Contrasting range changes of terrestrial orchids under future climate change in China.

Climate change has impacted the distribution and abundance of numerous plant and animal species during the last century. Orchidaceae is one of the largest yet most threatened families of flowering plants. However, how the geographical distribution of orchids will respond to climate change is largely unknown. Habenaria and Calanthe are among the largest terrestrial orchid genera in China and around the world. In this paper, we modeled the potential distribution of eight Habenaria species and ten Calanthe species in China under the near-current period (1970-2000) and the future period (2081-2100) to test the following two hypotheses: 1) narrow-ranged species are more vulnerable to climate change than wide-ranged species; 2) niche overlap between species is positively correlated with their phylogenetic relatedness. Our results showed that most Habenaria species will expand their ranges, although the climatic space at the southern edge will be lost for most Habenaria species. In contrast, most Calanthe species will shrink their ranges dramatically. Contrasting range changes between Habenaria and Calanthe species may be explained by their differences in climate-adaptive traits such as underground storage organs and evergreen/deciduous habits. Habenaria species are predicted to generally shift northwards and to higher elevations in the future, while Calanthe species are predicted to shift westwards and to higher elevations. The mean niche overlap among Calanthe species was higher than that of Habenaria species. No significant relationship between niche overlap and phylogenetic distance was detected for both Habenaria and Calanthe species. Species range changes in the future was also not correlated with their near current range sizes for both Habenaria and Calanthe. The results of this study suggest that the current conservation status of both Habenaria and Calanthe species should be adjusted. Our study highlights the importance of considering climate-adaptive traits in understanding the responses of orchid taxa to future climate change.

Geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms in China.

China covers a vast territory harbouring a large number of aquatic plants. Although there are many studies on the ß-diversity of total, herbaceous or woody plants in China and elsewhere, few studies have focused on aquatic plants. Here, we analyse a comprehensive data set of 889 aquatic angiosperm species in China, and explore the geographic patterns and climatic correlates of total taxonomic and phylogenetic ß-diversity as well as their turnover and nestedness components. Our results show that geographic patterns of taxonomic and phylogenetic ß-diversity are highly congruent for aquatic angiosperms, and taxonomic ß-diversity is consistently higher than phylogenetic ß-diversity. The ratio between the nestedness component and total ß-diversity is high in northwestern China and low in southeastern China. The geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms in China are obviously affected by geographic and climatic distances, respectively. In conclusion, the geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms are consistent across China. Climatic and geographic distances jointly affect the geographic patterns of ß-diversity of aquatic angiosperms. Overall, our work provides insight into understanding the large-scale patterns of aquatic angiosperm ß-diversity, and is a critical addition to previous studies on the macroecological patterns of terrestrial organisms.

Metagenomic Features Characterized with Microbial Iron Oxidoreduction and Mineral Interaction in Southwest Indian Ridge.

