ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Testicular development and serum sex steroid profiles during the annual sexual cycle of the male sturgeon hybrid the bester (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 48 (1996), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Testicular development in the adult male F1 sturgeon hybrid, the bester (Huso huso L. female x Acipenser ruthenus L. male), was examined monthly in relation to serum sex steroid levels. Spermatogenesis lasted for 1 year, with meiosis generally starting in September and spermiogenesis in November, although there was considerable variation in testicular developmental stages between fish sampled monthly. Testicular development continued, slowly, during the winter months until April. Fish did not exhibit spontaneous spermiation, and phagocytotic activity of Sertoli cells became prominent from May onwards. Androgen levels increased during Spermatogenesis and remained high throughout the pre-spermiation period. In the degeneration stage, 11-ketotestosterone concentrations declined to low levels, while testoster- one levels remained high. The serum concentration of 17,20β-dihydroxy-4-pregnen-3-one was low throughout the reproductive cycle. Based on these results, it is suggested that the time appropriate for induction of final maturation would be from November–December to April when the testes are in the late stage of development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1996.tb01802.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Ovarian development and serum sex steroid and vitellogenin profiles in the female cultured sturgeon hybrid, the bester (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 48 (1996), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Changes in serum levels of estradiol-17/J (E2), testosterone (T), 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) and vitellogenin (VTG), in cultured adult female bester were examined in relation to ovarian development during a 1-year sampling period. Considerable variations in oocyte development were found among fish. Oocytes at previtellogenic stage (≥0–6mm in diameter) generally started to develop concomitantly with the degeneration of the first batch of oocytes. In vitellogenic individuals, ovaries were comprised of more advanced oocytes with diameter ranging from 0–6 to 2–6 mm and in the post-vitellogenic class, oocytes attained their largest size (〉2–6mm) while the germinal vesicle was migrating towards the animal pole. Oocytes with a migrating nucleus were maintained during the winter period and massive degeneration started in April–May without germinal vesicle breakdown (GVBD) or ovulation occurring. Seasonal changes in E2, T and VTG levels were well correlated with the advancement of oogenesis. Their levels increased during vitellogenesis, whereas in the post-vitellogenic (migratory nucleus) stage the levels of E2 declined from 2–4 ng ml −1± to 1–2 ng ml −1 and VTG from 4–10 mg ml −1 to 0.–0.5 mg ml −1 while T levels remained high (50–60 ng ml −1). In contrast, serum levels of 17,20†-P were constantly low (less than 0.2 ng ml−L) throughout the reproductive cycle. These results indicate that the time appropriate for induction of artificial reproduction would be from October–November to April–May when the oocytes are in the late Stages of the development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1996.tb01812.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    In vitro steroidogenesis by testicular fragments and ovarian follicles in a hybrid sturgeon, Bester (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 1-14 
    Details
    ISSN: 1573-5168
    Keywords: Bester ; hybrid sturgeon ; testis ; ovary ; steroidogenesis ; 11-ketotestosterone ; 17β-estradial ; 17α ; 20β-dihydroxy-4-pregnen-3-one
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this study, developmental changes in the steroidogenic capacity of testicular fragments and isolated ovarian follicles of a hybrid sturgeon, Bester, at a variety stage of developments were examined. Testicular fragments or isolated ovarian follicles were incubated in L-15 medium in the presence or absence of different concentrations of five preparations; forskolin, human chorionic gonadotropin (HCG), pregnenolone (P5), 17α-hydroxyprogesterone (17αOHP) and testosterone (T) for 18 h at 15 °C. After incubation, concentrations of 11-ketotestosterone (11 KT) (testis) and, 17β-estradiol (E2) (ovarian follicles) and 17α,20β-dihydroxy-4-pregnen-3-one (DHP) (testis and ovarian follicles) were measured. 11KT was detected in the media following incubation with P5, 17αOHP and T. Its concentration was higher during late spermatogenesis and prespermiation and lower at the degeneration stage. Both P5 and 17αOHP were converted to DHP during the prespermiation stage. Forskolin had little stimulatory effect on the synthesis of 11KT and DHP and HCG did not induce the production of these steroids. E2 was detected in the medium following incubation of follicles with P5, 17αOHP and T at all stages of oocyte development. The concentration of E2 in the medium increased during vitellogenesis with the peak production occurring at the tertiary yolk stage. In contrast, the potencies of follicles to produce steroids shifted to the production of DHP during migratory nucleus stage. Forskolin and HCG had little effect on the synthesis of E2 and DHP. These results demonstrated that the failure of spontaneous spermiation or ovulation is not due to the insufficient synthesis of DHP, but may due to the lack of availability of precursors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007706128184
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    facet.materialart.
