1. Comparative morphology refines the conventional model of spider reproductionYongjia Zhan, He Jiang, Qingqing Wu, Huitao Zhang, Zishang Bai, Matjaž Kuntner, Lihong Tu, 2019, original scientific article Abstract: Our understanding of spider reproductive biology is hampered by the vast anatomical diversity and difficulties associated with its study. Although authors agree on the two general types of female spider genitalia, haplogyne (plesiomorphic) and entelegyne (apomorphic), our understanding of variation within each group mostly concerns the external genital part, while the internal connections with the reproductive duct are largely unknown. Conventionally and simplistically, the spermathecae of haplogynes have simple two-way ducts, and those of entelegynes have separate copulatory and fertilization ducts for sperm to be transferred in and out of spermathecae, respectively. Sperm is discharged from the spermathecae directly into the uterus externus (a distal extension of the oviduct), which, commonly thought as homologous in both groups, is the purported location of internal fertilization in spiders. However, the structural evolution from haplo- to entelegyny remains unresolved, and thus the precise fertilization site in entelegynes is ambiguous. We aim to clarify this anatomical problem through a widely comparative morphological study of internal female genital system in entelegynes. Our survey of 147 epigyna (121 examined species in 97 genera, 34 families) surprisingly finds no direct connection between the fertilization ducts and the uterus externus, which, based on the homology with basal-most spider lineages, is a dead-end caecum in entelegynes. Instead, fertilization ducts usually connect with a secondary uterus externus, a novel feature taking over the functional role of the plesiomorphic uterus externus. We hypothesize that the transition from haplo- to entelegyny entailed not only the emergence of the two separate duct systems (copulatory, fertilization), but also involved substantial morphological changes in the distal part of the oviduct. Thus, the common oviduct may have shifted its distal connection from the uterus externus to the secondary uterus externus, perhaps facilitating discharge of larger eggs. Our findings suggest that the conventional model of entelegyne reproduction needs redefinition.
Keywords: spiders, comparative anatomy, genital anatomy
Published in DiRROS: 23.07.2024; Views: 211; Downloads: 100
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2. The function of mating plugs in the spider Neriene emphana: mating strategy or sperm protection?Shuang Tian, He Jiang, Yongjia Zhan, Qingqing Wu, Matjaž Kuntner, Lihong Tu, 2023, original scientific article Abstract: Introduction: It is generally thought that mating plugs, where present, impede or reduce the possibilities of female subsequent mating. Behavioral studies on numerous spiders, where mating plugs are common, have generally supported this function. However, mating plugs in spiders could plausibly serve other functions as well. Namely, the structure of entelegyne spermathecae—the morphology of most spiders—could require a mechanism that would prevent sperm from leakage, desiccation, and backflow. Although the form and function of mating plugs in several spider species imply their potential adaptation for sperm protection, this function has never been empirically tested. Methods: Here, we test whether mating plugs in the sheet-web spider Neriene emphana serve as a sperm protective device by investigating its genital morphology, its copulation process, and the precise formation of its amorphous mating plugs. Results: This species constructs secretion plugs through male-female cooperation. Additionally, we found sperm plugs to be formed as a side product of sperm transfer, as well as an intermediate type of secretion plugs. These plug materials are transferred in different mating stages as documented by variations in the rhythm of male palpal application during copulation. We showed that complete copulations always resulted in formation of secretion plugs at spermathecal entrances via laborious deposition of male materials. Discussion: While our findings do not reject that secretion plugs in N. emphana prevent females from subsequent mating, we suggest that they must have evolved to provide sperm protection.
Keywords: entelegyne spermatheca, mating behavior, mating strategy, sperm protection mechanism, mating plug, secretion plug, sperm plug
Published in DiRROS: 15.07.2024; Views: 115; Downloads: 70
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3. Cell-type proteomic and metabolomic resolution of early and late grain filling stages of wheat endospermShuang Zhang, Arindam Ghatak, Mitra Mohammadi Bazargani, Hannes Kramml, Fujuan Zang, Shuang Gao, Živa Ramšak, Kristina Gruden, Rajeev K. Varshney, Dong Jiang, Palak Chaturvedi, Wolfram Weckwerth, 2023, original scientific article Abstract: The nutritional value of wheat grains, particularly their protein and metabolite composition, is a result of the grain-filling process, especially in the endosperm. Here, we employ laser microdissection (LMD) combined with shotgun proteomics and metabolomics to generate a cell type-specific proteome and metabolome inventory of developing wheat endosperm at the early (15 DAA) and late (26 DAA) grain-filling stages. We identified 1803 proteins and 41 metabolites from four different cell types (aleurone (AL), sub-aleurone (SA), starchy endosperm (SE) and endosperm transfer cells (ETCs). Differentially expressed proteins were detected, 67 in the AL, 31 in the SA, 27 in the SE and 50 in the ETCs between these two-time points. Cell-type accumulation of specific SUT and GLUT transporters, sucrose converting and starch biosynthesis enzymes correlate well with the respective sugar metabolites, suggesting sugar upload and starch accumulation via nucellar projection and ETC at 15 DAA in contrast to the later stage at 26 DAA. Changes in various protein levels between AL, SA and ETC support this metabolic switch from 15 to 26 DAA. The distinct spatial and temporal abundances of proteins and metabolites revealed a contrasting activity of nitrogen assimilation pathways, e.g. for GOGAT, GDH and glutamic acid, in the different cell types from 15 to 26 DAA, which can be correlated with specific protein accumulation in the endosperm. The integration of cell-type specific proteome and metabolome data revealed a complex metabolic interplay of the different cell types and a functional switch during grain development and grain-filling processes.