The Southwest Indian Ridge (SWIR) is one of the typical representatives of deep-sea ultraslow-spreading ridges, and has increasingly become a hot spot of studying subsurface geological activities and deep-sea mining management. However, the understanding of microbial activities is still limited on active hydrothermal vent chimneys in SWIR. In this study, samples from an active black smoker and a diffuse vent located in the Longqi hydrothermal region were collected for deep metagenomic sequencing, which yielded approximately 290 GB clean data and 295 mid-to-high-quality metagenome-assembled genomes (MAGs). Sulfur oxidation conducted by a variety of Gammaproteobacteria, Alphaproteobacteria, and Campylobacterota was presumed to be the major energy source for chemosynthesis in Longqi hydrothermal vents. Diverse iron-related microorganisms were recovered, including iron-oxidizing Zetaproteobacteria, iron-reducing Deferrisoma, and magnetotactic bacterium. Twenty-two bacterial MAGs from 12 uncultured phyla harbored iron oxidase Cyc2 homologs and enzymes for organic carbon degradation, indicated novel chemolithoheterotrophic iron-oxidizing bacteria that affected iron biogeochemistry in hydrothermal vents. Meanwhile, potential interactions between microbial communities and chimney minerals were emphasized as enriched metabolic potential of siderophore transportation, and extracellular electron transfer functioned by multi-heme proteins was discovered. Composition of chimney minerals probably affected microbial iron metabolic potential, as pyrrhotite might provide more available iron for microbial communities. Collectively, this study provides novel insights into microbial activities and potential mineral-microorganism interactions in hydrothermal vents. IMPORTANCE Microbial activities and interactions with minerals and venting fluid in active hydrothermal vents remain unclear in the ultraslow-spreading SWIR (Southwest Indian Ridge). Understanding about how minerals influence microbial metabolism is currently limited given the obstacles in cultivating microorganisms with sulfur or iron oxidoreduction functions. Here, comprehensive descriptions on microbial composition and metabolic profile on 2 hydrothermal vents in SWIR were obtained based on cultivation-free metagenome sequencing. In particular, autotrophic sulfur oxidation supported by minerals was presumed, emphasizing the role of chimney minerals in supporting chemosynthesis. Presence of novel heterotrophic iron-oxidizing bacteria was also indicated, suggesting overlooked biogeochemical pathways directed by microorganisms that connected sulfide mineral dissolution and organic carbon degradation in hydrothermal vents. Our findings offer novel insights into microbial function and biotic interactions on minerals in ultraslow-spreading ridges.

Medial patellofemoral ligament reconstruction: A review.

INTRODUCTION: Reconstruction of the medial patellofemoral ligament (MPFL) is an effective surgical method for the treatment of lateral patellar instability. At present, there is not much controversies regarding the femoral attachment, however, the controversies regarding patellar attachment versus attachment, number of graft strands, tension, isometry and so on. The following electronic databases will be searched: PubMed, the Cochrane Library, Embase, Web of Science, Medline. We will consider articles published between database initiation and March 2021. MPFL in the subject heading will be included in the study. Language is limited to English. Research selection, data extraction, and research quality assessment were independently completed by 2 researchers. CONCLUSIONS: MPFL reconstruction is a reliable technique for the treatment of patellofemoral instability. The Schöttle point is still the mainstream method for locating the femoral attachment, the patellar attachment for single-bundle is located at the junction of the proximal one third and the distal two third of the longitudinal axis of the patella. For double-bundles, one is located in the proximal one third of the medial patellar edge and another is in the center of the patellar edge. Meanwhile, the adjustment of graft tension during operation is very important.

Impact of the Result of Continued Thrombolysis After Stenting Following Pharmacomechanical Thrombectomy for Iliofemoral Deep Vein Thrombosis-A Retrospective Study.

OBJECTIVE: The aim of this study is to compare the procedure and treatment outcomes of using either direct stenting alone following pharmacomechanical thrombectomy or continued catheter-directed thrombolysis after stenting for treatment of acute left iliofemoral deep vein thrombosis while clot removal degree achieved grade III. METHODS: From March 2018 to May 2019, 82 patients who underwent iliac venous stenting for treatment of acute left iliofemoral deep vein thrombosis with iliac vein stenosis after pharmacomechanical thrombectomy therapy using the AngioJet system while Clot removal degree achieved grade III were divided into two groups: Direct stenting alone group (n = 39) and continued catheter-directed thrombolysis after stenting group (n = 43). Comparisons were made regarding the treatment outcomes, stent patency rate, and Villalta scale between these two groups. RESULTS: No serious perioperative complications occurred. The mean urokinase dose and hospitalization time in the stenting alone group and continued catheter-directed thrombolysis after the stenting group were 0.30 million U versus 1.76 ± 0.54 million U and 4.85 ± 0.93 days versus 6.33 ± 1.02 days, (P < .001). In the first 30 days after the operation, there were 3 recurrent episodes of deep vein thrombosis in the stenting alone group (P = 0.064). Each patient has completed at least one year of follow-up, the mean follow-up was 15.95 ± 3.44 months. Overall cumulative stent patency rates were 87.2% in stenting alone group and 97.7% in continued catheter-directed thrombolysis after stenting group at 12months (P = 0.037). The Villalta scores at 12 months had a significant difference between the two groups. The mean Villalta scores in the stenting alone group and continued catheter-directed thrombolysis after the stenting group were 4.44 ± 1.63 and 1.63 ± 1.29, respectively (P < 0.001). CONCLUSION: When the clot removal degree of pharmacomechanical thrombectomy thrombectomy reaches grade III, both stenting alone and continued catheter-directed thrombolysis after stenting are effective treatment modalities. For young patients with low bleeding risk, continued catheter-directed thrombolysis after stenting has a better patency rate and a lower 1-year post-thrombotic syndrome risk and does not increase major bleeding events. However, it may increase the time and costs of hospitalization accordingly.

