Old unreduced obturator dislocation of the hip:A case report

Obturator dislocation is a rare type of hip dislocation,accounting for about 2%-5%of all hip dislocations.The occurrence of old unreduced obturator dislocation is even more infrequent,with only 17 cases reported in nine studies,most of which were from the 1950s to 1980s in developing countries.CASE SUMMARY A 38-year-old woman from Hunan Province,China presented with stiffness of the left hip in abduction,flexion,and external rotation after falling from a 2-meter-tall tree onto her left knee 1.5 mo prior.Pelvic radiograph and computed tomography revealed obturator dislocation of the left hip accompanied by impaction fracture at the superolateral aspect of the left femoral head without associated acetabulum fracture.Open reduction was performed,resulting in restoration of the concentric alignment of the left hip.After surgery,6-wk skin traction was applied and the patient was kept in bed for an additional 2 wk.At 3 mo after surgery,the patient reported experiencing some pain,which did not affect the function of the affected limb,and some movement restriction but no abduction deformity or claudication was present.An X-ray showed that the left hip was homocentric,and there was no sign of posttraumatic arthritis or avascular necrosis.CONCLUSION Open reduction may be an effective treatment strategy for the rare condition of old unreduced obturator dislocation with short neglect time.

Cytological Studies on Unreduced Gamete Formation of Strawberries (Fragaria)

A diploid strawberry (Fragaria vesca L.) which can naturally produce unreduced gametes (2n pollen) and doubled-unreduced gametes (4n pollen) was used to study the cytological mechanism of 2n and 4n gamete formation. The result showed that the formation of 2n gamete was mainly due to the abnormal orientation of spindles at metaphase II. The normal orientation of two spindles at metaphase I was perpendicular to each other, which led to tetrad formation at the end of meiosis. Two kinds of abnormal orientation of metaphase II spindles, i. e. parallel spindles and triangle spindles, were observed. Of the parallel spindles, the 4 group chromosomes were distributed to 2 poles and formed a dyad which formed two 2n pollen grains further-ly. Of the triangle spindles, the 4 group chromosomes were distributed to 3 poles and formed a triad which formed one 2n pollen grain and two n pollen grains. In addition, a few very big pollen grains (4n pollen) which probably due to the fusion of the tetrad were found.

Production of aneuhaploid and euhaploid sporocytes by meiotic restitution in fertile hybrids between durum wheat Langdon chromosome substitution lines and Aegilops tauschii

Fertile F1 hybrids were obtained between durum wheat （Triticum durum Desf.） Langdon （LDN） and its 10 disomic substitution （LDN DS） lines with Aegilops tauschii accession AS60 without embryo rescue. Selfed seedset rates for hybrids of LDN with AS60 were 36.87% and 49.45% in 2005 and 2006, respectively. Similar or higher selfed seedset rates were observed in the hybrids of 1D （1A）, 1D （1B）, 3D （3A）, 4D （4B）, 7D （7A）, and 2D （2B） with AS60, while lower in hybrids of 3D （3B） ＋ 3BL, 5D （5A） ＋ 5AL, 5D （5B） ＋ 5B and 6D （6B） ＋ 6BS with AS60 compared with the hybrids of LDN with AS60. Observation of male gametogenesis showed that meiotic restitution, both first-division restitution （FDR） and single-division meiosis （SDM） resulted in the formation of functional unreduced gametes, which in turn produced seeds. Both euhaploid and aneuhaploid gametes were produced in F1 hybrids. This suggested a strategy to simultaneously transfer and locate major genes from the ancestral species T. turgidum or Ae. tauschii. Moreover, there was no significant difference in the aneuhaploid rates between the F1 hybrids of LDN and LDN DS lines with AS60, suggesting that meiotic pairing between the two D chromosomes in the hybrids of LDN DS lines with AS60 did not promote the formation of aneuhaploid gametes.

