Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Effects of Estradiol on in Vitro Maturation of Buffalo and Goat Oocytes

Hurum Maksura
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Narsisa Akon
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Md Nuronnabi Islam
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Ireen Akter
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Avijit Kumar Modak
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Asma Khatun
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Md Hasanur Alam
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Md Abul Hashem
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Md Ruhul Amin
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Mohammad Moniruzzaman
Department of Animal Science, Bangladesh Agricultural University, Mymensingh, Bangladesh

Abstract/ Executive Summary:

Purpose: The effects of estradiol on oocyte development seem to be varied among species. The present study investigated the effects of 17β-estradiol on in vitro maturation of buffalo and goat oocytes. Methods: Cumulus oocyte complexes (COCs) were aspirated from large antral follicles of slaughtered buffalo and goat ovaries. COCs were cultured in TCM-199 medium supplemented with 0, 0.5, 1, and 1.5 µg/mL of 17β-estradiol for in vitro maturation. Then, oocytes were used for the examination of state of nuclear maturation and cumulus expansion. Results: In both species, oocytes treated with 17β-estradiol showed a higher cumulus expansion rate than control (0 µg/mL treated). In buffalo, the percentage of oocytes matured to the metaphase II (MII) stage increased in the concentration-dependent manner of 17β-estradiol. Similarly, estradiol positively influenced nuclear maturation of goat oocytes in vitro. Conclusions: Estradiol has promoting effects on the normal progress of in vitro oocyte meiosis in buffalos and goats.

Keywords: 17β-estradiol, Buffalo, Goat, In vitro maturation, Oocyte

Location: In Bangladesh

Start Date:

End Date:

Program Area: Animal Health and Management

Commodity: Livestock

Objectives:

The aim of this study was to examine the effects of estradiol on in vitro maturation of oocytes from river buffaloes and Black Bengal goats.

Methodology:

Chemicals: Unless otherwise mentioned, all chemicals were purchased from Sigma-Aldrich (St. Louis). Collection and processing of ovaries: Ovaries were collected from indigenous river buffaloes and Black Bengal goats at local slaughter house and kept in a thermo flask containing 0.9% physiological saline for transportation to the laboratory. The ovaries were washed in Dulbecco's phosphate buffer saline (DPBS) solution supplemented with gentamycin (50 µg/mL) once and following three times in DPBS. After trimming surrounding tissues, ovaries were washed again with saline solution. Collection of COCs: The collection and in vitro maturation of cumulus oocyte complexes (COCs) were done according to Totey et al²¹ with some modifications. Briefly, COCs were aspirated from visible large antral follicles having diameter of 4-6 mm using a syringe (10 mL; Henke Sass Wolf) and needle (18 G; Henke Sass Wolf). COCs with oocyte of 120-125 µm in diameter (excluding the zona pellucida) were selected with the help of a stereomicroscope. Diameters of oocytes were measured using an ocular micrometer attached to an inverted microscope (Labomed, Inc). COCs containing healthy oocytes were selected based on their morphological appearance (uniformly granulated cytoplasm surrounded by multilayered compact cumulus cells) for further experimentation. In vitro maturation of COCs: The maturation medium was prepared with TCM-199 supplemented with 0.1 mg/mL sodium pyruvate, 0.08 mg/mL gentamycin sulfate, 5% (v/v) fetal bovine serum (FBS), and 100 ng/mL follicle-stimulating hormone (FSH).²² In order to investigate the effects of 17β-estradiol, maturation medium was also supplemented with 0, 0.5, 1.0, or 1.5 µg/mL of 17β-estradiol. COCs were placed in 50 µL maturation droplets of maturation medium under paraffin oil. Each droplet was placed in a separate culture dish (No. 430165, 35 mm cell culture dish, Corning Incorporated). They were cultured for 24 hours at 38.5°C temperature with 5% CO₂ in humidified air. Assessment of cumulus expansion and meiotic stage of oocytes: After in vitro maturation, the assessment of cumulus expansion was carried out as described by Maruska et al²³ with some modifications. Briefly, COCs with one or two layers expanded, one-half of the cumulus expanded, all layers expanded other than last layers of corona radiata, or all layers expanded, including corona radiate, were classified as expanded COCs. All of the COCs other than expanded COCs such as COCs without cumulus expansion (no observable sign of cumulus expansion) were classified as nonexpanded COCs. Cumulus cells surrounding the oocytes were mechanically removed with the help of 0.1% (w/v) hyaluronidase and using a small-bore pipette. Denudate oocytes were fixed in acetoethanol (acetic acid:ethanol = 1:3) for 48 hours and stained with 1% (w/v) aceto-orcein to examine the stage of oocyte maturation. The stained oocytes were classified on the basis of morphology of the chromatin and nuclear envelope.^24-27 Oocytes after resumption of meiosis, the stages were classified into early diakinesis (ED), late diakinesis (LD), metaphase I (MI) and metaphase II (MII). Oocytes showing cytoplasmic or nuclear abnormalities were considered degenerated oocytes. Data presentation and statistical analysis: All data from cumulus expansion and meiotic stage assessment experiments were subjected to one-way ANOVA followed by Tukey's HSD test (IBM SPSS Statistics 22). Differences at P < .05 were considered statistically significant.

Source of Information: Reproductive Medicine and Biology, September 2020

Article Link (Online Journal): DOI: 10.1002/rmb2.12350

Funding Source:

1.

Budget:

Total Budget (Tk.) :

Achievement/Findings:

The typical morphologies of COCs before and after in vitro maturation in the medium supplemented with 0, 0.5, 1, and 1.5 µg/mL of 17β-estradiol in buffaloes and goats, respectively. Assessment of oocyte maturation by visualization of cumulus expansion of COCs revealed a significant difference in expansion rate due to estradiol supplementation in both buffaloes and goats. In buffaloes, supplementation of in vitro maturation medium with 17β-estradiol (0.5, 1.0 and 1.5 µg/mL) significantly increased cumulus expansion rate (93%, 100%, and 100%, respectively) compared to control. In goats, supplementation of medium with 1 µg/mL 17β-estradiol significantly increased cumulus expansion rate (100%) compared to 0, 0.5, and 1.5 µg/mL groups (73%, 80%, and 70%, respectively). Estradiol has promoting effects on normalprogress of in vitro oocyte meiosis in buffalos and goats.

Knowledge Management: Journal