RBP-J promotes cell growth and metastasis through regulating miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis in colorectal cancer.

BACKGROUND: RBP-J is involved in number of cellular processes. However, the potential mechanisms of RBP-J on colorectal cancer (CRC) development have not been clearly defined. In this study, we aimed to investigate the role and molecular mechanism of RBP-J in CRC. METHODS: The expression levels of RBP-J and Tiam1 in CRC tissues and cells were evaluated by RT-qPCR or western blot. RBP-J was knocked down with sh-RBP-J or overexpressed by pcDNA3.1-RBP-J in CRC cells. Cell proliferation, migration and invasion abilities were analyzed by MTT, wound healing, and transwell assay, respectively. CHIP-qPCR, RIP and dual luciferase reporter assays were performed to confirm the interaction between miR-182-5p and RBP-J or Tiam1. Expression levels of p-p38 MAPK, p38 MAPK, Slug-1, Twist1 and MMP-9 were analyzed by western blot. G-LISA test was used to detect Rac1 activity. RESULTS: Our results showed that the expression of RBP-J and Tiam1 was significantly up-regulated in CRC tissues and cells. RBP-J overexpression promoted proliferation, migration and invasion of CRC cells. Moreover, RBP-J was found to directly target miR-182-5p promoter and positively regulate the Tiam1/Rac1/p38 MAPK signaling pathway in CRC cells. It was also proved that miR-182-5p can bind Tiam1 directly. Furthermore, experiments revealed that RBP-J could promote CRC cell proliferation, migration and invasion via miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis. In addition, knockdown of RBP-J reduced tumor growth and metastasis in CRC mice. CONCLUSION: RBP-J regulates CRC cell growth and metastasis through miR-182-5p mediated Tiam1/Rac1/p38 MAPK signaling pathway, implying potential novel therapeutic targets for CRC patients.

Modeling impacts of climate change on the potential distribution of six endemic baobab species in Madagascar.

Madagascar, a globally renowned biodiversity hotspot characterized by high rates of endemism, is one of the few remaining refugia for many plants and animal species. However, global climate change has greatly affected the natural ecosystem and endemic species living in Madagascar, and will likely continue to influence species distribution in the future. Madagascar is home to six endemic baobab (Adansonia spp., Bombacoideae [Malvaceae]) species (Adansonia grandidieri, A. suarezensis, A. madagascariensis, A. perrieri, A. rubrostipa, A. za), which are remarkable and endangered plants. This study aimed to model the current distribution of suitable habitat for each baobab species endemic to Madagascar and determine the effect that climate change will have on suitable baobab habitat by the years 2050 and 2070. The distribution was modeled using MaxEnt based on locality information of 245 occurrence sites of six species from both online database and our own field work. A total of seven climatic variables were used for the modeling process. The present distribution of all six Madagascar's baobabs was largely influenced by temperature-related factors. Although both expansion and contraction of suitable habitat are predicted for all species, loss of original suitable habitat is predicted to be extensive. For the most widespread Madagascar baobab, A. za, more than 40% of its original habitat is predicted to be lost because of climate change. Based on these findings, we recommend that areas predicted to contract in response to climate change should be designated key protection regions for baobab conservation.

