The genomic relationship between Glycine max (L.) Merr. and G. soja Sieb. and Zucc. as revealed by pachytene chromosome analysis

Summary This study was conducted with the objective of determining the genomic relationship between cultivated soybean (Glycine max) and wild soybean (G. soja) of the subgenus Soja, genus Glycine. Observations on cross-ability rate, hybrid viability, meiotic chromosome pairing, and pollen fertility in F ₁ hybrids of G. max × G. soja and reciprocals elucidated that both species hybridized readily and set mature putative hybrid pods, generated vigorous F₁ plants, had a majority of sporocytes that showed 18II + 1IV chromosome association at diakinesis and metaphase I, and had a pollen fertility that ranged from 49.2% to 53.3%. A quadrivalent was often associated with the nucleolus, suggesting that one of the chromosomes involved in the interchange is a satellited chromosome. Thus, G. max and G. soja genetic stocks used in this study have been differentiated by a reciprocal translocation. Pachytene analysis of F₁ hybrids helped construct chromosome maps based on chromosome length and euchromatin and heterochromatin distribution. Chromosomes were numbered in descending order of 1–20. Pachytene chromosomes in soybean showed heterochromatin distribution on either side of the centromeres. Pachytene analysis revealed small structural differences for chromosomes 6 and 11 which were not detected at diakinesis and metaphase I. This study suggests that G. max and G. soja carry similar genomes and validates the previously assigned genome symbol GG.Research supported in part by the Illinois Agricultural Experiment Station and U.S. Department of Agriculture Competitive Research Grant (85-CRCR-1-1616)     

Partial elimination of G1 and G2 periods in higher plant cells by increasing the S period

Meristematic cells from Allium cepa L roots can attain a steady-state of growth at both 15 and 25 °C in the presence of drugs, hydroxyurea and 5-amino-uracil, which reduce the rate of DNA synthesis. These drugs, at used concentrations, significantly lengthen the S period without altering the cell growth rate, as indicated by the maintenance of the generation time. It has been observed that steady-state populations respond to a gradual increase in S by a reduction of G2 until a minimum value; with larger lengthening of S, both G1 and G2 are reduced. Natural synchronous populations have been used to study cell cycle parameters during transition from the physiological steady-state to the new one created by the presence of the drug. G2 (but not G1) is reduced during transition even in the presence of maximum drug concentrations that do not alter the cell growth rate. Both the S period and the division time are lengthened during transition. These observations support the concept that certain fractions of G1 and G2 are expendable, because they have no role in the DNA-division sequence of cell cycle events. We conclude that cell size regulates the length of these fractions by means of a negative correlation.     

Chromosome-banding study in Gerbillinae (Rodentia). I. Comparative analysis of Gerbillus poecilops, G. henleyi and G. nanus

An analysis was made of the R- and C-banding of chromosomes of the following Gerbillus species (Rodentia, Gerbillidae): G. poecilops (Taif, Saudi Arabia), G. henleyi (Oursi, Burkina Faso; Kairouan, Tunisia), and G. nanus (Taif and Hofuf, Saudi Arabia; Sind desert, Pakistan). Their karyotypes show the same chromosome number (2n = 52), but a different N.F.a. (number of autosomal arms), ranging from 58 to 62 in the species overall, and from 58 to 60 among G. nanus forms, due to pericentric inversions involving chromosomes 1 and 4. Moreover, large inter-individual variations of heterochromatin segments of chromosomes 25, X, and Y were found. Considering morphology and karyotype, G. poecilops and G. henleyi appear to be rather monomorphous species, whereas G. nanus produces a series of forms as a consequence of speciation, in which both chromosomal and morphological differentiations occur that do not correlate.     

