. Therefore, a new method for Agrobacterium-mediated transformation of Taxus callus and suspension cultures was developed through identification of the optimal Agrobacterium strain, inclusion of an anti-necrotic cocktail (silver nitrate, cysteine, and ascorbic acid) and increased recovery time for cells after cocultivation, the time following infection with Agrobacterium tumefaciens. Application of the increased recovery time to transformation of T. cuspidata line PO93XC resulted in 200 calluses staining positive for GUS. Additionally, two transgenic lines have been maintained with stable transgene expression for over 5 yr. This method represents an improvement over existing transformation methods for Taxus cultures and can be applied for future metabolic engineering efforts.     

Molecular evidence for hybridization between invasive <Emphasis Type="Italic">Solidago canadensis</Emphasis> and native <Emphasis Type="Italic">S</Emphasis>. <Emphasis Type="Italic">virgaurea</Emphasis>

Hybridization between alien and native species is biologically very important and could lead to genetic erosion of native taxa. Solidago × niederederi was discovered over a century ago in Austria and described by Khek as a natural hybrid between the alien (nowadays regarded also as invasive) S. canadensis and native S. virgaurea. Although interspecific hybridization in the genus Solidago is considered to be relatively common, hybrid nature of S. × niederederi has not been independently proven using molecular tools, to date. Because proper identification of the parentage for the hybrid Solidago individuals solely based on morphological features can be misleading, in this paper we report an additive polymorphism pattern expressed in the ITS sequences obtained from individuals representing S. × niederederi, and confirm the previous hypothesis that the parental species of this hybrid are S. canadensis and S. virgaurea. Additionally, based on variability at the cpDNA rpl32-trnL locus, we showed that in natural populations hybridization occurs in both directions.     

Genetics and fine mapping of a yellow-green leaf gene (<Emphasis Type="Italic">ygl</Emphasis>-<Emphasis Type="Italic">1</Emphasis>) in cabbage (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. <Emphasis Type="Italic">capitata</Emphasis> L.)

Cabbage (Brassica oleracea var. capitata L.) is one of the most popular cultivated vegetables worldwide. Cabbage has rich phenotypic diversity, including plant height, head shape, head color, leaf shape and leaf color. Leaf color plays an important role in cabbage growth and development. At present, there are few reports on fine mapping of leaf color mutants in B. oleracea. In this study, a naturally occurring yellow-green leaf cabbage mutant (YL-1), derived from the self-pollinated progenies of the hybrid ‘Hosom’, was used for inheritance analysis and gene mapping. Segregation populations including F₂ and BC₁ were generated from the cross of two inbred lines, YL-1 and 01–20. Genetic analysis with the F₂ and BC₁ populations demonstrated that the yellow-green leaf color was controlled by a single recessive nuclear gene, ygl-1. Insertion–deletion (InDel) markers, designed based on the parental re-sequencing data, were used for the preliminary mapping with BSA (bulked segregant analysis) method. A genetic map constructed with 15 InDels indicated that ygl-1 was located on chromosome C01. The ygl-1 gene is flanked by InDel markers ID2 and M8, with genetic distances of 0.4 cM and 0.35 cM, respectively. The interval distance between two markers is 167 kb. Thus, it enables us to locate the ygl-1 gene for the first time in B. oleracea. This study lays the foundation for candidate gene prediction and ygl-1gene cloning.     

Features of expression of the <Emphasis Type="Italic">PsSst1</Emphasis> and <Emphasis Type="Italic">PsIgn1</Emphasis> genes in nodules of pea (<Emphasis Type="Italic">Pisum sativum</Emphasis> L.) symbiotic mutants

The sequences of the PsSst1 and PsIgn1 genes of pea (Pisum sativum L.) homologous to the symbiotic LjSST1 and LjIGN1 genes of Lotus japonicus (Regel.) K. Larsen are determined. The expression level of PsSst1 and PsIgn1 genes is determined by real-time PCR in nodules of several symbiotic mutants and original lines of pea. Lines with increased (Sprint-2Fix^– (Pssym31)) and decreased (P61 (Pssym25)) expression level of both genes are revealed along with the lines characterized by changes in the expression level of only one of these genes. The revealed features of the PsSst1 and PsIgn1 expression allow us to expand the phenotypic characterization of pea symbiotic mutants. In addition, PsSst1 and PsIgn1 cDNA is sequenced in selected mutant lines, characterized by a decreased expression level of these genes in nodules, but no mutations are found.     