LncRNA FTX Promotes Colorectal Cancer Cells Migration and Invasion by miRNA-590-5p/RBPJ Axis.

Colorectal cancer (CRC) is one of the most lethal human cancers all over the world. Moreover, it ranks fourth for cancer-related deaths among males. Although many efforts have been made to cure CRC, the effect remains limited. It has been reported that lncRNA five prime to Xist (FTX) was upregulated in CRC. However, the mechanism by which lncRNA FTX regulates the progression of CRC remains largely unknown. In this study, qRT-PCR was performed to detect the expression of FTX, miR-590-5p and Recombination signal binding protein for immunoglobulin kappa J region (RBPJ) in CRC tissues or cells. Protein expression in cells was measured by western blot. MTT assay was used to test the cell viability. Moreover, transwell was performed to examine the cell migration and invasion. Luciferase report assay was performed to verify the relation between miR-590-5p and FTX or RBPJ. It was found that FTX was upregulated in CRC tissues and cells. Knockdown of FTX or overexpression of miR-590-5p can inhibit the proliferation, migration, and invasion of CRC cells. Besides, silencing of FTX could inhibit the expression of migration and invasion-related proteins in CRC cells. Meanwhile, miR-590-5p was the target of FTX, and RBPJ was the direct target of miR-590-5p. Inhibition of miR-590-5p could reverse the inhibitory effect of FTX on the progression of CRC. These findings suggested that knockdown of FTX could inhibit the tumorigenesis of CRC in vitro, which may serve as a potential novel strategy for treatment of CRC.

Endovascular treatment for long segment iliac artery occlusion involving the iliac artery opening.

OBJECTIVE: This retrospective nonrandomized study investigated the outcomes of endovascular therapy for long-segment iliac artery occlusion involving the iliac artery opening. METHODS: During a 5-year period (from Mar 2012 to Mar 2017), 32 patients (two women and 30 men; mean age, 69.0 years; range, 51-90 years) received endovascular therapy, with or without catheter-directed thrombolysis (CDT), for long-segment iliac artery occlusion (mean lesion length, 129.8 mm; range, 74.7-189.3 mm). RESULTS: The technical success rate was 90.6% (29 of 32). The major complication rate was 3.5%, but no in-hospital mortality was recorded. The access site complication rate was 10.3%. The clinical symptoms of 29 patients were significantly improved. All 29 patients were followed up for 6-40 months, with an average of 16.7 ± 10.9 months. The primary patency rates were 96.6 ± 3.4% at 6 months, 86.6 ± 7.3% at 12 months, 79.4 ± 9.6% at 24 months, and 66.2 ± 14.5% at 36 months. CONCLUSIONS: Depending on the characteristics of the disease, endovascular treatment with an individualized, rational choice of approach and with fine-tuning of the operation is a safe and effective treatment for long-term iliac artery occlusion involving the opening of the iliac arteries. Customization of the treatment is also the key to a successful operation and to ensuring good postoperative efficacy.

A new species of Ophryotrocha (Annelida, Eunicida, Dorvilleidae) from hydrothermal vents on the Southwest Indian Ridge.

Dorvilleids were collected from hydrothermal vents on the Southwest Indian Ridge by manned submersible Jiaolong. These represent a new species of Ophryotrocha that is here described as Ophryotrocha jiaolongisp. n. This is the first dorvilleid described from vents on the Southwest Indian Ridge. It most closely resembles another vent species, Ophryotrocha akessoni Blake, 1985 from the Galapagos Rift, but can be distinguished by its antennae, palps, jaw structure. The new species has particularly distinctive mandibles, which allow it to be easily identified.

