Morphology, ultrastructure, and germ cell cluster formation in ovarioles of aphids.

摘要: The structure of aphid ovaries, including ovipare and virginopare morphs five species, was investigated by light electron microscopy. Aphids contain telotrophic meroistic ovarioles. amount distribution cytoplasmic components nurse cells, nutritive cords, young oocytes are nearly identical to those known from scale insects heteropterans. Each ovariole has a constant number cells oocytes. In ovaries morphs, the cell nuclei enlarge endomitosis (n = 28 n-210 n), whereas in remain small 22 n-24 n). Furthermore, virginoparae previtellogenic growth is highly reduced, vitellogenesis chorionogenesis blocked totally. Embryogenesis starts immediately after shortened growth. each ovariole, all germ descendants belong one cluster that follows 2n rule. normally contains 25 (32) but other mostly smaller numbers also occur. contrast polytrophic ovarioles, more than will develop into an oocyte. Drepanosiphum platanoides, 16 (2n-1 ) exist cluster, whereas, Metopolophium dirhodum, 8 (2n-2 24 + 2n-2 found. many ovarioles Macrosiphum rosae, 21 nourish 11 Models formation discussed.