Polytene chromosome maps in four species of tsetse flies Glossina austeni, G. pallidipes, G. morsitans morsitans and G. m. submorsitans (Diptera: Glossinidae): a comparative analysis

Photographic polytene chromosome maps from pupal trichogen cells of four tsetse species, Glossina austeni, G. pallidipes, G. morsitans morsitans and G. m. submorsitans were constructed and compared. The homology of chromosomal elements between the species was achieved by comparing banding patterns. The telomeric and subtelomeric chromosome regions were found to be identical in all species. The pericentromeric regions were found to be similar in the X chromosome and the left arm of L1 chromosome (L1L) but different in L2 chromosome and the right arm of L1 chromosome (L1R). The L2 chromosome differs by a pericentric inversion that is fixed in the three species, G. pallidipes, G. morsitans morsitans and G. m. submorsitans. Moreover, the two morsitans subspecies appeared to be homosequential and differ only by two paracentric inversions on XL and L2L arm. Although a degree of similarity was observed across the homologous chromosomes in the four species, the relative position of specific chromosome regions was different due to chromosome inversions established during their phylogeny. However, there are regions that show no apparent homology between the species, an observation that may be attributed to the considerable intra—chromosomal rearrangements that have occurred following the species divergence. The results of this comparative analysis support the current phylogenetic relationships of the genus Glossina.     

Microsatellite mapping of <Emphasis Type="Italic">Ae. speltoides</Emphasis> and map-based comparative analysis of the S,G, and B genomes of Triticeae species

The first microsatellite linkage map of Ae. speltoides Tausch (2n = 2x = 14, SS), which is a wild species with a genome closely related to the B and G genomes of polyploid wheats, was developed based on two F₂ mapping populations using microsatellite (SSR) markers from Ae. speltoides, wheat genomic SSRs (g-SSRs) and EST-derived SSRs. A total of 144 different microsatellite loci were mapped in the Ae. speltoides genome. The transferability of the SSRs markers between the related S, B, and G genomes allowed possible integration of new markers into the T. timopheevii G genome chromosomal maps and map-based comparisons. Thirty-one new microsatellite loci assigned to the genetic framework of the T. timopheevii G genome maps were composed of wheat g-SSR (genomic SSR) markers. Most of the used Ae. speltoides SSRs were mapped onto chromosomes of the G genome supporting a close relationship between the G and S genomes. Comparative microsatellite mapping of the S, B, and G genomes demonstrated colinearity between the chromosomes within homoeologous groups, except for intergenomic T6A^tS.1G, T4AL.5AL.7BS translocations. A translocation between chromosomes 2 and 6 that is present in the T. aestivum B genome was found in neither Ae. speltoides nor in T. timopheevii. Although the marker order was generally conserved among the B, S, and G genomes, the total length of the Ae. speltoides chromosomal maps and the genetic distances between homoeologous loci located in the proximal regions of the S genome chromosomes were reduced compared with the B, and G genome chromosomes.     

Glucose-6-phosphate dehydrogenase (G6PD) electrophoretic variants and the PvuII polymorphism in Southern African populations

Summary Southern African Bantu-speaking negroid and San populations were examined with regard to the glucose-6-phosphate dehydrogenase (G6PD) PvuII restriction fragment length polymorphism (RFLP) showing alleles of 4kb and 1.6 kb, called Type 1 and Type 2, respectively. The standardized disequilibrium coefficient for the electrophoretic G6PD types and PvuII alleles in the Southern African population was 0.28. The molecular lesion causing the Gd^A mutation is the same in the San and Southern African negroid populations. Gd^A chromosomes are found in association with both the Type 1 and Type 2 alleles, whereas none of the 62 Gd^B chromosomes from the Southern African populations had the Type 2 allele. Five of the 44 Gd^B chromosomes studied in the American Black population had the Type 2 allele, indicating that the Gd^B allele in the two populations may have different origins. The presence of all 3 A^– deficiency mutations in the G6PD A gene, in a region where the ancestral population was thought to have predominantly G6PD B, may be explained by their origin in Africa after the divergence of the races.     

G2 arrest and differentiation in the petal of Tradescantia clone 4430

The floral organs of Tradescantia clone 4430 were used to investigate, in terms of cell cycle parameters, cellular behaviour during the maturation of a terminally differentiating system. Petals were sampled at different stages of development for (a) cell number; (b) nuclear DNA content by cytophotometry; (c) [³H]thymidine incorporation into nuclei by autoradiography; and (d) pigment production by spectrophotometry. DNA synthesis was confirmed by measurement of [³H]thymidine incorporation into TCA-insoluble material and changes in DNA content by colorimetric estimation of DNA extracts by diphenylamine. The development of the petal involved four sequential steps. First, there was an increase in cell number, an event characterized by mitoses, DNA synthesis, a few cells in G2 and a predominance in G1. Second, there was a cessation of cell division and DNA synthesis when all the cells accumulated in G1. Third, there was a shift of a large proportion of the total cell population from G1 to the G2 stage of the cell cycle and finally, there was pigment production. In addition, cytophotometric analysis of individual tissues in the mature petal revealed tissue specific differences in the proportion of cells in G2.     

