Application of surrogate broodstock technology in aquaculture

Fisheries Science - Surrogate broodstock technology facilitates the production of donor-derived gametes in surrogates, and comprises transplanting germ cells of a donor into recipients of a...     

Development of a simple method for sperm cryopreservation of Scombridae fishes in outdoor environments

We developed a simple dry shipper method for cryopreserving the sperm of Scombridae fish in outdoor environments. First, we undertook a preliminary study to optimize the sperm cryopreservation conditions using bullet tuna, Auxis rochei (Risso, 1810) sperm. We found that the optimum cryomedium contained 90% foetal bovine serum (FBS) or 300 mM trehalose as an external cryoprotectant and 10% dimethyl sulfoxide (DMSO) as an internal cryoprotectant. Under these optimized conditions, the post‐thaw sperm had a duration of motility of 500 s and a motility rate of >70%. We then performed practical trials of the optimized protocol in various outdoor environments (e.g., fishing boats and ports) using the sperm of five Scombridae species: chub mackerel, Scomber japonicus (Houttuyn, 1782); blue mackerel, S. australasicus (Cuvier, 1832); skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758); longtail tuna Thunnus tonggol, (Bleeker, 1851) and Pacific bluefin tuna, T. orientalis (Temminck & Schlegel, 1844). The post‐thaw sperm of all five of these species had a duration of motility of 650 s and a motility rate of >70%, indicating that this simple method can be used to obtain high‐quality cryopreserved sperm of various Scombridae species in outdoor environments.     

日本以农协为主推进智慧农业发展经验及对中国的启示

日本农业面临严峻的农业人口老龄化与农业人口减少的问题,且以小型田块和山地耕地居多,农业劳作不便。为了解决上述问题,保障粮食供应,振兴地方经济,日本正大力发展智慧农业。日本农协协助制定了新的农业基本法以及农林水产信息化战略以支持农业的发展,并在农业机械自动化、农用信息系统、农村网络改造、农用航空、植物工厂等方面开展了大量的科技创新与应用,推动了日本现代农业的发展,日本以140.4万人且主体为老龄人口的核心农户实现了近1.3亿人口的主要粮食自给自足。日本农协多层级、多部门、全方位覆盖农业流程的服务,为智慧农业的落地助力。纵观日本智慧农业的发展历程与成效,借鉴其成功经验,对中国农业发展提出如下建议：应当创新农业体制机制,打通信息、人力、资源的流通渠道;优化农村营商环境,发挥好地方、高校、企业等不同主体的优势,立足乡村振兴角度对智慧农业技术进行长期的实证化研究;借鉴日本农协在农业生产、销售、推广、管理上的经验,因地制宜,积极探索,夯实根基,有助于推进中国乡村全面振兴,加快农业农村现代化和建设智慧农业强国。     

Expression of mRNAs for interleukin-4, interleukin-6 and their receptors in porcine corpus luteum during the estrous cycle

There is increasing evidence that inflammatory cytokines regulate corpus luteum (CL) function in many species. The purpose of the present study was to determine whether interleukin (IL)-4 and IL-6 are expressed in the porcine CL, and whether these cytokines influence porcine luteal steroidogenesis. The gene expressions of IL-4, IL-6 and their specific receptors were determined in the CL of Chinese Meishan pigs during the estrous cycle. Moreover, the effects of these cytokines on progesterone (P(4)), estradiol-17beta (E(2)) and prostaglandin (PG) F2alpha secretion by cultured luteal cells were investigated. IL-4 and IL-6 mRNAs were detected in the CL at all luteal stages. Furthermore, mRNAs of the receptors for IL-4 and IL-6 were clearly expressed in the CL throughout the estrous cycle. Real-time PCR analysis revealed that IL-6 receptor (IL-6R) mRNA expression was higher in the regressed CL (days 19-21 after ovulation) than in the CL at other stages (P<0.01). Exposure of cultured luteal cells obtained from mid-stage CL (days 8-11) to IL-6 (1-100 ng/ml), it inhibited P(4) and E(2) secretion by the cells (P<0.05). Although IL-4 (1-100 ng/ml) did not significantly alter P(4) secretion, it inhibited E(2) secretion by the cells (P<0.05). Neither IL-4 nor IL-6 had any effect on PGF2alpha secretion by the cells. These results suggest that IL-4 and IL-6 are locally produced in the porcine CL, and that they inhibit steroid production from luteal cells via their specific receptors. Collectively, both IL-4 and IL-6 may play roles in regulating porcine CL function throughout the estrous cycle.     

Cutaneous hybrid cyst in a sprague-dawley rat

This report describes a spontaneous hybrid cyst in a Sprague-Dawley (SD) rat. A 52-week-old, male SD rat had a cutaneous cyst on the left mystacial pad. Histologically, the cyst wall showed infundibular differentiation with keratohyalin granules in the granular layer and matrical differentiation comprising basaloid epithelial cells with trichohyalin granules. The cyst cavity was filled with lamellar, flaky keratin and aggregates of shadow cells. Immunohistochemically, the infundibular-type epithelium was positive for cytokeratin (CK) AE1/AE3, CK KL1 and CK14 but negative for CK15, whereas the matrical-type epithelium was negative for all four CK isoforms examined. These immunohistochemical properties of the infundibular- and matrical-type epithelia were similar to those of the infundibulum and inferior segment of normal hair follicles, respectively. Based on these findings, the cyst was diagnosed as a hybrid cyst, comprising more than one type of cyst arising from various parts of the pilosebaceous unit.     

