نتایج جستجو برای: accessory glands
تعداد نتایج: 54578 فیلتر نتایج به سال:
Fertilization is an indispensable step for formation of a zygote in sexual reproduction, leading to species survival. When mating occurs, sperm is transported to the female reproductive tracts via the seminal plasma (SP). SP is derived from male accessory sex glands and it plays pivotal roles for fertilization in animals. However, molecular mechanisms of SP or a fluid derived from male accessor...
The anatomy of the internal organs of the male reproductive apparatus (MRA) of adults and pupae was compared among 51 species of bees, including representatives of six families. Four different types of MRA were found. The type I is present in males of the less derived families (Colletidae, Andrenidae, and Halictidae) and is characterized by three seminiferous tubules per testis, which are almos...
We studied the expression and distribution of transforming growth factor-beta (TGF-beta) isoforms in the rat male accessory sex glands and the epididymis. Our data demonstrate the expression of both TGF-beta1 and -beta3 isoforms in ventral prostate (VP), seminal vesicle (SV), coagulating gland (CG), and epididymis (E) by Northern blot analysis. In addition, there was differential expression of ...
White rhinoceroses suffer from a low rate of reproduction in captivity. This study examines the role of male reproductive function as a contributing factor. We used ultrasonography to image accessory sex glands, testis and epididymis. Electroejaculation provided 36 ejaculates from 21 rhinoceroses. Based on the percentage of progressively motile spermatozoa, semen was categorized in three groups...
The exceptional abilities of stink bugs (Hemiptera: Pentatomidae) to colonize a diverse group of plants have been attributed to the feeding behaviors and the functions of the salivary complex of these insects. Here, we describe the ultrastructure of the salivary glands of the Neotropical brown stink bug, Euschistus heros, which is a major component of the pentatomid pest complex on soybeans, Gl...
results the main pathological finding observed in the prostrate and seminal vesicle glands, using light microscope, revealed congestion in the connective tissue and vacuolization in the secretory units of epithelial cells and epithelium rupture at 50 and 100 µg/kg doses of bpa. ultrastructure study showed vacuolization of mitochondria, condensation of nuclei and disappearance of nucleus in the ...
While sperm competition risk favours males transferring many sperm to secure fertilizations, females of a variety of species actively reduce sperm numbers reaching their reproductive tract, e.g. by extrusion or killing. Potential benefits of spermicide to females include nutritional gains, influence over sperm storage and paternity, and the elimination of sperm bearing somatic mutations that wo...
Breast neoplasm may develop in ectopically located glandular tissue. This paper presents an interesting and rare case of a 50-year-old female who despite regular mammography screening examination developed an invasive accessory breast cancer. Clinical examination revealed a 2 cm - tumour localized 4 cm below the left inframammary fold. The lesion was immobile, the skin and the atrophic nipple w...
Male pales weevils, Hylobius pales (Herbst), were sexually immature upon emergence from their pupal cells. During the first 2 wk of adult life the concentration of sperm bundles in the testes increased, and a lumen containing a granular material began to form in the accessory glands. Most individuals had active sperm when 2 wk old. Four-week-old males had a large concentration of sperm bundles,...
The common vole is one ofthe most numerous rodents in Europe and Asia but its reproductive biology is not fully described. It is thought that females reach reproductive abilities at a very young age, however, there is no data concerning male sexual maturation. The aim of the present study was to determine the rate of sexual maturation of males of the common vole. Research was carried out on 4, ...
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