Incipient Genome Differentiation in Gossypium. I. Chromosomes 14, 15, 16, 19 and 20 Assessed in G. HIRSUTUM, G. RAIMONDII and G. LOBATUM by Means of Seven a-D Translocations

The genus Gossypium is favorable for study of genome divergence at several levels. Early stages of divergence have been studied among four D genomes by comparing chiasma frequencies (reciprocal exchanges) between pairs of genomes and between individual counterpart chromosomes marked by heterozygous translocations. D₅ (G. raimondii) shows barely detectable differentiation from from D_h (G. hirsutum), whereas D₇ (G. lobatum) is considerably less closely related to D_h than is D₅. Fragmentary data suggest that D_2–2 (G. harknessii) falls between D₅ and D₇ in its relationship to D_h. Since chiasma frequencies in individual chromosomes and marked regions exhibit the same order of relationships as their corresponding whole genomes, it is concluded that the genome differentiation is generalized (i.e., nucleus-wide) rather than localized in specific chromosomes or chromosome regions. Estimates of relationships based on reciprocal exchange frequencies agree with those based upon preferential synapsis in allohexaploids reported previously. Since preferential synapsis and reciprocal exchange frequencies reveal the same order of relationships, it is concluded that to some extent they reflect common underlying changes in chromosome properties, despite recent evidence that synapsis and crossing over are under independent genetic control.     

Development and characterization of a potent producer of penicillin G amidase by mutagenization

Summary The penicillin G amidase (PGA) activity of a parent strain of E. coli (PCSIR-102) was enhanced by chemical mutagenization with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). After screening and optimization, a penicillinase deficient mutant (MNNG-37) was isolated and found effective for the production of penicillin G amidase as compared to the parent strain of E. coli (PCSIR-102). Penicillin G amidase activity of MNNG-37 appeared during an early stage of growth, whereas PCSIR-102 did not exhibit PGA activity due to the presence of penicillinase enzyme which inhibits the activity of enzyme PGA. However, MNNG-37 gave a three-fold increase in enzyme activity (231 IU mg⁻¹) as compared to PCSIR-102 (77 IU mg⁻¹) in medium containing 0.15 and 0.1% concentrations of phenylacetic acid, respectively which was added after 6 h of cultivation. The difference in K _m values of the enzyme produced by parent strain PCSIR-102 (0.26 mM) and mutant strain MNNG-37 (0.20 mM) is significant (1.3-fold increase in K _m value) which may show the superiority of the latter in terms of better enzyme properties.     

Gene mapping in the common shrew (Sorex araneus; Insectivora) by shrew-rodent cell hybrids: chromosome localization of the loci for HPRT,TK, LDHA,MDH1, G6PD,PGD, and ADA

We selected the common shrew (Sorex araneus) to generate the first insectivore gene map. Shrew-Chinese hamster and shrew-mouse somatic cell hybrid cells were constructed. When the 119 shrew-rodent clones were characterized, only shrew chromosomes were found to have segregated. A panel of hybrid clones was selected for gene assignment. The genes for hypoxanthine phosphoribosyl transferase (HPRT), glucose-6-phosphate dehydrogenase (G6PD), and malate dehydrogenase 1 (MDH1) were assigned to shrew Chromosome (Chr) de [which is the product of a tandem fusion between the original mammalian X Chromosome (Chr) and an autosome], the genes for adenosine deaminase (ADA) and 6-phosphogluconate dehydrogenase (PGD) to Chromosome jl, the gene for thymidine kinase (TK) to Chromosome hn, and the gene for lactate dehydrogenase (LDHA) to chromosome ik. Further studies are in progress.     