    Unknown
    In Vivo oocyte maturation and ovulation in females and spermiation in males of hybrid sturgeon, bester (2018)
    Details
    Publication Date: 2021-05-19
    Description: Bester, a hybrid sturgeon (Huso huso L. females ´ Acipenser ruthenus L. males), neither spermiate nor ovulate in the captivity. Thirteen-year-old adult male and female bester were injected with LH-RHa (0.1-0.3 mg/kg B.W.) intramuscularly and spawning status of the treated fish was checked 24-48 hours later. Additionally, changes in serum levels of DHP in both the responded and the non-responded individuals were monitored 0, 1, 3, 6, 9, 12, 24, 48 and 72 hours after treatment. Between 70-100 percent of the LR-RHa injected males individuals, and 11-40 percent of the females spawned 24-48 hours after the treatment; the rest did not respond to the injection. In the responded males, 3-9 hours after the treatment, serum levels of DHP increased; while in the females it occurred first after 12-24 hours. In contrast, during the same period, serum levels of DHP remained low in all non-responded individuals. The present study indicated that using 0.1-1.3 mg/kg B. W. of LH-RHa can induce oocyte maturation and ovulation in the females and spermiation in the males cultured bester. The results suggested additionally DHP as an appropriated steroid that could be used in the final maturation stage of the gonads.
    Description: Published
    Keywords: Huso huso L. ; Acipenser ruthenus L. ; Bester ; Oocyte maturation ; Ovulation ; Spermiation ; DHP ; LH-RHa ; Female ; Male
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.59-66
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    In Vivo oocyte maturation and ovulation in females and spermiation in males of hybrid sturgeon, bester (2021)
    In:  http://aquaticcommons.org/id/eprint/22216 | 18721 | 2018-02-24 14:38:33 | 22216 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-06-30
    Description: Bester, a hybrid sturgeon (Huso huso L. females ´ Acipenser ruthenus L. males), neither spermiate nor ovulate in the captivity. Thirteen-year-old adult male and female bester were injected with LH-RHa (0.1-0.3 mg/kg B.W.) intramuscularly and spawning status of the treated fish was checked 24-48 hours later. Additionally, changes in serum levels of DHP in both the responded and the non-responded individuals were monitored 0, 1, 3, 6, 9, 12, 24, 48 and 72 hours after treatment. Between 70-100 percent of the LR-RHa injected males individuals, and 11-40 percent of the females spawned 24-48 hours after the treatment; the rest did not respond to the injection. In the responded males, 3-9 hours after the treatment, serum levels of DHP increased; while in the females it occurred first after 12-24 hours. In contrast, during the same period, serum levels of DHP remained low in all non-responded individuals. The present study indicated that using 0.1-1.3 mg/kg B. W. of LH-RHa can induce oocyte maturation and ovulation in the females and spermiation in the males cultured bester. The results suggested additionally DHP as an appropriated steroid that could be used in the final maturation stage of the gonads.
    Keywords: Aquaculture ; Biology ; Bester ; Oocyte maturation ; Ovulation ; Spermiation ; DHP ; LH-RHa
    Repository Name: AquaDocs
    Type: article , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 59-66
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...