[Development and application of Jingcen DY-1 spraying tanker for Oncomelania hupensis snail control].

OBJECTIVE: To develop a Jingcen DY-1 type spraying tanker for Oncomelania hupensis snail control and evaluate its effect of field application as well as the cost. METHODS: The currently available tractor was used as a vector, and the mechanical and electrical equipments and containers were integrated with shafts, pipelines and electric lines to produce a spraying tanker for snail control, with the functions of carrying people and molluscicides, generating electric power and getting water, mixing stocking solutions, adjusting molluscicide solutions evenly, and spraying drugs. The volume of the molluscicide solution, flow rate of water injection, and the flow rate, range and advance speed of the spray gun were tested, and the solution concentrations of molluscicide in the tanker and at the muzzle of the spray gun at different time were detected. Meanwhile, the molluscicidal effect and cost of the spraying tanker were analyzed by the field test. RESULTS: The volume of the liquid storage pot of the Jingcen DY-1 type spraying tanker was 1 800 L, the flow rate of water injection was 400 L/min, the flow rate and the spray range of the standard spray gun were 110-200 L/min and 19.70-23.50 m, respectively, the efficiency of drug spraying of the spraying tanker was 6 000 m/h, and the ratio of spray width (m) to march speed (m/min) was 1:200. When 5 min post mother liquid recirculating, the average concentration of the molluscicide at the upper-, middle- and lower-layers of the liquid storage pot was (1030.39 ± 43.00) mg/L, with a variation coefficient of 4.17%. The average concentration of the molluscicide in the spraying process (spraying for 2, 4, 6, 8, 9 min) was (953.00 ± 68.87)mg/L, with a variation coefficient of 7.22%. The concentration of the residual drug in the liquid storage pot post spraying was 1 000.43 mg/L, which reached the effect concentration for snail control. After spraying for 7 days in the field, the average density of living snails reduced by 88.20% as compared to that before spraying, and the adjusted mortality of snails was 87.65%. The unit cost of Jingcen DY-1 spraying tanker was 0.086 7 Yuan/m². which reduced by 58.20% as compared to that of the conventional spraying tanker. CONCLUSIONS: Jingcen DY-1 type spraying tanker for snail control which integrates various equipments together can effectively control the concentration and dose of the molluscicide, and the machine is labor-saving, efficient, economic and well adapted, and is worthy to be widely applied.

Aquaticitalea lipolytica gen. nov., sp. nov., isolated from Antarctic seawater.

A Gram-stain-negative, rod-shaped bacterium, designated Ar-125T, was isolated from Antarctic seawater. It produced carotenoid-like pigments and did not produce Bchl a. Ar-125T was positive for hydrolysis of DNA, aesculin, gelatin, starch, Tween 40 and Tween 60. The sole respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine, one unidentified aminolipid, one unidentified glycolipid and two unidentified lipids. The principal fatty acids were branched-chain fatty acids, including iso-C15 : 0, iso-C15 : 1 G, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), iso-C16 : 0, iso-C17 : 0 3-OH, iso-C16 : 0 3-OH and iso-C15 : 0 3-OH, as well as C15 : 0. The genomic DNA G+C content was 31.8 mol%. On the basis of 16S rRNA gene sequence analysis, Ar-125T is closely related to the species of the genera Bizionia(with 16S rRNA gene pairwise sequence similarity of 93.7-96.5 %), Formosa(94.3-95.8 %), Gaetbulibacter(94.2-95.7 %), Geojedonia(95.5 %), Gelidibacter (93.3-95.4 %), Meridianimaribacter(95.3 %) and Psychroserpens (94.8-95.3 %), of the family Flavobacteriaceae. Phylogenetic analysis indicated that it represented an independent lineage and that the closest relatives were members of the genus Gelidibacter. Differential phenotypic properties and chemotaxonomic differences, together with phylogenetic distinctiveness, revealed that Ar-125T could be differentiated from members of closely related genera. Therefore, it is proposed that Ar-125T represents a novel species in a new genus, for which the name Aquaticitalea lipolytica gen. nov., sp. nov. (type strain Ar-125T =CGMCC 1.15295T =JCM 30876T) is proposed.