The distribution of Gossypium hirsutum chromatin in G. barbadense germ plasm: molecular analysis of introgressive plant breeding

Cotton is unusual among major crop plants in that two cross-fertile species are widely cultivated for a common economic product, fiber. Both historical evidence and classical genetic studies suggest that many improved forms of Gossypium barbadense (Sea Island, Egyptian, and Pima cottons) may include chromatin derived from G. hirsutum. Using 106 restriction fragment length polymorphism (RFLP) loci well distributed across the cotton genome, we revealed the amount and genomic distribution of G. hirsutum chromatin in 54 G. barbadense collections from around the world. The average G. barbadense collection was comprised of 8.9% alleles apparently derived from G. hirsutum. Pima cultivars (7.3 %) had fewer G. hirsutum alleles than Sea Island (9.0%) or Egyptian (9.6%) cultivars. G. hirsutum alleles were not randomly distributed, as 57.5% of the total introgression observed was accounted for by five specific chromosomal regions that span less than 10% of the genome. The average length of an introgressed chromosome segment was 12.9 cM. Overlap of introgressed chromatin in different breeding programs hints that retention of these G. hirsutum chromosomal segments may impart a selective advantage to G. barbadense genotypes. Although cluster analysis generally grouped germ plasm from common classes and/or breeding programs together, no 2 genotypes were identical — thus differences in the length and repertoire of introgressed chromosome segments also permit DNA fingerprinting of G. barbadense cultivars.     

Examination of fine‐scale spatial‐temporal overlap and segregation between two closely related congeners Gadus morhua and Gadus ogac in coastal Newfoundland

The spatial and temporal movement patterns of sympatric juvenile Atlantic cod Gadus morhua and Greenland cod Gadus ogac were studied using high‐resolution radio‐acoustic positioning in a coastal area of Newfoundland during the summers of 2009 and 2010. A total of 20 fish (10 G. ogac and 10 G. morhua) were equipped with acoustic transmitters and monitored for periods up to 23 days. Most fishes showed high site fidelity with mean residence times of 12·4 (G. morhua) and 14·4 days (G. ogac). A few individuals showed a transient use of the study area, ranging distances up to c. 4 km. Mean daily home ranges [95% kernel utilization distributions (KUDs)] and core activity areas were significantly larger for G. morhua (3·8 and 0·5 ha) than for G. ogac (2·7 and 0·3 ha). Home ranges were not related to total length (L_T) for G. morhua but showed a weak positive relationship for G. ogac. Gadus morhua occupied larger areas during the day while G. ogac occupied slightly larger areas at night. Mean rates of movement for G. ogac and G. morhua ranged from 0·83 to 1·24 and 0·76 to 1·76 L_T s^?1, respectively, and were highest during crepuscular periods. Overall, G. morhua were wider ranging, moved at faster rates and were active throughout the diel cycle compared to G. ogac of the same size. It is suggested that differential use of space and activity periods plays an important role in the successful coexistence of these two species.     

Sizes of G1 and G2 populations in starved Tetrahymena

Feulgen cytophotometry and autoradiography were used to study DNA content and DNA synthesis in starved and starved-refed Tetrahymena pyriformis GL-C. It was found that (1) the cell population shows a limited increase in cell number during starvation and this increase is restricted to the first 7 h of starvation; (2) at the end of starvation, there is a portion of the cell population whose DNA content is similar to that for standard G2 cells; (3) a significant portion of the dividing cells at the first division following refeeding in the presence of [³H]TdR are unlabeled; (4) these unlabeled cells are among the first to divide and, upon division, generally enter into a cell cycle either lacking a G1 phase or with a shortened G1 phase.     

Genome analysis of the moss Physcomitrella patens (Hedw.) B.S.G.

A wild-type (WT) strain of the moss Physcomitrella patens (Hedw.) B.S.G., two mutants derived from it (PC22 and P24), and a somatic hybrid, PC22(+)P24, were analysed. Staining of metaphases revealed 54±2 chromosomes in the somatic hybrid and 27 chromosomes in the wild type and the two mutants. Using flow cytometry (FCM), DNA contents were calculated to be 0.6 pg (WT, PC22), 1.2 pg (P24), and 1.6 pg (PC22(+)P24) per nucleus, respectively. Southern hybridization provided evidence for at least one family of highly repetitive DNA and, furthermore, revealed different amounts of repetitive DNA in the four genotypes. However, these sequences cannot account for the 100% increase in the nuclear DNA amount in mutant P24, relative to wild type. In FCM analyses every moss geno-type generated just one single peak of fluorescence, indicating an arrest in the cell cycle during the daytime. Thermal denaturation of wild-type DNA revealed a G+C content of 34.6% for total DNA and 38.6% for plastid DNA. A cDNA library of 1.2 × 10⁶ independent clones was established, from which sequences homologous to cab and rbcS, respectively, were isolated. These genes show significant homologies to those of higher plants, and, likewise, comprise multigene families. No restriction fragment length polymorphisms could be detected between the four moss genotypes using these cDNA probes.This article is based in part on doctoral studies of M.F. and MW at the University of Hamburg, Faculty of Biology     

