Atkinsiella parasitica sp. nov. isolated from a rotifer,Brachionus plicatilis

A new species ofAtkinsiella (Lagenidiales, Oomycetes),Atkinsiella parasitica is described and illustrated. It was isolated from the eggs and bodies of a rotifer,Brachionus plicatilis, with fungal infection in 1992. The rotifer was reared in a hatchery as the first food supply for seed production of crustaceans and fishes. The fungus is characterized by producing monoplanetic, lateral biflagellate zoospores, and infrequently branched discharge tubes. Optimum temperature for the fungus was 25°C. The fungus was considered an obligate marine fungus, because its growth was observed only on PYGS medium including seawater.     

The shift from C-19 to C-21 steroid synthesis in spawning male common carp, Cyprinus carpio, is regulated by the inhibition of androgen production by progestogens produced by spermatozoa

There is a rapid shift in the steroidogenic pathway from androgen to progestogen production in spawning male common carp, Cyprinus carpio. Experiments were conducted to determine the mechanism regulating this shift using in vitro cultures of testicular fragments and isolated sperm of spermiating male carp. The levels of 11-ketotestosterone (11-KT) continually increased for 48 h with or without gonadotropin (GtH) stimulation, suggesting that 11-KT is the principal androgen produced by carp testes. Ovine prolactin (oPRL) enhanced GtH-stimulated 11-KT production, but by itself had no effect. Gonadotropin, carp pituitary extract, and pregnenolone all enhanced the production of 11-KT, testosterone (T), and 17 alpha-hydroxyprogesterone (17-P) in a dose-dependent manner. No 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17,20 beta-P) was detected in response to any of these agents; 17 alpha,20 alpha-dihydroxy-4-pregnen-3-one (17,20 alpha-P) was not measured. Both 17,20 beta-P and 17,20 alpha-P inhibited 11-KT production in a dose-dependent manner in the presence of either GtH, 17-P, or T. Isolated sperm and testicular fragment preparations both produced 17,20 beta-P and approximately tenfold more 17,20 alpha-P when incubated with 17-P. Only testicular fragments, however, produced 11-KT. We conclude that androgen synthesis occurs only within somatic cells of common carp testes. GtH, and perhaps PRL, stimulates the production of steroid precursors that, under normal physiological conditions, are metabolized to androgens.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clasping structure in the double cone of the retina of the turtle (Gyoclemys reevesii)

Summary The double cone of the turtle retina was reconstructed three-dimensionally from electron micrographs of 400 serial sections. Cytoplasm of the accessory cone extends bilaterally to surround the principal cone incompletely. The cytoplasmic extensions are 0.1 m in width and 2 m in length at their longest portions. They arise at approximately the median portion of the ellipsoid (consisting of mitochondria) and terminate at the level of the outer limiting membrane. The possible function of these extensions as a clasping structure is discussed.     

The levels of main urinary metabolite of prostaglandin F1α and F2α in human subjects measured by radioimmunoassay

Radioimmunoassay technique for measuring 5α,7α-dihydroxy-11-keto-tetranorprosta-1,16-dioic acid, the main urinary metabolite of PGF₁α and PGF₂α (PGF₂α-MUM), was further improved.It was postulated based on some experimental data that the PGF₂α-MUM exists in the urine mostly as dioic acid form, not as δ-lactone formThe daily excretion of PGF₂α-MUM in men ranged from 14.43 μg to 36.14 μg and in women from 5.21 μg to 14.25 μg.     

Metabolism of PG in man: Effect of furosemide on the excretion of the main metabolite of PG F2α

The excretion rates of main urinary metabolite of PG F₂α were measured radioimmunologically in 4 healthy persons and in 13 essential hypertensives. The resting values were 9.3±0.73 in the former and 10.4±2.17 ng/min in the latter. There was no significant differences between them. The excretion of the metabolite decresed prominently after the administration of furosemide. The percent decrease was 57% in healthy persons and 70% in essential hypertension. The percent result supports that furosemide inhibit the catabolism of PG F₂α.     