Muricauda antarctica sp. nov., a marine member of the Flavobacteriaceae isolated from Antarctic seawater.

A Gram-stain-negative, rod-shaped bacterium with appendages, designated Ar-22(T), was isolated from a seawater sample collected from the western part of Prydz Bay, near Cape Darnley, Antarctica. Strain Ar-22(T) grew optimally at 35 °C, at pH 7.5 and in the presence of 1-3% (w/v) NaCl. The isolate was positive for casein, gelatin and Tween 20 decomposition and negative for H2S production and indole formation. Chemotaxonomic analysis showed that MK-6 was the major isoprenoid quinone and phosphatidylethanolamine was the major polar lipid. The major fatty acids were iso-C(17:0) 3-OH, iso-C(15:1) G, iso-C(15:0) and C(16:1)ω7c/iso-C(15:0) 2OH. The genomic DNA G+C content was 44.8 mol%. Comparative 16S rRNA gene sequence analysis revealed that strain Ar-22(T) is closely related to members of the genus Muricauda, sharing 94.2-97.3% sequence similarity with the type strains of species of the genus Muricauda and being most closely related to the Muricauda aquimarina. Phylogenetic analysis based on the 16S rRNA gene sequence comparison confirmed that strain Ar-22(T) formed a deep lineage with Muricauda flavescens. Sequence similarity between strain Ar-22(T) and Muricauda ruestringensis DSM 13258(T), the type species of the genus Muricauda, was 96.9%. Strain Ar-22(T) exhibited mean DNA-DNA relatedness values of 40.1%, 49.4% and 25.7% to M. aquimarina JCM 11811(T), M. flavescens JCM 11812(T) and Muricauda lutimaris KCTC 22173(T), respectively. On the basis of phenotypic and genotypic data, strain Ar-22(T) represents a novel species of the genus Muricauda, for which the name Muricauda antarctica sp. nov. (type strain Ar-22(T) =CGMCC 1.12174(T) = JCM 18450(T)) is proposed.

8-Hydroxyquinoline derivatives induce the proliferation of rat mesenchymal stem cells (rMSCs).

A series of 8-hydroxyquinoline derivatives with different substituted groups at 2- or 5-position have been synthesized and characterized. Their effects on the proliferation of the rat marrow-derived mesenchymal stem cells (rMSCs) have been evaluated by MTT assay and flow cytometry. We also analyzed the ability of these compounds to regulate the proliferation of rMSCs and the relationship with the structures of 8-hydroxyquinoline. Compounds 8-11, in which, the vinyl-substituents are on the 2-position of 8-hydroxyquinoline, appear to be able to induce the proliferation of rMSCs. These results show that compounds 8-11 provide a kind of new substances for regulating the proliferation of rMSCs.

Identification and characteristics of a novel E1 like gene nUBE1L in human testis.

A gene, presumably involved in spermatogenesis, was identified and characterized by using cDNA microarray. Hybridization intensity was 2.13 fold higher in adult testis than that in fetal testis. The full length of this gene was 4288 bp and it encoded a 578 amino acid protein. Conserved structure and amino acid sequence analysis revealed that the protein contained 1 Thif-domain, 2 UBACT-domains, and a functional active site cysteine lay upstream of UBACT domain, all of them also existed in ubiquitin-activating enzyme E1 and E1 like proteins. So we named this gene as a novel ubiquitin-activating enzyme E1 like gene (nUBE1L). Expression profile showed that nUBE1L was predominantly expressed in testis. Comparison of the expression of nUBE1L in different developmental stages of testis indicated that it was highly expressed in adult testis. In conclusion, nUBE1L is a novel human E1 like gene highly expressed in adult testis, which plays key role in ubiquitin system, and accordingly influences spermatogenesis and male fertility.