Identification of candidate genes for key fibre‐related QTLs and derivation of favourable alleles in Gossypium hirsutum recombinant inbred lines with G. barbadense introgressions

Fine mapping QTLs and identifying candidate genes for cotton fibre‐quality and yield traits would be beneficial to cotton breeding. Here, we constructed a high‐density genetic map by specific‐locus amplified fragment sequencing (SLAF‐seq) to identify QTLs associated with fibre‐quality and yield traits using 239 recombinant inbred lines (RILs), which was developed from LMY22 (a high‐yield Gossypium hirsutumL. cultivar) × LY343 (a superior fibre‐quality germplasm with G. barbadenseL. introgressions). The genetic map spanned 3426.57 cM, including 3556 SLAF‐based SNPs and 199 SSR marker loci. A total of 104 QTLs, including 67 QTLs for fibre quality and 37 QTLs for yield traits, were identified with phenotypic data collected from 7 environments. Among these, 66 QTLs were co‐located in 19 QTL clusters on 12 chromosomes, and 24 QTLs were detected in three or more environments and determined to be stable. We also investigated the genomic components of LY343 and their contributions to fibre‐related traits by deep sequencing the whole genome of LY343, and we found that genomic components from G. hirsutum races (which entered LY343 via its G. barbadense parent) contributed more favourable alleles than those from G. barbadense. We further identified six putative candidate genes for stable QTLs, including Gh_A03G1147 (GhPEL6), Gh_D07G1598 (GhCSLC6) and Gh_D13G1921 (GhTBL5) for fibre‐length QTLs and Gh_D03G0919 (GhCOBL4), Gh_D09G1659 (GhMYB4) and Gh_D09G1690 (GhMYB85) for lint‐percentage QTLs. Our results provide comprehensive insight into the genetic basis of the formation of fibre‐related traits and would be helpful for cloning fibre‐development‐related genes as well as for marker‐assisted genetic improvement in cotton.     

Lack of synergistic effect between X-ray and UV irradiation on the frequency of chromosome aberrations in PHA-stimulated human lymphocytes in the G1 stage.

PHA-stimulated human lymphocytes in the G1 stage were irradiated with UV radiation and X-rays, and the cells were analyzed for chromosomal aberrations in the first mitotic division. The frequency of dicentric chromosomes after single X-irradiation in the G1 stage was about twice the yield in the G0 stage. No increase in the yield of dicentrics was observed after combined irradiation with UV and X-rays. This is contrary to the finding for G0 lymphocytes, where a 2-fold increase of chromosome aberrations was observed. UV irradiation of G1 lymphocytes induced chromatid-type aberrations whereas no significant yield of dicentric chromosomes was observed. This is in agreement with previous findings in Chinese hamster cells in the G1 stage [7]. Irradiation of G0 lymphocytes with UV radiation induce a low frequency of dicentric chromosomes. Thus, the present data indicate that the ratio between chromosome-type and chromatid-type aberrations is different in the G1 and G0 stages in human lymphocytes irradiated with UV radiation.     

The fate of multivalents during meiotic prophase in the hybrid Gibasis consobrina x G. karwinskyana Rafin. (Commelinaceae)

The chromosomes of the two closely related diploid species, Gibasis consobrina and G. karwinskyana (Commelinaceae; 2n=2x=10), are morphologically alike, yet form few chiasmate associations at metaphase I in the f₁ hybrid. During meiotic prophase, however, synaptonemal complexes join the majority of the chromosomes of the complement in complex multiple pairing configurations. The F₁ hybrid between different tetraploid genotypes of the same two species similarly forms multivalents during meiotic prophase, which are subsequently eliminated in favour of strictly homologous bivalents before metaphase I. One quadrivalent comprising interchange chromosomes inherited from one of the parents, usually persists to first metaphase. Evidently the resolution of multivalents to bivalents at first metaphase, which accounts for diploidisation, is not attributable to the elimination of multivalents per se, but of multivalents comprising chromosomes of limited homology.     