Genome-wide characterization and stress-responsive expression profiling of <Emphasis Type="Italic">MCM</Emphasis> genes in <Emphasis Type="Italic">Brassica oleracea</Emphasis> and <Emphasis Type="Italic">Brassica rapa</Emphasis>

The Minichromosome maintenance protein [MCM (2-7)] complex is associated with helicase activity for replication fork formation during DNA replication. We identified and characterized each 12 putative MCM genes from Brassica oleracea and Brassica rapa. MCM genes were classified into nine groups according to their evolutionary relationships. A high number of syntenic regions were present on chromosomes C03 and A03 in B. oleracea and B. rapa, respectively, compared to the other chromosomes. Expression analysis showed that most of the MCM(2-7) helicase-subunit genes and their coregulating MCM genes were upregulated during hydroxyurea (HU) induced stress in B. oleracea. In B. rapa, MCM(2-7) helicase genes BrMCM2_2, BrMCM7_1, BrMCM7_2 and their co-regulating genes were upregulated during replication stress. During cold stress, BoMCM6 in B. oleracea and BrMCM5 in B. rapa were remarkably upregulated. During salt stress, BoMCM6_2, BoMCM7_1, BoMCM8, BoMCM9, and BoMCM10 were markedly upregulated in B. oleracea. Hence, our study identified the candidate MCM family genes those possess abiotic stress-responsive behavior and DNA replication stress tolerance. As the first genome-wide analysis of MCM genes in B. oleracea and B. rapa, this work provides a foundation to develop stress responsive plants. Further functional and molecular studies on MCM genes will be helpful to enhance stress tolerance in plants.     

Polysaccharide-based silver nanoparticles synthesized by <Emphasis Type="Italic">Klebsiella oxytoca</Emphasis> DSM 29614 cause DNA fragmentation in <Emphasis Type="Italic">E. coli</Emphasis> cells

Silver nanoparticles (AgNPs), embedded into a specific exopolysaccharide (EPS), were produced by Klebsiella oxytoca DSM 29614 by adding AgNO₃ to the cultures during exponential growth phase. In particular, under aerobic or anaerobic conditions, two types of silver nanoparticles, named AgNPs-EPS^aer and the AgNPs-EPS^anaer, were produced respectively. The effects on bacterial cells was demonstrated by using Escherichia coli K12 and Kocuria rhizophila ATCC 9341 (ex Micrococcus luteus) as Gram-negative and Gram-positive tester strains, respectively. The best antimicrobial activity was observed for AgNPs-EPS^aer, in terms of minimum inhibitory concentrations and minimum bactericidal concentrations. Observations by transmission electron microscopy showed that the cell morphology of both tester strains changed during the exposition to AgNPs-EPS^aer. In particular, an electron-dense wrapped filament was observed in E. coli cytoplasm after 3 h of AgNPs-EPS^aer exposition, apparently due to silver accumulation in DNA, and both E. coli and K. rhizophila cells were lysed after 18 h of exposure to AgNPs-EPS^aer. The DNA breakage in E. coli cells was confirmed by the comparison of 3-D fluorescence spectra fingerprints of DNA. Finally the accumulation of silver on DNA of E. coli was confirmed directly by a significant Ag⁺ release from DNA, using the scanning electrochemical microscopy and the voltammetric determinations.     

<Emphasis Type="Italic">Rf5</Emphasis> is able to partially restore fertility to Honglian-type cytoplasmic male sterile <Emphasis Type="Italic">japonica</Emphasis> rice (<Emphasis Type="Italic">Oryza sativa</Emphasis>) lines

Three-line japonica hybrids have been developed mainly on Chinsurah Boro II (BT)-type cytoplasmic male sterile (CMS) lines of Oryza sativa L., but the unstable sterility of some BT-type CMS lines, and the threat of genetic vulnerability when using a single cytoplasm source, have inhibited their use in rice cultivation. Previously, the sterility of Honglian (HL)-type japonica CMS lines derived from common red-awned wild rice (Oryza rufipogon) has been proven to be more stable than that of BT-type japonica CMS lines. Here, we genetically characterized HL-type japonica CMS lines and the restorer-of-fertility (Rf) gene for breeding HL-type japonica hybrids. HL-type japonica CMS lines displayed stained abortive pollen grains, unlike HL-type indica CMS lines. The BT-type japonica restorer lines, which contain Rf, had different capabilities to restore HL-LiuqianxinA (HL-LqxA), an HL-type japonica CMS line, and the restorers for the HL-type japonica CMS lines could be selected from the preexisting BT-type japonica restorers in rice production. A genetic analysis showed that the restoration of normal fertility to HL-LqxA was controlled by a major gene and was affected by minor effector genes and/or modifiers. The major Rf in SiR2982, a BT-type japonica restorer, was mapped to a ~100-kb physical region on chromosome 10, and was demonstrated to be Rf5 (Rf1a) by sequencing. Furthermore, Rf5 partially restored fertility and had a dosage effect on HL-type japonica CMS lines. These results will be helpful for the development of HL-type japonica hybrids.     

Increase in Salt Tolerance of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> by <Emphasis Type="Italic">TaDi19</Emphasis>

The gene expression profile chip of salt-resistant wheat mutant RH8706-49 under salt stress was investigated. The overall length of the cDNA sequence of the probe was obtained using electronic cloning and RT-PCR. An unknown gene induced by salt was obtained, cloned, and named TaDi19 (Triticum aestivum drought-induced protein). No related report or research on the protein is available. qPCR analysis showed that gene expression was induced by many stresses, such as salt. Arabidopsis thaliana was genetically transferred using the overexpressing gene, which increased its salt tolerance. After salt stress, the transgenic plant demonstrated better physiological indicators (higher Ca²⁺ and lower Na⁺) than those of the wild-type plant. Results of non-invasive micro-test technology indicate that TaDi19-overexpressing A. thaliana significantly effluxed Na⁺ after salt treatment, whereas the wild-type plant influxed Na⁺. Chelating extracellular Ca²⁺ resulted in insignificant differences in salt tolerance between overexpressing and wild-type A. thaliana. Subcellular localization showed that the gene encoding protein was mainly located in the cell membrane and nucleus. TaDi19 was overexpressed in wild-type A. thaliana, and the transgenic lines were more salt-tolerant than the control A. thaliana. Thus, the wheat gene TaDi19 could increase the salt tolerance of A. thaliana.     