Wheat breeding in the hometown of Chinese Spring

The common wheat landrace Chinese Spring(CS) was made famous by the work of Ernie Sears, a great cytogenetist, who developed a number of CS-based aneuploid series that were used to identify individual wheat chromosomes. Based on this, a standard karyotype and nomenclature system was developed for wheat chromosomes that allowed wheat researchers to analyze and manipulate the wheat genome with unprecedented precision and efficiency. Nevertheless, not much is known about the utilization of CS at its hometown, Chengdu in Sichuan province, during early wheat breeding activity. In this review, we follow the speculation that CS is a selection from the Cheng-du-guang-tou(CDGT) landrace. We provide a description of how CDGT became a founder landrace for wheat breeding activities in early times. We show that CDGT-derived varieties were reinforced genetically by crosses to six more exotic parents. These varieties remained the major elite cultivar for several decades. Later, synthetic hexaploid wheats were introduced into the breeding program, firstly using those from CIMMYT and later using materials produced with local tetraploid wheat and goat grass. Finally, we discuss the strategies and future directions to improve wheat yield and resistance through an expanded genetic basis,especially by recapturing lost genetic variations from landraces and related wild species, a process that may set an example for wheat breeders in China and elsewhere.

Pseudogamous Apomixis in Maize and Sorghum in Diploid-Tetraploid Crosses

Apomictic seed development is a complex process including formation of unreduced embryo sac,parthenogenetic embryo development from the egg cell,and endosperm formation either autonomously,or due to fertilization of polar nuclei by the sperm(under pseudogamous form of apomixis).In the latter case,an obstacle to the normal endosperm development is disturbance of maternal(m)-to-paternal(p)genomic ratio 2m:1p that occurs in the cases of pollination of unreduced embryo sac with haploid sperms.Usage of tetraploid pollinators can overcome this problem because in such crosses maternal-to-paternal genomic ratio is 4m:2p that provides formation of kernels with plump endosperm.Using tetraploid lines as pollen parents we observed formation of plump kernels on the ears and panicles of diploid maize and sorghum accessions.These kernels had hybrid endosperm and diploid maternal-type embryo or hybrid embryo with different ploidy level(2n,3n,4n).The frequencies of plump kernels on the ear ranged from 0.2-0.3%to 5.7-6.2%counting from the number of ovaries.Maternal-type plants were found in two maize lines,their frequency varying from 10.7 to 37.5%of the progeny plants.In CMS-lines of sorghum pollinated with tetraploid sorghum accessions,the frequency of plump kernels ranged from 0.6 to 14.0%counting from the number of ovaries;the frequency of maternal-type plants varied from 33.0 up to 96.1%.The hybrid nature of endosperm of the kernels that gave rise to maternal-type plants has been proved by marker gene expression and by SDS-electrophoresis of endosperm proteins.These data testify to variable modes of seed formation under diploid×tetraploid crosses in maize and sorghum both by amphi-and by apomixis.Therefore,usage of tetraploid pollinators might be a promising approach for isolation of apomixis in maize and sorghum accessions.

Development of gold catalysts supported by unreducible materials:Design and promotions

Gold catalysis had been considered a highly efficient candidate for heterogeneous catalysis.It is well established that reducible-material-supported Au NPs are more reactive than the unreducible materials,unless specific modifications are carried out.However,unreducible materials such as carbon materials,silica,and alumina have particular advantages,including the easily controlled surface property,adjustable microscopic structure,earth-abundant reserves,and facile industrial manufacture.New strategies,influences,and mechanisms of modification to enhance the catalytic performance and thermal stability of unreducible-material-supported gold catalysts are among the most attractive research topics in gold catalysis.However,to the best of our knowledge,reports and reviews focused on unreducible-material-supported gold catalysts are lacking.Herein,the above concept will be thoroughly discussed regarding several typical unreducible supports,including the commonly used silica,alumina,carbon materials,and hydroxyapatite.The currently prevailing modification strategies will be summarized in detail from the aspects of theoretical conceptualization and practical methodology,including the ingenious synthesis method for catalyst with a specific structure,the currently prosperous electrostatic adsorption,colloid immobilization,and the applicative thermal gaseous treatment.The influences of physical and chemical modifications on the surface chemistry,electronic structure,interaction/synergy between Au-support/promoter,catalyst morphology and water precipitation will be also summarized.It is assumed that the review will shed light on significant studies on unreducible support in gold catalysis with the purpose of catalytic promotion and the promotion of the potential industrial demands in advance.Furthermore,the review will provide new insights into unreducible supports that can be potentially applied in gold catalysis.

