Ultrastructural Localization of Intracellular Calcium During Spermatogenesis of Sterlet (Acipenser ruthenus)

2016 ◽  
Vol 22 (6) ◽  
pp. 1155-1161 ◽  
Author(s):  
Amin Golpour ◽  
Martin Pšenička ◽  
Hamid Niksirat
Keyword(s):  
Intracellular Calcium ◽  
Developmental Stages ◽  
Physiological Function ◽  
Male Gamete ◽  
Ultrastructural Localization ◽  
Acrosomal Vesicle ◽  
Acipenser Ruthenus ◽  
Calcium Deposits ◽  
Late Stages ◽  
Sterlet Acipenser Ruthenus

AbstractCalcium regulates many intracellular events such as growth and differentiation during different stages of gamete development. The aim of this study was to localize and quantify the intracellular distribution of calcium during different developmental stages of spermatogenesis in sterlet, Acipenser ruthenus, using a combined oxalate–pyroantimonate technique. The distribution of calcium was described in spermatogonium, spermatocyte, spermatid, and spermatozoon stages. In the spermatogonium and spermatocyte, calcium deposits were mainly localized in the nucleus and cytoplasm. The spermatid had calcium in the nucleus, developing acrosomal vesicle, and cytoplasm. Intracellular calcium transformed from scattered deposits in spermatogonia and spermatocyte stages into an unbound form in spermatid and the spermatozoon. The proportion of area covered by calcium increased significantly (p<0.05) from early to late stages of spermatogenesis. The largest proportion of area covered by calcium was observed in the nucleus of the spermatozoon. In conclusion, although most of the intracellular calcium is deposited in limited areas of the spermatogonium and spermatocyte, it is present an unbound form in the larger area of spermatids and spermatozoa which probably reflects changes in its physiological function and homeostasis during the process of male gamete production in spermatogenesis.

Adolescent Development and Capacity Building

2018 ◽  
Author(s):  
Esther F. Akinsola ◽  
Anne C. Petersen
Keyword(s):  
Capacity Building ◽  
Adolescent Development ◽  
Developmental Stages ◽  
Decision Makers ◽  
Developmental Tasks ◽  
Cultural Contexts ◽  
Global Policy ◽  
Development Capacity ◽  
The Social ◽  
Late Stages

This chapter describes adolescent development within the context of capacity building, reviews the global adolescent capacity-building initiatives, and provides a link between developmental tasks of adolescence and capacity building. It highlights the importance of incorporating assessment of adolescents’ capacity-building needs at individual, community, and organizational levels into global policy and programs and suggests effective approaches to building adolescent development capacity that include adopting the “stage–environment–fit,” in which stage represents the developmental stages (early, middle, late stages) of adolescents and emphasizes developmental tasks of adolescence, while environment represents the social and cultural contexts in which the adolescents live. That adolescents need to be engaged as planners, decision-makers, and participants in programs that build their capacity and translation of global policies into policies of governments is emphasized.

scholarly journals Ancient Sturgeons Possess Effective DNA Repair Mechanisms: Influence of Model Genotoxicants on Embryo Development of Sterlet, Acipenser ruthenus

2020 ◽  
Vol 22 (1) ◽  
pp. 6
Author(s):  
Ievgeniia Gazo ◽  
Roman Franěk ◽  
Radek Šindelka ◽  
Ievgen Lebeda ◽  
Sahana Shivaramu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Dna Repair ◽  
Embryo Development ◽  
Hatching Rate ◽  
Embryo Survival ◽  
Dna Repair Mechanisms ◽  
Acipenser Ruthenus ◽  
Repair Mechanisms ◽  
Sterlet Acipenser Ruthenus