Ontogenic and morphological study of gonadal formation in genetically-modified sex reversal XYPOS mice

Mammalian sexual fate is determined by the presence or absence of sex determining region of the Y chromosome (Sry) in the “bipotential” gonads. Recent studies have demonstrated that both male and female sexual development are induced by distinct and active genetic pathways. Breeding the Y chromosome from Mus m. domesticus poschiavinus (POS) strains into C57BL/6J (B6J) mice (B6J-XY^POS) has been shown to induce sex reversal (75%: bilateral ovary, 25%: true hermaphrodites). However, our B6N-XY^POS mice, which were generated by backcrossing of B6J-XY^POS on an inbred B6N-XX, develop as males (36%: bilateral testis with fertility as well as bilateral ovary (34%), and the remainder develop as true hermaphrodites. Here, we investigated in detail the expressions of essential sex-related genes and histological features in B6N-XY^POS mice from the fetal period to adulthood. The onsets of both Sry and SRY-box 9 (Sox9) expressions as determined spatiotemporally by whole-mount immunohistochemistry in the B6N-XY^POS gonads occurred 2–3 tail somites later than those in B6N-XY^B6 gonads, but earlier than those in B6J-XY^POS, respectively. It is possible that such a small difference in timing of the Sry expression underlies testicular development in our B6N-XY^POS. Our study is the first to histologically show the expression and ectopic localization of a female-related gene in the XY^POS testes and a male-related gene in the XY^POS ovaries. The results from these and previous experiments indicate that the interplay between genome variants, epigenetics and developmental gene regulation is crucial for testis development.     

Pathological features of proteinuric nephropathy resembling Alport syndrome in a young Pyrenean Mountain dog

The renal biopsy tissue from a 9-month-old, male Pyrenean Mountain dog with renal disorder and severe proteinuria was examined. Ultrastructural examination revealed multilaminar splitting and fragmentation of the glomerular basement membrane (GBM) and diffuse podocyte foot process effacement. Immunofluorescent staining for α(IV) chains revealed presence of α5(IV) and complete absence of α3(IV) and α4(IV) chains in the GBM. Immunohistochemistry also revealed decreased and altered expression of nephrin and podocin in the glomeruli compared with normal canine glomeruli. These results suggested that the glomerular disease of the present case might be consistent with canine hereditary nephropathy resembling human Alport syndrome caused by genetic defect of type IV collagen, and indicated possible contribution of podocyte injury to severe proteinuria in this case.     

Microbial decomposition of 2-oxo-4-methyl-6-ureidohexahydropyrimidine in soil

The microbial decomposition of 2-oxo-4-methyl-6-ureidohexahydropyrimidine (CDU), a slow-release nitrogenous fertilizer, in soil, and its N release were investigated by the soil perfusion method with a soil which had received yearly applications of CDU for 5 yr. The decomposition of CDU proceeded in two steps with an initial lag and intermediate stagnation period, and total decomposition was complete in 24 days in the first perfusion culture. In subsequent perfusions. CDU was decomposed without lags within less than 3 days. Urea and NH₄⁺ were released during CDU decomposition.Two species of CDU-decomposing bacteria were isolated from perfused soil. Both grew well in a medium containing CDU as a sole source of carbon and nitrogen, and released urea and NH⁺₄, but each species could decompose only 50% of the CDU supplied. One could decompose the (−)CDU isomer and the other the (+)CDU isomer. They were identified as members of the genera Arthrobacter and Corynebacterium, respectively.The relationship of the CDU-decomposition pattern to the growth of these two species of bacteria in the soil perfusion cultures was demonstrated. It is suggested that the growth of the two species may contribute to the slow-release behaviour of CDU in soils which have a history of CDU application.     

A dinuclear Ni(mu-H)Ru complex derived from H2

Models of the active site in [NiFe]hydrogenase enzymes have proven challenging to prepare. We isolated a paramagnetic dinuclear nickel-ruthenium complex with a bridging hydrido ligand from the heterolytic cleavage of H2 by a dinuclear NiRu aqua complex in water under ambient conditions (20 degrees C and 1 atmosphere pressure). The structure of the hexacoordinate Ni(mu-H)Ru complex was unequivocally determined by neutron diffraction analysis, and it comes closest to an effective analog for the core structure of the proposed active form of the enzyme.     

土地利用对土壤性质影响的区域差异研究

 【目的】研究探讨土地利用对土壤性质影响的区域差异性。【方法】选择4类土地利用方式（天然林、人工林、灌丛和耕地），分别在山西寿阳县和四川丹棱县野外采集土壤样方进行测定，利用统计分析法研究土地利用对土壤性质影响的区域差异。【结果】不同土地利用方式对土壤性质的影响差异显著。人类活动干扰小的土地利用方式的土壤有机质、全氮含量和含盐量等普遍高于人类影响较强的土地利用方式。相同的土地利用方式对土壤性质的影响具有空间差异。即便在相同的土地利用方式下，不同的耕作制度和田间管理措施（灌溉、施肥、农药等）也会造成土壤特性的区域异质性。【结论】不同土地利用方式对土壤性质影响的区域差异揭示了人类活动对环境变化影响的区域差异，可以在一定程度上解释“人-地”的复杂性关系，研究结果可为国家在区域土地规划、作物栽培布局和水土保持政策制订等提供科学依据。