Expression of a novel bHLH-Zip gene in human testis.

AIM: To identify specifically expressed genes in the adult and fetal testes. METHODS: A human testis cDNA microarray was established. Then the mRNA of adult and fetal testis was purified and probes were prepared by a reverse transcription reaction with the testis mRNA as template. The microarray was hybridized with probes of adult and fetal testes. The nucleic sequences of differentially expressed genes were determined and homologies were searched in the databases of the GenBank. RESULTS: When hybridized with adult or fetal testis probes, the positive clones were 96.8 % and 95.4 %, respectively. Among these genes, one was a new testis-specific gene, which was named TSP1. TSP1 was highly expressed in human adult testis. The cDNA of TSP1 was 1,484 bp in length. The cDNA sequence of this clone was deposited in the Genbank (AF333098). TSP1 was also determined as Interim Gen Symbol (Unigene, No. Hs.98266). Protein analysis showed that TSP1 contained two functional domains: an N-terminal basic helix-loop-helix (bHLH) and a C-terminal leucine zipper (Zip). Homologous analysis showed that the 430 amino acid sequences deduced from the 1293 bp open reading frame (ORF) had a homology with the human gene FLJ2509 (AK098575). TSP1 had also a sequence homology with Spz 1 protein of mouse. Expression profiles showed that TSP1 was specifically and strongly expressed in the testis. CONCLUSION: TSP1 is a gene highly expressed in adult testis. It may play an important role in spermatogenesis in the humans.

[Study on the relationship of balanced translocation t(1;12) with spermatogenesis].

OBJECTIVES: To investigate the relationship between chromosome balanced translocation t(1;12) (q24;q24) and spermatogenesis in infertile twin brothers. METHODS: For twin brothers, karotype were determined. The levels of testosterone, FSH and LH were detected. YRRM1, DAZ and DYS240 were analyzed. In younger brother a biopsy was taken from testis. RESULTS: Chromosome analysis for both twin brothers revealed a karotype of 46, XY, t(1;12) (q24;q24). Sperm count was less than 1.0 x 10(6)/ml. There was no deletion for YRRM1, DAZ and DYS240 gene on Y chromosome. Photomicrograph of seminiferous tubules showed the arrest of spermatogenesis. CONCLUSIONS: Chromosome balanced translocation t(1;12) (q24;q24) may be the cause of the spermatogenesis arrest in infertile twin brothers. Gene in the point of translocation may be related to spermatogenesis.

Expression of a novel HsMCAK mRNA splice variant, tsMCAK gene, in human testis.

Identification of specifically expressed genes in the adult or fetal testis is very important for the study of genes related to the development and function of the testis. In this study, a human adult testis cDNA microarray was constructed and hybridized with 33P-labeled human adult and embryo testis cDNA probes, respectively. After differential display analyzing, a number of new genes related to the development of testis and spermatogenesis had been identified. One of these new genes is tsMCAK. tsMCAK was expressed 2.62 folds more in human adult testis than fetal testis. The full length of tsMCAK is 2401 bp and contains a 2013 bp open reading frame, encoding a 671-amino-acid protein. Sequence analysis showed that it has a central kinesin motor domain and is homologous to HsMCAK gene of the somatic cells. Blasting human genome database localized tsMCAK to human chromosome 1P34 and further investigation showed that it is a splice variant of HsMCAK. The tissue distribution of tsMCAK was determined by RT-PCR and it is expressed highly and specifically in the testis. Southern blot studies of its expression in patients with infertility indicated its specific expression in spermatogenic cells and its correlation with male infertility. The above results suggested that tsMCAK is a candidate gene for the testis-specific KRPs and its specific expression in the testis was correlated with spermatogenesis and may be correlated with male infertility.