DNA damage caused by exogenous or endogenous factors is a common challenge for developing fish embryos. DNA damage repair (DDR) pathways help organisms minimize adverse effects of DNA alterations. In terms of DNA repair mechanisms, sturgeons represent a particularly interesting model due to their exceptional genome plasticity. Sterlet (Acipenser ruthenus) is a relatively small species of sturgeon. The goal of this study was to assess the sensitivity of sterlet embryos to model genotoxicants (camptothecin, etoposide, and benzo[a]pyrene), and to assess DDR responses. We assessed the effects of genotoxicants on embryo survival, hatching rate, DNA fragmentation, gene expression, and phosphorylation of H2AX and ATM kinase. Exposure of sterlet embryos to 1 µM benzo[a]pyrene induced low levels of DNA damage accompanied by ATM phosphorylation and xpc gene expression. Conversely, 20 µM etoposide exposure induced DNA damage without activation of known DDR pathways. Effects of 10 nM camptothecin on embryo development were stage-specific, with early stages, before gastrulation, being most sensitive. Overall, this study provides foundational information for future investigation of sterlet DDR pathways.

Role of Ca2+ in the IVM of spermatozoa from the sterlet Acipenser ruthenus

2017 ◽  
Vol 29 (7) ◽  
pp. 1319 ◽  
Author(s):  
Olga Bondarenko ◽  
Borys Dzyuba ◽  
Marek Rodina ◽  
Jacky Cosson
Keyword(s):  
Sperm Motility ◽  
Seminal Fluid ◽  
Mature Male ◽  
Sperm Maturation ◽  
Wolffian Duct ◽  
Testicular Spermatozoa ◽  
Acipenser Ruthenus ◽  
Sterlet Acipenser Ruthenus ◽  
Motility Parameters

The role of Ca2+ in sturgeon sperm maturation and motility was investigated. Sperm from mature male sterlets (Acipenser ruthenus) were collected from the Wolffian duct and testis 24 h after hormone induction. Testicular spermatozoa (TS) were incubated in Wolffian duct seminal fluid (WDSF) for 5 min at 20°C and were designated ‘TS after IVM’ (TSM). Sperm motility was activated in media with different ion compositions, with motility parameters analysed from standard video microscopy records. To investigate the role of calcium transport in the IVM process, IVM was performed (5 min at 20°C) in the presence of 2 mM EGTA, 100 µM Verapamil or 100 µM Tetracaine. No motility was observed in the case of TS (10 mM Tris, 25 mM NaCl, 50 mM Sucr with or without the addition of 2 mM EGTA). Both incubation of TS in WDSF and supplementation of the activation medium with Ca2+ led to sperm motility. The minimal Ca2+ concentration required for motility activation of Wolffian duct spermatozoa, TS and TSM was determined (1–2 nM for Wolffian duct spermatozoa and TSM; approximately 0.6 mM for TS). Motility was obtained after the addition of verapamil to the incubation medium during IVM, whereas the addition of EGTA completely suppressed motility, implying Ca2+ involvement in sturgeon sperm maturation. Further studies into the roles of Ca2+ transport in sturgeon sperm maturation and motility are required.

The role of the IGF-I system for vitellogenesis in maturing female sterlet, Acipenser ruthenus Linnaeus, 1758

2007 ◽  
Vol 150 (1) ◽  
pp. 140-150 ◽  
Author(s):  
S. Wuertz ◽  
A. Nitsche ◽  
M. Jastroch ◽  
J. Gessner ◽  
M. Klingenspor ◽  
...  
Keyword(s):  
Acipenser Ruthenus ◽  
Igf I ◽  
Sterlet Acipenser Ruthenus

Effects of antifreeze proteins on cryopreserved sterlet, Acipenser ruthenus sperm quality

Cryobiology ◽  
2018 ◽  
Vol 85 ◽  
pp. 184
Author(s):  
Miaomiao Xin ◽  
Jan Sterba ◽  
Anna Shaliutina-Kolesova ◽  
Borys Dzyuba ◽  
Serhii Boryshpolets ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Antifreeze Proteins ◽  
Acipenser Ruthenus ◽  
Sterlet Acipenser Ruthenus

scholarly journals Location of fishing points of sterlet (Acipenser ruthenus L. 1758) for forensic-ichthyological examination