Pollination in Geonoma macrostachys and Three Congeners,G. acaulis,G. gracilis,and G. interrupta

A continuous 15 month study of the floral ecology of four syntopic understorey palm species of Genoma was conducted in Amazonian Peru lowland rainforest. The spicate inflorescences of G. macrostachys, G. acaulis and G. gracilis are strictly protandrous and the plants are functionally dioecious. Data suggest that in G. macrostachys and G. acaulis pollination is based on a mimicry system, the pistillate flowers mimicking the staminate ones in colour, shape and scent. Pollen-collecting meliponine bees (Hymenoptera, Apidae, Meliponinae) and pollen-feeding syrphid flies (Diptera, Syrphidae) which visit inflorescences during both sexual stages are the pollinators of G. macrostachys. Geonoma acaulis is pollinated by small pollen-feeding weevils (Coleoptera, Curculionidae, Derelomini) that visit male and female spikes. Additionally, in G. macrostachys another pollinator type, viz. euglossine bees (Hymenoptera, Apidae, Euglossinae), which are attracted and rewarded by both types of flowers may account for long-distance pollination. The palm G. gracilis shows a very distinct pollination system. Although opportunistic insect visitors are attracted to the inflorescences of this species it seems to be mainly anemophilous because pollen becomes powdery during an thesis. The branched inflorescences of G. interrupta are also protandrous, but unlike the other species of Geonoma observed, staminate and pistillate anthesis of individual flowers are, for the most, overlapping. A broad spectrum of visitors is attracted (bees, wasps, flies, and beetles), which all may act as pollinators. Outcrossing is especially encouraged during the purely female phase at the end of the flowering cycle when there are no more staminate flowers in the inflorescence. Effects on the reproductive biology and population structure of different pollination systems and breeding system are discussed.     

The structure,meiotic behaviour and effects of B chromosomes in Briza humilis Bieb. (Gramineae)

A single population of Briza humilis contained two types of B chromosome, one a large (B^L) and the other a small (B^S) acrocentric. DNA measurements show that the B^L chromosome contains approximately twice as much DNA per unit length as the members of the regular complement. The meiotic pairing behaviour of the Bs is variable and B^L and B^S are seen to pair in some cells. The presence of B^L depresses the chiasma frequency of the regular complement but the chiasma frequency of A and B chromosomes does not appear to be related. The transmission rate of the B chromosomes is variable and the B^L shows a non-disjunction mechanism during microsporogenesis that is absent during megasporogenesis. For the B^S chromosome the transmission rate is very low and there is no evidence of a non-disjunction mechanism. In general seeds containing B^L chromosomes germinate more slowly than those without B chromosomes.     

A phase I study of neuroblastoma with the anti-ganglioside GD2 antibody 14.G2a

Summary Nine patients with neuroblastoma stage IV were treated with the murine monoclonal antibody 14.G2a, directed against disialoganglioside GD2. The antibody was injected daily for 5–10 days and the total applied dosage ranged between 100 mg/m² and 400 mg/m². The peak serum levels of mAb 14.G2a ranged from 28 µg/ml to 61 µg/ml. Pharmacokinetic data obtained in three patients indicated that the serum elimination of mAb 14.G2a fits a two-compartment model, with an -half-time (t _1/2 ) between 0.66 h and 1.98 h and a -half-time (t _1/2 ) between 30.13 h and 53.33 h. All patients presented with a human anti-(mouse IgG) antibody response either during or shortly after therapy. Eight patients showed a continuous decrease in complement component C4 during therapy, as well as an initial decrease in C3c and an initial increase in C3a, all suggesting an activation of the complement cascade. Side-effects consisted of allergic reactions like pruritus, exanthema, urticaria and of severe pain, predominantly located in the abdomen and lower extremities, which required the use of continuous intravenous morphine. Four patients additionally developed a transient hypertension and one patient experienced a transient nephrotic syndrome. Three patients were treated in an adjuvant setting and are not evaluable for tumor response. Of the remaining six patients, two had a complete remission, two showed a partial remission, and two patients did not respond to treatment.Supported by the Deutsche Krebshilfe