Lagenidium myophilum infection in the coonstripe shrimp,Pandalus hypsinotus

A fungal infection occurred in juvenile coonstripe shrimps,Pandalus hypsinotus, cultured at Hokkaido Institute of Mariculture, Hokkaido, Japan. The fungus was identified asLagenidium myophilum, the same fungus that had previously been isolated from the abdominal muscle of adult northern shrimps,Pandalus borealis, and larvae of the coonstripe shrimp. Histopathologically, numerous nonseptate hyphae were observed in the lesions, and melanized hemocytes were present within the blackened areas. The optimum temperature for growth of the present strain was 25–30°C, and the optimum NaCl concentration for growth was 0.5–1.0%. Its biological characteristics were compared with those ofLagenidium myophilum isolated from diseased larval coonstripe shrimp and adult northern shrimp. The fungus was pathogenic toward shrimps of the genusPandalus, which live in deep sea areas. The fungus could infect shrimps at various stages, from larva to adult.     

SETD2 epidermal deficiency promotes cutaneous wound healing via activation of AKT/mTOR Signalling

ObjectivesCutaneous wound healing is one of the major medical problems worldwide. Epigenetic modifiers have been identified as important players in skin development, homeostasis and wound repair. SET domain–containing 2 (SETD2) is the only known histone H3K36 tri‐methylase; however, its role in skin wound healing remains unclear.Materials and MethodsTo elucidate the biological role of SETD2 in wound healing, conditional gene targeting was used to generate epidermis‐specific Setd2‐deficient mice. Wound‐healing experiments were performed on the backs of mice, and injured skin tissues were collected and analysed by haematoxylin and eosin (H&E) and immunohistochemical staining. In vitro, CCK8 and scratch wound‐healing assays were performed on Setd2‐knockdown and Setd2‐overexpression human immortalized keratinocyte cell line (HaCaT). In addition, RNA‐seq and H3K36me3 ChIP‐seq analyses were performed to identify the dysregulated genes modulated by SETD2. Finally, the results were validated in functional rescue experiments using AKT and mTOR inhibitors (MK2206 and rapamycin).ResultsEpidermis‐specific Setd2‐deficient mice were successfully established, and SETD2 deficiency resulted in accelerated re‐epithelialization during cutaneous wound healing by promoting keratinocyte proliferation and migration. Furthermore, the loss of SETD2 enhanced the scratch closure and proliferation of keratinocytes in vitro. Mechanistically, the deletion of Setd2 resulted in the activation of AKT/mTOR signalling pathway, while the pharmacological inhibition of AKT and mTOR with MK2206 and rapamycin, respectively, delayed wound closure.ConclusionsOur results showed that SETD2 loss promoted cutaneous wound healing via the activation of AKT/mTOR signalling.     

北京市湿地生态补偿标准研究

确定合理的湿地生态补偿标准是构建有效湿地生态补偿机制的关键。以北京市境内的湿地为研究对象,利用DPSIR模型明晰北京市湿地生态补偿的机理;基于问卷调查数据,分别利用二元Logistic模型和Tobit模型对影响受调查者受偿态度和受偿意愿的相关因素进行分析;运用条件价值法以及考虑时间价值和经济社会发展阶段的修正湿地生态系统服务价值确定最终的生态补偿标准,并对北京市制定湿地生态补偿机制提出了政策建议。研究结果表明：（1）北京市合理的湿地生态补偿标准为2.728×10⁴-4.84×10⁴元hm^-2a^-1;（2）地区差异、受调查者对湿地保护政策的了解程度以及湿地与社区之间的关系显著影响其受偿态度;（3）地区差异、年龄、受教育程度、家庭收入情况、对生态补偿的了解程度显著影响其受偿意愿;（4）为减少将来推进湿地生态补偿过程中可能遭遇的潜在阻碍,北京市应该加强湿地保护相关政策的宣传普及工作,注重对基层政策落实情况的监督,协调湿地政策与社区的关系;（5）有必要结合地区特征制定差异化的湿地生态补偿标准。研究结果可为今后北京市探索建立湿地生态补偿机制、提升湿地保护效率提供科学数据和理论参考。     

Characterization of a G protein α subunit encoded gene from the dimorphic fungus-Tremella fuciformis

Antonie van Leeuwenhoek - Tremella fuciformis is a dimorphic fungus which can undertake the reversible transition between yeast and pseudohypha forms. G protein α subunit (Gα) carries...