<Emphasis Type="Italic">In vitro</Emphasis> Blastogenesis inhibited by <Emphasis Type="Italic">Erwinia carotovora</Emphasis><Emphasis Type="SmallCaps">L</Emphasis>-Asparaginase

Escherichia coliL-asparaginase, an antileukaemic agent in man¹, inhibits in vitro mitogen or antigen-induced blastogenesis in man^2,3 and in animals (M. Bennett, E. G. Mayhew and T. Han, unpublished data) and suppresses bone-marrow derived antibody precursor cells in the mouse⁴. We now report that another L-asparaginase preparation—from Erwinia carotovora—also possesses antileukaemic activity^5,6 and has a more pronounced immunosuppressive effect on in vitro blastogenesis than the E. coli enzyme.     

Computational and spectroscopic data correlation study of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>'-bisarylmalonamides (Part II)

To complement a previous UV study, we present a quantitative evaluation of substituent effects on spectroscopic data (¹H and ¹³C NMR chemical shifts as well as FT-IR absorption frequency) applied to N,N'-bisarylmalonamides, using simple and extended Hammett equations as well as the Swain-Lupton equation. Furthermore, the DFT CAM-B3LYP/6–311+G(d,p) method was applied to study the impact of different solvents on the geometry of the molecules and their spectral data. Additionally, experimental data are correlated with theoretical results; excellent linear dependence was obtained. The overall results presented in this paper show that N,N'-bisarylmalonamides are prominent candidates for model molecules.     

Natively oxidized amino acid residues in the spinach cytochrome <Emphasis Type="Italic">b</Emphasis><Subscript><Emphasis Type="Italic">6</Emphasis></Subscript><Emphasis Type="Italic">f</Emphasis> complex

The cytochrome b ₆ f complex of oxygenic photosynthesis produces substantial levels of reactive oxygen species (ROS). It has been observed that the ROS production rate by b ₆ f is 10–20 fold higher than that observed for the analogous respiratory cytochrome bc₁ complex. The types of ROS produced (O₂^{??, 1}O₂, and, possibly, H₂O₂) and the site(s) of ROS production within the b ₆ f complex have been the subject of some debate. Proposed sources of ROS have included the heme b _p , PQ _p ^?? (possible sources for O₂^??), the Rieske iron–sulfur cluster (possible source of O₂^?? and/or ¹O₂), Chl a (possible source of ¹O₂), and heme c _n (possible source of O₂^?? and/or H₂O₂). Our working hypothesis is that amino acid residues proximal to the ROS production sites will be more susceptible to oxidative modification than distant residues. In the current study, we have identified natively oxidized amino acid residues in the subunits of the spinach cytochrome b ₆ f complex. The oxidized residues were identified by tandem mass spectrometry using the MassMatrix Program. Our results indicate that numerous residues, principally localized near p-side cofactors and Chl a, were oxidatively modified. We hypothesize that these sites are sources for ROS generation in the spinach cytochrome b ₆ f complex.     

Distinguishing between <Emphasis Type="Italic">X</Emphasis>, <Emphasis Type="Italic">Y</Emphasis> and <Emphasis Type="Italic">YY</Emphasis>-bearing Human Spermatozoa by Fluorescence and DNA Content

Assays for DNA content show that human spermatozoa with X, F or YY chromosome constitutions can be reliably distinguished by their fluorescence with quinacrine.     

<Emphasis Type="Italic">X</Emphasis> Chromosome Inactivation in Cells from an Individual heterozygous for Two <Emphasis Type="Italic">X</Emphasis>-Linked Genes

THE Lyon hypothesis of X chromosome inactivation predicts that in mammalian females, somatic cells are mosaic with respect to whether the active X chromosome is of maternal or paternal origin and that this chromosomal mosaicism is heritable somatically¹. Studies of cell clones derived from females who were heterozygous for genes at one of several X-linked loci^2–6 have provided good evidence for such mosaicism. Proof that only one of the two X chromosomes, however, is active in any given cell rests on the demonstration that the cell or its clone expresses all of the X-linked genes from one parent and none from the other parent. For this purpose it is useful to examine cloned cells from female subjects for genetic markers representing allelic genes at two or more of the parental loci. This study was undertaken to determine whether genes at the X-linked loci for glucose-6-phosphate dehydrogenase (G6PD) and phosphoglycerate kinase (PGK) are consistently expressed in the eis position in cloned cells as would be expected from a single parental contribution.