Ovary structure and transovarial transmission of endosymbiotic microorganisms in Marchalina hellenica (Insecta,Hemiptera, Coccomorpha: Marchalinidae)

Szklarzewicz, T., Kalandyk‐Kolodziejczyk, M., Kot, M. and Michalik, A. 2011. Ovary structure and transovarial transmission of endosymbiotic microorganisms in Marchalina hellenica (Insecta, Hemiptera, Coccomorpha: Marchalinidae). —Acta Zoologica (Stockholm) 00 :1–9. The paired ovaries of Marchalina hellenica are composed of about 200 ovarioles of telotrophic type. In each ovariole, a trophic chamber, vitellarium and ovariolar stalk can be distinguished. The tropharia comprise trophocytes and early previtellogenic oocytes (termed arrested oocytes) or trophocytes only. The arrested oocytes are not capable of further development. In the vitellaria, single oocytes develop that are connected to the tropharium by means of broad nutritive cords. The number of germ cells (trophocytes and oocytes) constituting ovarioles is not constant and may range between 25 and 32. Numerous endosymbiotic bacteria occur in the cytoplasm of trophocytes. The endosymbionts are transported via nutritive cords to the developing oocyte. The obtained results are discussed in a phylogenetic context.