2019 ◽  
Vol 2019 (4) ◽  
pp. 70-78
Author(s):  
Gleb Igorevich Volosnikov
Keyword(s):  
Statistical Processing ◽  
Time Interval ◽  
Research Station ◽  
Meristic Characters ◽  
Representative Sampling ◽  
Acipenser Ruthenus ◽  
Sturgeon Species ◽  
Kolmogorov Smirnov ◽  
Academy Of Sciences ◽  
Sterlet Acipenser Ruthenus

The paper describes the details of the investigative actions taken in terms of the struggle against poaching, where the researchers of the Tobolsk Complex Research Station of the Ural Branch of the Russian Academy of Sciences carry out the forensic ichthyologic examination of illegally caught water bioresources. The researchers often encounter the need to investigate or confirm the alleged place of catching fish species submitted for examination. There have been considered the possibilities to determine the habitat of the caught sturgeon species, in particular sterlet (Acipenser ruthenus L. 1758) using direct comparative analysis and statistical processing of meristic characters of the alleged populations, because there is evidence of existing broodstocks of this species, linked to the specific water areas. The analysis was carried out using 357 specimens of sterlet caught in 4 different areas of the Lower Irtysh. Absence of significant differences in the means of meristic characters in the species of the studied groups can be explained by insufficiently representative sampling, which is frequent in forensic ichthyologic examinations. Nevertheless, according to a number of characteristics, one can speak of a certain heterogeneity of the samples, which indicates the presence of features in the distribution of individuals in the population. Additional statistical data processing by means of Kolmogorov–Smirnov non-parametric two-sample criterion demonstrates a reliable interpopulation difference in meristic characters including the case of scanty sampling. Expanding the study in terms of increasing the number of samples and pairs for comparison, as well as feasibility of analyzing the meristic characters in a longer time interval is being considered.

CYTOLOGICAL STUDIES OF THE DEVELOPMENT OF METAPHASE I IN HYBRIDS BETWEEN TRITICUM TIMOPHEEVI ZHUK. AND T. DURUM DESF.

1961 ◽  
Vol 39 (1) ◽  
pp. 81-108 ◽  
Author(s):  
E. B. Wagenaar
Keyword(s):  
Late Stage ◽  
Developmental Stages ◽  
Progressive Increase ◽  
Cell Populations ◽  
Equatorial Plate ◽  
Triticum Timopheevi ◽  
Late Stages ◽  
I Cells ◽  
Metaphase I

In two hybrids between Triticum timopheevi Zhuk. and T. durum Desf., which have irregular meioses, metaphase I was subdivided into four developmental stages, early, medium, late, and very late. This subdivision was based on the presence in the anthers of other stages that occurred together with metaphase I. It was then discovered that in metaphase I cell populations there was a progressive increase of univalents from the early and medium stages to the very late stage. This phenomenon can be explained on the assumption that metaphase I is of shorter duration in the less irregular cells which pass into anaphase I earlier than the more irregular cells. As a consequence of this developmental phenomenon at metaphase I, the anaphase I and telophase I cells in the late anthers contained fewer lagging chromosomes than the anaphase I and telophase I cells in the very late anthers. Despite these numerical differences, the degrees of lagging were remarkably similar in both stages; approximately 70% of these univalents lagged at late and very late stages in both hybrids.During metaphase I many univalents of the irregular cells moved towards the equatorial plate, became oriented, and lagged at anaphase I and telophase I. It was found that the univalents of the least irregular cells accumulated somewhat faster at the plates than those of the more irregular cells.Considering the relationships between all of the available data, the hypothesis is advanced that when a certain number of univalents have accumulated at the equatorial plate a state of equilibrium is established and anaphase I is initiated. On the basis of this hypothesis an explanation of the trends observed at metaphase I is given.

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