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In Chara tomentosa during mid spermiogenesis (phases V, VI, VII) when the amount of nuclear protamine-type proteins increases, while the amount of histones decreases, in connection with chromatin remodelling, an extensive RER system filled with dark, fine-granular substance is observed. The intermembranous space of the nuclear envelope is filled with a homogenous substance which looks similar. The most extensive ER system can be observed in phase V, which is at the beginning of nuclear protein exchange. The results presented in this paper correspond with the earlier suggestion based on Chara vulgaris spermioge nesis studies, that ER takes part in a protamine-type protein synthesis, which enter a nucleus by endocytosis, through an inner nuclear envelope membrane.
Development of spermiogenesis and sizes of seminiferous tubules of the testes and epididymal duct were studied in 45 young European bisonBison bonasus (Linnaeus, 1758) males from an enclosed breeding centre and a free-ranging population in the Białowieża Forest. Of 13 males in age class II (up to two years), four showed the presence of elongated late spermatids: one male aged 15 months from the enclosed breeding centre and three from the free-ranging population (2 males aged 18 months and one about 24 months old). Of 7 males from age class III (up to 3 years), four showed spermiogenesis, of which the youngest, 26 and 32 months old, were from enclosed breeding. Spermiogenesis was observed in males with high body weight in a given age class. In males of age class I (up to one year old), the mean diameter of the seminiferous tubules was 49.8 μm, in class II — 110.7 μm, and in class III — 162 μm, the mean diameter of the epididymal duct being 110.8 μm, 187.2 μm and 273.4 μm, respectively. Measurements of seminiferous tubules and epididymal duct were significantly correlated with age and body weight of males and differed significantly between the three age classes.
The aim of the present study was to determine how often spermiogenesis occurs in young male European bison up to 3 years old. Research was performed on sections of the testes and epididymes collected from 51 male bison aged 2-3 years. The animals were divided into 2 age groups: young males up to 2 years and young males up to 3 years old, with further separation into specimens with or without spermiogenesis. The animals were culled during the autumn-winter seasons in 1994-2008 (after rutting period) in the Bialowieża Primeval Forest. Spermiogenesis in the 2-year-old animals was a rare condition found in 16.7% of cases. However, at the age of 3 years more than half of the individuals examined (53.3%) had spermiogenesis. Young males up to 2 years old with spermiogenesis were characterized by a significantly higher body weight and their right testis also weighed more than the left testis of the animals without spermiogenesis, the difference being on the border of statistical significance. There was no significant differences in the body mass and weight of the left testis between older animals, up to 3 years old, with or without spermiogenesis. However, young males up to 3 years old with spermiogenesis were characterized by a significantly higher weight of the right testis than those without spermiogenesis.
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