Synthetic hexaploid wheat and its utilization for wheat genetic improvement in China

Synthetic hexaploid wheat （Triticum turgidum x Aegilops tauschii） was created to explore for novel genes from T. turgidum and Ae. tauschii that can be used for common wheat improvement. In the present paper, research advances on the utilization of synthetic hexaploid wheat for wheat genetic improvement in China are reviewed. Over 200 synthetic hexaploid wheat （SHW） accessions from the International Maize and Wheat Improvement Centre （CIMMYT） were introduced into China since 1995. Four cultivars derived from these, Chuanmai 38, Chuanmai 42, Chuanmai 43 and Chuanmai 47, have been released in China. Of these, Chuanmai 42, with large kernels and resistance to stripe rust, had the highest average yield （〉 6 t/ha） among all cultivars over two years in Sichuan provincial yield trials, outyielding the commercial check cultivar Chuanmai 107 by 22,7%. Meanwhile, by either artificial chromosome doubling via colchicine treatment or spontaneous chromosome doubling via a union of unreduced gametes （2n） from T. turgidum-Ae, tauschii hybrids, new SHW lines were produced in China. Mitotic-like meiosis might be the cytological mechanism of spontaneous chromosome doubling. SHW lines with genes for spontaneous chromosome doubling may be useful for producing new SHW-alien amphidiploids and double haploid in wheat genetic improvement.

Two unisexual artificial polyploid clones constructed by ge-nome addition of common carp(Cyprinus carp)and crucian carp(Carassius auratus)

A polyploid hybrid fish with natural gynogenesis can prevent segregation and maintain their hybrid vigor in their progenies. Supposing the reproduction mode of induced polyploid fish being natural gynogenesis, allopolyploid hybrid between common carp and crucian carp into allo-polyploid was performed. The purpose of this paper is to describe a lineage from sexual diploid carp transforming into allotriploid and allotetraploid unisexual clones by genome addition. The dip-loid hybrid between common carp and crucian carp reproduces an unreduced nucleus consisting of two parental genomes. This unreduced female pronucleus will fuse with male pronucleus and form allotriploid zygote after penetration of related species sperms. Allotriploid embryos grow nor-mally, and part of female allotriploid can produce unreduced mature ova with three genomes. Ma-ture ova of most allotriploid females are provided with natural gynogenetic trait and their nuclei do not fuse with any entrance sperm. All female offspring are produced by gynogenesis of allotriploid egg under activation of penetrating sperms. These offspring maintain morphological traits of their allotriploid maternal and form an allotetraploid unisexual clone by gynogenetic reproduction mode. However, female nuclei of rare allotriploid female can fuse with penetrating male pronuclei and result in the appearance of allotetraploid individuals by means of genome addition. All al-lotetraploid females can reproduce unreduced mature eggs containing four genomes. Therefore, mature eggs of allotetraploid maintain gynogenetic trait and allotetraploid unisexual clone is pro-duced under activation of related species sperms.

Synthesizing double haploid hexaploid wheat populations based on a spontaneous alloploidization process

Doubled haploid （DH） populations are useful to scientists and breeders in both crop improvement and basic research. Current methods of producing DHs usually need in vitro culture for extracting haploids and chemical treatment for chromosome doubling. This report describes a simple method for synthesizing DHs （SynDH） especially for allopolyploid species by utilizing meiotic restitution genes. The method involves three steps： hybridization to induce recombination, interspecific hybridization to extract haploids, and spontaneous chromosome doubling by selfing the interspecific Fis. DHs produced in this way contain recombinant chromosomes in the genome（s） of interest in a homogeneous background. No special equipment or treatments are involved in the DH production and it can be easily applied in any breeding and/or genetic program. Triticum turgidum L. and Aegilops tauschii Coss, the two ancestral species of common wheat （Triticurn aestivum L.） and molecular markers were used to demonstrate the SynDH method.