title: Seasonal morphological changes in the ovary of the Jungle crow (Corvus macrorhynchos).
abstract: Morphometric and histological studies were conducted to examine the seasonal ovarian changes in the Jungle crow of the Kanto area, Japan, from December to June. The ovary weights, largest diameters and atresias of the ovarian follicles and steroid-producing cells were examined. Hematoxylin and eosin-stained ovary sections and ImageJ software were used. The most developed ovary weight increased 373-fold in April, compared to those in December, followed by a 29-fold decrease in June. The average largest follicle diameter of the December and the January ovaries were 1.03 ± 0.35 and 1.05 ± 0.3 mm, respectively. The average largest follicle diameter increased by 2-fold in February, 4-fold in March and 8-fold in April, compared to those of December and January. Thereafter, the average largest follicle diameter declined by 6-fold in June. The average ovary weight and the largest follicle diameter in April increased significantly (P < 0.05) compared to those of December and January, followed by a significant decrease (P < 0.05) in June. The ovary weight correlated well with the expansion of the largest follicular diameter. Non-bursting and bursting atresias of smaller follicles were more common in the December, January, February and June ovaries, and bursting atresias of larger follicles were more common in the March, April and May ovaries. Ovarian steroidogenic cells became heavily charged with lipids in December, January, February and June, and they depleted their lipids in March and April, which might be due to steroid synthesis. Our results indicate that there are significant seasonal histomorphologic variations in the Jungle crow ovary.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya, Tochigi 321-8505, Japan.
authors.forename: Muhammad Nazrul
authors.initials: MN
authors.lastname: Islam
authors.forename: Xiao Bo
authors.initials: XB
authors.lastname: Zhu
authors.forename: Masato
authors.initials: M
authors.lastname: Aoyama
authors.forename: Shoei
authors.initials: S
authors.lastname: Sugita
mesh_terms: D000818:Animals; D046368:Crows / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D009929:Organ Size; D006080:Ovarian Follicle / Q000033:anatomy & histology*; D010053:Ovary / Q000033:anatomy & histology* / Q000166:cytology / Q000378:metabolism; D012621:Seasons; D013256:Steroids / Q000096:biosynthesis
chemical_list: D013256:Steroids