Ovary maturatıon stages and histological investigation of ovary of the Zebrafish (Danio rerio)

Abstract

Microscopic ovary features of Zebrafish were analyzed. Samples were fixed in Bouin's solution, mounted in parafin and cut into 6-7 µm-thick slices which were stained with Hematoxylin and Eosin (HE), methylene blue and using Periodic-acid Schiff method (PAS). The thin sections in ultramicrotome with the thickness of approximately 0,5-0,7 µm were examined by using Jeol electron microscope following contrasting with Uranyl Acetate-Lead Citrate. The zebrafish was an extremely dynamic organ in which follicles underwent asynchronous development. The oocytes of Zebrafish ovary were observed in various phases. The oocyte development of zebrafish was divided into four stages (primary growth, cortical alveolus, vitellogenic and mature oocyte). Oocyte diameters were observed to vary between 0.,08 mm and 0.76 mm.

Gamma irradiation during gametogenesis in young adult zebrafish causes persistent genotoxicity and adverse reproductive effects

“…Although the fish survived the exposure, massive pathological changes in the gonads and reproductive failure were found, especially at the higher dose (31 Gy). Gametogenesis is the process in which cells undergo cell division and differentiation in order to form the mature male or female germ cells, which in zebrafish lasts for approximately four weeks between 3-5 months of age (Koç et al, 2008;Laan et al, 2002). In fish, successful reproduction is dependent upon a good body condition and sufficient energy reserves.…”

Histological assessment of seasonal gonad maturation of red mullet (Mullus barbatusL., 1758) in Antalya Bay of Mediterranean in Turkey

“…Glamuzina et al (1998), Valdés et al (2004) and Mackie et al (2009) morphologically examined mature females in 6 stages. Koç et al (2008) state that oogenesis in the majority of osteichthyes can be divided into five, six or eight stages. This study morphologically and histologically examined females in 7 stages; immature female, chromatin-nucleolus, perinucleolus, cortical alveoli, vitellogenesis, maturity and post-ovulation.…”

“…Çelik (2005), Mc Millan (2007, Çakici and Üçüncü (2007), Mackie et al (2009) and Kokokiris et al (2014) report that oocyte cytoplasm contains cortical alveoli near the outer surface in the glycoprotein structure. According to Koç et al (2008), granular structures in the ooplasm increase, cortical alveolar structures grow as the oocyte grows, the follicle size increases and the area surrounding the oocyte nucleus becomes opaque. During this stage, the nucleus grows.…”

“…Moreover, in a later phase of this stage, the cortical alveoli multiply and expand to fill the oocyte and the egg yolk globules are mostly round and densely stained. Koç et al (2008) state that, in the vitellogenesis stage, the oocyte grows in size, the egg yolk globules grow in size and number, the granular structures in the cortical alveoli stage become larger, and the nucleus becomes irregular in shape. According to Mahmoud (2009), the ovary is often filled with previtogenic and vitellogenic oocytes at different stages of the egg yolk, most of the vacuoles are linked to each other and voids among egg yolk granules in the cytoplasm are formed.…”

Herbicide Diuron as Endocrine Disrupting Chemicals (EDCs) through Histopathalogical Analysis in Gonads of Javanese Medaka (Oryzias javanicus, Bleeker 1854)

“…The histology slides were observed and pictured using Leica Histology Microscope (Leica Microsystems, Heerbrugg, Switzerland) with a color camera, which was connected directly to a monitor using a Leica's Application Suite Version 3.2.0. For the analysis of the maturation of the ovary stages, the observed oocytes were divided into four stages: perinucleolar oocytes, cortical alveolar oocytes, late vitellogenic oocytes, and mature oocytes [21]. Atretic oocytes or atresia can be indicated by the breakdown of ovarian follicles and the irregular form of oocytes [20].…”