Keywords: wheat, proteomics and metabolomics, aleurone, sub-aleurone, starchy endosperm, endosperm transfer cells
Published in DiRROS: 15.07.2024; Views: 110; Downloads: 108
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4. A spider mating plug functions to protect spermHe Jiang, Yongjia Zhan, Qingqing Wu, Huitao Zhang, Matjaž Kuntner, Lihong Tu, 2024, original scientific article Abstract: Mating plugs in animals are ubiquitous and are commonly interpreted to be products of mating strategies. In spiders, however, mating plugs may also take on functions beyond female remating prevention. Due to the vagaries of female genital (spermathecal) anatomy, most spiders face the problem of having to secure additional, non-anatomical, protection for transferred sperm. Here, we test the hypothesis that mating plugs, rather than (or in addition to) being adaptations for mating strategies, may serve as sperm protection mechanism. Based on a comparative study on 411 epigyna sampled from 36 families, 187 genera, 330 species of entelegyne spiders, our results confirm the necessity of a sperm protection mechanism. We divided the entelegyne spermathecae into four types: SEG, SED, SCG and SCD. We also studied detailed morphology of epigynal tracts in the spider Diphya wulingensis having the SEG type spermathecae, using 3D-reconstruction based on semi thin histological series section. In this species, we hypothesize that two distinct types of mating plug, the sperm plug and the secretion plug, serve different functions. Morphological details support this: sperm plugs are formed on a modified spermathecal wall by the spilled sperm, and function as a temporary protection mechanism to prevent sperm from leaking and desiccating, while secretion plugs function in postcopulation both as a permanent protection mechanism, and to prevent additional mating. Furthermore, with the modified spermathecal wall of S2 stalk, the problem of shunt of sperm input and output, and the possibility of female multiple mating have been resolved. Variation in spermathecal morphology also suggests that the problem of sperm protection might be resolved in different ways in spiders. Considering mating plugs of varying shapes and origins in the vast morphospace of spiders, we conclude that mating plugs might serve different purposes that relate both to mating strategies, as well as to sperm protection.
Keywords: spiders, mating strategies, mating plugs, sperm protection mechanism
Published in DiRROS: 19.06.2024; Views: 181; Downloads: 116
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5. Gasdermin D permeabilization of mitochondrial inner and outer membranes accelerates and enhances pyroptosisRui Miao, Cong Jiang, Winston Y. Chang, Haiwei Zhang, Jinsu An, Felicia Ho, Pengcheng Chen, Han Zhang, Caroline Furtado Junqueira, Iva Hafner Bratkovič, 2023, original scientific article Published in DiRROS: 19.12.2023; Views: 547; Downloads: 83
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6. Thermal-deformation model of a SR-modified A356 aluminum alloyYongyue Liu, Xianglai Xu, Jiangxiong Cheng, Hongwei Sun, Xueping Ren, Peng Jiang, 2022, original scientific article Keywords: A356 aluminum alloy, Sr modification, microstructure, thermal-deformation model
Published in DiRROS: 22.06.2022; Views: 745; Downloads: 219
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7. Study of a modified melamine sponge and its lipophilic and hydrophobic propertiesYuan Ma, Tao Li, Fei Jiang, Sheng Ma, Xiaomeng Wu, Weijie Wang, Zhenfa Zi, Wenliang Chen, Ping Na, 2022, original scientific article Keywords: super hydrophobicity, oil-water separation, melamine sponge, oily pollutants
Published in DiRROS: 22.06.2022; Views: 660; Downloads: 142
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8. Effect of temperature on MgO activity in the CaO-SiO[sub]2-MgO-Al[sub]2O[sub]3 system measured by molten tinYongchun Guo, Fengman Shen, Haiyan Zheng, Shuo Wang, Xin Jiang, Qiangjian Gao, 2022, original scientific article Keywords: blast furnace, slag system, activity of MgO, reference-slag, method, enthalpy, solution
Published in DiRROS: 22.06.2022; Views: 607; Downloads: 189
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